3.5. Andean Obsidian Distributions through Time

While obsidian spatial distributions are well demonstrated, it is more difficult to ascertain the temporalpatternsbecause many of the obsidian artifacts from the south-central Andes that have been sourced are from an uncertain temporal provenience. The Andean obsidian sourcing literature, organized and published primarily by Richard Burger, has provided a temporal context for obsidian samples wherever possible. Temporal control for obsidian artifacts fall into three categories

(1) excavated contexts with a temporal association.

(2) surface materials spatially associated with temporally diagnostic artifacts.

(3) direct chemical sourcing of temporally-sensitive diagnostic projectile points.

Good temporal control from excavated contexts is preferred, but a number of the samples are from the number 2group, above, because the samples have weak temporal control and are from sites that are assumed to be single component based solely on diagnostic artifacts. Finally, a fourth method, obsidian hydration dating, has been used in the Andes but with mixed results. The high diurnal and seasonal temperature variation in the Andean highlands suggests that hydration dating can only be reliably used as a relative dating method in conjunction with14C dates (Ridings 1996).

Chronologies based on stages on the one hand, and periods or horizons on the other, are used in Andean archaeology. Some pan-Andean research, such as studies of regional obsidian exchange, have used the horizons absolute chronology developed by John H. Rowe (1967) in collaboration with Dorothy Menzel and based on the Ica ceramic "master sequence". This approach allows for a maximum of compatibility between regional datasets and it has been used widely, and even extended into the Titicaca Basin (Burger, et al. 2000). However, archaeological research conducted in the Lake Titicaca Basin has largely followed a chronology based on evolutionary stages that differs from the horizon chronology primarily during the Formative Period and the Tiwanaku Period (Hastorf 1999;Kolata 2003;Stanish 2003: 85-90). As the bulk of Chivay type obsidian artifacts are found in the Lake Titicaca Basin, this dissertation will review Andean obsidian distributions using a Titicaca Basin chronology, and it will follow the Formative Period temporal divisions used by Stanish (2003). These regional data will be presented in terms of three major temporal periods in order to be consistent with the framework adopted with the new data reported for this dissertation.

 

Titicaca Chronology

Years cal. AD/BCE

Late Prehispanic

Late Horizon

A.D. 1476 - 1532

Late Intermediate

A.D. 1100 - 1476

Tiwanaku

A.D. 400 - 1100

Early Agropastoralists

Late Formative

500 BCE - AD400

Middle Formative

1300 - 500 BCE

Early Formative

2000 - 1300 BCE

Terminal Archaic

3300 - 2000 BCE

Archaic Foragers

Late Archaic

5000 - 3300 BCE

Middle Archaic

7000 - 5000 BCE

Early Archaic

9000 - 7000 BCE

Table 3-9. Temporal organization of data.

These three major temporal divisions serve to differentiate the major forces that appear to have structured obsidian procurement and distribution. Rather than focusing on the "preceramic" and "ceramic" dichotomy, which is only peripherally related to obsidian use, a decision was made to present data in terms of these three major divisions. Furthermore, socio-political changes that accompanied obsidian circulation in the Terminal Archaic are better considered in conjunction with the later developments in the Formative than together with the earlier periods of the Archaic.

The use of the term "Archaic Foragers" is not meant to suggest that no pastoralism occurred prior to 3300 BCE Many scholars place the initial domestication sometime between the Middle and the Late Archaic in the chronological terms used here (Browman 1989;Kadwell, et al. 2001;Wheeler 1983;Wing 1986). However, initial domestication and adoption of a dedicated pastoralist economy are distinct events, and the evidence from a number of sites in the south-central Andean highlands suggests that the process of shifting to a food producing economy in the Andean highlands featuring camelid pastoralism and agriculture based largely on seed-plant and tuber cultivation was complete by circa 3300 BCE in the Upper Colca region. Likewise, these divisions between "forager" and "pastoralist" are not meant to suggest that foraging activities ceased in the Terminal Archaic, merely that foraging diminished in importance in terms of caloric intake and food security.

The Early, Middle, and Late Archaic Periods have the additional benefit of being differentiated by relatively consistent changes in projectile point morphology through prehistory. A projectile point typology has recently been developed by Klink and Aldenderfer (2005) that synthesizes data from previously developed point typologies with new evidence from stratified Archaic and Formative excavations in the region. This typology has proven to be extremely useful for investigating surface distributions of projectile points, and it will was used throughout this dissertation both for assessing the age of obsidian points on a regional scale, and for assigning temporal categories to surface sites identified in the course of our 2003 survey work.

/Figs_Ch3/Proj_pt_chron.jpg

Figure 3-10. Projectile Point Typology with Titicaca Basin chronology (Klink and Aldenderfer 2005)

 

The temporal groups shown in Figure 3-10 visibly depict the changes in temporal control provided by projectile point evidence between the "Archaic Foragers" and the "Early Agropastoralists". With the advent of series 5 projectile point styles in the Early Agropastoralists time, the forms of projectile points became a far less effective means of differentiating time periods because projectiles do not change with as much regularity. Series 5 projectile points, except for type 5a, are diagnostic only to the time after the domestication of camelids and the dominance of food producing, pastoral economy. The following review will examine only a few of the most significant aspects of these distributions by time period, with a focus on insights from obsidian exchange on the preceramic and Early Agropastoralist stages of Andean prehistory.

3.5.1.Archaic Foragers in the South-Central Andes

To date, relatively few Archaic archaeological sites have been excavated in the area of the south-central Andean highlands, and therefore the regional knowledge of this important time period is limited. A brief overview of each period will be provided here, with an emphasis on archaeological sites containing Chivay type obsidian, in order to contextualize the regional relationships and interactions that were occurring during these preceramic periods. This review will focus on the western slope of the Andes and the Lake Titicaca Basin, the region where Chivay type obsidian abounds. Much of the Archaic Foragers obsidian in the literature that has been sourced was derived from undated, surface contexts from sites that are assumed to date to the Archaic based on projectile point styles or other inference by archaeologists. Klink and Aldenderfer's (2005) projectile point typology permits the classification of site occupations by time period with greater certainty during the Archaic when projectile point styles change with regularity. In some cases, the projectile point typology can be used to assign a date range to temporally diagnostic obsidian projectile points that have been directly analyzed for chemical provenience.

In Burger et al.'s (2000: 275-288) review, procurement and exchange during the preceramic is evaluated through chemical provenancing data from 87 obsidian samples, 70 of which are from the Chivay source. Unfortunately, of the thirteen sites where the samples were collected in the south-central highlands, only three sites (Chamaqta, Asana, and Sumbay) contain excavated contexts placing the samples in preceramic levels. The other samples are assigned to the preceramic group through inference from projectile points, or because they are from a-ceramic sites. The difficulty in this arises from the fact that obsidian was used with much greater frequency in the beginning of the pastoralist periods, as was mentioned above in the case of the Ilave valley (Section 3.4.4 ).

