Direct Access

Direct household procurement of goods is largely structured by the geographic relationships between consumer residence and a given resource. Access to products from complementary ecological zones by consumers who undertake a personal voyage to acquire and gather those goods is a form of direct access. For resources that are widely distributed in ecological areas or along altitudinal bands, direct access is a recurring theme in Andean prehistory. The procurement of unique or unevenly distributed or resources, such as salt or obsidian, is a different configuration entirely in a vertically organized region like the Andes, because distant consumers are forced to articulate with production areas far beyond their immediate and complementary neighbors in an altitudinally stratified exchange relationship. This kind of multiethnic, direct household procurement for salt occurs in the Andes to this day (Concha Contreras 1975: 74-76;Flores Ochoa 1994: 125-127;Oberem 1985 [1974];Varese 2002).

Direct access by foragers was the first mode of procurement in the Andes, and this acquisition mode probably dominated in Early Holocene prior to the population growth that permitted the development of reciprocity networks. The procurement of raw materials in a manner that is incidental to other subsistence activities is a more efficient means of acquiring these goods, an activity described as "embedded procurement" by Binford (1979: 279). Communities, ethnic groups, and even prehistoric states appear to have maintained direct access to resources in other zones, and (as is stipulated by the definition of the direct accessmode) this kind of articulation is for direct consumption or redistribution on the level of the corporate or state entity. This is part of a much celebrated pattern in Andean research, a feature known as vertical complementary (Murra 1972), a topic that will be returned to in more detail below. Direct access by states to unusual sources of raw material such as metals and minerals are well documented in the Andes. These include as Inka mine works, and distinctive Inka artifacts and architecture are commonly encountered in association with the procurement areas. In access between herding and agricultural sectors, there is also an ethnographically documented direct access mode described as "ethnic economies". In this direct access mode, ethnic groups will control parallel strips of vertical land holdings, and sometimes non-contiguous tracts, ranging from lower agricultural zones to high puna that may lie several thousand vertical meters above. This pattern is documented on the eastern slope of the Andes for the Q'eros of Cuzco (Brush 1976;Flores Ochoa, et al. 1994) and several communities in northern Potosí in Bolivia (Harris 1982;Harris 1985). The important concept of the direct access organization is that entities that were consuming the goods were directly responsible for acquiring them. If there is inter-household barter or transfer of any kind, then the arrangement likely belongs to a type of reciprocity relationship.

Reciprocity

The institution of reciprocity is important in all societies, and in the contemporary Andes reciprocal relationships are elaborate and permeate village life. It is an arrangement for the transfer of labor or goods that is organized without coercive authority between entities equal in status, although sometimes disputes are settled by community leaders. Andean labor reciprocity includes agricultural work, roof raising, canal cleaning, terrace building, and other services; as such, reciprocity structures the traditional village economy in the Andes (Alberti and Mayer 1974;Stanish 2003: 67). These kinds of reciprocal arrangements are frequently delayed, although compensation can be accelerated through recompense in products. For example, a herder might bring a caravan down to a farming area in the lower valleys and spend some days contributing labor to the agricultural harvest in exchange for some portion of the yield.

In many premodern economic transactions relationships of balanced reciprocity structured these arrangements. Two forms are likely in the Andes, that include (1) a multitude of small, household exchanges creating "down-the-line" artifact distributions (see Figure 2-2), presumably this type of exchange is responsible for the long distance transmission of small, portable goods for much of the pre-ceramic period. A second form consists of (2) barter exchange relationships with regular long distance caravans that articulated with settlements, and perhaps at periodic fairs, that transported goods over potentially greater distances. This mode would effectively consist of unadministered trade. The institution of reciprocity will be explored in more specific contexts below.

Redistribution

The basis of relations between political elites and non-elites in the prehispanic Andes was shaped by redistribution. In Andes during the later prehispanic period, redistributive mechanisms linked elites to non-elites through the redistribution of consumables like coca, and feasts of food and chichabeer in exchange for labor and political support. "The manipulation of redistributive economic relationships among the elite and their retainers, most notably of exotic goods and commodities, stands at the core of the development of Prehispanic Andean complex societies" (Stanish 2003: 68). Often these surplus goods were produced through efficient mechanisms orchestrated by elites, and the benefits and prestige derived from these surpluses would be accrued disproportionately by political leaders.

The central collection of goods for redistribution or use by the state includes taxation which, in the Inka period, was through mit'alabor. With respect to the exchange of lithic raw materials, Giesso (2003) argues that at Tiwanaku household stone tool production was a form of taxation. Giesso cites ethnohistoric evidence referencing the Inka period and argues that the household knapping of projectile points could have contributed to the provisioning of the state armory. The means by which non-local material arrived in the Tiwanaku homeland is unclear, but in the Inka case the raw material was acquired locally or it was provided by the state (Giesso 2003: 377). Earle (1977: 215) argues that redistributionshould be considered as two major groups with leveling mechanisms on one side and complex institutional mechanisms for wealth accumulation on the other (see Section 2.2.4).

Administered Trade

Non-market administered trade was another major means of transfer in the prehispanic south-central Andes. Building on Polanyi's classic definition of non-capitalist economic types, Charles Stanish (2003: 69) describes a form of elite-administered, non-market trade that was capable of procuring non-local goods and that provided wealth to elites as follows. Garci Diez's Titicaca Basin visita, a 16^thcentury Spanish census document (Diez de San Miguel 1964 [1567]), describes how local elites in the Lake Titicaca Basin would have their constituents organize llama caravans for trading expeditions to adjacent regions. In neighboring areas such as the Amazon basin to the east, the Cusco valley, and western slope valleys, agricultural goods such as corn, fruits, and other products were sweeter, faster growing, and more abundant than in the Titicaca Basin. The colonial visitaindicates that, based on the colonial currency, corn in the Titicaca Basin was worth 5.7 to 6.9 times the amount that it was worth in the Sama valley (an area in modern-day southern Bolivia) where it was abundant. Stanish (2003: 69-70) argues that administered trade benefited elites because they were able to appropriate this difference in value, and through feasting and other ceremonial functions, a portion of this wealth was redistributed to commoners. It is important to mention that these same colonial sources indicate that the commoners also organized trading ventures and would take advantage of these elite-organized journeys to conduct private barter exchange on the side. With reference to herders conscripted into elite orchestrated trade caravans "those in Lupaca country 'who had their own cattle [cargo llamas]' (Diez de San Miguel 1964 [1567], f. 13v) went to the coast and to the lomas to barter on their own. …the maize growers on the irrigated coast were eager for the highlander's animals, their wool and meat" (Murra 1965: 201). Thus, elites organized large caravans and apparently possessed the surplus wealth and the camelid caravan animals in advance to initiate the trading expedition, but the herders that they conscripted also engaged in household-level barter. For the elites, their organizational efforts earned them significant wealth and status for a relatively modest outlay of costs. For the herders, it appears that they were able to embed household economic transactions with their mit'alabor service by conducting their side barter activities. Apparently, even the powerful Lupaca elite had to concede some independent trade activity to their caravan drivers. What, then, of the relationship between caravanerosand elites during earlier periods, when elites probably had less consolidated power than during the contact period?

The evidence suggests that "administered trade" was not the first form of long distance caravan exchange. As mentioned above, relationships of balanced reciprocity have long served to articulate herders with those living in complementary ecozones such as sierra agriculturalists, coastal fishers, and residents of the eastern lowlands. But the long distance transport of diffusive goods like obsidian are well-demonstrated and form a continuous network configuration that contrasts with the segmentary, vertically organized exchange between valley and puna (Figure 2-3). Archaeological distributions (Browman 1981;Burger, et al. 2000;Dillehay and Nuñez 1988;Nuñez and Dillehay 1995 [1979]) and contemporary ethnoarchaeological studies (Lecoq 1988;Nielsen 2000;West 1981) attest to the capacity for small scale, household-level organization of multi-week caravan expeditions. This evidence suggests that there were probably at least two major types of long distance caravans operating from the Late Formative onwards. The question then becomes: what was the relationship between household-level caravans and elite-administered trade? Did elites co-opt functions that were previously coordinated on the household level? If elites acquired control of some segment of caravan traffic, what strategies did elites use to wrest control from caravan drivers that, the evidence suggests, were very independently-minded people (Browman 1990: 419-420;Nielsen 2000: 517-520)? These questions concerning the origins and configurations of regional interaction in the south-central Andes are at the center of this discussion of changes in obsidian procurement and the regional circulation of goods in prehistory on the perimeter of the Lake Titicaca Basin.

Vertical complementarity

The contrasting ecological zonation found in low-latitude mountain regions worldwide has resulted in distinctive social configurations that appear to reduce risk, broaden the selection of products available in a given zone, and provide opportunities for strategic advancement by particular individuals or groups. These configurations have been investigated in two broad sets by Andeanists. First, there are a number of scholars who address vertical complementarity as a general process that is comparable with other mountain regions of the world. Second, there is a particular configuration known as "Vertical archipelagos" first described by John Murra (1972) that has been widely discussed in the Andean literature.

Horizontal complementarity

Soon after Murra published his 1972 paper about vertical complementarity, researchers began noting that vertical complementarity is only one of a number of strategies employed in the Andes. A different kind of geographical interaction pattern, one that stays within broad regions such as the altiplano or the littoral, has been called horizontal complementarity. Contrasted with Murra's vertical complementarity model, in horizontal complementarity polities would directly control many parcels in a given niche. Here, the adaptationalist argument is somewhat less obvious since a horizontal complementarity strategy seems redundant unless particular resources were only available in one sector of a given horizontal territory. This phenomenon could reflect a cultural mechanism for the continued social integration of communities distributed widely across a vast region. An analogous situation can be observed in the culturally-constructed Yanamamö trade for ceramic wares, maintained to provide a social catalyst for villages to come together for feasting and marriage-making, despite the risk of conflict and treachery (Chagnon 1968).

Relations of horizontal complementarity between coastal valleys have been observed on the littoral (Netherly 1977;Rostworowski 1977;Shimada 1982), and for the higher altitude altiplano area where this kind of organization is referred to as the "altiplano mode of economic integration" (Browman 1977) and, to a lesser extent, the modern "extended type of Andean zonation" (Brush 1977: 12-16;Gade 1975). The extended type takes place in regions of expansive, contiguous production where exchange forms the basis for circulating products from other zones. In the expansive altiplano where there are fewer impediments to travel and, with the domestication of camelids, relatively low transport costs with cargo animals, materials may have been conveyed over substantial distances.

Figure 3-4. Subsistence exchange for products by ecozone versus single-source, diffusive goods.

A general schematic of these contrasting relationships is shown in Figure 3-4. While there is a great deal more complexity and variability to economy and exchange than is communicated in Figure 3-4, for example tubers are grown in the high elevation zones and herding does occur below 3800 masl, the purpose is to highlight the contrasting network characteristics. These two characteristics include

(1) Subsistence exchange.The acquisition of products available by zone contrasts

(2) Diffusive.The network for goods that radiate diffusively, such as obsidian and salt.

While the mixed agropastoral strategies are also very common, particularly in ecotone areas such as the puna rim, the subsistence exchange that articulates dedicated pastoralists with agriculturalists has been documented ethnographically in many studies of which only a selection are shown in Figure 3-4 (Bastien 1978;Brush 1977;Custred 1973;Flores Ochoa 1968;Palacios Ríos 1981;Winterhalder and Thomas 1978).

Ecological complementary has long served to transfer goods between ecozones, however the movement of goods laterally through areas of homogeneous resources, such as horizontal complementarity across the puna, implies other mechanisms of transfer. In addition to strategies described previously, it has been proposed that large periodic markets are a possible solution to the problems of social and economic integration among agropastoralists living in widely distributed settlements.

Browman (1990: 405-411) reviews the evidence for prehispanic and colonial period markets in the Peruvian and Bolivian altiplano. The colonial period aggregations in the Andes are products of historical circumstances, however Browman's evidence suggests that periodic fairs in some form were a feature of the prehispanic economy. While evidence concerning the actual goods exchanged at periodic fairs during the prehispanic period is scarce, these events could have been an effective way for obsidian to have been distributed in highland Peru and these fairs will be discussed in more detail below. Seasonal or annual gatherings are also ethnographically known among foragers in arid regions of the world with low population densities (Birdsell 1970: 120;Steward 1938). Social aggregations in some form can be expected to date back to the foraging period and these aggregations probably included, among other activities, the exchange of goods.

