Ch8 Implications of Results and Conclusion

Major Findings from the Upper Colca Project

8.1. Introduction

This chapter reviews the most significant findings of the Upper Colca Archaeological Research Project. The principal results will be summarized by time period, and then these larger findings of this research will be reviewed thematically by looking at the evidence with respect to specific issues such as quarrying, production, and modes of regional interaction. Subsequently this chapter will return to the four models for obsidian circulation in the Andes that were introduced earlier, in Section 3.7. This chapter concludes with a review of the theoretical implications of the research as well as a brief discussion of future directions in research at raw material sources in the Andes.

8.2. Review of major findings

Summarizing the results presented in Chapters 6 and 7, a number of changes in obsidian procurement at the Chivay source correspond to changes recognized regionally in south-central Andean development. While the activities at the Chivay source area did not exactly meet the expectations of the project that were implied by patterns of regional consumption data. The differences between the expectations and the results of the Upper Colca project are informative, and these differences will be highlighted in the text. The differences appear to be largely the result of a historical bias in research, in that there has been a predominant focus on the more socially complex, later episodes in Andean prehistory. For example, obsidian has been found in many ceremonial Tiwanaku contexts and in the Tiwanaku core area such that some investigators in the heartland area argue that the Chivay source was state-controlled (Giesso 2003). Yet, in numerous studies in the Colca region, and this study of the Chivay source in particular, archaeologists have yet to find definitively Tiwanaku artifacts in the Colca area. Contrasting with this lack of evidence from the Tiwanaku period, consider the evidence from earlier periods: the Terminal Archaic and Early Formative. While relatively few sites have been excavated that date to the Archaic / Formative transition in the south-central Andean highlands, the evidence from the Chivay source shows that obsidian production intensified during that time. Indeed, a review of the little evidence available from Terminal Archaic and Early Formative sites in the adjacent consumption zone indicates a spike in obsidian consumption during that time.

In other words, archaeologists in the south-central highlands have historically focused on late prehispanic complex polities, and today the legacy of data from excavations aimed at regional centers has biased the overall picture of obsidian consumption towards the later Prehispanic period. While there were major social and economic changes underway in the third millennium BC, the findings here reveal that obsidian was one of the earlier materials to show a distinct increase in production and circulation in the south-central Andes.

8.2.1. Archaic Foragers (10,000 - 3300 BCE)

During the lengthy Forager period there were a number of gradual changes that may be observed in obsidian procurement and circulation. Obsidian appears to have been procured directly from the Maymeja area since at least the Middle Archaic. Evidence from the dating of a glacial moraine, and from obsidian consumption at the distant site of Asana, suggests that the Maymeja area itself was glaciated until approximately 9000 cal BCE.

The Ob1 material (obsidian free of heterogeneities) appears to have been used preferentially for tool production over the Ob2 material (obsidian with heterogeneities) throughout the Forager period, as was true in later times. During the Late Archaic, obsidian use for projectile point production declined and points were chiefly made from fine-grained volcanic stone, such as the andesite material common in Block 2.

Establishing the degree of embeddedness of obsidian procurement during particular periods of the Archaic Forager time frame is not a straightforward task. If evidence of advanced reduction stages is taken as a sign of more embedded procurement, then the evidence for advanced reduction comes in several forms.

(1) There was a greater proportion of diagnostic points identified for series 1-4 points than series 5 points in Block 1.

(2) Most of the diagnostic points identified in the Block 1 area are incompletely flaked and were broken longitudinally as would occur during production.

(3) The bases of latitudinally snapped, non-obsidian projectile points were encountered that appeared to have been discarded in the Maymeja area. The implication is that as the hafts were reused for newly-made obsidian projectile points, the broken bases were discarded from hafts that were being retained.

Embedded procurement may have taken the form of blank production with later advanced reduction occurring in adjacent blocks, such as Block 2 that contains stronger evidence of Archaic residential occupation.

Elsewhere in the study region more distinct site size differences are apparent during the Archaic Foragers period. Operating within the confines of surface survey information, sites were differentiated into residential bases and small logistical sites based primarily on lithic artifact density and diversity, shelter opportunities, and other site features. Archaic occupation in the high puna area of Block 2 appears to have been more long-term. Dense scatters, and variability in lithic materials were encountered, along with identifiable series 1-4 projectile points at a various late stages of manufacture and use. The sites with an abundance of flakes of fine-grained volcanic stone all have a Late Archaic component, and given the predominance of fine-grained volcanic material in the production of Late Archaic point types, the presence of andesite and rhyolite flakes at sites in Block 2 appears to correlate most strongly to Late Archaic occupation. Archaic Forager sites with no pastoral component rarely had obsidian flakes, and obsidian use appears to have been relatively diminished. This lack of obsidian flaking debris in Forager sites is further supporting evidence for embedded procurement and source-area tool production during the Archaic Forager times.

Numerous projectile points diagnostic of the Archaic Forager period were found in Blocks 4 and 5, but the surface of these sites was dominated by evidence from later reoccupation and therefore it is difficult to isolate these lithic concentrations as belonging to the non-pastoral or pastoral period. Rock shelters in Block 5, like Mollepunku and Kakapunku, appear to have had high rates of reoccupation throughout prehistory.

The Block 3 area around Callalli has the lightest evidence of Archaic Forager period occupation. Chert production sites on river banks, and some small, isolated sites in sheltered areas, provide the bulk of the evidence in this region. Perhaps the paucity of the Archaic Forager component in Block 3 reflects the better hunting opportunities elsewhere, such as on the high puna, and better vegetation and gathering opportunities in the lower altitude Colca valley downstream. It appears that the Callalli area was relatively lightly occupied during the Archaic and perhaps the more specialized ecology of the puna above and the lush valley below were more conducive to Archaic Forager subsistence. The sites identified here appear to have been the result of short-term stays in the course of travel through the river valley.

8.2.2. Early Agropastoralist

Obsidian procurement in the Early Agropastoralist period took place in the context of sweeping changes in economic and political circumstances in the south-central Andes. A marked increase in interregional exchange was complemented by greater sedentism and possible circumscription, an increased reliance on food production, and early evidence of social ranking in the form of differences in supra-household architecture and grave goods. The social and economic integration of altiplano communities through networks of regular camelid caravans has been proposed as an important preliminary stage in early economic coalescence in south-central Andean highland communities prior to the emergence of regional polities of the Late Formative (Browman 1981;Dillehay and Nuñez 1988). While an increased reliance on camelid pastoralism is evident from regional settlement patterns and faunal assemblages, the date of the onset of the system of regional caravan networks is difficult to establish.

The existing evidence from diagnostic ceramic distributions suggest that regional integration through regular caravan traffic occurred when particular styles became more widely distributed, such as Middle Formative Qaluyu pottery, or earlier with Early/Middle Formative fiber-tempered pottery in the southern Titicaca Basin. However, the regional styles of projectile points changed dramatically in a time period that is earlier still: the Terminal Archaic (3300 cal BCE). While changes in projectile point styles are likely connected to technological modification, such as the use of bow and arrow and differences in hafting, the widespread adoption of the series 5 projectile points throughout the central and south-central Andes from the Junin puna to northern Chile suggests that interregional contact was pervasive.

Evidence showing that quarrying and workshop activity at the Chivay source began during the latter part of the Terminal Archaic, suggests that the regional economy was already becoming relatively integrated and responsive to non-local demand. First, the evidence from this period shows that production targeted larger nodules that served to signal surplus and abundance, and would retain greater use-life with distance from the source. Second, the quarrying activity appeared to focus on obtaining the Ob1 obsidian nodules of clear or grey material. Finally, the date inferred for the construction of a swept path out of the Chivay source quarry area appears to coincide with production at the source; although the specific dating of the construction of the road is tenuous. Changes in the regional demand, the responsiveness of procurement, and the ability to transport obsidian, are part of a larger suite of changes during the Terminal Archaic and Early Formative, and this production system will be discussed below in the context of regional integration during that time period.

The Early Agropastoralist period in Block 2 shows evidence of growing pastoral herds and the construction of a variety of well-established animal control structures. These Block 2 facilities, many of which are abandoned today, are notable in that a variety of ceramics and lithic artifact styles are scattered on the surface of these sites. These pastoral structures may be interpreted as corrals, or some other animal control structure but with additional ritual functions. For example, at the site of Pausa, three large ovals varying in size from 20m in diameter to 50m in diameter were examined. These structures are delimited by solidly placed large rocks between 30-100cm across and the ovals have several curious attributes: (1) the ovals, regardless of size, all have 26 to 28 large rocks, (2) niches along the east side of the largest oval suggest that this structure was more than merely a corral, (3) the quantity of obsidian and ceramics at the site of Pausa far exceeds similar configurations elsewhere in Block 2, suggesting a particularly important function for this site. The 2003 testing at two of the Pausa structures revealed what appears to have been a domestic hearth dating to the Late Formative, around AD200, and the construction of a secondary structure and platform at the end of the Late Formative around AD400. The evidence from surface ceramics distributions suggest that these Late Formative dates are linked to a number of those corral mounds. Advanced-stage obsidian reduction is found in abundance at these mound structures, which implies that the people pasturing the expanding herds of camelids in Block 2 were involved in obsidian tool manufacture, but the presence of exclusively small, advanced stage flakes (never greater than 4 cm) implies that these people were not responsible for the initial quarrying of large nodules since the evidence shows that they never discarded large flakes or cores in Block 2.