Obsidian materials from both the Chivay and Alca sources were transported relatively long distances from the Early Archaic onward, indicating that material from these obsidian sources has properties that were prized at a relatively early date. Sites such as Asana and Qillqatani, both over 200 linear km from the Chivay source, contain non-local obsidian through much of the preceramic sequence despite the immediate availability of high quality cherts, as well as the lower-quality Aconcahua obsidian, in the local area. This evidence underscores the nature of obsidian provisioning in the Archaic Period. As compared with later pastoralist use of obsidian, Archaic foragers were relatively selective in their use of raw materials. This may reflect the priority placed on dependable hunting technology as compared with the shearing and butchering needs of pastoralists, or the different social and symbolic priorities attached to obsidian by hunters versus herders.

/Figs_Ch3/ArchForagers_region.jpg

Figure 3-11. Chivay type obsidian distributions during the "Archaic Foragers" time
(circa 10,000 - 3,300 BCE).

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

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

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

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

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

Chivay obsidian in the Early Archaic

Evidence of human use of the Chivay Source beginning in the Early Archaic Period comes from survey work adjacent to the source and from excavations at the site of Asana, 200 km away in Moquegua. As will be discussed in Chapter 7, during the course of survey work in the area of the Chivay source in 2003 the Upper Colca team collected several dozen Early Archaic type projectile points, the majority of them made from obsidian. Evidence for the regional consumption of Chivay obsidian begins with the site ofXAsanaXthat were described earlier in SectionX3.4.1XandXTable 3-4X. Aldenderfer(1998: 157, 163;2000: 383-384)encountered small quantities of obsidian in two levels belonging to the Asana II/Khituña Phase, placing them in the Early Archaic Period. In level PXXIX just one obsidian flake from Chivay was identified in an assemblage consisting of 1,152 lithic artifacts weighing 746 g. This level could not be dated directly, but it is assessed at 9400 uncal bp as it lies stratigraphically above a14C sample from level XXXIII dating to 9820±15014C yr bp (Beta-40063; 10,000-8700 BCE).

Obsidian from Chivay appeared in greater quantity in level PXXIV where eleven flakes of Chivay obsidian made up 0.36% of the lithic assemblage by count. These flakes were all small tertariary flakes, chunks, and shatter, suggesting to Aldenderfer(1998: 163)that a bifacial core of Chivay material was reduced on site. A14C sample from level PXXIV dated to 8720±120 bp (Beta-35599; 8250-7550 BCE). The Khituña phase has been interpreted by Aldenderfer(1998: 172-173)as representing a residential base in the high sierra and the beginnings of permanent settlement above 2500m in elevation. This interpretation is based on the presence of high sierra and puna lithic raw materials, but no coastal materials.

In surface contexts in the Ilave valley, surveys directed by Aldenderfer(1997)located three obsidian projectile points in forms that are possibly diagnostic to the Early and Early-Middle Archaic transitional period (types 1A, 3A, 3B). These three points were analyzed using a portable XRF unit in 2005 and all three were found to be of the Chivay type(Craig and Aldenderfer In Press).

Alca obsidian at Quebrada Jaguay

The earliest obsidian identified in the south-central Andes comes from one of the oldest confirmed sites in South America, the Paleo-Indian site of Quebrada Jaguay 280 near the coast north of Camaná, Arequipa. Sandweiss et al.(1998)report that Alca type obsidian was the dominant lithic material at the site in the Terminal Pleistocene and Early Holocene phases that were identified. Twenty-six Alca type obsidian flakes came from the older occupation that occurred during the Terminal Pleistocene and the context is dated by twelve14C dates on charcoal falling between 11,105±260 bp (BGS-1942; 11,700-10,400 BCE) and 9850±170 bp (BGS-1956; 10,100-8700 BCE). A later occupation contained one flake of Alca obsidian and it belonged to the Early Holocene II phase dated by four14C samples falling between 8053±115 (BGS-1944; 7350-6650 BCE) and 7500±130 (BGS-1700; 6600-6050 BCE). Three other obsidian flakes from the Alca source were collected but they could not be assigned to a temporal context.

Sandweiss et al. observe that the Chivay source is "less than 20 km further; the absence of Chivay obsidian at QJ-280 may indicate that this source was covered by glacial readvance during the Younger Dryas (circa 11,000 to 10,00014C yr B.P.)"(Sandweiss, et al. 1998: 1832). The Maymeja volcanic depression of the Chivay obsidian source indeed shows notable evidence of recent glaciation, but obsidian matching the "Chivay Type" is also found in smaller nodules on adjacent slopes outside the Maymeja zone as well as in the streambed below Maymeja having eroded through alluvial erosion (see Section4.5.1for maps and a discussion of the Chivay obsidian source geography). Procurement of obsidian from Chivay did not necessarily require entering the Maymeja area, however better source material can be obtained from the within the area.

Regional scale GIS analyses show Quebrada Jaguay to be 154 linear km from the Alca source, or 35.7 hours by the hiking function. In contrast, the trip to Quebrada Jaguay from the Chivay source is 170 linear km and 41.5 hours by the hiking function. Despite this relatively difference in distance, no Chivay obsidian was found at Quebrada Jaguay. It is worth noting that, despite this early find of Alca obsidian on coast, both the Alca and the Chivayobsidian types were predominantly found at high altitude throughout prehistory based on current evidence from obsidian sourcing studies. In the bigger picture, the coastal Quebrada Jaguay paleoindian finds are anomalous for Alca distributions. The next lowest altitude context for Alca to date is at the site of Omo in Moquegua, a Tiwanaku colony site at 1250 masl dating to the Middle Horizon.

Recent work by Kurt Rademaker and colleagues at the Alca source has shown that bedrock outcrops of obsidian are found as high as 4800 masl, and there are large pieces found at 3,800 masl that appear to have been transported downslope by glacial action and colluviation (K. Rademaker 2005, pers. comm.). Deposits of Alca obsidian at much lower elevations have been reported that are probably the result of pyroclastic flows(Burger, et al. 1998;Jennings and Glascock 2002). These deposits found close to the floor of the Cotahuasi valley at 2500 masl were probably available throughout the Younger Dryas and perhaps further sub-sourcing of Alca obsidian will better answer the question of which Alca deposits were being consumed during the Terminal Pleistocene by the occupants of Quebrada Jaguay.