Evidence for barter, markets, and marketplaces in theAndes

"They did not sell… nor did they buy… they thought it was a needless operation" and all universally planted what they needed to support their households and thus did not have to sell foodstuffs, nor raise prices nor did they know what high prices were…(Garcilaso 1960 [1609]: 153; cited in Murra 1980: 142).

Was obsidian exchanged through a market system reflecting supply and demand in the prehispanic Andes? Were exchange specialists present in the prehispanic Andean highlands? If so, when did they appear and what did they transport? While extensive exchange has been documented in the prehispanic Andes, it is widely believed by Andeanists that exchange in the prehispanic central Andes was not based on market institutions. Building on the typology developed in Chapter 2 following Renfrew(1975)and Salomon(1985), differing degrees of specialization and independence can be expected to have existed among actors in exchange relationships (Figure 2-2andFigure 3-3). If specialized traders were present in prehispanic Andes, how did they interface with state authority during the Middle Horizon and Late Horizon, and what was their position during periods of regional conflict like the Late Intermediate Period?

Much of the evidence supporting the alleged lack of market-based exchange is derived from studies of Inka economic organization, where ethnohistorical accounts and archaeological datasets converge. A great deal has been written on the topic of Inka economy, and obsidian exchange was relatively diminished during this period, therefore this discussion will be limited to a few relevant issues regard exchange specialization. Several of the sixteenth century chroniclers are clear that while barter was widespread, the barter values of goods did not reflect fluctuations in supply and demand as in a market economy. However, the lack of consensus on the issue of markets and commerce during the Inka period stems from inconsistency in the cronistasthemselves. As reviewed by Murra(1980: 139-152)and LaLone(1982)the denial of a market exchange by Garcilaso de la Vega (quoted above) can be contrasted with numerous accounts of large and small markets, and a long tradition of barter exchange of various types.

The issue of Late Horizon marketplaces and market exchange is explored here because one of the principal questions that may be considered with changing obsidian distributions through time is the possible role of commercialism in prehispanic Andean exchange. The appearance of exchange specialists, such as freelance caravans moving certain commodities and responding to the changes in barter values that result from surpluses and shortages, would have presented a mode of transport distinctive from that of local reciprocal exchange or regional or state redistribution.

The vertical archipelago model functioned as an alternative to trade for goods from neighboring areas because "regional differences in production were, by preference, handled by means of colonization instead of through barter or trade."(Murra 1965: 201). As mentioned, Stanish argues that Murra initially excluded exchange mechanisms because of a perceived association between exchange and market economies. Further it can be argued, building on Appadurai(1986: 33), that in certain contexts of ranked or stratified societies with elaborate redistribution mechanisms, market systems of exchange represent a threat to the centralized ideological power of redistribution. "There is great advantage to leaders who are able to portray their resource-control strategies as reciprocity, redistribution, and generosity. Non-centralized resource-control strategies are, by definition, not 'control' strategies"(LaLone 1982: 296). If centralization is a principal determinant of state control on market exchange, were the peripheries involved in greater numbers of barter transactions?

Limitations of ethnohistory and ethnography

Ancient economy in the Andes has been most fruitfully studied by combining archaeological evidence with ethnohistoric and contemporary sources. General models of great importance to Andean studies such as vertical complementarity, the question of the commerce in the prehispanic economy, and a structure of dual organization in the Inka administration are examples of models emerging from ethnohistoric sources but with empirical support from archaeological research. Ethnohistorically based models also have their limitations in that they can unduly influence interpretation much in the way that the "tyranny of ethnography"(Wobst 1978)should not necessarily define the range of archaeological possibility and inference. Ethnographic sources are valuable for the evidence of pastoral patterns, the priorities of caravan drivers, and the articulation between mixed and specialized pastoral and agricultural practices. However, modern features including the presence of the cash economy, markets, truckers plying the highways, and various modern job opportunities impact the structure of exchange relationships and caravan transport(Browman 1990;Nielsen 2000).

Ethnographic studies of contemporary llama caravan drivers are focusing, by necessity, on relatively marginalized communities that are sufficiently conservative to continue to herd llamas despite a variety of often more lucrative alternatives (Lecoq 1988;Nielsen 2000). Scholars have noted, however, that caravan drivers enjoyed relatively high status and autonomy in the late prehispanic and early colonial period which contrasts strongly with the economically marginalized modern day caravanero(Murra 1965). Furthermore, herding has become relatively low status in many regions of the contemporary Andes because the economic focus has moved downslope since Spanish contact due to the growth of the coastal economy and the importation of various low altitude crops and livestock. In other words, the prominence of caravan drivers as central economic agents has been greatly diminished in recent centuries, and ethnographically documented interactions with agriculturalists is one circumstance in which this relative shift in power may result in distorted perceptions of prehispanic interaction patterns. The relatively high status accorded to truck drivers and other purveyors of goods and information in contemporary Andean villages was likely to have been ascribed, instead, to the relatively cosmopolitan drivers of llama caravans during prehispanic times.

Estimating travel velocity

A computer model for estimating travel speed based on topography, where velocity over a segment of trail is calculated as function of slope, could be derived using the function presented by Tobler (1993) for hiking and horseback riding (the source of cost paths shown in Figure 3-5). While these topography based calculations have serious limitations (Connolly and Lake 2006: 252-255), for general estimates over larger regions with measurable changes in terrain steepness these estimates are superior to the simple use of slope for estimating velocity. Such models would preferably be derived using original data from fieldwork, perhaps based on a contemporary study that takes into account the size and weight of the cargo animal, the amount and type of cargo, and the performance of the cargo animals based on trail conditions mapped using GPS receivers.

In the course of ethnoarchaeological fieldwork accompanying a llama caravan in Bolivia, Nielsen (2000: 449;2001: 184) notes that there were differences in the going and returning portions of a 2-3 month caravan journey that had implications for the overall travel speed. The out-going trip involved visits with companions and a variety of rituals at propitious locations along the route. During the return journey, in contrast, no rituals were performed but the animals moved more slowly because they were carrying large loads of produce uphill from the eastern lowlands; and they had been traveling for months and reportedly their feet hurt. Thus the lack of ritual performance and visiting and bartering saved time, but the walking speeds were slower, breaks were longer, and layover rest days were more frequent and longer.

Evidence of relative travel distances in the region

In the Mantaro region of the central Andes, Earle (2001: 310) notes that long distance exchange (classified as taking place over a distance of 50 km or greater, to lands beyond those held by the local ethnic group), rarely includes staple items. During the Late Intermediate and Late Horizon, items that were found in the Mantaro area include items of metal and shell described as "wealth items", emphasizing the political nature of long distance exchange in this period.

While Colca valley obsidian was primarily conveyed throughout the Titicaca Basin during prehispanic times by unspecified groups, during the colonial period Colca valley polities are known to have been dominant caravan operators in the region. Residents of the Colca valley owned large camelid herds and they were responsible for extended caravan journeys to the altiplano during the Colonial period. Documentary evidence shows that the Collaguas from the main Colca valley initiated caravans to transport products, such as Arequipa wine to Cusco and Canas, and Colca corn to "wherever they would like to sell it" (Crespo 1977: 56). A testament to the role of the Collaguas, and the Colca valley in Arequipa more generally, comes from Toledo's (1924 [1570-1575]) visita generaldescribing populations of Colca community members resettled as farmers in the new city of Arequipa, Yanahuara, and environs. Toledo states that these Collaguas mitimaesgroups should produce wine in these lower-altitude areas for transport to Cusco and to the mines of Potosí in Bolivia over 700 km to the south-east (Málaga Medina 1977: 114).

Yapa and over-reciprocation

Barter relationships are often cemented with a yapa:a little bonus given to the buyer that takes the form of an over-reciprocation to assure future transactions (Browman 1990: 421;Sahlins 1972: 303). The magical powers attributed to the yapanotwithstanding, Sahlins' (1972: 308-314) develops a functional economic explanation for over-reciprocation where it serves a similar mechanism to price fluctuations in market-based societies. When an over abundance of product A relative to product B exists in a barter situation based on traditional equivalencies (hence, a lower value for A may result, in a market system), the provider of product A may over-reciprocate and thus, based on the morality of reciprocal arrangements, guarantee future compensation from the trade partner.

The primitive trade partnership is a functional counterpart of the market's price mechanism. A current supply-demand imbalance is resolved by pressure on trade partners rather than exchange rates. Where in the market this equilibrium is effected by a change in price, here the social side of the transaction, the partnership, absorbs the economic pressure. The rate of exchange remains undisturbed - although the temporal rate of certain transactions may be retarded (Sahlins 1972: 311).

The discrepancy that must be resolved synchronically in neoclassical market economics is resolved diachronically in reciprocal arrangements (Danby 2002). Browman (1990: 421) does not believe the over-reciprocation device described by Sahlins is in evidence in the Andes. As Browman observes, there is ethnographic evidence that suggests that barter rates do, in fact, fluctuate in response to supply and demand. The arrangement described above is one possible configuration that occurred in prehistoric circumstances, however, and it is a possible means of assuring the long term persistence of exchange relationships (Burchard 1974;Mayer 1971).

Seasonal fairs and the temporality of caravans

If seasonal fairs and aggregations were a feature of the prehispanic altiplano, as discussed by Browman (1990), interactions may have taken notably different forms in those contexts. Seasonal fairs may have had the significance of religious festivals in the contemporary Andes where the devout sometimes travel for weeks in order to arrive at auspicious times. Fairs and cultural occasions may, then, have been blended with economic transactions.

Scheduled festivals with elaborate dances, music, and costumes are a major cultural contribution in contemporary altiplano communities like Paratía (Flores Ochoa 1968) and despite the lack of simple material correlates for archaeological study, cultural items like song and dance were probably significant features in a variety of prehispanic reciprocal exchange contexts (J. Flores Ochoa 2005, pers. comm. July 2005). Despite the relative marginalization of altiplano cities in the modern economy (or perhaps a reflection of this marginalization), traditional festivals endure as important cultural features in the Titicaca Basin. Citing early twentieth-century sources, Browman (1990: 409) reports that at major shrine at Copacabana, Bolivia, between 40,000 and 50,000 "traders" would converge at times scheduled to coincide with ceremonies at the shrine.

If economic transactions occurred in association with these festivals in prehispanic times, either as a central feature or relegated to the periphery of the cultural events, the transactions may have assumed certain characteristics of marketplace exchange. These characteristics would have included public knowledge of barter equivalences and perhaps more immediate, synchronic exchange due to the short time period of convergence at the festival. As mentioned, however, marketplace concentrations do not necessarily imply true "market economies" with fluctuating prices reflecting supply and demand (LaLone 1982). Assuming that economic transactions that may have occurred at these fairs did not create moral conflict (by debasing sacred ceremonies with lowly economic transactions, in a Euro-American perspective) they would have created an excellent context for the transfer of both cultural goods and prestige items, and for the control of certain exchange practices by administrators or elites. Nevertheless the problem remains that dedicated agriculturalists with harvest goods for exchange would have been absent from these fairs on the altiplano because dedicated agriculturalists would not have the schedule or the herd demographics that would have permitted them to initiate long distance caravans. Therefore a variety of strategies probably developed to allow the transfer of products with the emergence of caravans that traveled, on the large scale, according to schedules dictated by seasonal gatherings, harvest schedules, and other economic and cultural circumstances. These developments imply the emergence of something of a continuum between the more alienable exchange that occurred in seasonal gatherings, and more inalienable barter that occurred in the intimate exchange context of compadrazgorelationships.

Availability, demand, and mobility

Chivay was largely conveyed into the Lake Titicaca area by Titicaca Basin communities and polities that were organized around the lake and the adjacent broad altiplano. For sites in the Lake Titicaca Basin, the database shows that 453 obsidian artifacts have been sampled from all time periods, and 408 (90%) of the samples were of the Chivay obsidian type. Another interesting aspect to this pattern is that the proportion of Chivay obsidian holds true for the north Titicaca Basin as well as the south when the two areas are considered separately. Using Bandy's (2005: 92) division of the Titicaca Basin where the site of Camata and northward are considered the North Basin, and with the South Basin extending as far south as Khonkho Wankane and south-west to Qillqatani, all obsidian samples in the region were aggregated from the entire prehispanic period. The LIP site of Cutimbo, though slightly south of Camata, was joined with the North Basin sites while Incatunahuiri and the Ilave valley sites were counted with the South Basin.