In the upper Colca drainage in Block 3, the Early Agropastoralist evidence is less defined than was the occupation in the Block 2 puna area. The quality of pasture is known to be considerably better, particularly for alpacas, above 4200 masl. Several sherds of non-local ceramics with similarities to Middle Formative (Qaluyu) and Late Formative (Pukara) in the Lake Titicaca Basin were encountered in the course of work in this area which suggests that the Callalli area was a major cross-roads and thoroughfare, as it is today. Obsidian was found primarily in the form of finished bifacial tools, but some obsidian production was encountered in Terminal Archaic contexts at the rock shelter of Quelkata, and at the open air site of Taukamayo. While the test unit at Taukamayo produced Tiwanaku period dates (circa AD 650), many of the ceramics that were observed in the landslide debris appear to date to the Formative.

8.2.3. Late Prehispanic

Evidence from regional consumption patterns indicate that while Chivay obsidian was in wide circulation within the Tiwanaku economic sphere, the regional distribution and quantity consumed declined during the subsequent LIP and Late Horizon. As one of the research questions motivating this study at the Chivay source, evidence was specifically sought to explain the economic circumstances around obsidian production in Late Prehispanic contexts. New evidence will be reviewed that was acquired from fieldwork in 2003, and later in this chapter contrasting models of production will be explored in more detail.


No direct evidence of Tiwanaku was encountered at the Chivay source or in the immediate vicinity during fieldwork in 2003. A single obsidian preform was encountered that appears to have been an early stage of a type 4E (Tiwanaku stemmed) projectile point in Block 2, but the identification is not definitive. Titicaca Basin materials were encountered deriving from particular time periods in the form of non-local decorated ceramics, such as sherds of possible Qaluyu and Pukara (Formative) styles, and Colla and Chucuito (LIP and Late Horizon) ceramic styles, but no Tiwanaku pottery was encountered any where in the Upper Colca research area. In Block 3, a calibrated radiocarbon date of A.D. 650 - A.D. 780 (Figure 7-3) from Taukamayo places the occupation in the Tiwanaku period, but no Tiwanaku or Wari evidence was found at the site. Rather, pottery akin to the local Chiquero material was encountered that is diagnostic to the Formative in the main Colca valley (Wernke, 2003). The asymmetrical relationship between Chivay obsidian consumption in the Tiwanaku economic sphere, and the lack of Tiwanaku diagnostic materials in the Chivay source area will be discussed in more detail below.

Local Middle Horizon patterns are of particular interest because regional distributions of these ceramics may shed light on the nature of the frontier relationship between Tiwanaku and Wari that appears to have been occurring in the upper Colca valley during the latter half of the first millennium AD. Ceramics in the local Middle Horizon style (Wernke 2003: 466-478) were encountered in Block 2, but these sherds were confined to the northern half of Block 2. Middle Horizon pottery was found scattered throughout Block 3. A single local Middle Horizon sherd was found mid-way between the Chivay source and the town of Chivay, and one sherd was found in Block 6 upstream of Tuti. In short, the Colca Middle Horizon type defined by Wernke was encountered throughout the Upper Colca study area although, as discussed in Chapter 6, there is a distinct zone in Block 2 south of which the local MH pottery is not found.

Late Intermediate Period

Ceramics of the local Collagua style dominate the decorated ceramics found throughout the Upper Colca survey area. Pastoral facilities are rich in decorated ceramics resembling the main Colca Valley styles described by Wernke and others and underscoring the close links between Collagua polity in the Colca valley, and their expanding herding sector on the adjacent puna. Sherds of the Colla type, the Lake Titicaca Basin LIP style, were found in the northern part of Block 2 and also along the trail leading from Block 2 towards Block 1 and the Colca valley. Relatively close economic and cultural links are expected between LIP groups in the Colca and the Titicaca Basin as these groups shared a number of traits including the Aymara language, chulpamortuary architecture, and the defensive pukarahilltop settlements. Yet, interestingly, no Colla sherds were encountered in Block 3, the upper Colca valley, although the ceramics and architectural evidence shows that the Collagua presence was relatively strong in this area. This may be explained in terms of ecological complementarity, as one might expect the Colla to have been actively trading with the lower Colca valley agriculturalists, but the upper Colca valley is at the same elevation as the Titicaca Basin and thus it had relatively little to complement the goods available in the Titicaca Basin.

The LIP occupation of Block 3 appears to have been focused around agricultural plots and pastoralism in the adjacent high puna. Evidence of abandoned agricultural plots was noted both upstream and downstream of Callalli (3,900 masl) with furrowed areas that were likely planted in frost resistant crops like quinoa or tubers.

Late Horizon

During the Late Horizon the reorganization that took place under Inka rule is evident in settlement pattern changes and ceramics distributions. At the Chivay obsidian source, the highest quantity of diagnostic ceramics were those in Late Horizon styles. These ceramics may be derived from the mortuary structures that were encountered in the Maymeja source area, or the LH ceramics may be a reflection of the increased investment in water control projects and expanded herding. A possible extension to the Huarancante canal capturing water from Quebrada de los Molinos would have had its origins precisely at the Maymeja workshop at the Chivay source.

Elsewhere in the survey area the Inka period introduced a number of changes including distinctive differences in long-distance interaction. In Block 2, the Late Horizon component appears to have been consolidated around a few larger sites. The presence of Titicaca Basin pottery is notably lower in the Late Horizon in Block 2, and Cusco Inka styles are introduced in that area. Fourteen sherds of Colla style pottery (Titicaca Basin LIP) were found in Block 2, and these were primarily scattered in the northern half of the block. By the subsequent Late Horizon only two Chucuito style sherds (Titicaca Basin LH) were found in Block 2. The most common decorated pottery was the local LH Collagua-Inka and the Collagua-3 style. In Block 3, settlement became concentrated at agricultural plots along natural river terraces near the confluence of the Río Colca and Río Llapa in an area known as Callalli Antiguo. A concentration of structures with non-local Inka pottery along the principal road system on the south side of the Colca suggests that this site may have had administrative functions in the Late Horizon settlement pattern.

8.2.4. Discussion

This review of the major findings from research in 2003 shows that, in general, it was regional forces that dominated the changes that were observed in obsidian procurement through time. Raw material for use in the local economy was relatively steady, with local cherts dominating Block 3 assemblages in most time periods, and local fine-grained volcanics prevalent in Block 2 during the Late Archaic. However, changes on the regional scale in long-distance interaction and in demand for obsidian beginning in the Terminal Archaic introduced distinct intensification in procurement of obsidian. The later changes that occurred in the Early Pastoralists and Late Prehispanic times reflected the growing intensification in both agricultural and pastoral economies in the Colca. In contrast, the procurement and circulation of Chivay obsidian is relatively sustained and is not subject to this expanded production in later times.

8.3. Production and interaction

The Upper Colca project research in the Chivay source area provides new evidence of lithic procurement and organization in the vicinity a raw material source of regional significance. In this section, specific themes will be discussed concerning Chivay obsidian procurement and production based on research in the vicinity of the Chivay source.

8.3.1. Lithic raw material use in the vicinity of the Chivay source

Within the larger survey area, the radial attenuation pattern of obsidian artifacts around the Chivay obsidian source is a common characteristic of single-point raw material sources. This attenuation resembles a distance-decay pattern, but on a local scale. Obsidian artifacts dominate the assemblages in Survey Blocks 1, 4, and 5; the ones that are adjacent to Chivay source, while locally available chert and quartzite are well-represented in assemblages in Block 3, the upper Colca river valley. The impetus for quarrying in the Maymeja area appears to have been driven by a demand for larger obsidian nodules, and for obsidian material with few heterogeneities. Complete artifacts with > 30% cortex, including tools, flakes, and cores, were considerably larger in Block 1 than in other blocks. In surface assemblages in Block 2, which lies the same distance from the Chivay source as Block 3, obsidian dominates the lithic artifacts and andesite and other fine-grained volcanics are also present. On the surface of Blocks 1, 4, and 5, close to the Chivay source, obsidian cores and cortical flakes are more common, and in Blocks 1 and 5 bifacial thinning flakes (BTF) were relatively common with the highest fraction of BTF being located at the site of A03-910 in Block 5.

Variability in the use of Ob1 and Ob2 material

Earlier it was noted that there was variability in obsidian knapping quality both in original geological exposures and in artifact materials. Obsidian containing heterogeneities such as air bubbles, ash particles, fractures, and occasionally inclusions, were observed in different areas of the Chivay source. While the majority of tools were produced on homogeneous glass (referred to here as "Ob1"), a substantial fraction of flakes and cores, and some tools, were observed in the "Ob2" material containing heterogeneities. When the Ob2 heterogeneities are very small, the knapping quality of the material appears to have not been compromised albeit the material is visibly less pure. A large percentage of the flakes in Block 3 were Ob2 obsidian, while all of the projectile points made from Ob2 obsidian were found in Block 2 in the high puna.

Visual characteristics of Chivay obsidian vary across the source area as well. Colors recorded for artifacts during the phase II lithics analysis included black, grey, transparent (clear), and dark banding was visible in grey and transparent obsidian. Banding resulting from concentrations of tiny magnetite crystals is common in light grey and transparent material. High numbers of transparent flakes were encountered in Block 1 and Block 2, which is along the direct route from the Chivay source to the Lake Titicaca Basin where obsidian from the Colca is known as the "transparent type" (Giesso 2003). Obsidian color and translucence was difficult to quantify during lab analysis, and it is possible that the distinction between grey and clear obsidian may be connected to flake thickness where thinner flakes appear to be less grey due to greater quantity of light passing through.

8.3.2. Quarrying for non-local consumption

Evidence from 2003 Upper Colca project excavation and survey work suggest that the large nodules excavated from the quarry pit in Maymeja were not being used by local consumers in Blocks 2 and 3. While cortical flakes larger than 4 cm were relatively common in Maymeja, the cortical flakes (> 20% dorsal cortex) in Block 2 never exceeded 4 cm in length, and in Block 3 rarely so, which implies that the starting nodule size is far smaller in these consumption areas. When all obsidian flakes are considered, including those with no cortex in case all early stage decortication was occurring in the Maymeja area, the above pattern is reinforced.