Quispisisa Obsidian in the Early Archaic

Another early use of obsidian in the Andes is the evidence of Quispisisa obsidian in levels dated to ~9000 uncalBP or 8500-7750 cal BCE (Burger and Asaro 1977;Burger and Asaro 1978;Burger and Glascock 2000;MacNeish, et al. 1980) from Jaywamachay a.k.a. "Pepper cave" (Ac335) located at 3300 masl in Ayacucho in the central Peruvian highlands. As was recently explained by Burger and Glascock (2000;2002), for nearly three decades the Quispisisa obsidian source was mistakenly believed to have been located in the Department of Huancavelica, but in the late 1990s the true Quispisisa source was finally discovered in the Department of Ayacucho. Jaywamachay is the closest of the sites excavated by MacNeish's team to the newly located Quispisisa source. It is 81.3 linear km or 22.0 hours walking calculated using the hiking function, while the bulk of the sites excavated by MacNeish were in the Ayacucho valley approximately 120 km from the relocated Quispisisa source. The Puzolana (Ayacucho) obsidian source is located close to the Ayacucho valley and high-quality, knappable obsidian is available at this source, but the maximum size for these nodules is 3-4 cm, significantly limiting the potential artifact size for pieces made from this source (Burger and Glascock 2001). It is interesting to note that, in several cases in the south-central Andes, the Archaic Period foragers seem to have ignored small sized or low-quality obsidian sources that later pastoralists ended up exploiting. The Aconcahua source near Mazo Cruz, Puno, previously described, was not used at the adjacent Qillqatani rock shelter until the Middle Formative (Frye, et al. 1998), and it was not used at Asana until the Terminal Archaic (Aldenderfer 2000: 383-384).

Burger and Asaro(1977: 22;1978: 64-65 )chemically analyzed a projectile point of Quispisisa obsidian found at La Cumbre in the Moche Valley that was reportedly from a context dated to 8585±280 bp or 8500-6800 cal BCE(Ossa and Moseley 1971). The investigator, Paul Ossa, now doubts the Early Archaic context and instead believes the point may be Middle Horizon in date (Richard Burger, 11 March 2006, personal communication), but it is still a noteworthy case of long distance transport within the Wari Empire, and it perhaps involved the use of coastal maritime transport. Using the relocated Quispisisa source in the Department of Ayacucho the linear distance is 846.7 km and by the hiking function the distance is calculated as 199.8 hours, primarily confined to the coast.

Discussion

Regional relationships indicated by both stylistic criteria and obsidian distributions point to high mobility during the Early Archaic Period. Recent evidence of projectile point similarities from northern Chile suggest that mobility was high along the Pacific littoral, and between the sierra and puna during the Terminal Pleistocene and Early Holocene around 25° S latitude(Grosjean, et al. 2005;Nuñez, et al. 2002). During the Early Holocene, foraging groups resided around high altitude paleo-lakes on the altiplano of northern Chile between 20° S and 25° S latitude that persisted longer than did the paleo-lakes at the latitude of Lake Titicaca. These lakes subsequently dried up during the Middle Archaic Period and occupations declined until the end of the Late Archaic Period but this distributions point to the mobility and early high altitude occupation of the adjacent puna of Atacama.

On the whole, obsidian proveniencing and analysis has shed light on human activities during the Paleoindian period and Early Archaic at a regional scale. Chemical analysis techniques, non-destructive XRF analysis in particular, are becoming more pervasive because the methods are being refined and the equipment is becoming more portable. Further field research will provide a greater understanding of this time period, but evidence will also likely to emerge from existing collections as obsidian projectile points diagnostic to the Early Archaic are systematically provenienced.

Middle Archaic (7000 - 5000 BCE)

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

Obsidian distributions during the Middle Archaic

At the site of Asana on the western slope of the Andes, Aldenderfer(1998: 223)observed architectural features that suggest that a longer residential occupation of the site by entire coresidential groups was occurring in the latter part of the Middle Archaic Muruq'uta phase.One flake of obsidian from the Chivay source was found in the upper levels of theMuruq'uta phase (XTable 3-4X).This occupation dates to the Middle Archaic -Late Archaic transition as the flake was stratigraphically above a14Csample that dated to 6040 ± 90 bp (Beta-24634; 5210-4720 BCE).

At the rock shelter of Sumbay SU-3 obsidian was recovered from excavation levels that date to as far back as the transition between the Middle and Late Archaic (SectionX3.4.3X).

Discussion

Relatively little is known about the Middle Archaic in the south-central Andean highlands. Elsewhere in the south-central Andes, archaeologists have noted an absence of settlement during the mid-Holocene timeframe corresponding to the Middle and Late Archaic Periods. In the dry and salt puna areas of northern Chile, and along the south coast of Peru, a significant decline or absence of mid-Holocene sites has led investigators to refer to this period as the silencio arqueológico(Nuñez, et al. 2002;Núñez and Santoro 1988;Sandweiss 2003;Sandweiss, et al. 1998). This designation apparently does not apply to the Titicaca Basin or to the sierra areas of the Osmore drainage where no Middle Archaic occupation hiatus has been observed.

With gradual population increases and adaptation to the puna, social networks extending across the altiplano and connecting communities and their resources residing in lower elevations with puna dwellers, were probably beginning to take form. Exchange of resources, including obsidian, between neighboring groups may have been in the context of both maintaining access to resources and risk reduction. From a subsistence perspective, Spielmann (1986: 281) describes these as buffering, a means of alleviating period food shortages by physically accessing them directly in neighboring areas, and mutualism,where complementary foods that are procured or produced are exchanged on a regular basis. Another likely context for obsidian distribution during the Archaic Period is at periodic aggregations. Seasonal aggregations have been well-documented among foragers living in low population densities, where gatherings are the occasion for trade, consumption of surplus food, encountering mates, and the maintenance of social ties and ceremonial obligations (Birdsell 1970: 120;Steward 1938). If analogous gatherings occurred among early foragers in the south-central Andes it have would created an excellent context for the distribution of raw materials, particularly a highly visible material like obsidian that was irregularly available in the landscape.

Late Archaic (5000 - 3300 BCE)

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

Chivay obsidian during the Late Archaic

Evidence of Late Archaic obsidian use comes from excavations at the previously discussed sites of Asana, Qillqatani, and Sumbay. Several obsidian samples in the Burger et al. (2000) study were of portions of diagnostic projectile points that resemble types in Klink and Aldenderfer's (2005) point chronology. From illustrations and text(Burger, et al. 2000: 279, 281)the Qaqachupa sample appears to belong to the Late Archaic. Burger et al. describe this point as resembling a Type 7 point from Toquepala in Ravines'(1973)classification, and Klink and Aldenderfer(2005: 44)mention that their Type 4D point strongly resembles the Toquepala Type 7, making it diagnostic to the Late Archaic.