Table 3-3. Obsidian in the north and south Titicaca Basin by counts and percents.

These patterns reveal that Chivay obsidian accounts for approximately 90% of obsidian from the Titicaca Basin, with a greater presence of Alca obsidian in the North Basin. It seems that the presence of obsidian from alternative sources, whether it was the Tumuku source (still unlocated) or other obsidian sources further to the south, counter balances the access to Alca type in the North Basin. This pattern, with heavy use of Chivay obsidian in the South Basin, reflects overall integration in the Titicaca Basin through prehistory as well as the lack of high quality obsidian sources with large nodules south of the Chivay source, until one arrives at the Zapaleri source close to the frontier of Bolivia, Argentina and Chile, located 700 km to the south of Lake Titicaca (Yacobaccio, et al. 2004: Fig. 1). It has been noted that, in cultural terms, the Chivay distributions are especially linked to areas integrated by the Tiwanaku state, the Pukara polity, and with their predecessors: the Middle Formative communities linked by Yaya-Mama stylistic features (Burger, et al. 2000). However, what is particularly compelling about the evidence from obsidian is that these social and economic links in obsidian exchange appear to predate the cultural-stylistic links and become defined in the Terminal Archaic roughly 1000 years earlier than regional evidence of the Yaya-Mama stylistic attributes that first appear at Chiripa in the southern Lake Titicaca Basin.

The distribution of Alca material is confined by the availability of Quispisisa on one side and Chivay on the other, but nevertheless Alca obsidian was transported the furthest with material during the Middle Horizon being conveyed as far as the Wari sites of Huamachuco and Marca Huamachuco near Cajamarca (Burger, et al. 2000: 336). Alca material was also transported the furthest distance at an early date, as it was conveyed 769 km to Chavín de Huantar during the Early Horizon where it was found in both elite and commoner contexts (Burger, et al. 2000: 313-314). Quispisisa predominates in Wari assemblages but it also circulated widely before the Middle Horizon, such as the 589 km to Chavín de Huantar during the Early Horizon.

Terrain adjacent to source

The altitudes of obsidian consumption sites (XFigure 3-6X) also reflect the terrain adjacent to each of the sources. The Quispisisa source is in an area with deep river valleys and a number of the sites sampled are from lower elevation or coastal contexts. The Alca source is similarly close to deep river valleys, but it also borders the altiplano and the much of the Alca samples came from the highlands of the Department of Cusco. The Chivay source is on the periphery of the broad altiplano and with no major altitude loss it was possible to transport material to a variety of sites that include Pikicallepata to the northeast and Qillqatani to the southeast. Further detail on these obsidian distributions are described below, and are published elsewhere (Burger, et al. 2000; cited in Craig 2005: 908-916;Frye, et al. 1998;Giesso 2000).

Small quantities of material and regional models of exchange

The actual volume or weight of obsidian at Qillqatani is relatively small. Obsidian from the Chivay source appears in small quantities in nearly every stratum in the approximately 8000 year sequence. The most informative data on long distance exchange come not from the total mass of obsidian, but from the variability in the relative percentage of obsidian flaked and obsidian tools in each lithic assemblage through the sequence. Nevertheless, the weight of obsidian tools at Qillqatani totals 43 g, and the sum of the weight of obsidian flakes is 382 g out of a total of 11,085 g of lithic material. Thus, the entire quantity of obsidian excavated at Qillqatani is only about 1.5% of the cargo that could be carried by a single llama.

These figures are meant to highlight a central issue with obsidian studies overall: the actual quantities of obsidian encountered and evaluated from the consumption sites throughout the south-central Andes are relatively low. The significance of obsidian circulation over the larger region is not matter of weight or volume, but rather a question of consistency and changes in the proportions of particular sources utilized over time. These data from Qillqatani underscore this issue. A comparison of the persistence of non-local obsidian at Qillqatani as of level 24 (X

Table 3-6XandXTable 3-7X) with the non-local obsidian at Asana (XTable 3-4X) during earlier periods of the Archaic, suggests that on a regional scale mechanisms of exchange, or direct acquisition, were more intermittent during the earlier Asana phases. In contrast, Qillqatani has high quality cherts and low quality Aconcahua type obsidian available in the immediate proximity of the rock shelter. Thus, the question becomes: why transport Chivay obsidian 200 km when alternative materials are locally available? Further, why was the transmission of Chivay obsidian so consistent through time? In this perspective the low but consistent quantities of Chivay obsidian that were conveyed throughout the south-central Andean highlands during the prehispanic period can be seen as a gauge of highland interaction and horizontal complementarity, with wider implications for exchange.

IlaveValley

In the Ilave valley, obsidian was scarce prior to 3300 BCE, but it appears in a number of Terminal Archaic and Formative contexts after that date. Diagnostic projectile points from the Ilave area reveal a dramatic change in material type with the Terminal Archaic.

Figure 3-9. Comparison of projectile point counts in the Ilave Valley and the Upper Colca.

Using only diagnostic projectile points from the Klink and Aldenderfer (2005) point typology, these data reveal a shift to greater use of obsidian with series 5 projectile points. Following the point typology, all series 1 through 4 points are diagnostic to the Terminal Archaic or earlier, except for types 4C and 4E which have been excluded from this analysis. The lower part ofXFigure 3-9Xreveals data classified into the same three groups, but with data from the Chivay obsidian source area resulting from the 2003 Upper Colca project. Comparing these two datasets reveals that with the advent of Series 5 points in the Terminal Archaic after 3300 BCE there is a sudden upswing in obsidian use in the Ilave consumption zone that corresponds perfectly with a dramatic shift in projectile point production at the Chivay source area itself. There appear to have been pan-regional changes occurring with the widespread adoption of series 5 style projectile points, the use of obsidian, and these changes are possibly related to the greater use of the bow and arrow.

Jiskairumoko (95-189)

The site of Jiskairumoko was excavated using a broad, horizontal décapage technique between the years 1999 and 2002, and Craig's (2005) dissertation forms the site archive. Radiocarbon dates fromexcavation work at Jiskairumoko range from the Late-Terminal Archaic transition with a date of 4562±73bp(AA58476; 3520-3020 BCE)through to the end of the Early Formative, with a date of3240±70bp (Beta-97321; 1690-1390 BCE). Note that Craig (2005) has the Terminal Archaic dating to 3000-1500 BCE, while in the Upper Colca Project and in this dissertation the period dates to 3300 - 2000 BCE All references to the "Terminal Archaic" have been adjusted to the latter time range in this document unless otherwise noted.

Craig and Aldenderfer chemically characterized 68 bifacially-flaked obsidian tools from excavated contexts at Jiskairumoko (96% of all obsidian tools from Jiskairumoko) by sending these items to M. Steven Shackley at the UC Berkeley Archaeological XRF Lab(Craig 2005: 513, 908-916). The samples were compared with four geological samples that provided to Shackley from nodules that I had collected from Chivay source in 2003. Three of the nodules provided to Shackley were from the Maymeja area and one was from east of Cerro Hornillo. The XRF results showed that 97% of the Jiskairumoko obsidian tools (n = 66) were from the Chivay source and 3% (n = 2) were from the Alca source. These values diverge slightly from obsidian type distributions in the Titicaca Basin more generally (XTable 3-3X), where 90.5% (n = 466) of all of the obsidian artifacts tested to date from the Titicaca Basin are Chivay type. These data indicate that the people at Jiskairumoko were more intensively using Chivay obsidian in the Terminal Archaic and Early Formative than were Titicaca Basin residents over all, especially in contrast to the variety in obsidian types that emerge from samples dating to later times.

Obsidian artifacts from excavations at Jiskairumoko reveal that obsidian was used in similar proportions for projectile points from excavated contexts as for points from surface contexts in the Ilave valley. Craig(2005: 685)observes that 18% (n = 54) of the excavated Jiskairumoko projectile points are made from obsidian. He also notes that 50% of these have edge modification in the form of serration or denticulation while only 15% of non-obsidian points have edge treatment, a statistically very significant pattern that he attributes to the symbolic importance of this material. Obsidian was found, along with other lithics and a carved camelid effigy, in Burial 1 at Jiskairumoko in the grave of an elderly adult female with cranial deformation, a primary deposit dating to the Terminal Archaic or 3019-2859 cal BCE(Craig 2005: 680-682). Graves excavated in the Ilave valley area also contain a variety of non-local grave goods including obsidian, lapis, and gold, but non-local grave goods only occur in contexts dating to the Terminal Archaic and later.

Early Archaic (circa 10,000 - 7,000 BCE)

Evidence from the Early Archaic in the south-central Andes is slim, but it is accumulating gradually. The available data suggest that during this time period human groups went from initial exploration of the highlands to more stable, year around occupation of the sierra and puna. The best evidence from the highlands comes from a handful of stratified sites in the region with Early Archaic components, as well as distributional evidence from archaeological survey work(Aldenderfer 1997;1998;1999;2003;Craig 2005: 452-484;Klink 2005;Nuñez, et al. 2002;Santoro and Núñez 1987;).

A regional study of projectile points from excavated contexts by Klink and Aldenderfer(2005: 31, 53)noted that projectile point styles diagnostic to the Early Archaic (Series 1 and Types 4a, 4b) and the Early-Middle Archaic transition (Type 2a) have a broad geographical distribution. These types are found throughout a region that includes the littoral, western sierra, and puna areas of extreme northern Chile and southern Peru, and as far north as Pachamachay cave in the Junin puna(Rick 1980). Given the low population densities of that time period, this wide regional stylistic distribution suggests that a high degree of mobility was being practiced in the Early Archaic and first part of the Middle Archaic. Further to the north, in contrast, raw material types in the Junin puna of central Peru suggest to Rick(1980)that very low forager mobility was occurring throughout the early preceramic period. Early Archaic obsidian distribution data largely confirm with the model of high mobility and show that humans found good sources of lithic raw material in the sierra early, and then transported the material or exchanged it widely from a relatively early date.

Current paleoclimate evidence indicates that glaciers advanced during the late glacial between 11,280 and 10,990¹⁴C yr bp, and then, despite cool temperatures, the glaciers receded rapidly, perhaps as a result of reduced precipitation(Rodbell and Seltzer 2000). Glaciers were in approximately modern positions in southern Peru by 10,900¹⁴C yr bp (circa 11,000 cal BCE). The Early Archaic Period, with reference to diagnostic projectile point styles(Klink and Aldenderfer 2005), begins at circa 9000 cal BCE During the Early Holocene and the first part of the Early Archaic conditions were wetter and cooler than modern conditions. Subsequently, during the latter part of the Early Archaic, the climate began an episode of long-term aridity that lasted through the Late Archaic(Abbott, et al. 1997;Argollo and Mourguiart 2000: 43;Baied and Wheeler 1993;Paduano, et al. 2003: 272). Opportunities in the highlands for human foraging groups were created by a number of new ecological niches for plants and animals that opened up during the Early Holocene. These niches represented a resource pull for mobile foragers that countered the increased difficulty of subsistence in the hypoxic, high altitude environment faced by the non-adapted early settlers in the highlands(Aldenderfer 1999). A review of the evidence for forest cover on the altiplano during the Archaic, with deforestation occurring as a result of pastoral intensification, is provided by Gade(1999: 42-74).

During the Late Pleistocene lacustrine period, paleo-Lake Titicaca (Lake Tauca) was much larger but only a few meters higher than is modern Lake Titicaca (Clapperton 1993: 498-501). Radiocarbon dates on shells show that Lake Tauca was probably still present as late as 10,080¹⁴C yr bp (or 9900 cal BCE). Sediment cores from Lake Titicaca indicate that there was an increase in sub-puna vegetation and fire from vegetation prior to 9000 BP (Paduano, et al. 2003: 272). Evidence from paleoclimate records and fluvial geomorphology point to a time of increased aridity and salinity in Lake Titicaca, with short, episodic moist spells beginning around 8000 cal BCE and continuing through the Middle Archaic and Late Archaic Periods (Rigsby, et al. 2003;Wirrmann, et al. 1992). The climatic data for this time suggest that with deglaciation in the Early Holocene a resource niche opened up that exerted a pull on plant and animal species towards the high altitude regions, and that early human groups responded to these opportunities by colonizing the high Andes.