It appears that large nodules, perhaps in excess of 30cm on a side, were quarried and at least some of the nodules were processed in the immediate area of the quarry, yet only 15 km from this location none of the obsidian flakes measure over 4cm in size. It is conceivable that this is a case of extremely accelerated distance decay where, despite an abundance of small obsidian flakes in excavated or surface contexts, large flakes were never being discarded under any circumstances based on the evidence from 2003. However, excavated assemblages from Qillqatani 200km to the south-east disproves this idea of accelerated reduction. The evidence from Qillqatani in the Terminal Archaic and Early Formative (see Section 3.4.2 and Figure 3-7), show that precisely when there is a wealth of obsidian at the Chivay source workshop, some of the largest flakes of obsidian were being discarded at Qillqatani. Sourcing studies and visual characteristics of these artifacts indicate that assemblages from these levels at Qillqatani were entirely Chivay type obsidian (Table 3-5).

How was the obsidian quarried at Maymeja? The quarrying may have been conducted with local cobbles of rhyolite and andesite, in a manner akin to what is described by Burton (1984) at the Tuman metamorphic hornfels quarry in New Guinea, however no evidence of hammerstones or digging sticks were encountered as quarrying tools in the 2003 excavation unit at the quarry.

The men worked with simple tools. Hammerstones of up to 2 kg were made from waste rock at the quarry and were pounded against the weak planes of the rock face until these could be forced open and a part of the face brought down. The hammers were hand held. Fire was never used at the Tuman quarries, as it was elsewhere; it was an unsuitable technique for the conditions. Wooden stakes or wedges would have been the only other mechanical tools (Burton 1984: 241).

Digging sticks made of wood or bone may have been used at Chivay, but if the wood staves were abandoned on the surface they were likely to have been recovered and possibly burned by local pastoralists as this area short of fuel-wood. The lack of hammerstones at Chivay is puzzling. Rademaker et al. (2004) report finding digging sticks and hammerstones at quarry pits in the vicinity of the Alca source. Fire does not appear to have been used at the Chivay source quarry pit as has been reported at non-obsidian quarries (Holmes 1919;Purdy 1984) as neither carbon nor fire-affected obsidian (Lloyd, et al. 2002) were observed in test units.

8.3.3. Site visibility at Maymeja and warfare in the Colca area

A pattern that was noted in the distribution of knapping locations in the Maymeja area of the Chivay source is for nodules to have been transported small distances (less than one km) to promontories and overlooks for processing. While LIP and LH pottery are sometimes found near these scatters, the association with the Late Prehispanic time block is not secure because is likely that these high visibility overlooks were reused, and that the scatters belong to multicomponent sites.


Figure 8-1. View westward from obsidian production area A03-210 towards main Colca valley, settlements on north bank of Río Colca near Coporaque are visible. Ignimbrites and tuff outcrops in the lower Maymeja area are in the foreground in this photo.

On a local scale, this evidence probably reflects a pattern where herder would establish themselves on overlooks and knap obsidian while monitoring the herd. In several instances, however, extensive scatters were observed on large-scale promontories that over look the entire Quebrada de los Molinos (e.g., the sites A03-570 and A03-578) and beyond. One relatively large scatter, A03-209 "Maymeja 7", was found 700m west of the Maymeja workshop area, far from other resources. The principal attribute of this location was its commanding view of the main Colca valley including terrain well beyond the town of Yanque, as well as the approach to Maymeja via Quebrada de los Molinos.

Was obsidian projectile point manufacture associated with provisioning for warfare? If conflict were occurring in the Colca valley, one possible explanation for this pattern is that local groups who were familiar with the obsidian source were conducting initial reduction while simultaneously monitoring events in the main valley. Some features associated with conflict would have been visible from the obsidian source including communication such as smoke signals. Stanish (2003: 219-220) and Arkush (2005: 162-163) discuss ethnohistoric (Garcilaso 1960 [1609]: Bk. 6, Ch. 7) and twentieth-century evidence for the use of smoke signals in Late Prehispanic Titicaca Basin contexts. Other evidence of conflict visible from afar might include the movement of large number of people and animals, associated dust columns, and smoke from burning houses or fields. While advanced reduction stage artifacts, such bifacial thinning flakes and broken preforms, were not found in unusually high densities in these high visibility locations, medium stage reduction debris was evident.

Conversely, there also exists evidence that contradicts connections between obsidian and warfare in the Andes. Relatively few pieces of direct evidence link obsidian points with lethal injuries in human remains (Ravines 1967). Analysis of 144 individuals from coastal Chinchorro burials (circa 2500 BCE, Terminal Archaic) in what is now Arica, Chile on the Peruvian border, found that 1/3 of all adults showed trauma from interpersonal violence and that males were three times more likely than females to have skull trauma from percussive force such as clubs and sling stones. Most of the later LIP and LH evidence of conflict also involves percussion weapons like slings and maces, although writing in the sixteenth century, Cobo reports that bow and arrow were important in warfare (1990 [1653]: 216-217).

Despite the indeterminate evidence for obsidian use in warfare in the highlands, the link between reduction and high visibility in these locations is strong. The high visibility and environmental exposure of these positions along the west rim of Maymeja, as compared with Averagevisibility in Block 1, was calculated using the GIS Visibility index layer. The construction of the Visibility index GIS layer is described in Section 5.9.2 (Tripcevich 2002).


Visibility Index

Mean for sites in Block 1


A03-209 "Maymeja 7"


A03-571 "Valdivia 1"


A03-578 "Valdivia 8"


Table 8-1. Visibility index values of high visibility production locations.

Site A03-209 offers particularly sweeping views of the main Colca valley including Pampa Finaya and pukaras on the north side of the Río Colca, while A03-571 and A03-578 provide high visibility of the Quebrada de los Molinos approach to the obsidian source.

8.3.4. Quarry pit and associated workshop activities

The evidence of obsidian production activities on the south side of Maymeja at the Chivay source remains some of the strongest evidence of production in the region. The evidence from this sector of Maymeja demonstrate that obsidian production was intensified on this area of the source. While the Maymeja workshop is very small when compared on a global or even on a regional scale, the 2003 test unit Q02-2u3, that was 1x1m across and 72cm deep, produced approximately 750 kg of culturally derived flaked stone artifacts. It is difficult to estimate the area over which these depths and densities continue, but a 3x4m area at ~70 cm depth can be advanced as a conservative estimate. The 2003 survey showed that while obsidian reduction zones were numerous in the Maymeja area, none compared with this workshop site [A03-126] in terms of density or stratification. As will be discussed below, the evidence from this area of the source provided the most significant contributions in the form of: (1) temporal control, (2) evidence of intensified production, and (3) links to the pastoral economy.

Temporal control

Temporal evidence in this area came principally from three radiocarbon dates acquired from the workshop test unit [Q02-2u3] that placed activities in the workshop area between the Terminal Archaic and the Middle Formative. These dates are important because they are earlier than evidence of discrete production activity has been found elsewhere in the region, and furthermore it serves to explain the dearth of ceramics in the workshop area because the activities begin during the Preceramic period.

Unfortunately, quarrying at the Q02-2 quarry pit itself was not able to be directly dated because no datable organic materials were encountered in the Q02-2u2 test unit. Inference from three possible lines of evidence suggests that the excavation of this quarry pit occurred during the Early Formative Period (2000 - 1300 cal BCE). These lines of evidence include:

(1) Analysis of the workshop Q02-2u3 test unit, 600m downslope of the quarry pit in question, shows evidence of the arrival of larger cores and intensification of production in a distinct event during the Early Formative.

(2) The total lack of ceramics associated with the quarry pit itself, the aceramic ancient road "Camino Hornillo" [A03-268] leading away from the quarry, and the sites in the immediate vicinity of the quarry are consistent with the early dates of activity at the workshop as ceramics should not be expected.

(3) The only diagnostic artifact found along Camino Hornillo [A03-268] was an obsidian projectile point in the 4f style that is diagnostic to the Terminal Archaic.

It is possible that obsidian hydration dating may provide evidence linking obsidian flakes excavated from the quarry pit Q02-2u2 with obsidian from dated layers in the workshop Q02-2u3 unit through relative dating. Brooks (1998: 447-451) ran obsidian hydration on ten samples with Glascock from MURR on obsidian from Juscallacta, but the resulting dates were far older than expected, confirming a general skepticism among archaeologists regarding hydration dating as an absolute dating method. An application of hydration dating at the Maymeja quarry would have to overcome two principal obstacles. First, hydration dating has been shown to be unreliable in areas with large temperature fluctuations and particularly in places where there are diurnal temperature changes (Anovitz, et al. 1999) as is certainly the case in the Chivay source area. Second, the samples from the two contexts may not be comparable because the obsidian flakes from the workshop unit Q02-2u3 are often in saturated soils as they are adjacent to a bofedal, while in contrast the obsidian at the quarry pit Q02-2u2 is in very dry sandy ash, and therefore environmental moisture is much greater in one circumstance than in another. Obsidian hydration rates are sensitive to the amount of moisture in the vicinity of the obsidian sample.