Asana

In excavated data from Asana, in Moquegua, one sample of Chivay obsidian was found in a Muruq'uta phase occupation in Level XIV-West lying above a palimpsest dated to 6040±90 (Beta-24634; 5210-4766 BCE) (Aldenderfer 1998: 269), as shown above in SectionX3.4.1X. This level lies on the Middle Archaic / Late Archaic transition. Interestingly, Chivay obsidian disappears at Asana subsequent to this time period. Furthermore, evidence of lower raw material diversity in the Late Archaic lithic assemblage point to greater geographical circumscription.

Qillqatani

Chivay obsidian at Qillqatani is first found in the Late Archaic level WXXX dated to 5620±120 (Beta-43927; 4800-4200 BCE). The Chivay material is the second oldest obsidian fragment identified from Qillqatani (SectionX3.4.2X), the oldest obsidian is from an as-yet unknown source. Notably, the assemblages from the Qillqatani excavations do not begin to contain obsidian from the Chivay source until considerably later date than did the excavations from Asana.XFigure 3-7Xreveals that both obsidian tools and debris increase as a percentage of the assemblage in the Late Archaic. The counts of obsidian, however, are still relatively low.

Qillqatani is slightly further away than Asana than from the Chivay source, and it is at a higher altitude and further to the east. It has been suggested that perhaps the obsidian was transported via a coastal route at this early date (Frye, et al. 1998). As mentioned, Alca obsidian was also found on the coast in the Terminal Pleistocene levels although, like Chivay, Alca obsidian distributions conform over the long term to a highlands orientation. As no Chivay obsidian as ever been found below the 1250 masl (at Omo), and all Archaic Period Chivay obsidian is found above 3000 masl, the littoral route between Chivay and Asana seems improbable.

IlaveValley

Craig and Aldenderfer(In Press)report that two obsidian projectile points from the Ilave valley in a type 3f form, diagnostic to the Late - Terminal Archaic were analyzed in 2005 with a portable XRF unit and were found to be of the Chivay type.

Sumbay

At Sumbay SU-3,three obsidian samples were analyzed from excavated contexts and all three turned out to be of the Chivay type(Burger, et al. 1998: 209;Burger, et al. 2000: 278), as shown in SectionX3.4.3X. Two14C dates were run and returned dates from the early part of the Late Archaic(Ravines 1982: 180-181). One sample was from stratum 3 and it was dated to 6160±120 (BONN-1558; 5400-4750 BCE). Another sample was from above it in stratum 2 and it dated to 5350±90 (BONN-1559; 4350-3980 BCE). One of the three obsidian samples came from Stratum 4 of unit 5, while the other two samples came from higher levels. The Stratum 4 sample probably dates to the Middle Archaic.

Discussion

Obsidian from securely dated Late Archaic contexts show something of a reduction in regional distribution and a greater focus on locally available lithic material, suggesting a reduction in mobility or exchange in the Late Archaic. Similarly, projectile point styles became increasingly more limited in spatial distribution, with greater local variability during the Late Archaic implying reduced mobility(Klink and Aldenderfer 2005: 53). This is consistent with Aldenderfer's(1998: 260-261)observations about reduced mobility during the Late Archaic Qhuna Phase occupation at Asana when the occupants ceased to use non-local lithic raw materials. During this phase, Aldenderfer also describes increasingly formalized use of space at Asana, evidence of a ceremonial complex, and greater investment in seed grinding. In short, during this time a circumscribed population with reduced mobility was probably living in higher densities and exhibiting signs of ceremonial activity that are consistent with the scalar stress model for the emergence of leadership(Johnson 1982).

It is also worth considering the impact that scarcity may have on valuation. The lack of discarded obsidian signifies that it was not being knapped or resharpened and it was probably not abundant, but that does not mean that obsidian was not known in the larger consumption zone during this period. In the subsequent time period, the Terminal Archaic, obsidian becomes abundant on a regional scale at the same time as a host of other social and economic changes were occurring. This period, and the previously discussed Middle Archaic, correspond with what was referred to as the silencio arqueologico(Núñez and Santoro 1988)due to a dearth of archaeological data observed by investigators working in Northern Chile. The reduced evidence of circulation of obsidian from Chivay appears to correlate with a reduction in archaeological evidence regionally.

Thereis strong representation of Chivay obsidian in Arequipa at Sumbay, and it is likely that Late Archaic projectile point forms are found in the North Titicaca Basin as reported by Burger et al. (2000). However, at Asana there is little obsidian from the Colca. Possibly these reduced distributions of obsidian reflect the reduced mobility and more complex architectural investment in Late Archaic contexts at Asana(Aldenderfer 1998), and prior to the development of extensive, long distance exchange that were potentially initiated by early caravan networks during the Terminal Archaic.These conclusions, however, on not based on particularly robust data, as the sample of sites for this time period is relatively small.

Discussion and review of the Archaic Foragers period

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

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

3.5.2.Early Agropastoralist obsidian distributions

The "Early Agropastoralists" period (3,300 BCE - A.D. 400) begins with what appears to have been a shift to a chiefly pastoral lifeway, greater regional interaction, and a more intensive production and circulation of obsidian from the Chivay source area in the Terminal Archaic. In this discussion, the Early Agropastoralists period continues through the Late Formative and subsequently beginning AD400, with the ascendancy of Tiwanaku, the "Late Prehispanic" time block begins. The changes during the Terminal Archaic that mark the beginning of the Early Agropastoralist time include the growing importance of food production, the expanded production and circulation of obsidian, and socio-political differentiation that began to appear in the Terminal Archaic, phenomena of greater interest to this research than the presence or absence of pottery.

/Figs_Ch3/Early_AgroPast_region.jpg

Figure 3-12. Chivay type obsidian distributions during the "Early Agropastoralists" time (3,300 BCE - AD 400).

Why an "Early Agropastoralists" time block?

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

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

Terminal Archaic (3300 - 2000 BCE)

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

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

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

Chivay obsidian during the Terminal Archaic

While the number of excavated Terminal Archaic sites is relatively small, general processes are apparent from recent work at several sites in the south-central Andean highlands.

At Ch'uxuqullu on the Island of the Sun, Stanish et al.(2002)report three obsidian samples from the Chivay source in Preceramic levels. Eight obsidian flakes were found in aceramic levels and were described as being from a middle stage of manufacture, and three of these were sourced with NAA. Two samples came from levels with a14C date of 3780±100bp (Teledyne-I-18, 314; 2500-1900 BCE) and a third Chivay obsidian sample comes from an aceramic level that immediately predates the first ceramics level which occurred at 3110±45bp (AMS-NSF; 1460-1260 BCE). Citing paleoclimate data, the authors observe that boat travel was required to access the Island of the Sun at this time.