Middle Archaic (7000 - 5000 BCE)

The Middle Archaic Period, as with the preceding period, is still poorly understood in the region as very few highland sites containing stratified deposits have been studied from this period. In the Lake Titicaca Basin paleo-climatic evidence points to significant aridity, a lake level approximately 15m below the current stand, and high salinity in Lake Titicaca that is comparable to that of modern day Lake Poopó(Abbott, et al. 1997;Wirrmann and Mourguiart 1995). Human occupation during the Middle Archaic in the Lake Titicaca Basin was notably higher than in the preceding period, but research shows that settlement continued to occur in the upper reaches of the tributary rivers and not adjacent to the shores of the saline Lake Titicaca(Aldenderfer 1997;Klink 2005).

Late Archaic (5000 - 3300 BCE)

The Late Archaic in the south-central Andes signals the beginning of economic changes in the lead-up to food production, and furthermore the first signs of incipient social and political differentiation are evident in a few archaeological contexts. Some of the obsidian samples reported by Burger et al(2000: 275-288)with possible Late Archaic affiliations are from surface contexts at multicomponent sites and it is therefore difficult to confidently assign these samples to any particular period of the Archaic.

Discussion and review of the Archaic Foragers period

The transport of obsidian from both the Chivay and Alca sources fluctuated during the Archaic Foragers period, and the distribution remained confined to the sierra and altiplano areas of the south-central Andes. The small and irregular quantities of obsidian consumed throughout the region could have been procured and transported by mobile foragers, or conveyed through down-the-line exchange networks. Conceivably exchange could have taken place a seasonal gatherings as well, based on analogy from other foraging groups worldwide, although there is no direct empirical support for such gatherings in the south-central Andean Archaic. At Asana, the most well-stratified highland Archaic site investigated to date, evidence of non-local obsidian was intermittent and consisted of very small quantities of material in a pattern that is perhaps exemplary of the discontinuous nature of regional exchange during this time.

Obsidian from the Quispisisa source (340 linear km to the north-west of the Chivay source), was likewise used primarily in highland contexts during the Archaic Foragers period, particularly in rock shelters excavated by MacNeish and colleagues in the central highlands. While Quispisisa material was circulated at a number of preceramic coastal sites(Burger and Asaro 1978), current evidence suggests that those contexts post-date 3300 cal BCE (i.e., cotton preceramic) and are therefore Terminal Archaic in the terms used here. It appears that while Quispisisa material was used widely on the coasts subsequent to the Archaic Foragers period, material from Chivay and Alca were virtually always confined in the highlands with the exception of the earliest obsidian evidence of all: Alca at Quebrada Jaguay. In the Archaic Foragers period, as in later periods, the evidence from obsidian is contrary to the widely-discussed Andean vertical complementarity models, because obsidian distributions suggest that the movement of people or products between ecologically complementary zones was not widespread.

Why an "Early Agropastoralists" time block?

In lieu of the traditional preceramic / ceramic divide in archaeology, the "Early Agropastoralist" time block was defined for this project because, in many ways, the conditions during the final millennium of the Archaic had more in common with events in the Formative than with the preceding Archaic Periods. Differentiating sites as "Early Agropastoralist" beginning in the Terminal Archaic requires that one delimits a firm boundary on a process that was millennia in the making. Considering the Terminal Archaic as the beginnings of agropastoralism, and thereby linking it to the attendant settlement distribution that includes series 5 projectile points, connects cultural and economic evidence from throughout the region with a generalized estimate of when food production took hold in terms of scheduling, mobility, and prioritizing the needs of agricultural planting and herding. As mentioned, the term "Early Pastoral" is not meant to imply that no food production occurred before this date and hunting and gathering did not persist after this date. Indeed the current evidence suggests that camelids were first domesticated sometime during the Middle or Late Archaic, probably after 5000 BCE (Browman 1989;Kadwell, et al. 2001;Wheeler 1983;Wing 1986). The "Early Agropastoralist" period refers to a period after 3300 BCE that features a predominantly food producing economy in the highlands including intensive pastoralism, as well as seed-plant and tuber cultivation. These changes in food production may have been linked to the accumulating evidence of increased rainfall and shortening of the dry season beginning circa 2500 cal BCE (Baker, et al. 2001;Marchant and Hooghiemstra 2004;Mourguiart 2000). These changes in economy are joined by evidence of increased sedentism, widening stylistic distributions pointing to long distance cultural integration, and the beginnings of social differentiation apparent in architecture and grave goods. The circulation of obsidian was linked to these phenomena because increased regional interaction was perhaps articulated through camelid caravans, although the presence of caravans in the Terminal Archaic is being explored, not assumed, in this study.

In the Titicaca Basin, the changes incurred between the Terminal Archaic and the Late Formative are monumental. However, from the perspective of the Chivay source the intensification revealed archaeologically, both at the source and in the consumption zone, is notable beginning in the Terminal Archaic, and the intensification does not change notably throughout the Formative Period. Defining the ending of the "Early Agropastoralist" period as the end of the Late Formative is similarly problematic. By the Late Formative, the economic influence of Pukara and other regional centers probably impacted the peoples of the Upper Colca, but direct evidence returning from Pukara, only 140 km away, is scarce in the Colca. In contrast, during the Tiwanaku times, regional states with socio-economic impacts over hundreds of kilometers dominated both the circulation of goods like obsidian, and regional settlement organization.

Terminal Archaic (3300 - 2000 BCE)

The Terminal Archaic ushers in a suite of social and economic changes in the south-central Andes and, consistent with these developments, obsidian begins to circulate in significantly greater quantities during this period. Obsidian is increasingly used for projectile points during the Terminal Archaic, a trend that continues into the Formative Period (Burger, et al. 2000: 294).

Regional patterns in Terminal Archaic sites are somewhat difficult to assess from surface finds because the Terminal Archaic is lacking in exclusive diagnostic artifacts in both the lithic or ceramic artifact classes. As is shown inXFigure 3-10X, the most common projectile point styles that belong to the Terminal Archaic, such as Types 5B and 5D, also persist through the ceramic periods, leaving only type 5A and part of type 4F as diagnostic to exclusively the Terminal Archaic (Klink and Aldenderfer 2005: 48). Furthermore, by definition, the Terminal Archaic is a preceramic period, which precludes a ceramic means of assigning chronology. From site organization characteristics, a site might be considered to be a Terminal Archaic site if it has pastoralist attributes but it is aceramic and has series 5 projectile point types represented that belong, at least partially, to the Terminal Archaic.

The beginnings of the Andean agropastoral strategy are apparent during this period at sites like Asana where seasonal residential movement occurred between the high sierra and the puna (Aldenderfer 1998: 261-275;Kuznar 1995). Another attribute of the Terminal Archaic at Asana is a disappearance of ceremonial features. Evidence for a shift from hunting to pastoralism comes primarily from evidence of corrals (Aldenderfer 1998), from changes in the ratio of deer to camelid remains, and from the ratio of camelid neonate to adult remains. At sites where the process has been observed, the transition to full pastoralism at various sites in the Andes is usually perceived as a gradual process dating to sometime between 3300 to 1500 BCE At Qillqatani, however, the transition was relatively abrupt and it occurred in level WXXIV that dates to approximately 2210-1880 BCE (XTable 3-1X).

Early Formative Period (2000 - 1300 BCE)

In this time period, new socio-economic patterns became well established in the south-central Andes while the distribution of Chivay obsidian was at its maximum both in geographic extent and in variability of site types. During this time period, societies were characterized by sedentism, demographic growth, increased specialization, and early evidence of social ranking(Aldenderfer 1989;Craig 2005;Stanish 2003: 99-109).

At sites like Jiskairumoko in the Titicaca Basin, architecture from the Terminal Archaic consisted of pithouses with internal storage, ground-stone, and interments with grave goods that included non-local items (like obsidian) that were presumably of value(Craig 2005). During the Early Formative around 1500 BCE this architectural pattern gives way to larger, rectangular, above-ground structures that lacked internal storage.

As reviewed by Burger et al. (2000: 288-296) using the Ica "Master sequence" chronology under the roughly contemporaneous "Initial Period" (though the Early Formative ends 300 calendar years earlier), the distributions of obsidian are notable in their extension both north and south from the Chivay source, and in their concentrations at early centers like Qaluyu. Obsidian from Chivay also persists on the Island of the Sun in the Early Formative(Stanish, et al. 2002).

Middle Formative Period (1300 - 500 BCE)

During the Middle Formative Period, social ranking became established in the Titicaca Basin. The changes are most evident in the settlement structure as some regional centers grew to become far larger than their neighbors and feature sunken courts, mounds, and specialized stone and ceramic traditions. Stanish(2003: 109-110)interprets these changes in terms of an ability of elites to mobilize labor beyond the household level.

The stylistic evidence suggests that during the Middle Formative the north and south Titicaca Basin were relatively separate spheres, with Qaluyu pottery in the north and fiber-tempered Chiripa ceramics in the south extending only as far north as the Ilave river. However, Chivay obsidian is encountered in both the North and South Basin. Christine Hastorf (2005: 75)suggests that by the end of this period (the Early Upper Formative) evidence of ethnic identity and ritual activity is supported by ritual architectural construction and non-local exchange goods. It is further inferred that "Plants such as coca ( Erythroxylumsp.), Anadenanthera ( A. colubrine, A. peregrine), and tobacco (Nicotiana rustica)surely would have been present in the Basin by this time, perhaps associated with snuff trays…"(Hastorf 2005: 75). An increase in long distance exchange is commonly found as part of a complex of features associated with ideological and social power during the Middle Formative in the region, and it appears that existing exchange routes, such as the one along the Western Cordillera connecting Chivay with Qillqatani, were increasingly routed towards the Titicaca Basin regional centers during this time.

Late Formative Period (500 BCE - AD 400)

During the Late Formative, significant social ranking developed and dominated the socio-political landscape in the Lake Titicaca Basin. The complex polities that emerged on either end of Lake Titicaca were distinguished by architecture, stoneworking, and ceramic traditions. A three-tiered site size hierarchy is evident in the Late Formative, and the construction of prominent terraced mounds with sunken courts occurred in a few major sites at this time. The elite ceramics and stoneworking, and the construction of elaborate mounds as a venue for large-scale feasts and human sacrifice at sites like Pukara and early Tiwanaku, can be interpreted as a means of demonstrating the large-scale organization of labor by elites (Stanish 2003: 143).

The patterns of obsidian circulation that emerged at the end of the Middle Formative became very well established in the Late Formative. Excavations at centers in the North Basin have found a reduction in the presence of Alca obsidian in the Titicaca Basin, but the Alca material is still present although it is found in minor quantities at the larger sites as compared with Chivay obsidian. The diversity of obsidian types in the Titicaca Basin samples reported by Burger et al. (2000: 306-308) for this time span is low, as compared with the diversity of types used in the Cusco area, because in the Titicaca Basin it is virtually all Chivay obsidian.

In recent excavation work at Pukara on the central pampa at the base of the Qalasaya, Elizabeth Klarich (2005: 255-256) found that obsidian was generally available and obsidian use was not associated with any intrasite status differences. Probable representations of obsidian points and knives appear in Pukara iconography, and small discs have been found at Pukara and Taraco that were possible ceramic inlays (Burger, et al. 2000: 320-321). The Late Formative Period on the southern end of the Titicaca Basin has small amounts of Chivay obsidian at Chiripa and Kallamarka. InGiesso's (2000: 167-168)review of lithic evidence from several Formative Period sites he found no obsidian use in these collections except for samples from Khonkho Wankane which recent research directed by John Janusek has revealed to be principally a Late Formative center. The furthest confirmed examples of transport of Chivay obsidian are these examples encountered in southern Titicaca Basin sites. The two furthest confirmed contexts for Chivay obsidian transport are represented bytwo samples from a Late Formative context at Kallamarka (Burger, et al. 2000: 308, 319, 323) and six samples found at Khonkho Wankane (Giesso 2000: 346), both about 325 km from the Chivay source, or 72 hours by the walking model.