Intensified obsidian production

Episodes of intensified production were apparent in test excavation units at both the quarry pit and the workshop. At the quarry pit, the upper most levels (2 and 3) of the test unit showed evidence of concentrated activity, and because this test unit was in a debris pile, the strata are reversed so that levels 2 and 3 are the result of some of the deepest quarrying work at the quarry pit. In level 2a a number of discarded obsidian nodules were encountered measuring approximately 7 cm in length, and the thickness and angle of these strata indicated that quarrying was active and was resulting in a build-up in the discard zone. The low quantities of bifacial retouch or culturally-flaked stone of any kind in these upper levels at Q02-2u2 suggests that during the final episodes of excavation at the quarry it was purely whole nodules that were being extracted and transported away.

At the Q02-2u3 workshop, down the slope, intensified production was most apparent in levels 5 and 4 with evidence of the availability of larger cores taking the form of the discard of large cores and cortical flakes. These levels are interpreted as representing greater regularity in reduction strategies because they were thicker levels and production was more abundant, yet artifact morphology and variability was consistently low. In level 5, evidence was encountered that suggests that some proportion of cores were being transported away while others, even relatively large cores, were discarded at the workshop. In level 4, a similar strategy was in place, where it appears that medium and large cores with certain desirable characteristics were exported after some reduction, and some large flake blanks were also exported, but a fairly large percentage of cores and large flakes were discarded, suggesting that there was an abundance of material. Level 4 was thicker than other natural levels and it showed distinct evidence of abundance in large nodules, and relatively wasteful production, with large cores being sampled and discarded, along with the discard of large flakes. The presence of Kombewa flakes in levels 4 and 5, a flake-as-core technique, suggests that some variability in knapping strategies was practiced.

These characteristics changed dramatically in level 3 when discarded cores and flakes became much smaller and more advanced reduction seemed to have been occurring. The number of retouched flakes drops significantly, but concurrently the number of broken bifaces increased to thirteen, indicating that some advanced reduction was occurring. Activities in level 3 are distinct from all other levels and difficult to characterize because they seem contradictory. On the one hand, reduction strategies were more variable as some advanced reduction was occurring and heavy rotation and conservation of cores was taking place; while on the other hand, there were relatively large cores (cluster #3 type cores) being discarded as well as some cortical flakes in the level 3 assemblage. The peculiar pattern detected in level 3 may be due to a combination of a return to more local and variable production, combined with scavenging from the richness of the discarded material in the previous occupation level. By the ensuing level, level 2, the assemblage appears to have continued the pattern of variable reduction strategies but with lessened access to large nodules. In sum, the evidence from intensification at the quarry and the workshop suggests that workshop reduction began in the Terminal Archaic, quarry excavation and workshop production intensified and became more regular during the Early Formative, and ultimately during the final levels workshop activities returned to more haphazard localized production.

Links to the pastoral economy

The final pattern evident in the intensified obsidian production that was documented in the southern part of Maymeja is the correlation between pastoralism and obsidian production. There is the simple fact that it is physically easier for pastoralists to access and circulate obsidian. Burger and Asaro (1977: 41) note that tool-quality obsidian is found on geologically young volcanoes which, in the Andes, are from the Late Miocene and are typically found above 4000 masl where pastoralists reside. Furthermore, herders have the cargo animals to transport nodules. Based on the 2003 survey of the Chivay source, obsidian is available in a number of locations between 4950 and 5000 masl on the flanks of Cerro Hornillo. Obsidian lag gravels, often material with heterogeneities, blanket the Maymeja area and occur on a wide range of slopes on the eastern flanks of Hornillo. Obsidian is also eroding from a gully on the north side of Maymeja in an exposure labeled Q02-1. While there is reason to believe quality obsidian nodules lie underneath the tephra rich soils in a number of areas around Hornillo, it is surely no coincidence that the most high volume and persistent source of water in the region is adjacent to the Maymeja workshop, and the quarry pit is upslope to the east, as close to the workshop as possible along the 4970 masl contour.

Three principal patterns link obsidian production with pastoralism in this area:

(1) Maymeja production. The Maymeja workshop is adjacent to a water source and a rich grazing area, and a maintained, but relatively clean and unoccupied, corral [A03-127] sits adjacent to the Maymeja workshop. Construction in this area follows the margin of the rich bofedal, small circular structures and eroded terraces were evident here, and obsidian flakes litter the area. The second highest densities of flaked obsidian were found in the lower, northwestern portions of Maymeja close to the modern estancia [A03-570]. It is possible that these two zones were occupied simultaneously, as each residential sector adjoins a separate, large bofedal.

(2) Local Scale. Throughout the highland portion of the 2003 survey, especially in Block 2, concentrations of obsidian flakes were almost always associated with pastoralist site features. A road leads away from the quarry pit that suggests that loaded caravans departed to the south from the Chivay source along a route referred to as Camino Hornillo. This route is in an unsurprising location, as the road climbs out of Maymeja along the least-steep possible route, and following this road caravans could soon join the regional trail network near Lagunas Lecceta, just a few kilometers to the south.

(3) Regional Scale. The consumption of Chivay obsidian is largely associated with pastoralist sites. It expands on a regional scale in the Terminal Archaic with pastoralism, and on the western foothills of the Andes both obsidian and herding corrals are rare below an altitude of 1200 masl.

The simple association of obsidian with pastoral activities of shearing and butchering appears plausible on one level and such applications of obsidian probably facilitated its widespread distribution (Section 3.6). Despite this functionalist association between obsidian and pastoralism, several particulars of obsidian consumption patterns run contrary to this view. First, high-quality cherts with excellent fracture properties are available throughout the Titicaca Basin and given the quantity and size of Titicaca Basin herds, particularly in the Late Formative and onwards, one would expect much greater quantities of obsidian consumption as herd sizes grew. In fact, obsidian consumption appears to have been relatively reduced as populations and herds grew during Late Prehispanic times. Second, in the Chivay obsidian consumption zone sufficiently large flakes for shearing and butchering (for example, 2 cm or larger) are relatively rare in both surface and excavated contexts. Curation of obsidian in tool form does not appear to have been a priority except for in the production of projectile points.

The links between pastoralism and obsidian circulation appear to have more indirect than the functional connection would suppose. The development of regional caravan exchange, including long-distance circuits and the relative ease of transporting weight, served to move stone into regions where such materials were rare. The second probable connection is the social and symbolic link that obsidian provides between consumers, non-local trade networks, and representation of alliance and affiliation. Obsidian possession was one of a number of ways of differentiating ones self. Evidence of access to non-local raw materials, mediated through camelid caravans and pastoral economy, was one possible way to demonstrate social connections and access to goods and knowledge in other forms. Additional aspects of the social and symbolic links with obsidian exchange will be discussed below.

8.3.5. Pottery and lithic production

Few correlations were noted between pottery distributions in the 2003 Upper Colca survey and obsidian production and circulation. Pottery is scarce in the Maymeja area of the Chivay source. Most of the diagnostic Prehispanic ceramics in the Maymeja area belong to the LIP and Late Horizon, and this occupation probably reflects the presence of resources like pasture and water, and the construction of mortuary structures in the Maymeja area. Pottery resembling the "Chiquero" style described by Wernke (2003) as Formative was not encountered at all in the obsidian source area, or even in the Blocks 4 and 5 vicinity of the source. Pottery resembling the Chiquero style was common in Block 2 on the puna, but the only site in Block 3 with this pottery was Taukamayo [A02-26], a site that is interpreted here as a stop for non-local caravans passing through the upper Colca valley. Another factor linking Taukamayo with Block 2 was that Taukamayo contained the highest density of obsidian debris in Block 3, where obsidian was abundant.

While there are spatial associations between Chiquero and Formative Period sites in the main Colca valley, as documented by Wernke (2003), testing at Taukamayo revealed that this style of pottery persisted into later levels. These sherds were found in A02-26u1 test unit in levels dating to AD650-780, over 250 years into the Tiwanaku period used by Stanish in the Titicaca Basin, and corresponding with Williams' (2001) dates for the first Wari occupation of Cerro Baúl. In the main Colca valley, Wernke notes that Chiquero pottery is replaced by the red-slipped Colca "Middle Horizon" style that includes Wari influences in characteristics such decoration and the constricted, cumbrous bowl form (Malpass and De la Vera Cruz 1986;Wernke 2003: 468-469). One possible explanation for the continued use of Chiquero-like pottery in the seventh century AD in the upper Colca near Callalli, while the diagnostic Middle Horizon ware began to be used in the main Colca valley, is that Wari influences arrived in the principal agricultural sector of Colca valley from adjacent Wari-influenced agricultural regions as part of a suite of agriculture related technologies. Developments in the Colca such as expanded terracing, irrigation, and other agricultural methods supposedly appear during the Middle Horizon in the Colca. In terms of the geographic origins of the Colca Middle Horizon style, Wernke (2003: 470) notes that these ceramics have stylistic similarities both with the low-lying areas like Chuquibamba and Majes, as well as with Wari-influenced ceramics in highland Cusco, but significantly the Middle Horizon and LIP styles in the Colca show no relation to Tiwanaku-related ceramics traditions.

8.3.6.Projectile Points

The major insights provided by projectile points from this research are as follows. First, projectile points were a principal diagnostic artifact type and points were analyzed according to Klink and Aldenderfer's (2005) point typology in order to assign temporal control to surface materials in the survey area. According to the point typology, styles from the Terminal Archaic and later that were encountered (principally, series 5b and 5d), are not particularly time sensitive because the styles continued in use throughout the ceramic period (see Figure 3-10). As obsidian production intensified during the Terminal Archaic there is a strong correlation between obsidian and 5b and 5d point styles in the region, however the point typology could not be used to further study changes in obsidian production because the typology is not time-sensitive during the Terminal Archaic to Late Horizon time block.

Diagnostic projectile points recovered in the course of this research show that the Chivay source area was occupied since the early Holocene. Obsidian is used for the majority of projectile point manufacture in the Upper Colca project area except during the Late Archaic when heavy, stemmed points are used throughout the south-central Andes, and andesites dominate projectile point materials even close to the Chivay source.