The Ilave Valley and Jiskairumoko

Terminal Archaic projectile points in the Ilave valley demonstrate the dramatic shift in the frequency and use of obsidian that occurred in this time period (SectionX3.4.4X). XRF analysis of 68 obsidian artifacts excavated from Jiskairumoko show that the Chivay source was used with particular intensity in this period. The XRF study found that 97% of obsidian bifaces from Terminal Archaic and Early Formative levels at Jiskairumoko were from the Chivay source, however published obsidian studies from all time periods show that typically 90% of all obsidian analyzed from Titicaca Basin sites are from the Chivay source (XTable 3-3X).

Qillqatani

The percentages of obsidian tools and debris remain generally similar to those in the Late Archaic level except that the counts are much higher (XFigure 3-7X). By count, obsidian tools are doubled, and obsidian debris is 4.3 times greater, and all the obsidian has visual characteristics of the Chivay type (Aldenderfer 1999).

Based on the density of obsidian, the relationship with the Chivay source area 221 km away seems to be well-established by this time, and it is a relationship that becomes even more well-developed in the Early Formative. Six samples of obsidian were analyzed at the MURR facility from Terminal Archaic contexts that are associated with a radiocarbon date of 3660±120 (Beta-43926; 2210-1880 BCE). All six obsidian samples were from the Chivay source.

Asana

At the site of Asana, obsidian reappears at the end of the Terminal Archaic during the Awati Phase dated to3640±80 (Beta-23364; 2300-1750 BCE)where it makes up 0.4% of lithic materials, but this obsidian was not from the Chivay source. It was judged from distinctive visual characteristics to have come from the Aconcagua obsidian source only 84 km to the east of Asana, near the town of Mazo Cruz(Aldenderfer 2000). Aconcahua type obsidian has characteristics that are less desirable for knapping due to fractures and perlitic veins that cross cut the material (see Appendix B.1), and while it was possible to derive sharp flakes for shearing and butchering functions, the material was probably not used for projectile point production(Frye, et al. 1998).

The shift to Aconcahua obsidian in the Awati phase at Asana is particularly puzzling given the evidence for Chivay obsidian circulation at this time period. It is precisely at the end of the Terminal Archaic that a dramatic spike in the use of Chivay obsidian at Qillqatani (SeeXTable 3-5XandXFigure 3-7X) took place. One may ask: Why is it that when the occupants of Qillqatani are importing Chivay obsidian in unprecedented quantities, the people of Asana are getting only small quantities of low-quality obsidian? In addition, this low-quality obsidian comes from Aconcahua, a source adjacent to Qillqatani?

Given the pattern of early Chivay obsidian at Asana, these Terminal Archaic distributions suggest that the high sierra residents at Asana were not participating in an altiplano-based circulation of goods as the Qillqatani residents. The residents of Asana never again participate in the circulation and consumption of Chivay obsidian, while at Qillqatani the consumption of Chivay material continues strongly for another one thousand years.

Other obsidian types during the Terminal Archaic

Obsidian from alternative sources in the circum-Titicaca region, including the unlocated sources of Tumuku and Chumbivilcas types, are used in greater quantity during the Terminal Archaic judging from associated projectile point evidence provided in Burger et al.(2000: 280-284).

Evidence from close to the Alca obsidian source provides new information about long distance interaction during Terminal Archaic. At the site of Waynuña at 3600 masl(Jennings 2002: 540-546)and less than one day's travel from the Alca obsidian source, recent investigations have uncovered a residential structure with evidence from starch grains resulting from the processing of corn as well as starch from arrowroot, a plant necessarily procured in the Amazon basin(Perry, et al. 2006). Given the long distance transport of arrowroot, it is conceivable that the plant material arrived as a form of reciprocation or direct transport from travelers moving between the Amazon and the Alca obsidian source. The Cotahuasi valley also has major salt source and other minerals that would potentially draw people procuring such materials. The starch samples were found in a structure on a floor dated by two14C samples. One sample was dated to 3431±45 (BGS-2576) 1880-1620 BCE, and another was 3745±65 (BGS-2573) 2350-1950 BCE

Further north, the Quispisisa type obsidian was particularly abundant during the Terminal Archaic at the preceramic coastal shell mound site of San Nicolas, along the Nasca coast, in a context associated with early cotton(Burger and Asaro 1977;Burger and Asaro 1978: 63-65). Quantitative data on the consumption of obsidian at San Nicolas are unavailable and the temporal control is weak because the "cotton preceramic" date is derived from association with cotton and no ceramics, not from direct14C dating.

Discussion

The distribution of obsidian from all three major Andean obsidian sources: Chivay, Alca, and Quispisisa, expanded considerably during the Terminal Archaic. It is notable that both the Chivay and Alca sources expanded, but the distribution remained confined to the sierra and altiplano areas of the south-central Andes. In comparison, obsidian from the Quispisisa source (340 linear km to the north-west of the Chivay source), has been found in significant quantities in Ica on the coast of Peru. While many of the early coastal obsidian samples have weak chronological control, the quantities of Quispisisa obsidian found in possible Archaic contexts is noteworthy. The fact that Chivay obsidian has never been found in coastal areas, and Alca is not found on the coast after the Paleoindian period, is remarkable considering the extensive evidence of coastal use of Quispisisa obsidian beginning in the Terminal Archaic.

Early Formative Period (2000 - 1300 BCE)

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

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

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

Chivay obsidian distributions

At Qillqatani, obsidian flakes are available in quantity during this Titicaca time period which roughly overlap with the Formative A and B (XTable 3-5X). Seven obsidian samples were analyzed at MURR that all corresponded with the Chivay source. These samples were found in levels adjacent to a context that dated to2940±70bp (Beta-43925; 1380-970 BCE).

It appears that obsidian was being obtained as nodules or blanks and being knapped down to projectile points. Obsidian flakes represent 15% by count (n = 160) of all the flakes in the period "Formative A", and obsidian projectile points represent 12% by count of all points in this level(Aldenderfer 1999).

Obsidian is first found at Qaluyu dated to ~3250 uncal bp which calibrates to 1640-1420 BCE(Burger, et al. 2000: 291-296), or the end of the Early Formative where Burger et al. report evidence of nodules or blanks arriving for further reduction at the source. Some of the Chivay obsidian found at Qaluyu were medium sized pebbles; one example Burger et al. analyzed had the dimensions 1.9 x 1.4 x 1.2 cm. Qaluyu is 140 linear km from the Chivay source, or 34.6 hours by the hiking model, so it is roughly 70% of the distance of Qillqatani from the source. There are substantial quantities of obsidian at Qaluyu during the subsequent Middle Formative.