At Qillqatani, the obsidian returns to being primarily Chivay type during the Late Formative although 1 out of the 9 obsidian artifacts analyzed from Late Formative levels was of the Tumuku type (SectionX3.4.2X). During the Late Formative there is a steady decline in the percentage of debitage made from obsidian at Qillqatani, a trend that continues in the Tiwanaku period.

In the Colca Valley, there are few traces of the Late Formative consumers of Chivay obsidian. As will be further explored in this research project, there is very little Qaluyu or Pukara material diagnostic to the Middle or Late Formative in the Chivay obsidian source region. Steven Wernke found a diagnostic classic Pukara sherd with a post-fire incised zoomorphic motif that resembles a camelid-foot from a Formative site above the town of Yanque in the Colca (Wernke 2003: 137-138).

Pukara materials are known to have circulated, probably through trade links, throughout the south-central Andes. Pukara sherds have been found in the valley of Arequipa in association with the local Formative Socabaya ceramics (Cardona Rosas 2002: 55). In the Moquegua valley, both Chiripa-related and Pukara pottery have been found (Feldman 1989), and a Pukara textile was found in a possible elite grave context in the Ica Valley (Conklin 1983).

Discussion and review of "Early Agropastoralists" obsidian

From the Terminal Archaic through the Formative Periods the circulation and consumption of obsidian expanded dramatically. Chivay and Alca obsidian is found in a wide variety of sites from isolated rock shelters to early regional centers, and it appears in consistent quantities that differ considerably from the intermittent nature of regional obsidian supplies in preceding periods. The increased circulation of obsidian is part of a spectrum of changes that began in the Terminal Archaic, but obsidian distribution patterns are particularly useful because they are quantifiable.

In some ways obsidian appears most closely linked to tasks associated with camelid pastoralism, such as shearing and butchering. However, in the central Andean littoral, Quispisisa obsidian is found in density in "cotton preceramic" and Initial Period (i.e., Terminal Archaic and Early Formative) coastal sites where presumably pastoralism, if present, was a very minor part of the economy. Furthermore, in the south-central Andean highlands obsidian is found in pastoralist rock shelters but also in regional centers, and the small discarded obsidian flakes and small projectile points do not appear to have served as adequate shearing implements due to their size.

Social complexity during first part of the "Early Agropastoralists" period is manifested most prominently along the Pacific littoral. In the coastal context of what is now the Department of Lima, in central Peru, monumental architecture dating back to 3000 BCE is well-established at the site of Aspero, and the transition to yet more monumental preceramic construction at sites slightly inland has been documented in recent research(Haas, et al. 2005;Shady Solis, et al. 2001). The shift inland is argued to be related, among other things, to the increased importance of harnessing labor surpluses through the production of cotton for anchovy nets and textiles, and to competitive monument building between elites. Evidence of exchange with highland and Amazonian groups is apparent in the form of tropical feathers and other non-local prestige goods. While these developments occurred over one thousand km to the north of the Chivay area along the Pacific coast, early complex organization is also reported in northern coastal Chile in the Chinchorro II and III traditions spanning the Late Archaic through the Middle Formative(Rivera 1991). A long history of cotton production for nets and textiles, imported wool textiles, elaborate burial traditions, and long distance exchange with the highlands and the Amazon characterize the later Chinchorro tradition. These regional patterns underscore the wide scope of the changes that occurred during the Early Agropastoralists time. It has been argued that the beginning of social inequality in the highland Andes may have been stimulated indirectly by demand for wool from aggrandizers in coastal societies(Aldenderfer 1999).

Returning to evidence from highland obsidian distributions, the widespread circulation of obsidian during the Terminal Archaic and Formative is perhaps best discussed in the terminology used in the historical model of Nuñez and Dillehay(Dillehay and Nuñez 1988;1995 [1979]). While this adaptationalist model has theoretical limitations, it serves as a useful alternative to evolutionary chiefdom models that assign a paramount role to central-places in exchange, despite the decline of central-place models in geography(Smith 1976: 24). Following the Nuñez and Dillehay model, it is possible that what is occurring in the Terminal Archaic and Early Formative is the emergence of regular exchange pattern between Qillqatani and Chivay that took the form of a caravan trade "axis" along the western Cordillera. This exchange pattern is among the earliest systematic and demonstrable cases of the circulation of diffusive items through largely homogenous altiplano terrain (XFigure 3-4X) in the pattern that has also been described as horizontal complementarity or the "Altiplano mode"(Browman 1981). Subsequently, during the Middle and Late Formative in the Titicaca Basin, former "axis settlements" like Qillqatani, and the Western Cordillera axis more generally, became relatively less important in long distance exchange relationships. Regional centers in the Titicaca Basin like Taraco, Pukara, Chiripa, Khonkho Wankane, early Tiwanaku, and other centers, expanded in influence during this period of peer-polity competition. In these circumstances, the acquisition and ceremonial use of exotic goods appears to have been an important part of the competitive strategies of aggrandizers. Other evidence for Titicaca Basin-based exchange dynamics include the possible production of hoes of Incatunahuiri olivine basalt at Camata around 850-650 BCE that were then transported and used in southern Titicaca Basin sites(Bandy 2005: 96;Frye and Steadman 2001). While the nature of the relationship between emerging elites in Titicaca Basin polities and caravan drivers that provided links between settlements throughout the region is difficult to describe with precision, it appears that interregional articulation became considerably more elaborate by the end of the Early Agropastoralist period.

Tiwanaku and Wari (AD400 - 1100)

Following the Titicaca Basin chronology the Tiwanaku period begins with the emergence of the Tiwanaku state during the time that has been called "Tiwanaku IV" beginning around AD400 (Stanish 2003). This is centuries earlier than the start of the Middle Horizon, as defined by the presence of Wari in Ica. Wari in Ica spans the period from approximately AD 750 - 1000.

Late Intermediate Period (AD1100 - 1476)

Current evidence suggests that following the collapse of the Tiwanaku state, a prolonged drought occurred until AD1200 after which time Aymara chiefdoms emerged in the region referred to as Collasuyu by the Inka. A central question of this time period concerns the extent to which obsidian distributions can reveal whether Tiwanaku period interaction patterns persisted into the LIP in the forms assumed by economic organization and long distance exchange. While the LIP is known as the auca runaor the "time of strife" when fortified hilltop refuges " pukaras"were constructed in abundance in the Titicaca Basin and adjacent territories, the weapons used in these conflicts appear to have primarily been percussion weapons like slings and clubs, and not obsidian tipped-projectiles.

Late Horizon (AD1476-1532)

The expansion of the Inka Empire during the Late Horizon resulted in a restructuring of the long distance movement of goods. The ability of the Inka state to transport stone is vividly demonstrated by the transport of hundreds of andesite ashlars weighing up to 700 kg apiece the 1600 km distance from Cusco to Saraguro, Ecuador (Ogburn 2004;Ogburn 2004). The ability to move people and goods over long distances was an integral part of state apparatus; however, it is evident from obsidian distributions that not all goods were more widely distributed during the Late Horizon.

It appears that if the Inka had a particular demand for a substance it could be acquired from over great distances. The Late Horizon was referred to as the "tin horizon" by Lechtman (1976) due to the lengths that the Inka would go to procure tin for copper production. In the Mantaro Valley, tin was not present in Late Intermediate Period coppers but it was found in all seven copper implements from Late Horizon levels where it made up, on average, 5% of the metal composition (Earle 2001: 311;Owen 2001: Tables 11.1-11.3). This tin is thought to have come from mines in Bolivia or southern Peru, and this exchange was facilitated by the Inka state (Lechtman 1976). Thus tin was transported from southern Peru, perhaps from the vicinity of obsidian rich lands of Arequipa, but apparently little obsidian was transported along those same Inka transportation routes.

Ethnohistoric accounts indicate that during the Late Horizon the control of natural resources sometimes occurred through restricted access to raw material sources in the Andes. Access to tunnels leading to particularly rich gold deposits at Inka gold mining operations were restricted at the tunnel mouths (Burger and Glascock 2002: 364;Sancho de La Hoz 1968 [1534]: ch. XVIII: 332). The deposits of other natural resources, such as obsidian, are distributed across the geological landscape such that directly controlling access would have been difficult or impossible.

Burger et al.(2000: 343-347)report very little Chivay obsidian circulating in contexts that are definitely Late Horizon in date. Small quantities of obsidian were found in Cusco, and these turned out to be entirely of the Alca type except for one notable case of Chivay material at Machu Picchu. In one of the only cases of Chivay obsidian use in the department of Cusco since the Late Formative, several unmodified nodules of Chivay obsidian were identified from a collection of small obsidian pebbles excavated by Hiram Bingham in 1912 at the gateway to Machu Picchu. Burger et al. (2000) note the significance of the unmodified state of these small obsidian pebbles, as the small size of these nodules suggest that it was not the tool-making potential, but rather the natural glass itself that was "suitable in its apparently natural state as an offering or sacred object comparable to quartz crystals"(Burger, et al. 2000: 347;Rowe 1946: 297). This view is consistent with observations about the possible significance of the 'essence' of obsidian as natural glass in Andean cosmology that will be explored in more detailed below.

Discussion and review of "Late Prehispanic" obsidian

Obsidian distributions during the Late Prehispanic period reflect the dramatic changes in economy and ideology imposed by powerful states in the region. In the Tiwanaku and Wari spheres of influence obsidian circulation achieved its largest known extent. Particularly intriguing are the examples of non-local obsidian consumption in close proximity to rival obsidian sources, a phenomenon that occurs twice during the Middle Horizon. Three samples of Chivay obsidian were found close to the Sora Sora obsidian source in western Bolivia in a possibly Tiwanaku context (Burger, et al. 2000: 340), and Quispisisa and Alca obsidian were found at the Wari-influenced site of Achachiwa, only 46 km downstream of the Chivay source, in the lower Colca valley (Brooks 1998: 447). During the LIP this pattern of high mobility and sprawling interregional contact is reversed as regional circulation of obsidian is curtailed and the Chivay regional pattern returns to a distribution confined to the Colca region and the North Titicaca Basin. Finally, during the Inka period, obsidian appears to have had a largely diminished significance, particularly in contrast to other materials that were circulated prodigious distances by the Inka. This discussion of the spatial distributions of prehispanic obsidian will be complemented by a review of the uses and forms that obsidian artifacts assume in the archaeological and ethnohistoric record.

Hafting in the Andes

Archaeological evidence shows that bifacially flaked obsidian implements were hafted in a variety of ways. The majority of the hafting evidence from the Andes comes from coastal sites due to superior preservation. Projectile points were hafted to spears, spear thrower darts, and arrow shafts. Obsidian bifacial tools were also hafted to wood or bone handles for use as knives. Hafting materials varied regionally, but hafting was often accomplished using gum or resin, and hafts supported with cotton string have been found in some coastal sites (Carmichael, et al. 1998: 79).

Evidence of use of obsidian

The artifact types predominantly manufactured from obsidian include projectile points and tools for cutting and shearing tasks. While simple flakes are wide-spread and were probably used abundantly for butchering, scraping, and shearing purposes, the utility of obsidian flakes is frequently discounted when flakes are relegated to the "debitage" or "debris" class. In Andean studies bifacially-flaked instruments are the most commonly analyzed obsidian artifact class in archaeological reports from sites in the Andes.

Obsidian artifacts are sometimes found in association with iconographic representations of dark colored artifacts that are similar in appearance to the very obsidian artifacts found in that context (Burger and Asaro 1977: 15). Such is the case with black-tipped darts and knives depicted on Ocucaje 8 through Nasca 6 ceramics and textiles, and obsidian artifacts found in tombs from those contexts. Building on the discussion in Burger and Asaro (1977: 13-18), examples of obsidian artifacts from the south-central Andes follow.

Table 3-10. Examples of obsidian use in the south-centralAndes (part 1).

Table 3-11. Examples of obsidian use in the south-centralAndes (part 2).

Many of these examples are shown in Appendix C. of this volume. While the diversity of artifact forms was relatively low, it is evident that the visual and fracture properties of obsidian were relevant to the tools that were used from this material. Further north in the Andes, in Ecuador, a greater percentage of obsidian artifacts seems to have filled a primarily decorative role, including abead, an ear spool, and three polished mirrors(Burger, et al. 1994: 246).