Projectile point styles diagnostic to the Terminal Archaic and later are overwhelmingly made of obsidian. This pattern holds in the regional consumption zone as well, supporting the assertion that it is during the Terminal Archaic that obsidian becomes more widely known, and that the Chivay source area acquires new significance in the geography of prehispanic Andean peoples. Evidence from consumption contexts shows that projectile points were the principal formal artifact made from obsidian, and as most obsidian was procured during the time period associated with Series 5 point styles, the formal tools produced from the material were predominantly small, triangular points. It is interesting, therefore, that this research encountered evidence that ancient peoples appear to have targeted larger nodules and the maximizing of obsidian quality and nodule size because the objective pieces were quite small.

The small size of series 5d projectile points provides examples that sometimes defy the expectations of distance-decay. In the excavation work in Block 2, in the A02-39u4 test unit in a level dated to the Late Formative extremely small 5d point was encountered. This complete point [L03-60.3] was delicately pressure flaked; it measured just 1.3 cm in length, and it weighed less than 0.1g. This remarkably small point was noticed in the fine 1/16" screen. However, 29 complete obsidian projectile points were identified in the Block 2 area that weighed less than 1g, all series 5 points, and it is clear that small, light projectiles were the intended product in this type of obsidian production. Yet, these sites were just one day's travel from the obsidian source and obsidian is relatively abundant in Block 2 and these points beg the question: "why economize with material by knapping such miniscule projectile points?" As was observed by Close (1999) with North African bladelets, artifact forms can trump the expectations of distance decay and very small artifacts may be produced in areas that are rich in raw material. Production at the Chivay obsidian source area in certain periods in prehistory appears to have been one such context.

If the production of types 5b and 5d projectile points, with a mean length of 3-4 cm, was the objective then why excavate for 15-20 cm long nodules at Maymeja? First, the utility of freshly struck obsidian flakes for a variety of cutting and shearing tasks is widely recognized as a principal appeal of this material. Therefore a large nodule represents the potential for producing formal tools, but a large obsidian nodule also represents a transportable and exchangeable source of sharp flakes. Second, in the distance-decay context of single source raw materials like obsidian, large nodules contain greater potential both in terms of prestige for the owner, because evidently the owner is closer to the source of these desired goods, but also in terms of exchangeability and possible tool forms. Thus, even if tiny projectile points were the ultimate tool form for obsidian, the acquisition of large nodules that were then conveyed directly to distant consumers with the aid of pack animals probably represented the largest return in terms of both symbolic and material wealth for the procurer.

8.3.7.Regional caravans and local interaction

Ethnohistoric and ethnographic accounts attest to the prominence of the Colca in regional trade networks both in terms of the size and capability of pastoralists in the upper Colca area to launch long-distance caravans, and for the draw created by the Colca valley agricultural sector on regional caravans. While archaeological evidence of passing camelid caravans is often subtle, in the course of survey work in 2003 a number of features were encountered that are potentially linked to caravan mobility.

Pastoral bases and caravan stops

The most extensive pastoral features in the Upper Colca survey area lie in the dense Block 2 occupation along the eastern toe of the Huarancante lava flow. The area has been occupied fairly consistently since the Early Archaic and a distinctive land use pattern was documented in 2003 related to pastoral occupations, including corrals and associated residential structures, along the margins of the lava flow. As is characteristic of pastoral occupations, the structure of these sites is blurred by multiple non-contemporaneous occupations, refuse disposal is shallow, and stone corral walls and rock shelters serve as the few permanent feature types that persist through time from previous pastoral occupations (Nielsen 2000: 480-483). The Block 2 survey revealed that many of the larger estancias contain multicomponent sites, indeed most of these choice locations are occupied to this day in some capacity. However, the small and mid-sized pastoral bases in the area show more variability, as ceramic distributions suggest that some sectors were settled while others were abandoned at times in prehistory. The number of active corrals and the herd size potential in a given time period is difficult to estimate due to this pattern of shifting locations for small and mid-sized pastoral bases.

Based on systematic survey work in 2003 it appears that a number of the animal control features in Block 2 exceed the local capacity for seasonal grazing and were perhaps linked to short-term stays by passing caravans. These large animal control structures primarily take the form of vestiges of corrals that appear as bases of stone enclosures on top of low mounds rising from surrounding pampa. While it is difficult to estimate animal numbers due to shifting pastoral occupation, seasonal changes in land use, and the brevity of the 2003 observational period, the conditions in Block 2 appear to be the "Caravan rest areas" that were first discussed in Section 3.2.5.

Caravan rest areas

Larger sites that are the result of repeated occupation as rest areas are well documented in ethnoarchaeological accounts of camelid caravans (Lecoq 1988: 185-186;Nielsen 2000: 461-462, 500-504;West 1981: 70). According to these accounts, in the course of a multi-week caravan journey the team will rest periodically, usually for two or three nights, in order to allow for recovery by the animals and for conducting routine maintenance tasks by the caravan drivers such as repairing cargo panniers and stitching up the shoes made for the llamas' feet. Typically, these rest areas are situated adjacent to a rich grazing area with plentiful water and little competition for pasture access. The rest stops commonly are located immediately before or after a strenuous section of trail.

The Block 2 area is something of a natural bottleneck at the transition zone between the Colca valley and the puna, and it also contains the largest bofedal in the study area. The Block 2 puna is situated just outside of the rugged volcanic terrain that rings the Colca valley. It is the first extensive area of prime grazing encountered after caravans have crested the ascent out of the Colca, and the ascending animals would have presumably been loaded with agricultural cargo. It is therefore unsurprising that large corral facilities were encountered in this location.

The lithic and ceramic artifacts associated with these abandoned corral features are also telling. While local LIP and LH sherds are common in Block 2, the unslipped Chiquero-style pottery of Formative production, are also widespread in Block 2. Obsidian flakes are extremely common in the vicinity of these mounds. As demonstrated in the testing work at A03-39, small hearths and obsidian knapping at medium and advanced reduction stages occurred on the margins of these corral structures.

Obsidian knapping at rest areas

One plausible scenario for the quantity of obsidian in the Block 2 area would have caravan drivers resting for several days after the arduous climb from the Colca valley and knapping obsidian in the Block 2 area while their herds recover from the climb. Perhaps caravans would periodically venture into the Maymeja area of the Chivay source and recover larger nodules. Local herders also use the Block 2 puna and perhaps they were involved in obsidian procurement. Local herders, arguably more familiar with the obsidian source itself, could have brought obsidian to this area and passing caravans resting in the area may have traded for nodules and this would have contributed more obsidian to the Block 2 area.

The evidence from Block 2, however, is overwhelmingly of advanced stage obsidian reduction, and therefore if whole nodules were being exported from the Chivay source in whole form then they were not being knapped at Block 2. This evidence suggests that nodules were being reduced at the Maymeja workshop over in Block 1, or being exported from the region in whole form. Primary reduction and the use of large obsidian artifacts was not occurring in Block 2. As mentioned above, 10% of the flakes in Block 2 were over 4cm in length and neither cortical, nor non-cortical, flakes approach this size potential in Block 2. The absence of large flakes in this area, a zone rich in small obsidian flakes, is curious and it suggests that non-local caravans were responsible for the quarrying activity in Block 1. The larger (15-20 cm long), Ob1 nodules would have had to have been quarried, and some fraction of them knapped, in the Maymeja zone and then transported from the region without further processing in areas such as Block 2.

Was there multiethnic access at the Chivay source?

A principal question concerning the Chivay obsidian source area, when it was finally located in the 1990s, was whether cultural materials showing Titicaca Basin stylistic affiliation would be found at the source area. The lack of known Pukara or Tiwanaku materials in the vicinity of the source, as confirmed by the Upper Colca research project, suggests that access to the source was not physically restricted, and that perhaps neighboring groups were granted access as needed. Other plausible explanations are that, even in the Middle Horizon, material moved through down-the-line trade and no diagnostic, non-perishable materials were reciprocated back to the source area. Alternately, a freelance trading entity was responsible for transporting the material towards Titicaca, but this group traded exclusively with Titicaca Basin polities and curiously none of the material found its way into the Wari sphere despite the proximity of Wari-influenced sites in the lower valley. Given Tiwanaku's demonstrated strategy of placing colonies, sometimes integrated multiethnic, directly adjacent to resources of interest (Goldstein 1989), it seemed possible that a site with a Tiwanaku component would be found adjacent to the Chivay source.

The obsidian data do not appear to conform to the expected pattern of postulated multiethnic "artisan islands" within the vertical archipelago model proposed by John Murra (1972, pp. 442-443) in which rare or restricted resources such as metal ores, or here different obsidian types, are shared by different groups; in this case, each group (Huari and Tiahuanaco) would have had colonies to acquire the resource for the distant homeland (Burger, et al. 2000: 342).

A central goal of the 2003 research at the Chivay source was to examine the source area for evidence of such "artisan island" sites, but no such sites were encountered.

Circuits, caravans and exotic goods

The circuit mobility model of Nuñez and Dillehay (Dillehay and Nuñez 1988;1995 [1979]) depicts the regional integration between "axis settlements" as articulated by circuits of caravan traffic (Section 3.2.6). Some of these circuits grew to become the dominant exchange routes in a region. Despite the historical and adaptational focus of the circuit mobility model, the model's emphasis on the integrating role of camelid caravan networks linking dispersed communities in the altiplano highlights the importance of regional context in the emergence of political power in the transegalitarian milieu of the Titicaca Basin Formative.