Discussion

Paleoclimatic studies have documented a decline in abundance of arboreal species in the Lake Titicaca Basin and an increase in open-ground weed species reflecting disturbed soils after ca. 1150 cal BCE(Paduano, et al. 2003: 274). This has been interpreted as reflecting intensification in food production and population that occurred during the Early Formative. Some argue that the grasslands of the altiplano are an anthropogenic artifact of a human induced lowering of the treeline due in part to the expansion of camelid pastoralism(Gade 1999: 42-74). The increasing sedentism, cultivated plants, expanding camelid herds and the growing influence of prominent settlements like Qaluyu in regional organization signify that significant socio-economic dynamism was underway by this period. The evidence of hierarchy takes the form of "very moderate social rank" acquired by certain individuals, such as religious specialists(Stanish 2003: 108). These traits are first suggested by jewelry, grave goods, and non-residential structures in the Terminal Archaic, but they become further elaborated during the Early Formative after 2000 BCE.

There is no evidence of political ranking in the structure of settlement distributions between Early Formative sites in the Lake Titicaca Basin, and all the sites are less than one hectare in size(Stanish 2003: 108), but the evidence of obsidian circulation from Qillqatani and other pastoral sites suggests of regional exchange system not yet focused around Lake Titicaca. Evidence acquired from the earliest occupational levels at Titicaca Basin regional centers suggest that regional interaction was low. At the site of Chiripa, in the southern Lake Titicaca Basin, Matthew Bandy describes traces of sodalite beads, obsidian, and sea shell in excavations from Early and Middle Formative contexts.

It is clear, then, that long distance trade in mortuary and prestige items took place as early as the Early Chiripa phase [1500-1000 BCE]. Equally clear, however, is that this early exchange involved very small quantities of the objects in question. This trading would seem to have been very sporadic and infrequent. There is no evidence in the Early Formative Period for the sort of regular caravan trade postulated by Browman (his "altiplano mode"; see Browman 1981: 414-415) (Bandy 2001: 141).

However, the evidence for obsidian distributions at Qillqatani that are discussed here point to routine exchange, perhaps by caravan trade, along on the Western Cordillera in the Early Formative. It appears that future regional centers like Chiripa were not yet participants in these exchange networks.

The dynamic nature of interregional interaction that occurred during the Early Formative is evident from the diversity in obsidian types at sites, and the lack of geographical restrictions that appear to structure exchange during later periods. While settled communities were evident, the lack of hierarchy and centralization suggests that they were not integrated by supra-local organization. Yet the economic basis for long distance relationships appears to have taken form by the Early Formative. The decentralized and variable nature of exchange in this period, which is abundantly evident at Qillqatani and yet not evident at sites like Chiripa, implies that another form of integration was linking communities, like the residents of Qillqatani, with the Chivay source 221 km to the north-west.

Middle Formative Period (1300 - 500 BCE)

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

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

Chivay obsidian distributions

Chivay obsidian occurs in small quantities at a number of Middle Formative sites in the southern Basin including Chiripa and Tumatumani, and it persists at Ch'uxuqullu on the Island of the Sun. At Tumatumani, 3% of the projectile points are made from obsidian(Stanish and Steadman 1994). Bandy(2001: 141)reports that at Chiripa they recovered only small quantities of obsidian in the time spanning 1500-200 BCE and these were in the form of finished bifaces. For the entire time span, after four excavation seasons, they report only 87.1g of obsidian. Tumuku type obsidian was identified in Chiripa in Condori 1B component circa 1500-1000 cal BCE levels(Browman 1998: 310, dates calibrated). At the site of Camata, on the lakeshore south of the modern city of Puno, four obsidian samples were analyzed from contexts that range from circa 1500 - 500 cal BCE and all four were of Chivay type obsidian(Frye, et al. 1998;Steadman 1995).

The evidence from the North Titicaca Basin regional centers is even more intriguing as there is a significant presence of Alca type obsidian during the early part of the Middle Formative, and Chivay obsidian is found in the Cusco Basin during this time. Qaluyu, Pikicallepata, and Marcavalle all contain both Chivay and Alca obsidian between approximately 1100 - 800 cal. BCE, the early part of the Middle Formative(Burger, et al. 2000: 292;Chávez 1980: 249-253). Subsequent to this overlap in obsidian use, there appears to have been significant overlap in other stylistic attributes as well. These similarities include common traits in ceramic vessel forms between Chanapata vessels in the Cusco area and Qaluyu vessels in the North Titicaca Basin(Burger, et al. 2000: 292).

However, during the latter part of the Middle Formative after 800 BCE the Yaya-Mama religious tradition first emerges at the site of Chiripa(Bandy 2004: 330;Chávez 1988), a tradition that eventually unifies the north and south areas of the Titicaca Basin during the Late Formative. As noted by Burger et al.(2000: 311-314), with the appearance of the Yaya-Mama tradition the Alca and Chivay obsidian distributions become more asymmetrical. Alca obsidian makes up 16% (n = 9) of the obsidian in a pre-Pukara context at the site of Taraco on the Titicaca lake edge in the North Basin, however while Chivay obsidian was found at Marcavalle and other Cusco sites previously during the Early Formative, obsidian from the Chivay source is absent during the Middle Formative and it does not re-appear in the Cusco region again until the Inka period. Alca obsidian, on the other hand, expands outward during this period as it is found in the Titicaca Basin to the south-east, and it is also is transported a great distance to Chavín de Huantar. Both of these examples of long distance transport have been attributed to religious pilgrimage(Burger, et al. 2000: 314).

Qillqatani

At Qillqatani, the Middle Formative comprises the bulk of Formative B layers and all of the Formative C layers (see Qillqatani data in Section X3.4.2X). In Formative B layers, Chivay obsidian is the only type represented in the four samples that were analyzed and the lithic assemblage suggests that formal tools were not being produced at the site as no evidence of obsidian tools were found in these levels. Obsidian flakes, however, persist as 18% of the lithic assemblage from that level. Subsequently, in the Formative C level that begins around 900 BCE and corresponds approximately with the latter half of the Middle Formative as well as the rise of the Yaya-Mama tradition in the south Titicaca Basin, there is a distinctive shift in the use of obsidian at Qillqatani. Whereas all prior obsidian samples from Qillqatani were Chivay after the initial Middle Archaic sample, the obsidian samples in Qillqatani Formative C levels are only 60% from the Chivay source.