The evidence of use lithics may also take the form of cutting and scraping marks on faunal remains, but the lithic material type can rarely be established by these means. The continued use of glass and obsidian in modern contexts for shearing, butchery, and castration suggests that the prehispanic metals such as copper and bronze did not displace obsidian and other lithic materials for utilitarian tasks. Prehispanic metals were used largely for display, although metals were used in some weaponry, such as mace-heads (Lechtman 1984).

Obsidian in warfare

The evidence for obsidian use in conflict in the Andes comes from a variety of archaeological and ethnohistorical sources, but it is primarily in the form of indirect evidence. The data reveal a great expansion in the production of small obsidian projectile points after the onset of a food producing economy. The majority of Late Horizon weapons that the Spanish faced during their invasion appear to have been bola stones and percussion weapons like maces and slings(Cahlander, et al. 1980;Korfmann 1973), as well as padded armor.

Archaeologists working in the south-central Andes vary historically in their assessment of the use of projectiles in the highland region(Giesso 2000: 43). Bennett(1946: 23)asserts that the use of bow and arrow were not important on the altiplano, Metraux(1946: 244-245)says that spear throwers were in use, while Kidder(1956: 138)indicates that evidence from projectiles show that arrows were widely used at Tiwanaku. Of the projectile points analyzed by Giesso from Tiwanaku, 19% were made from obsidian, with the highest concentration of points coming from excavations in the civic/ceremonial core at the Akapana East, K'karaña, and Mollo Kontu mounds(Giesso 2000: 228-238).

In a dramatic example of obsidian use as a weapon, one archaeological findError! Reference source not found.shows a probable spear or dart point penetrated the victim's abdomen from the left anterior abdomen and lodged on the anterior side of the lumbar vertebra.

Evidence of use of the bow and arrow in warfare

One of the strongest patterns in obsidian distributions in the south-central Andes is the sudden onset of obsidian use with series 5 projectile points in the Terminal Archaic, after 3300 cal BCE In defining the small type 5D projectile points Klink and Aldenderfer(2005: 54)suggest that the widespread adoption of these point types may reflect the use of bow and arrow technology, as these points fallwithin the size range described by Shott (1997: Table 2) as associated with arrow points (although with substantial overlap with the size of the smaller dart points).

Figure 3-14. Type 5d projectile points from a Terminal Archaic level at Asana and Early Formative levels at Qillqatani, from illustration in Klink and Aldenderfer (2005: 49).

Additional metrics for differentiating arrowheads from dart and spear points have been suggested by Thomas (1978: 470) and Patterson (1985). With Mesoamerican projectile points, Aoyama (2005: 297) has found a very significant correlation between evidence from microwear analysis and projectile dimensions in his effort to differentiate arrowheads from dart and spear points. The relationship between the mass of the item and the velocity and distance of the projectile are discussed in detail by Hughes (1998). She notes that the innovation of fletching allowed for balanced projectiles that had smaller projectile tips and lighter shaft materials, which in turn permitted greater distance and velocity in weapons systems (Hughes 1998). On a related point, the notched base in all type 5 projectile styles reflects a change in hafting technology. Greater impact loads can be absorbed by mounting projectiles tips with notched bases into slotted hafts (Hughes 1998: 367;Van Buren 1974).

Obsidian has a number of attributes that make it a particularly effective material for projectile point tips, most notably are the predictableconchoidal fracture qualities of obsidian that allow it to be pressure flaked into very small projectile points. The sharpness of freshly knapped obsidian margins is unrivalled, andethnographicallyobsidian is renowned as a brittle material that can fracture on impact, causing the fragments to produce greater bleeding in the victim of an obsidian projectile (Ellis 1997: 47-53). In materials science, obsidian has extremely low compression strength because it has no crystalline structure (Hughes 1998: 372). Due to the brittleness or lack of compression strength, missed shots can result in many broken obsidian projectile tips, and perhaps for this reason obsidian was not the predominant material for projectile point production until after the domestication of camelids when hunting was decreasingly the primary source of meat (as inferred from the ratio of camelid to deer bone in excavated assemblages).

Increased velocity and distance is possible with the use of bow and arrow, and obsidian has greater penetrating power, although lower durability, than other material types. Do these changes suggest a greater use of projectiles for warfare? Greater use of small, fletched projectiles might be expected in contexts where the individual needs (1) increased distance from the target (2) increased velocity, perhaps due to change in prey or to the use of padded armor. The use of obsidian may increase in contexts where one needs (1) a material that can be knapped into small, light projectiles as discussed above, (2) increased penetration with sharper material, (3) decreased concern for durability because in warfare the weapon will perhaps be retrieved by the opponent.

Although empirical evidence for warfare is scarce in the Terminal Archaic in the highlands, a study of 144 Chinchorro individuals from Terminal Archaic contexts in extreme northern Chile found that one third of the adults suffered from anterior cranial fractures that probably resulted from interpersonal violence, and men were three times more likely than women to have these wounds (Standen and Arriaza 2000). These wounds appear to have been caused by percussion weapons like slings, but the coastal evidence for interpersonal violence in this time period is strong. Additional support for the introduction of the bow and arrow in the Terminal Archaic come from the region among Chinchorro burials in coastal Northern Chile. Bows among the Chinchorro grave goods date to circa 3700 - 1100 cal. BCE, or the Terminal Archaic and Early Formative (Bittmann and Munizaga 1979;Rivera 1991;Standen 2003).

Possible use of poisons on projectile tips

A potential explanation of widespread adoption of the small type 5D projectile points is the greater availability of poisons that reduced the need for heavy, destructive projectiles.South American poison arrows are usually quite small and such arrows are frequently tipped only with a sharpened wooden point. According to Ellis(1997: 55),virtually all ethnographic examples of arrow use include some kind of poison applied to the arrow in order to have either a toxic or a septic effect on the victim. Ellis observes that due to the great variety of substances used to create such toxins, in many regions of study these substances would probably contaminate any chemical attempt to use residue analysis to differentiate the types of poisons used, or even the prey that was hunted, with a particular used projectile point.

A variety ofhighly effective poisons are applied to the tips of projectiles by hunters in the Amazon Basin today(Heath and Chiara 1977).In the prehispanic Andean highlands, trade contacts with the Amazonian lowlands to the east may have made available poison concoctionsfor application to projectiles, most notoriously the fast acting paralysis alkaloid curareprepared from the vine Chondrodendron tomentosum(Casarett, et al. 1996).

Bernabé Cobo (1990 [1653]: 216-217) discusses the use of bow and arrow with poisons by "expert marksmen" in his chapter on warfare. Hedescribes the widespread and expert use of the sling for warfare, which is consistent with reports elsewhere on the use of slings, but then he states that bow and arrow were more significant in warfare.

The most widespread weapon of all the Indies, not only in war but also in the hunt, was the bow and arrow. Their bows were made as tall and even taller than a man, and some of them were eight or ten palms long, of a certain black palm called chontawhose wood is very heavy and tough; the cord was made of animal tendons, cabuya, or some other strong material; the arrows, of a light material such as rushes, reeds, or cane, or other sticks just as light, with the tip and point of chontaor some other tough, barbed wood, bone, or animal tooth, obsidian point, or fish spine.

Many used poisoned arrows, their points anointed with a strong poison; but, among the nations of this realm, only the Chunchosused this poisonous herb on their arrows, and it was not a simple herb, but a mixture of various poisonous herbs and vermin; and it was so effective and deadly that anyone hit by one of those poisoned arrows who shed blood, even though it might be no more than the blood resulting from the prick of a needle, died raving and making frightful grimaces(Cobo 1990 [1653]: 216-217).

The Chunchos ethnic group is described as living in the "forests east of Lake Titicaca on the border of the Inca Empire".It is possible that Amazonian poisons became available in altiplano during the Terminal Archaic due to expanding exchange networks, together with Amazonian hallucinogenics and other lowland products, dramatically altering the efficacy of arrows. As a sharp but lightweight weapon, obsidian tipped arrows would have represented an effective poison delivery system to animal and human victims alike.

While there is no direct evidence for the use of Amazonian poisons on the altiplano, the dramatic change in projectile technology with the type 5D type, co-eval with expanding exchange networks in the region, suggest that a new technology for weapons systems, such as poisons and new shaft and fletching materials, may have influenced the design of projectiles in this time.The transitional economic context of the Terminal Archaic involved many changes, including shifts in both food production and interregional exchange, and the technology of lithic production show significant alterations that correspond to this period.

Multiethnic access to geological sources in the Andes

Salt procurement in the Amazon basin on the eastern flanks of the Andes provides an example of multiethnic access to a raw material source. During annual voyages to the Chanchamayo salt quarry ten days outside of their territory, the Asháninka of the Gran Pajonal (Ucayali, Peru) combine salt procurement with exchange with neighboring groups who share access to the source(Varese 2002: 33-35). Arturo Wertheman, a missionary who traveled through the region in 1876, explains

Throughout the year small bands of Asháninka traders traveled [the Gran Pajonal] paths to obtain salt, carrying with them tunics or ceramics to exchange for other items and for hospitality. With them traveled their traditions, their hopes, and the information of interest to their society. The Pajonal, the vast center of Campa territory not yet invaded by whites, appears to have been the center of culture and tradition through which the Indians journeyed, like a constant flow of life through their very society(Varese 2002: 120)

Other ethnographic examples of multiethnic access to salt quarries are mentioned in the ethnographic literature. Oberem(1985 [1974]: 353-354)describes access by both the Quijo and the Canelo people to a large rock salt quarry located on the Huallaga River, a tributary to the Amazon lying further north on the border of Peru and Ecuador.

In the Cotahuasi valley of Arequipa, to the north of the Colca valley, the rock salt mine of Warwa [Huarhua] has been exploited since Archaic times(Jennings 2002: 217-218, 247-251, 564-566). Access to the Warwa quarry, which lies near the border of the departments of Arequipa, Ayacucho, and Apurímac, is described by Concha Contreras(1975: 74-76)as including caravan drivers from all three of those neighboring departments.

El primer viaje lo hacen, mayormente, en el mes de abril. En esta época cientos de pastores se concentran en esta mina. El camino es estrecho y accidentado hasta llegar a la misma bocamina…Desde el fondo de la mina los pastores cargan a la espalda la cantidad de sal que necesitan llevar, de tal manera que hacen muchos viajes al socavón de la mina. En todo este tramo tardan 4 días, porque después de la mina, siguen cargando en la espalda hasta una distancia de aproximadamente cinco kilómetros, donde quedaron las llamas pastando, puesto que hasta la misma mina no pueden entrar juntamente con sus llamas(Concha Contreras 1975: 74).

There appear to be a number of protocols associated with salt acquisition at Warwa. Notably, the multiethnic visits by caravanners from various departments coincide in April despite the tight working quarters at the salt mine. Furthermore, there seems to be concern for impacts in the much-visited the mine area itself. The cargo animals are actually grazing a distance from the quarry and humans are obliged to carry the loads to these areas instead of attempting to load the animals close to the mine. These cases of multiethnic raw material access provide examples of the social and institutional nature of access to unique geological sources, and the focalized attention that these source receive from surrounding ethnic groups. The analogy with regional acquisition and diffusive transport of the raw material is perhaps the closest modern analogy to the nature of prehispanic obsidian quarrying that remains in the Andes.

How did the social and symbolic importance of obsidian change through time and space?

Obsidian flakes and bifacial tools were sometimes included as grave goods from the Terminal Archaic (3300 cal BCE) and onwards. Ethnohistoric accounts and archaeological evidence indicate that obsidian "knives" were employed in ritual practice as well as in medical procedures throughout the region, although it is not evident if these were bifacially-flaked tools or simply freshly struck flakes. In addition, concentrations of flakes of quartz as well as obsidian from a variety of non-local sources were found in the Tiwanaku ceremonial mound of Mollo Kontu in a regular pattern that was interpreted by Couture (2003) to indicate deliberate inclusion in clay fill rather than accidental redeposition.

Based on analogy from other goods, it is possible that in areas where obsidian is used in ceremonial contexts a finely-made obsidian implement may have been less likely to have been exchanged as an alienable product traded in barter. In some historical contexts, a ritual item may become a singular item and acquire a distinctive 'genealogy' related to its social history that precludes it from being bartered and circulated in equivalence for something ordinary such as a sack of potatoes (Hodder 1982;Kopytoff 1986).