The dynamic and decentralized Nunez and Dillehay model is compelling for understanding regional obsidian distributions in two ways. First, this model emphasizes the regular interaction that linked dispersed communities, often second-tier communities, across broad spaces. Obsidian appears to have had some social and symbolic significance, but it was only moderately rare and therefore it appears to have circulated relatively widely and continually between regional centers and also within second-tier and smaller communities. Thus the significance of obsidian is not principally as a "wealth item" like precious metals that served to differentiate elites in a type of network strategy (Blanton, et al. 1996). Rather, obsidian circulation, and the parties responsible for procuring and circulating it, depicts the subsistence level economic and cultural links upon which early aggrandizers likely constructed their political strategy.

During earlier time periods, such as during the Terminal Archaic when obsidian was first being intensified, it could be argued that obsidian was a rare "prestige technology" (Hayden 1998) that would confer advantages on the owner and would otherwise serve to differentiate people. Helms (1992: 159) describes how those conveying exotic materials were "long-distance travelers or contact agents as politico-religious specialists" in contact with the mysterious and distant (see discussion in Section 2.2.5). Such associations would arguably have been more likely during the earlier, emergent stages of regular caravan networks (e.g., the Terminal Archaic) under the assumption that sustained contact and diminished scarcity of a non-local material like obsidian would have probably reduced the social or symbolic power of such goods. Nevertheless, obsidian appears to have retained symbolically exotic associations that persisted in some form given the Late Prehispanic contexts: concentrations of obsidian in ritual mounds at Tiwanaku, and unmodified Chivay nodules at the gates of Machu Picchu (Section 3.5.3). However, given its abundance in the Early and Middle Formative sites, and the occurrence of obsidian in both commoner and elite contexts in the Late Formative, it would be difficult to argue that obsidian was status-conferring due simply to its non-local origin in that time period.

8.3.8.Models of regional obsidian circulation

The models developed here are evaluated against the evidence from the Chivay source acquired in the course of the Upper Colca project. This section, aims to address the models that were introduced in Section 3.7 with the new data acquired in 2003.

Model A: Direct acquisition

The Direct acquisition model describes personal visits to source areas by members of consumption households and it specifically excludes exchange of these goods between households. As per this model one should expect high variability in procurement methods, reduction strategies, and architectural and perhaps ceramics styles. Obsidian is found in both surface contexts and through quarrying, and presumably quarrying began to be practiced as the obsidian available from surface collection became more depleted. Thus, there is evidence in variability in procurement methods and in reduction strategies, however it is difficult to ascertain whether this variability results from procurement differences from non-local visitation, or from diachronic changes in available material.

It was previously suggested (Section 3.7.1) that during the Formative Period non-local visitors from the Lake Titicaca Basin, a known consumption zone for Chivay obsidian, may have left evidence of their presence during personal procurement. In the southern Titicaca Basin a distinct fiber-tempered early pottery tradition was used, but in both the north Titicaca Basin and the Colca area the contemporary pottery was grid tempered. One form of evidence of non-local personal procurement from the southern Titicaca Basin might take the form of sherds of fiber-tempered pottery from utilitarian vessels, although it may be difficult to differentiate from the evidence of fiber-tempered pottery the acquisition of obsidian through personal procurement from trade-item reciprocation. However, very little pottery, local or non-local, was identified in the Maymeja zone of the obsidian source and it is therefore difficult to use pottery to evaluate any of the procurement models. In the adjacent Block 2 survey area, obsidian scatters were often spatially coterminous with "Chiquero" pottery described by Wernke (2003) as a Formative style in the main Colca valley. As the Formative ceramics chronology in the Colca is still being defined, and there may have been differences in ceramic styles by altitudinal and ecological zone as well, it is difficult to definitively state whether all the pottery that appeared to belong to the Formative in the Chivay source area was indeed of local production.

Architecture at the Chivay source was also difficult to connect with the question of local versus non-local acquisition. Several circular structures approximately 2.5m in diameter were encountered in the area of the Maymeja workshop, but as the construction was eroded and appeared to have been expediently built, the association between these buildings and specific architectural traditions in the Colca valley or elsewhere is indeterminate. Wernke (2003) found that circular buildings were prevalent in the higher altitude portions of his survey. Further excavation in the workshop area may expose house floors or ceramics that indicate local or non-local cultural affiliation.

Direct acquisition certainly changed through prehistory from the earliest mobile foragers to the locals who procured material for household needs throughout the prehispanic past. Colca area residents probably procured obsidian for their needs from the Chivay source directly during visits to the high country that were embedded in hunting trips for viscacha, deer, and vicuña. Indeed, it was a local hunter from Chivay, Pedro Huaracha, that guided Sarah Brooks to the obsidian source in 1994 (Brooks 1998: 433-438). When non-local residents, such as residents of the Titicaca Basin, visited the Chivay source as they followed the Escalera-Lecceta route, it was perhaps for personal procurement but more likely it was in the context of caravan-mode circulation, either independent or administered, as described below.

Model B: Multiple reciprocal exchanges (down the line)

According to this exchange model, local upper Colca communities procured a sufficient excess of obsidian from the Chivay source to supply material into the exchange system for regional circulation. Two principal material expectations were described for this mode: first, the Chivay source area would contain local artifact styles and relatively low variability in procurement; second, that assemblages from the local Upper Colca communities would have some fraction of large obsidian flakes and perhaps cores consistent with the large nodules found in the Maymeja area.

As mentioned, ceramics and architectural evidence are in short supply at the Chivay source itself. There is spatial consistency in the procurement of obsidian, as the quarry pit and the workshop appear to have been repeatedly occupied over the years, but evidence from the both stratified test units show that quarrying and production was episodic. The earliest and the latest (upper-most) levels of the workshop test unit showed intermediate reduction events and some advanced reduction that may have been the result of irregular local visits to the source area.

One could argue that the intensified and regular production observed in the middle levels of the quarry pit test unit and the workshop test unit were the result of locals mining their adjacent obsidian source to meet the demands of the non-local reciprocal exchange network. However, two pieces of evidence contradict this proposal. First, as was described in Section 7.6, if locals were quarrying and producing quantities of obsidian at Maymeja one would expect some fraction of the large nodules to be represented in assemblages from local communities either in Block 2 or Block 3. In fact, very few flakes, cortical or non-cortical, over 4 cm in length were found in Blocks 2 and 3, while over 10% of flakes from the Block 1 Maymeja workshop were in that category. Second, the spatial evidence of intensification that was observed in production in the quarry and workshop was not reflected in evidence of intensified or concentrated obsidian deposits in the Block 2 and 3 areas. In Block 2, concentrations of obsidian flakes were found associated with corrals, but these were consistently small flakes. The question is if locals were responsible for intensified production at the Maymeja quarry, then which locals were conducting this work and why did they not use any of the large nodules in their local economy? The evidence suggests that locals were not involved in intensified obsidian quarrying and production in the Maymeja, but this does not preclude local residents guiding foreign caravans to the source area, or low intensity local procurement activity for local consumption and down-the-line exchange. Indeed, the concentrated obsidian deposits at Taukamayo in Block 3, although consisting of Ob2 material and relatively small flakes, may have been the result of local communities articulating with non-local caravans near the site of modern-day Callalli.

On the regional scale, down-the-line exchange is probably implicated in larger distributions of obsidian, particularly during the Archaic Period prior to the advent of caravan based mobility. A combination of direct, personal procurement and down-the-line exchange may have been the source of obsidian at sites like Asana and Qillqatani during the preceramic. There is evidence to suggest that during the Late Archaic these down-the-line networks may have become more segmentary and isolated. It is during the Late Archaic that Asana no longer contained Chivay obsidian, and projectile point styles during the Late Archaic became increasingly localized. Subsequently, in a dramatic change, during the Terminal Archaic and Early Formative regional exchange became far-reaching, the series 5 projectile point style appears with relatively little variation throughout the central and south-central Andes, and the knowledge of food production and other technologies became widespread. The evidence presented here suggests that exchange patterns, including obsidian procurement through down-the-line and direct acquisition, were relatively reduced during the Late Archaic. During the ensuing Terminal Archaic, with the initiation of regional caravans, major changes include an expansion of regular exchange and temporal consistency in obsidian supply at places like Qillqatani maintained through long-distance relationships as is described by Model C.

Model C: Independent caravans

The Independent Caravans model entails household level organization of long-distance caravans for the acquisition of specific goods from another region, or for moving goods between a number of communities in a loop and bartering for goods at various locations along the route. The material expectations of this type of obsidian circulation in the Chivay source area include episodic but intense procurement while a caravan was stopped at the obsidian source, and prompt transport of obsidian southward from the Maymeja source area to a principal thoroughfare that connects the Colca with regional travel routes.

The 2003 Upper Colca project results support an interpretation of obsidian production at the Maymeja quarry and the workshop through procurement and circulation by independent llama caravanners, with this mode occurring from the Terminal Archaic through at least the Early Formative. The 2003 results support this interpretation at a number of scales.

(1) Dates.The14C samples collected from the workshop test unit show that intensified production occurred between 2880 and 1260 cal BCE. Based on the evidence of intensity of production, levels 2 through 4 at the quarry pit test unit [Q02-2u2] are tentatively linked with levels 4 and 5 at the workshop [Q02-2u3].

(2) Camelid pastoralist emphasis.Why was obsidian from the quarry pit not reduced at the quarry pit? Instead it appears to have been transported down slope 600m to a site adjacent to water and to a lush grazing area. There are a number of links between pastoralism and obsidian production at the source area that have been explored in detail above.

(3) Transport.It does not appear that locals participating in down-the-line exchange networks were responsible for quarrying and then processing obsidian at the Chivay source workshop because obsidian flakes and cores in the local consumption sites were much smaller than one would expect if local pastoralists were quarrying for large nodules.