The other samples come from Aconcahua, a source of lower-quality obsidian that is near the Qillqatani shelter, and from Tumuku, an as-yet undiscovered source that may be located close to the three-way border between Peru, Bolivia, and Chile, and finally Alca obsidian occurs for the first and only time at Qillqatani in these levels. Given that Alca obsidian also occurs at Pukara, Incatunahuiri (surface) and at Taraco in quantity (16% of assemblage, n = 9), the presence of Alca obsidian at Qillqatani is consistent with the abundance of Alca material in circulation in that time. A sample of Alca obsidian has also been found on the Island of the Sun (Frye, et al. 1998), though it was from a surface context.

Table 3-6Xshows that obsidian tools in Formative C levels at Qillqatani are abundant (n = 19) and relatively large on average (1.21 g), and the non-obsidian tools were also very abundant (n = 187) for this level.

Discussion

Middle Formative obsidian distributions appear to demonstrate the emergence of a distinctive Titicaca Basin exchange sphere. One could argue that the emerging elites that mobilized labor to build the initial mounds and courts, and sponsored specialized artistry in stone and ceramics, may have precipitated a demand for greater exotic exchange goods as a source of prestige. Stanish(2003: 162)believes that this is the process that occurs later, during the Late Formative, when he argues that this process is connected to wealth generation for sponsoring feasts and other activities, though he admits the data are sparse. Evidence of long distance exchange from contexts belonging to the Early Formative and first half of the Middle Formative (1500-1000 BCE) at sites like Chiripa are sparse, irregular, and generally involve very small, portable goods; however the evidence from Qillqatani supports other models of more regular interaction along established exchange routes.

Late Formative Period (500 BCE - AD 400)

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

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

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

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

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

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

Discussion

The decline in forest cover in the Lake Titicaca Basin beginning during the Early Formative intensified throughout the Formative Period. Between 2500 - 800 cal. BCE a decline in fine particulate charcoal was detected in a lakecore drawn from the southern end of Lake Titicaca's Lago Grande(Paduano, et al. 2003: 274). The pollen and charcoal record indicates thatforest cover finally disappeared around AD0, coincident with population increases and resource pressure associated with Late Formative Period socio-economic intensification.

The obsidian circulation during the Late Formative shows distinct patterns in the Titicaca Basin and in Cusco. In the Titicaca Basin, the diversity of sources is reduced, with virtually all the material coming from Chivay and Alca, and the Alca samples are primarily affiliated with a single period at Taraco. Even at the site of Qillqatani, the diversity is reduced as compared with the previous Middle Formative level (Qillqatani Formative C). Current evidence suggests that the economic circulation was more integrated and that it was probably under some form of control by the dominant regional centers of this time. The furthest confirmed evidence of Chivay obsidian transport is from among Late Formative contexts at Kallamarka and Khonkho Wankane.Yet, diagnostic evidence from Titicaca Basin Late Formative polities in the Colca valley area is scarce. Part of the difficulty in understanding the Formative at the Chivay obsidian source area is that the Formative ceramic sequence in the Arequipa highlands is still being refined.

Discussion and review of "Early Agropastoralists" obsidian

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

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

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

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

3.5.3.The Late Prehispanic

During the Late Prehispanic period the circulation of Chivay obsidian was subjected to pan-regional forces by expansive Tiwanaku and Wari and again during the Inka period. While obsidian appears to have had fairly consistent use in both the Tiwanaku and Wari domains, the use of obsidian relative to other goods appears to have declined.

/Figs_Ch3/region_LatePrehispanic.jpg

Figure 3-13. Chivay type obsidian distributions during the "Late Prehispanic" time (AD 400 - 1532).

Tiwanaku and Wari (AD400 - 1100)

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

Obsidian consumption at Tiwanaku

Research by Martín Giesso (2000;2003) on the Tiwanaku lithic industry has revealed patterns in the differential use of lithic material in the region. First, it should be noted that obsidian is not abundant in the Tiwanaku core area in terms of the capital of the expansive state. Giesso (2003: 365-366) notes that obsidian artifacts make up only 0.8% of the lithics by count (n=86), of the collections at Tiwanaku. Yet the Tiwanaku core lies 315 km from the Chivay source in Euclidean distance, or 70 hours by the hiking function and therefore while obsidian is relatively scarce, it has been conveyed a considerable distance. The spatial distribution and the artifact form of obsidian at Tiwanaku are more analytically relevant than the total count or weight of obsidian which was quite small. Intrasite data on the contrasts in temporal and spatial use of obsidian at Tiwanaku are critical because, among other things, these data would provide a gauge of the relative persistence of access to the Chivay source as Tiwanaku's regional influence expanded.

Giesso's comprehensive source sampling showed that ten different types of obsidian were in use in the Tiwanaku heartland, although of these ten samples only four samples derive from known source locations. He notes that of the ten obsidian types, only Chivay (Cotallaulli) type is transparent and rest are described as "opaque". Giesso's spatial assessment of the distribution of lithic production activities in the core region showed that obsidian microdebitage was concentrated at certain mounds and in residential sectors as compared with chert, quartzite, and other locally available products. Giesso also organized a sourcing study of basalt artifacts in the Tiwanaku area, and he examined the contexts of production at the Querimita quarry located on the southwestern shores of Lake Poopó in Bolivia (Giesso 2003: 369) just over 300 km south of Tiwanaku. The evidence from Querimita on the production and consumption of basalt provides an interesting regional contrast to the spatial patterning of Chivay obsidian. There are both Wankarani (Formative) and Tiwanaku sites in the vicinity of the Querimita basalt source in the direction of the shores of Lake Poopó, but diagnostic Tiwanaku materials at the quarry itself are not reported (M. Giesso 2006, pers. comm.).

At Tiwanaku, quantities of obsidian and quartz have been found in the construction fill at the ceremonial Mollo Kontu mound, a structure that has served as a local fertility shrine. Nicole Couture argues that "quartz and obsidian fragments also served as mountain icons, in the way that exotic crystals, minerals, and rock candies are used today by Aymara yatiris, or ritual specialists, to represent mountains and thunder in rites to promote agricultural and social fertility" (Couture 2003: 225). Obsidian from Mollo Kontu has been traced to six different sources: Quispisisa, Chivay, Sora Sora, Cerro Zapaleri, and two unlocated sources (Giesso 2000). "The high density of quartz and obsidian artifacts, often five to ten pieces per excavation level, indicates that they were not accidentally included as part of redeposited rubbish, but rather were deliberately added to the clay fill" (Couture 2003: 215). The diversity in the Tiwanaku urban core was such that Chivay material represented a relatively low percentage (76%) of the material, although the ratio of Chivay material in Giesso and Glascock's study on the whole was 90% Chivay, which is typical for the Titicaca Basin. Interestingly, Giesso found that the 19 obsidian samples from the Akapana and Putuni were all transparent samples from the Chivay source, a pattern supported by the ceramics assemblage from those sites that was entirely local. This pattern suggests to Giesso (2003: 368) that a cultural strategy of "ideological purity" was taking place at that location at Tiwanaku due to exclusive use of those particular materials that are perceived as "local" to the Titicaca Basin. Giesso notes that obsidian is found in the form of standardized projectile points, type 4E according to Klink and Aldenderfer (2005), and that evidence of production is found in commoner residential contexts, whereas finished points are often associated with elite ritual contexts. This suggests to Giesso that labor contributions for some segment of the Tiwanaku heartland commoner population may have taken the form of projectile point manufacture.