However, on the whole, obsidian appears to be one of a number of products that escapes easy classification. On one hand, obsidian circulated in established networks controlled by llama caravan drivers who were responsible for the distribution of a variety of goods on the altiplano. These caravans appear to have been organized by households and derived communities of relatively humble means, to judge from other aspects of their material lives excavated at sites like Qillqatani. On the other hand, as a luminescent material with irregular spatial availability, obsidian had properties that qualify it as a "prestige good" in many contexts (Hayden 1998). In terms of rituals organized and performed on a local level, obsidian was probably one of a number of materials that were traditional but non-the-less slightly rare like ochre and shell. Craig (2005: 683-693) explores the evidence for the symbolic importance of discrete color groups in ritual items like ochre and obsidian in the Titicaca Basin Archaic and Formative site of Jiskairumoko by examining the patterning of obsidian and ochre in comparison to what were common-place, functional applications of these goods.

From the perspective of early aggrandizers in the Terminal Archaic and Formative Lake Titicaca Basin, obsidian probably represented a somewhat elusive product for labor investment and therefore was not a principal substance used in elite strategies by the time of the Middle and Late Formative. From the perspective of prestige technologies serving the agenda of aggrandizers by locking up surplus labor (Hayden 1998), the issue might be considered in terms of the following factors:

(1) Obsidian was relatively easy to acquire, perhaps too easily acquired, for the people living in the highlands of Arequipa; and it was not concentrated in specific, controllable points accessed only through mine shafts.

(2) Obsidian has functional properties that assured its continued circulation for the production of cutting and piercing implements, making it insufficiently rare to have served as a "preciosity" (Clark and Blake 1994;Goldstein 2000).

(3) While craft specialization was fostered in more closely-controllable contexts in regional centers during the Formative, obsidian sources were perhaps sufficiently distant to have escaped this kind of specialized craft production. In contrast, consider the various non-utilitarian obsidian products made by craftspeople in Mesoamerica, discussed above.

(4) As obsidian was primarily made into projectile point tips, it was perhaps associated with hunting, or the threat of violence. In some regional traditions, such as in Nasca iconography, obsidian appears to have been associated with trophy head taking. However, in the south-central Andean highlands there is no evidence of a direct association between violence, emerging leadership, and control of surpluses along the lines of Hayden's (1995) despotic leader model.

Obsidian products, particularly finely-made bifacial tools, were perhaps one of a series of items that served to differentiate status-seeking individuals in early transegalitarian contexts, but with later crafts investment obsidian appears to have been assigned a relatively specific role for projectile point production and for cutting implements.

Do changes in use of obsidian reflect local geographic availability?

One way to examine the social and symbolic significance of obsidian is to examine the changing use of the material as availability declines with distance from the geological source. To judge from the distant consumption zone, obsidian was used in both mundane contexts and also in ritual or ceremonial contexts. At Tiwanaku, obsidian was found dispersed into the fill of ceremonial mounds (Couture 2003). It is also sometimes found in Titicaca Basin burials as of the Terminal Archaic. As reported by Craig (2005: 570-574, 679-682), at Jiskairumoko and at other sites in the Ilave valley, obsidian has been found in burials dating to 3300 cal BCE and later along with other non-local goods including lapis lazuli (sodalite) beads, gold discs, and gold beads, as well as ritual items like a camelid effigy made from bone. If the associations of obsidian with ritual power were related to its non-local origins, one might expect this pattern to have been weaker in closer proximity to the Chivay source. Items from ritual contexts, such as grave goods from the Colca Valley, and in close proximity to the Chivay obsidian source, may provide data to test this hypothesis.

Do the unusual visual qualities of obsidian resonate with Andean traditions?

Andean traditions place a priority on visual attributes, and links between the visual purity of a material and its essence have been widely noted in some segments of the Andean literature. As a natural glass, the aqueous properties of obsidian cause the material to reflect light which may display the workmanship of obsidian artifacts, as well as the potential sharpness of obsidian tools. Obsidian used for prehistoric tool production was often a homogeneous glass that was visibly consistent, pure in color, and sometimes transparent or banded. The importance of visual qualities of metals in the Andes has received greater attention:

The social arena in which metallurgy received its greatest stimulus in the Andes was the arena dominated by status and political display. An underlying cultural value system that appears to have strongly influenced the visual manifestation of status and power was a color symbolism oriented around the colors of silver and of gold. The most innovative and interesting aspects of Andean metallurgy arose from attempts by Andean metalsmiths to produce metallic gold and metallic silver surfaces on metal objects that were made of neither metal (Lechtman 1984: 15).

In Andean metallurgy, the appearance of consistency in color, reflectivity and material was prioritized because visual characteristics conveyed information about the inherent essence and animation of the object (Lechtman 1984: 33-36).

There is little direct support in Andean archaeological or ethnohistorical sources for inference regarding how obsidian was perceived, but it would be consistent for obsidian, a stone with the appearance of watery luster, to be associated with ceremonial power and ritual sacrifice given the well-demonstrated importance of stone and water in Andean cosmology.

Were the visual differences between obsidian types in the Andes important?

Visible differences between obsidian chemical types in the region are principally in terms of nodule size, fracture characteristics, glass color, and cortex. While nodule size and fracture characteristics are believed to have been important determining factors in explaining which obsidian types were circulated widely in prehistory (Burger, et al. 2000: 348), glass color is more of visual aesthetic issue. The obsidian sources in the south-central Andes are predominantly black or grey. Obsidian from the Chivay source is often a transparent grey and banded, and Quispisisa obsidian sometimes has a red coloration, although Burger et al. (2000: 314) state that the Quispisisa type is visually indistinguishable from Alca obsidian. As with many goods with discrete places of origin, these visual differences communicate information about the spatial origin of the stone that would have visually linked the material with regions and socio-political groups to knowledgeable viewers. To Brooks (1998: 452;1997) the transparency of Chivay obsidian was a reason for its wide circulation in prehistory. Others have commented on the transparency of the material including Giesso (2000;2003), and Burger et al (2000: 296). Giesso (2003: 368) observes that archaeological and ethnographic evidence from the Andes indicate that "transparent elements were viewed as mediators between different cosmological worlds". Further study may permit evaluation of observed patterns in the contexts of obsidian use that are linked to color.

Discussion

The social and ritual significance of obsidian in particular prehispanic Andean contexts appears to have varied across time and space, and with further research in the region into evidence of production and consumption these differences will be better understood. Archaeologists have established that the visual attributes of particular materials like metal were important in the late Prehispanic Andes. If this mode of interpretation may be extended, high quality obsidian shares some visual characteristics with metal such as shininess and an appearance of material purity. Furthermore, obsidian from particular areas was often visually distinct and this may have conveyed information in regions such as Moquegua where a variety of obsidian types have been encountered. Obsidian was irregularly available across the landscape, and the mere possession of this highly visible material in obsidian-poor regions had possible social significance because it suggested that the holder participated in long distance exchange networks or had alliances with groups in obsidian-rich areas.

Description

Direct acquisition by the end user entails high mobility and multiethnic access to the Chivay source. In this model, those traveling to the source would procure only sufficient obsidian for their household or community needs and no more. The evidence of procurement at the source would be the direct impacts of communities of consumers where obsidian was perhaps circulated in a context of generalized reciprocity but specifically not exchanged against goods in truequebarter, as that is a different type of procurement. Thus, this category consists of direct, personal visits by the immediate consuming household throughout prehistory.

Table 3-12. Models of procurement and exchange for Chivay obsidian. Compare terms with those used in Figure 2-2 and Figure 3-3.

Based on low population densities during the Early Holocene it is assumed that the earliest regional consumers of Chivay obsidian in the south-central Andes, the residents of Asana circa 9400 BP, acquired obsidian directly. Direct household acquisition of resources, such as salt procurement, persists to this day in a few places in the Andean highlands. It is possible that the multi-ethnic nature of access to Andean salt mines may serve as a model for procurement that occurred at Chivay during much of prehistory.

As it is generally the altiplano pastoralists that possess the major means of transport, llama pack animals, and direct household procurement by such groups was perhaps common for many types of goods. For example, herders from the community of Paratía (Flores Ochoa 1968: 87-109), to the north-west of Juliaca in the department of Puno, made regular trips to the Colca valley to acquire agricultural goods. If Paratíans traveled directly, it is likely that they used the Quebrada Escalera route passing to the north of Nevado Huarancante which would pass only a few kilometers from the Maymeja area of the Chivay source. On the return voyage from the Colca, if llamas were not overly burdened, a special stop could have been made to acquire a few nodules of obsidian. Similarly, the household-organized llama caravans described by Nielsen (2001) could well have obtained lithic raw material for household consumption if their travel route passed adjacent to a scarce raw material source on a return journey.

This mode of transport requires that consuming households had the social and physical means to travel to the obsidian source. The ability to partake in regional transport, even in a logistical fashion described by Flores Ochoa and by Nielsen, required strong animals, the food security to undergo a risky journey, peaceful conditions and personal security on the isolated travel routes, probable social relationships or contracts with communities encountered along the way, and knowledge of the extraction source area. Conditions of multiethnic access were likely variable in prehistory and knowledge of travel routes and sources of raw material were best obtained through cordial relations with local groups. In short, this means of obsidian distribution requires relatively cosmopolitan travelers with the resources to personally visit the sources of goods needed by the household. This mode of transport is relatively inefficient because individual households or communities sharing resources, by definition, have to personally acquire and produce obsidian in this model of obsidian procurement.

Material Expectations

In the immediate vicinity of the obsidian source archaeological evidence of the direct acquisition mode would produce high variability in procurement, but relatively small quantities in production because consumption would be limited to the households of those visiting the source. Greater amounts of advanced reduction evidence, including bifacial thinning flakes and tools, broken and discarded during manufacture, will be in evidence at the source area. This type of procurement would have the greatest chance of resulting in diagnostic projectile points in the area as advanced reduction and potential discard in the area of the source is expected. When temporal control is available, primarily from datable organic material in excavated contexts, direct acquisition should result in irregular visits to the source area based on household need. In excavation units cultural material will likely be low-density, as soil and perhaps ash from adjacent active volcanoes will have time to accumulate as visitation rates are low.

There is some chance that undecorated, non-local pottery might be found in association with quarrying or with adjacent rest area bofedal zones. For example, Formative Period ceramics from the southern Lake Titicaca are typically fiber tempered, but in the north basin and in the Colca they are grit tempered. Evidence of fiber tempered plainware may have resulted from discard during direct access procurement by southern Titicaca Basin visitors. Other temper and paste characteristics may serve to identify non-local pottery. Alternately, non-local pottery may result from reciprocation activities (i.e., the Down-the-line model), but the notion here is that non-decorated, utilitarian pottery may have been too crude to have served as barter goods.

Description

The multiple reciprocal exchanges model involves the direct acquisition of obsidian by local people for the express purpose of transferring the obsidian to neighboring communities in exchange for other items. In this model, people residing in Chivay area, perhaps no more than one day's travel from the source, procure material and transport it to a location where the obsidian is then exchanged with neighbors.

This kind of procurement resembles Renfrew's (1975: 520) "Reciprocity" and the "Down-the-line" modes (see Figure 2-2), where goods are exchanged with neighboring groups of roughly equal status through a variety of configurations that are essentially reciprocal in some form. While a synchronic barter of obsidian for, say, a chunk of ochre from the neighboring region is easiest to describe conceptually, reciprocity relationships are a manifestation of a wide range of social mechanisms (Section 2.2.2). In the context of the Chivay area, reciprocal exchange arrangements such as barter for other products, or for grazing rights, for labor, or for social functions such as bridewealth, may be evident. Furthermore, delayed reciprocal arrangements between neighbors are extremely common. Evidence of Down-the-line exchange may be encountered in a wide variety of socio-political contexts from Archaic Foragers to agro-pastoralists living on the periphery of states during the Late Prehispanic. If demand for a product is sufficiently high, archaeological evidence may be encountered of individuals devoting themselves to procurement in order to satisfy regional demand, but substantial quantities of goods would have to be reciprocated because the households that are sponsoring this increased procurement would have fewer provisioners working to bring subsistence to the household. Thus, if down-the-line demand is sufficiently great then the households devoting themselves to elevated rates of procurement would need to barter products for subsistence goods. In the Andes, the pattern observed from items like salt (Concha Contreras 1975: 74-76;Nielsen 2000) suggests that in modern circumstances when demand, and barter values, are sufficiently high, then the down-the-line network may be simply by-passed in favor of procurement through personal or caravan acquisition. Caravans from the consuming zone or adjacent highland areas will make the journey to procure the material and transport it for household use and for barter (a combination of the Direct Access model and the Independent Caravans model).