(4) Regional consumption.The temporality of consumption in distant sites like Qillqatani suggests that regular, caravan-based exchange was the mode of transport between the source and the consumption zone. It seems more like that caravan traffic, rather than Direct Procurement and Down-the-line exchange, would have resulted in Chivay obsidian consistently representing 10% to 20% of the lithics assemblage at Qillqatani for a period of several thousand years.

That is not to imply that procurement and production for other modes of transport, including personal acquisition and down-the-line exchange, did not occur in Maymeja; only that the intensified production associated with quarrying work and concentrated reduction activities appear to have been linked to caravan-based export. While the pastoral link and the intensified production seem irrefutable, the challenge remains to differentiate independent from administered caravans.

Model D: Elite-sponsored caravans

Caravans organized and administered by elites are described in colonial documents from the Lake Titicaca Basin. According to these passages, Titicaca Basin herders could pay part of their annual labor obligations by contributing their labor and their caravan llamas to elite-organized long-distance caravan ventures that procured non-local goods that were, in turn, redistributed to the Titicaca Basin community in the form of feasts. Material expectations at the Chivay source for obsidian procurement and circulation under elite-sponsored caravans were discussed in Section 3.7.4. It could be relatively difficult to differentiate independent from elite-sponsored caravans from archaeological evidence because the actual caravanners in either case are commoners from altiplano herding communities.

Evidence of elite-organized obsidian procurement was not found, nor were walls or other defensive structures encountered that would have been protecting the obsidian source for some kind of access monopoly. Social mechanisms for monitoring and control of the source area are a possibility in prehistory but evidence of the use of distinctive artifact styles as a signal of "ownership" of the source area were not encountered in 2003. This is consistent with other obsidian sources in the Andes, such as Alca and Quispisisa (Burger, et al. 1998;Burger and Glascock 2002;Jennings and Glascock 2002), where quarrying remains and workshops rarely contain discrete evidence of hierarchy at the source, or even cultural affiliation from specific groups known to have used those sources, such as the Wari. In North America, in an examination of Mississippian chiefdom hoe production and consumption, Cobb (2000: 195) found no evidence of hierarchy at the Mill Creek quarries over the course of four centuries of quarrying. Cobb compares this with ethnographically documented quarrying in New Guinea for ceremonial axe blades, and similarly at this quarry no evidence was found of hierarchy in production in a tribal society, despite the fact that the blades were often finished at the quarry site (Burton 1984).

The geography of the Chivay source area presents natural defensive features, such as restricted entrances to the Maymeja area that are only available along a half-dozen routes that are not cliff faces. None of the access routes showed evidence of defensive fortification or restriction. In fact, these routes were generally improved with a roadway on one exit [A03-268] and a short portion of stairway on another egress. The consumption patterns of obsidian from the Late Formative until the Inka period do not suggest that evidence of elite-sponsored quarrying would be encountered (Section 3.5.3) Assemblages at Tiwanaku suggest to Giesso (2003) that the state controlled the acquisition of obsidian from Chivay (Cotallalli) and basalt from Querimita, however there are a number of articulation points between the Chivay source and the Tiwanaku core 300 km to the south-east where the state could exercise control of the obsidian entering the core region. Recent perspectives on the probable ethnic diversity subsumed by the corporate strategies of the Tiwanaku state (Goldstein 2005;Janusek 2004;Stanish 2002) highlight the variability that might be expected in the nature of relationships between Tiwanaku elites and communities in its periphery. If the internal ethnic constituency of the Tiwanaku state, and the polities that preceded Tiwanaku in the Titicaca Basin, were more diverse than previously thought, then it is possible that many of the corporate themes were a reflection of the need to centralize the political economy because the population was relatively heterogeneous.

In the Chivay source area, the only distinctive evidence of non-local, state-affiliated materials were sherds and architecture in styles belonging to the imperial Inka. These sherds and structures are almost certainly mortuary facilities, although it is also possible that they are shrines associated with water emerging from the spring in Maymeja. Given the reduced importance of obsidian in the Inka sphere, it seems unlikely that the Inka presence in the Maymeja area was related to administered obsidian production.


The above obsidian procurement and circulation models are not mutually exclusive, and the implications can be considered synthetically in light of previously discussed exchange models in the Andes. The evidence just presented suggests that while obsidian procurement and initial production at the Chivay source was predominantly direct procurement, and transport via direct and down-the-line models of circulation, there was an important period of intensified procurement of obsidian that occurred during the Terminal Archaic through the Early and Middle Formative Periods. Obsidian is available on the surface surrounding Cerro Hornillo and the many small scatters on the ridges and in shelters in this area suggest that informal production occurred at various times in prehistory. These scattered reduction sites were complemented by evidence of intensive production that occurred in the southern portion of Maymeja where it appears that the principal goal was acquiring larger nodules of obsidian.

Models that attribute the origins of long-distance trade caravans to administered trade based on elite strategies (Stanish 2003: 69) have similarities to the models that limit the inducement to long-distance exchange to elite competition (Berdan 1989: 99;Brumfiel and Earle 1987). Following this perspective, in a context of down-the-line exchange it was elite demands and finance for procuring non-local goods that prompted the development of regular, long-distance caravan exchange, and then trade expanded to accommodate the needs of the wider population. As discussed by Smith (1999: 113), these perspectives place multifaceted processes like exchange into dichotomous terms. Differentiating elite from commoner demands, and defining prestige and utilitarian goods across the wide prehistoric variability in time and space is especially difficult. In the Andes, if "virtually all trade in the Andes conforms to what Polyani referred to as 'administered trade'" (Stanish 2003: 69) then how does one explain the consistently high percentages of non-local lithics due to long distance trade, as documented in primarily Formative levels at Qillqatani? It is argued here that these percentages are in excess, in both quantity and regularity, of the sporadic incidence of obsidian one might expect from down-the-line exchange over 200 km of largely homogeneous puna. If this regular consumption of non-local goods is indeed the product of independent caravans that began in the Terminal Archaic then it demonstrates an upswing in long-distance interaction that was founded on camelid domestication but it predates evidence of social ranking.

8.4.Theoretical implications from obsidian procurement evidence

According to John Clark (2003: 34), the key concept in trade models is that "Trade has social evolutionary consequences. Without this foundational postulate nothing else matters". While obsidian studies in the Andes can also provide important insights on historical subjects such as the early peopling of the Andean highlands, and the changes in long distance interaction due to camelid caravans, the study of ancient exchange in the south-central Andes has direct bearing on exploring the basis and development of social and political power. Beginning from the assumption that long-distance exchange of products like obsidian in Late Archaic foraging contexts was based primarily on down-the-line exchange mechanisms, it is possible to develop inferences about the contexts of early caravan transport. Drawing on earlier discussions in chapters 2 and 3, the theoretical implications of early long-distance caravan exchange will be considered in terms of three principal variables: (1) herd size and status, (2) the scale of interaction, and (3) competitive behavior and exchange.

8.4.1. Herder status and herd size

The domestication of camelids is not sufficient cause for the development of long-distance caravan traditions. Ethnographic evidence suggests that caravans are organized by herders with sufficiently large herds and the economic stability to depart on a caravan journey for weeks or months. Herders have high labor productivity and scheduling that permits important members of the household to depart on long voyages (Section 3.2.3). Households that conduct long-distance caravans often have a herd that is large enough to contain a viable number of caravan animals, or they will lease animals from others in order to have sufficient camelids to make a journey worthwhile (Browman 1990: 400;Nielsen 2000: 387-388).

Pastoral wealth is primarily manifested in larger herd sizes, where wealthy herders in modern contexts will own hundreds or thousands of animals in the south-central Andes. While an ethos against accumulation may have existed in some contexts, for example among egalitarian foragers, pastoralists worldwide display a similar logic of accumulation with respect to herd size. "In pastoral societies, having more animals is better than having fewer. Because the pastoral economy is based on a continuous demand for successful animal reproduction to replace losses due to predation, disease and use, the accumulation per se of more animals is a socially sanctioned and desirable end in itself." (Aldenderfer 2001: 25). In a human behavior ecology framework, Aldenderfer (2006) suggests that the origins of pastoralism may have its roots in the costly-signaling value of the possession of large herds. Thus, herd size is linked to status and it represents one of the factors contributing to the ability of caravan drivers to organize long distance caravans, and, in turn, to acquire non-local goods as part of caravan activities.

8.4.2. The changing scale of regular interaction

While long-distance interaction through reciprocity networks and high mobility foraging had long existed, it is likely that, along with the development of long-distance caravan traditions commenced a period of unprecedented regularity in interaction over distance. Building on the argument that due to the importance of exotic goods, those who possess such goods, and the ability to transcend regional boundaries as discussed in Section 2.2.2 (Appadurai 1986: 33;Helms 1992: 159), caravan drivers may have been among the early agents able to traverse regional boundaries in a context of increased circumscription. From the perspective of "social distance" using Sahlins' (1972) terms, regular caravan traffic represents a change in the scale of integration extending the "tribal sector" (balanced reciprocity), as well as augmenting the interaction with the "intertribal sector" (balanced or negative reciprocity). Changes are also expected in distance-dependent formulas such as Hayden's (1998) "prestige technology" where goods that were formerly laborious to transport in quantity became increasingly available resulting, over the long term, in a decline in the exotic associations for goods like obsidian.