In a functioning Down-the-line system the flow of information is also important. The changes in the regional demand for a product like obsidian can return to the source area procurers through direct requests, or it might be reflected in increased barter value in a market context. Information exchange may also return specific demands from consumers as to the size, form, or quality of the source material. The temporal regularity of down-the-line reciprocal trade may also be quite variable, as down-the-line networks may dwindle and then be revived during a seasonal gathering or ceremonial occasion. Reciprocal relationships can take the form of mutualism and buffering, they may result from a need to complement the resources on a neighbor's territory, and they often present opportunities for ambitious individuals to advance their interests through differential access to non-local goods.

Material Expectations

Down-the-line procurement involves local people visiting the Chivay source and acquiring goods to supply the reciprocal exchange network, however large that it may be. In the quarry area one should expect local visitors, and therefore local styles in both discarded materials and local architecture. Procurement may take place in the context of embedded economic activities, such as hunting forays into the high country or pasturing of camelids in the rich bofedal adjacent to the source.

If reciprocation for obsidian takes the form of portable objects, such as non-local ceramics, one may encounter diagnostic, non-local goods in the communities adjacent to the obsidian source. These may be in the form of styles belonging to neighboring communities, or more exotic styles may be found on non-local goods that could have arrived through the exchange network from even more distant areas. There is a high likelihood that reciprocation for obsidian would have taken place in other forms as well: goods that are perishable, labor, or other assets that are otherwise less easy to detect.

If locals are involved obsidian procurement at the Chivay source one may also find that the large nodules available at the Chivay source are used in the local economy as well. That is, if nodules in the Chivay source are up to 30cm in length then large flakes, either cortical or non-cortical, may be expected to have been discarded in residential contexts in local communities. If large nodules are available then those that are not exchanged with reciprocal partners are put to use for local needs. Thus when large cores and flakes are procured in the Chivay source area, then appropriately large flakes should be discarded in the middens of communities in the adjacent consumption zone in the upper Colca.

Procurement and initial reduction at the source will have relatively low variability because it is conducted by the same local methods. Local people will have better knowledge of high quality extraction loci and perhaps there is lower variability in procurement locations as a result. As reciprocity networks, and particularly barter arrangements, are contingent on visual attributes of bartered items one should expect medium reduction of material at the source or in the adjacent communities. At the very least, nodules will be partially decorticated and an initial strike that provides entry into the core should be expected, as this serves to expose the quality of material on the interior to barter partners. Furthermore, if transport does not involve camelid cargo animals (because reciprocity is either taking place pre-domestication during the Archaic Forager period, or otherwise does not involve camelids) one might expect a greater concern for the weight of the nodules and therefore further reduction in the vicinity of the obsidian source.

More advanced reduction may also be expected as it minimizes risk and waste by producing blanks, preforms, and prepared cores in the vicinity of the source where obsidian is abundant. However, according to the Down-the-line model producers have the greatest social distance, and therefore the least information, about their consumers. Advanced reduction limits the possible forms that artifacts may take, and therefore producers would need to know what kinds of tools consumers were planning to produce in order to move beyond initial stages of reduction. Thus medium level reduction might be expected, but not an abundance of advanced reduction at the Chivay obsidian source.

Description

Long distance transport of goods by way of camelid caravans was well established in the prehispanic Andes. The strongest evidence for the importance of caravan transport comes in the form of ethnohistoric and ethnoarchaeological studies described earlier in this chapter, however archaeological evidence of caravan traffic is usually very light and it often requires inference from indirect evidence. The "Independent Caravans Model" described here consists of caravans organized on the household level, although ethnographic studies show that, in practice, the members of several households will often band together for company and for safety while participating in long distance caravans. It is worth pointing out that independent long distance transport does not necessarily involve cargo animals. It is possible that small quantities of obsidian were carried bytraveling peddlers. As a variant to this model, one should consider that peddlers carrying small portable items, mostly cultural goods like herbs, shell, feathers, but potentially small obsidian tools or cores, could have circulated objects widely without the assistance of llamas.

According to this model, a household with a sufficient number of cargo animals, usually castrated male llamas, will initiate a trade caravan by transporting goods that they expect will be in demand, to regions that they anticipate will have complementary goods to offer them. According to some descriptions, caravans are pursuing a directed acquisition of specific goods and then they return directly home, while other models describe entire circuits where herders acquire goods, travel, barter for other goods, travel some more, perhaps re-trade their new goods and so on; finally returning to their place of origin several months later.

The mere presence of products distributed over larger distances is not proof of caravan transport, either household organized or administered, because other modes such as direct acquisition and down-the-line models actually result in widely dispersed goods as well. Furthermore, many of the distinctive objects that archaeologists recognize as non-local are often small enough to have been transported without cargo animals. Establishing the beginnings of caravan transport is not a simple task because there is no one signature for long distance caravan organization that is distinctive from other modes of transport. Furthermore, many of the goods are believed to have been perishable, complicating efforts to interpret prehispanic trade caravan patterns. Finally, studies of contemporary caravans emphasize that diversified strategies characterize caravan driving, whether in making daily decisions while on the trail, or in the larger context of economy and exchange. It is thus difficult to define a consistent indicator for caravan activity.

Portable diagnostic artifacts, whether decorated ceramics or other exotic goods, are often relatively small and therefore the artifact weight and total quantity frequently cannot be used to differentiate between caravan transport, traveling peddlers, and down-the-line exchange. The temporal regularity of exchange, however, is a consistent measure that archaeologists can recover from stratified deposits. When regular caravan transport routes developed then the scheduling of such transport may have been linked to the timing of annual events such as harvests and annual ceremonies, and if so these cyclical patterns would result a steady accumulation of non-local goods through time. In contrast, down-the-line exchange depends upon the articulation of many individual exchanges and it is not linked to the acquisition of scheduled harvest products in the same manner as caravan transport and therefore the presence non-local goods would have been irregular.

In terms of the network configurations discussed earlier (Figure 2-3), the configuration that describes the diffusion of obsidian in the region is distinct from the configuration of the regular articulation between herders and farmers that involved the barter of pastoral products for agricultural products. However the regular conveyance of some agricultural goods adjacent to a raw material source creates a context for conveying larger quantities of obsidian regionally. Ethnographic studies indicate that caravans will opportunistically embed exchange into other activities. For example, Nielsen (2000: 488) explains that caravans primarily organized around salt transport would carry a variety of other trade items, and they would occasionally stop to procure raw materials, such as lithics, when the caravan route travels past a known source. Similarly, there is caravans that visited the Colca valley in prehistory from the Titicaca Basin were passing with 3 km of the Chivay source if they used one of the popular routes into the Colca from the south-east direction. Thus, procurement of obsidian was likely to have been associated with long distance exchange opportunities.

Material Expectations

Caravan procurement would have consisted of pastoralists traveling to the Chivay source, acquiring obsidian that they believed to have exchange value, perhaps processing the nodules to some extent, and then transporting the material to consumers or to other traders in areas far from Colca. As temporality is a significant part of caravan organization, regular and dense procurement activities are expected when a caravan undertakes a detour from the principal travel route. Some preparation or maintenance of the trail from the principal travel route to the obsidian source is expected if the animals are heavily laden. The amount of processing and initial reduction in the source area probably reflected the number of days that a caravan would have been willing stop, and conversely the transport of whole nodules is conceivable with the assistance of cargo animals such that some extra grams of weight were less of a limiting factor. As mentioned, cortex is often very thin on Chivay obsidian, therefore it would not be surprising if some percentage of the material transported away from the source area included unreduced, whole nodules.

Ethnoarchaeological studies report that caravan drivers look for camps that include high quality pasture, water, and corrals if possible. When these features occur close to an extraction site, a relatively dense obsidian processing area may be found nearby because herders can nourish their livestock while simultaneously working stone. Because of the temporality of caravan activity, procurement was probably intensive, though episodic, through time. When caravans or animals were present, processing would occur and then the material would be conveyed away and the quarry area would see little use until the next episode of intense production. Evidence of production may be variable, however, because caravans could also transport whole nodules without very much difficulty.

Many of the artifact types that were produced from obsidian transported by caravans can deduced based on archaeological evidence acquired from consumption contexts dating to the Terminal Archaic and later. The principal artifact form made from obsidian during the time that camelid caravans conceivably operated (subsequent to the Late Archaic), is the small triangular projectile point diagnostic to the Terminal Archaic and later. This is not to say that other tool forms were not being made, as other non-diagnostic biface forms could also date to the Terminal Archaic or later, however the vast majority of bifacially-flaked obsidian artifacts are projectile points. Furthermore, cores were likely transported away from the obsidian source because simple flakes serve as valuable cutting tools. Therefore, the majority of obsidian production would have prioritized the production of cores and flakes that serve as blanks for triangular point production. If advanced reduction occurred in the quarry area it is likely that small, triangular point forms were the objective.

Reduction strategies that target the production of small triangular points were probably relatively flexible because these point forms are not especially long or delicate, and therefore it would have been possible to produce the appropriate blanks from a variety of core forms. None-the-less, the overall variability in formal tools forms produced from obsidian is exceptionally low because series 5 points look quite similar. Therefore in terms of intensified production from the Terminal Archaic and onward, relatively consistent reduction strategies in the procurement workshop zone may be encountered.

Because these caravans were independent, one might expect slightly greater variability than in the other models of obsidian distribution because various individual households were participating in this procurement, and methodological variation by region might be reflected in the reduction methods. Finally, independent caravans may behave in other, relatively variable ways such as in architecture, in divergent ceramic styles, and in the types of obsidian pieces that were being exported.

Description

Ethnohistoric evidence suggests that elites commissioned long distance trade caravans to procure materials that were used in a variety of elite strategies at the regional center. As discussed above, Stanish argues that Titicaca Basin elite-administered long distance trade involved acquiring goods for favorable barter rates in distant valleys and then acquiring prestige from the redistribution of these goods. Late Prehispanic elites were probably in a good position to initiate large caravans: they had immense camelid herds and their followers owned them tax payments in the form of labor. In addition, elites would have had the surpluses necessary to initiate a large scale trading venture.

Would such caravans have visited the Chivay source and extracted obsidian for elite consumption or redistribution? Stanish (2003: 69) argues that all Prehispanic trade was administered trade, as opposed to market-driven trade, but he specifically excludes trade in obsidian as "small and light" and capable of being transported through down-the-line exchange. Obsidian does not appear to have been a high prestige item along the lines of precious metals in the prehispanic Andes. Under the Inka there is evidence of control of access to tunnels leading to rich gold mines in the Andes (Burger and Glascock 2002: 364). With obsidian, however, there is no evidence of elite control either in obsidian consumption patterns in regional centers, or in the Arequipa obsidian quarry areas that are generally dispersed and it would have proved difficult to limit access to them (Jennings and Glascock 2002: 115-116). Thus extensive elite-administered acquisition or redistribution of obsidian should not be expected. Nevertheless, given the importance of exchange and non-local goods in issues relating to the origins of social complexity, any evidence of elite-organized raw material procurement should be studied closely.

Material Expectations

Elite-administered caravans would be relatively difficult to differentiate from independent caravans in their source activities. Elite related diagnostic pottery may be encountered in the vicinity of the source area. There may have been some degree of greater standardization if these were part time or full-time specialists working for the elites. Elite-sponsored procurement may involve greater intensification than would be expected from independent caravan procurement because these task groups likely have been organized and dedicated to the procurement objective. Finally, the export of large nodules may have increased as elite-sponsored caravan trains were reportedly large and capable, and the weight of nodules would not have overly interfered with the progress of the caravan following this model. In addition, if the object of elites was prestige building, larger nodules would probably have been more impressive in the distant consumption zone. In short, differentiating elite sponsored caravans at the source may be relatively difficult unless pottery or some other diagnostic material is found to have been associated with procurement.