There is little detailed evidence with which to evaluate the social position of early caravan drivers, but one should consider the socially integrating role of caravans over the larger region (Dillehay and Nuñez 1988), as well as the status and influence that may be accorded such caravan drivers. Itinerant peddlers, roaming herbalists, and other travelers are also common in the south-central Andes, and these persons could have transported goods widely. Furthermore human bearers are well documented in the Andes and in contexts with tight and perhaps exploitative control of labor, human porters can be organized into extremely efficient transport teams. Regular caravan transport is, however, a distinctive development because caravans represent a relatively low-cost mode of transport that is associated with staples and bulk items (Nielsen 2000: 514) and to the extent that caravan transport became linked to key economic cycles like agricultural production, caravans became recurrent and perhaps anticipated along these regular routes.

Changes in the scale of interaction were linked to larger economic transformations that included small-scale food production and the creation of surpluses, widespread technological change, early social inequalities, and greater sedentism; all processes that potentially contributed to the importance of caravan linkages. The integrating role of early caravans, and the position and status accorded to caravan drivers in this process, deserves further consideration.

8.4.3. Aggrandizing behavior

Evidence of early social differentiation in the south-central Andean highlands take the form of public architecture and ritual features that occur in the latter part of the Late Archaic at Asana during the Qhuna Phase, 3800-3300 BCE (Aldenderfer 1998: 243-261) and exotic grave goods by the Terminal Archaic (circa 2900 BCE) at Jiskairumoko (Craig 2005: 570). While long-distance exchange of singular items, such as a finely knapped projectile tip of non-local material, are well-documented during the Archaic Forager period, these are arguably examples of 'tokens' used to reinforce social relationships across space through buffering and mutualism (Aldenderfer 1998: 301-302;Brown 1985;Spielmann 1986). At the end of the Late Archaic and into the Terminal Archaic there is evidence of a greater emphasis on creating surpluses and perhaps the first evidence of simultaneous or sequential hierarchy (Johnson 1982). The process of increasing complexity was not necessarily linear as, for example, at Asana in the Awati phase (the Terminal Archaic) where there appears to have been simpler social organization at the site focused on herding (Aldenderfer 1998: 275;Kuznar 1990).

What prompted this emergence of competitive behavior discussed above that perhaps lies at the root of the obsidian intensification witnessed at the Chivay source in the Terminal Archaic? These changes could have roots in gradual processes through the Late Archaic that include domestication, low-level food production, and regional packing resulting from population growth. The frictions that develop from circumscription and reduced mobility are argued to have prompted the emergence of more complex social forms. Alternately, highland complexity could have been prompted by the development of complex behaviors on the coast. On the Pacific littoral, albeit 700 to 1000 km north of what is now the Department of Lima, monumental mound building is documented for the period described here as the Terminal Archaic that is argued to be based on surpluses generated from the bounty of the sea, combined with the production of cotton for nets (Moseley 1975). Research in the Norte Chico area shows that during the third millennia BCE monumental construction at coastal sites like Aspero shifted to inland complexes (Haas, et al. 2004;Shady Solis, et al. 2001), perhaps reflecting the growing importance of inland cotton production for the construction of anchovy nets and also for textile trade. Coastal complexity based on cotton surplus may have stimulated highland trade in the production of a surplus in woolen textiles (Aldenderfer 1999: 218-219), as there is evidence for other highland and Amazon basin goods, such as tropical feathers, at preceramic sites on the central coast of Peru (Quilter 1991). While preservation problems in the highlands destroy evidence of preceramic textiles, the consumption of highland and Amazonian products is documented in coastal sites as far south as the Chinchorro III (2500 - 600 BCE) period in northern Chile (Rivera 1991: 15). Cultigens are also shared over a broad region, suggesting that interregional exchange was extensive during the Early and Middle Formative.

Was the intensified production that was observed at the Chivay source, and the regular consumption of obsidian at Qillqatani, a reflection of aggrandizing behaviors? The timing of the increased production and circulation of obsidian would suggest that it was, above all, a surplus productionenterprise that was a reflection of the changing social and economic context of the Terminal Archaic and Early Formative. The evidence from this research shows that the quarrying at the Q02-2 pit was best correlated with consistent acquisition of large obsidian nodules that were probably in excess of 15cm long, yet the finished tools produced during the Terminal Archaic and onward were very small projectile points, often less than 3 cm in length. Thus, the acquisition of large nodules was not out of necessity based on intended tool forms, but probably for some other signaling value which highlights the relevance of the abundance concept. The perception of surplus would have been enhanced through supply lines as large nodules were consumed. The willingness to excavate for obsidian when there was an abundance of smaller nodules available on the surface, underscores the importance of large nodules to ancient obsidian consumers.

The possession of non-local goods are well documented attributes of aggrandizing behaviors in transegalitarian contexts (Clark and Blake 1994;Hayden 1998), yet it is not necessarily an overt expression of status that one should expect in early stages of social differentiation. Instead, the possession and use of irregularly distributed material, which includes obsidian but also might include salt, herbs, and other semi-rare goods, is a visible testament to the regional integration afforded by emerging caravan networks. Thus, while most individual obsidian artifacts may not have been "wealth items" the regular possession of a surplus of scarce "ordinary goods" of cultural value (Smith 1999) had the effect of imparting prestige on the caravan drivers who amassed and circulated these goods. As these exchange networks matured, the availability of non-local goods probably changed dramatically and, as noted above, the scale of what was considered "exotic" probably diminished as well. In that sense, obsidian production and circulation was a reflection of a transegalitarian socio-political context where an individual's successful participation in the regional economy reflected well upon him or her, and that success likely included acquisition of non-local products and manipulation of surpluses.

8.5.Future research

Research at prehispanic obsidian sources offer great potential for contributing to the reconstruction of ancient patterns in interaction and production. While all archaeological research is cumulative, quarry research is especially so because every artifact that is sourced contributes to a better understanding of the entire configuration of production and interaction. Therefore one can expect increasing focus upon, and more significant results from research into raw material source areas as archaeological knowledge accumulates. One should also anticipate rapid improvements in the sourcing and knowledge of particular raw materials as technical equipment become more affordable.

8.5.1. Other Andean sources

Other obsidian sources in the Andes are in need detailed research. In the Andean highlands, studies of the Quispisisa obsidian source (Burger and Glascock 2000;Burger and Glascock 2002) is particularly important as this source has had a long history of use with regional significance extending far beyond the Ayacucho province. Recent work at the high altitude of the Alca source by Rademaker et al. (2004) indicates that extensive obsidian production was occurring on the north slopes of Nevado Firura between 4400 and 4800 masl, above the quarrying work documented by Jennings (2002;Jennings and Glascock 2002). Studies of these production areas will also require detailed examination through excavation because diagnostic materials on the surface of most quarries are slim. Two lithic sources in western Bolivia, the Sora Sora obsidian source and the Querimita basalt source (Giesso 2000;Giesso 2003;Glascock and Giesso 1994;Márquez Ostria, et al. 1975;Ponce Sanginés 1970),were examined by Giesso (2000) and as these materials occurred with frequency in the Tiwanaku core region, the source areas offer potential for providing further insights into Titicaca Basin prehistory that complement those provided here from the Chivay obsidian source.

8.5.2. Technological improvements

Innovations in chemical sourcing equipment are making raw material source studies all the more important with passing years. Improvements and reduced costs for portable XRF machines will make raw material sourcing a routine part of lab work. These technologies will have a substantial impact in archaeology because many raw materials that include volcanic rocks, ceramics, ochre, and metals can be sourced, and the maintenance of spatial databases of proveniencing evidence will become a vital task in its own right.

Improvements in remote sensing technologies will probably contribute to identifying raw material sources in coming years. The reflectance properties of high silica materials like obsidian present distinctive spectral values in the thermal bands that can be isolated using techniques like spectral mixture analysis (Lillesand, et al. 2004). Furthermore, disturbed soils are often distinctive in remote sensing imagery, offering another potential venue for differentiating ancient quarries (Carr and Turner 1996). While remote sensing appears to provide a more effective way to locate obsidian sources, there are two major limitations to this approach: (1) thermal band (TIR) imagery tends to be very coarse (e.g., 90m pixels from the ASTER sensor), (2) obsidian is relatively abundant in many regions but distinguishing tool-qualityobsidian from imagery is unlikely. Such technologies can, at minimum, save time by identifying most of the major obsidian sources in a given region and then these sources can be visited individually.

8.6. Conclusion

This research project was an effort to integrate an investigation of regional and theoretical relevance with innovative methodological approaches. The methodological contribution comes primarily in the form of a digital research structure with regional studies, fieldwork planning, data organization, lab analysis, and presentation having taken place entirely in a digital medium. The geographical theme of obsidian procurement and circulation, combined with the methodological needs of surface survey record-keeping, created a necessity for an accurate and systematic geographical data structure, a demand that was met here using GIS software.

The theoretical and regional contribution from this research project returns to a few major themes regarding obsidian procurement and circulation. This research has showed that the chronology of obsidian procurement and use has been expanded, based on diagnostic artifact types collected during a 33 km2surface survey and on eight14C dates selected from five out of eight test excavation units. The economic focus of those who intensified on obsidian production appears to have been pastoral, as the nearness of the workshop to rich grazing and perennial water was apparently more important than proximity to the obsidian quarry. The temporality of obsidian circulation suggests that the regularized contact, probably in the form of camelid caravans, linked long distance trade partners in sustained and perhaps seasonal exchange millennia before it is anticipated in evolutionary models. The emphasis in obsidian procurement appears to have been on large nodules of clear glass, despite fact that the dominant obsidian formal tool morphology the latter part of the prehispanic period was on tiny triangular points. This emphasis on large nodules was perhaps part of a status building competition among early leaders, because in the Titicaca Basin obsidian consumption perhaps represented linkages to the western polities and large nodules were possibly seen as evidence of sustained and direct exchange with outside groups along the western margins of the puna.