A comparison of the circulation and use of Chivay obsidian with Querimita basalt strongly suggests to Giesso that the source areas, production, and transport of both exotic materials were controlled by the Tiwanaku state. If so, research at the Chivay source should reveal some evidence of Tiwanaku materials as it did at Querimita, and perhaps research will reveal state mandated standardization of production activities. However, if no evidence of Tiwanaku presence is found at the Chivay source, then this suggests that the relationship between raw material procurement, long distance transport, and state sponsored activities involved a more nuanced relationship between the state and the peripheral economy.

Burger et al. (2000) also analyzed obsidian from Tiwanaku and in their study, from a collection of 18 samples, all from surface contexts, the results were all of the Chivay type. The original Burger and Asaro (1977) study of Bolivian obsidian revealed that three samples purportly from the site of "Sora Sora" were from the Titicaca Basin source, now known as the Chivay source. At 554 km from the Colca Valley this is the furthest reported transport of Chivay type obsidian to date. However, some doubts have arisen as to the spatial origin of these three samples supposedly from the site of Sora Sora (Burger, Dec 2006, pers. comm.), and given the anomalously high transport distance, these three samples are suspect unless additional supporting data become available. The second furthest reported conveyance of Chivay obsidian is 325 km to the Late Formative contexts of Kallamarka and to Khonkho Wankane in Bolivia, as mentioned above.

Obsidian consumption at Wari

At the imperial capital of Wari, obsidian flakes were likewise found in domestic contexts and have been interpreted as "kitchen waste" as no specialized obsidian production sites were found at the site of Wari (Isbell, et al. 1991: 48; contra ;Stone 1983). In the funerary area of Wari known as the Cheqo Wasi sector the obsidian artifacts include a broken knife, 79 flakes (both utilized and unutilized), and two triangular fragments of obsidian with flat surfaces that may have been polished mirrors (Benavides 1991: 64).

At the Wari site of Pikillacta, in the valley of Cusco, evidence from obsidian flakes found in household compounds suggests that obsidian production took place at the household level. In the Haycuchina and Waska Waskan residential clusters, evidence of craft production consists of "waste flakes" of turquoise-colored stone, obsidian, and broken marine shell all collected from the surface (McEwan 1991: 99). Obsidian flakes were found in middens at Pikillacta along with both utilitarian and elite ceramics.

Qillqatani

In Tiwanaku levels at Qillqatani there is a notable decline in the use of obsidian, and of the two specimens analyzed one was of the local low-quality Aconcahua type and the other was Chivay.XFigure 3-7Xreveals that there is a reduction in the percentage of obsidian in the assemblage from this level. In the "debris" category, obsidian falls below 10% for the first time since the Middle Archaic Period. Ceramics were clearly Tiwanaku influenced, but they were relatively poorly made (Aldenderfer in prep.). One may speculate that with the establishment of Tiwanaku colonies in Moquegua, the dominant caravan traffic patterns shifted to an east-west pattern in the Qillqatani area. It is also possible that if the Tiwanaku economic sphere was dominating the circulation of Chivay obsidian, then the material would probably have been conveyed more directly into the Basin and the western cordillera exchange would have been relatively diminished.

The Colca area during the Tiwanaku Period

Relatively little is known about the Colca valley in time periods prior to the Late Intermediate period. The political context of the Colca during this time is intriguing and somewhat ambiguous because the Colca valley lay on the frontier between Wari and Tiwanaku. External cultural influences in the Colca valley proper during the Tiwanaku times appear to have been entirely from Wari, yet Chivay obsidian is not found in Wari sites except in sites with a Tiwanaku component in Moquegua. Given the predominance of Chivay obsidian at Tiwanaku one might expect to encounter diagnostic Tiwanaku material somewhere close to the Chivay source. A number of scholars have commented on the surprising lack of Tiwanaku material in the Colca area given the obsidian distributions in the Tiwanaku heartland (Brooks 1998: 311-313, 454-459;Brooks, et al. 1997;Burger, et al. 1998: 211-212;Burger, et al. 2000: 340-342;).

The geographically closest Tiwanaku sites to the Colca in the department of Arequipa are found on the south-west edge of the city of Arequipa (85 km due south), with the best evidence coming from the site of Sonqonata (Cardona Rosas 2002: 78-87). The Arequipa highlands are largely unstudied, and the closest known Tiwanaku site to the Chivay source on the altiplano appears to be 147 km to the east in the department of Puno at the site of Maravillas just north of Juliaca (Stanish 2003: 189). Tiwanaku sites in this region are generally associated with lakeside agriculture or are found at cross-roads along major travel corridors (C. Stanish March 2006, pers. comm.), and to date no Tiwanaku sites are known in the largely pastoral periphery of the northwestern Lake Titicaca Basin in the direction of the Chivay source. Tiwanaku pottery has been found in Cuzco at Batan 'Urqo (Glowacki 1996: 245) and a Tiwanaku snuff tablet was found at La Real in the lower Majes valley of coastal Arequipa (García Márquez and Bustamante Montoro 1990: 28), but these appear to have been examples of trade goods along the Tiwanaku-Wari frontier.

In the main Colca valley close to the Chivay source, Wari-related ceramics have been excavated from a site just 4 km downstream from the town of Chivay and approximately 10 km from the Chivay obsidian source. A trench excavation exposed red-slipped wares from a domestic context with Tiwanaku Horizon dates in archaeological work associated with the William Denevan's Río Colca Abandoned Terrace Project at the site of Chijra (Malpass 1987: 61;Malpass and De la Vera Cruz 1986: 209, 216;Malpass and De la Vera Cruz 1990: 44-46, 57). Radiocarbon dates associated with these red-slipped wares came from a hearth in a house terrace and produced dates of 1140 ±80 (WIS-1713; AD680-1030) and 1290±90 (QL-4015; AD600-900) (Malpass 1987: 61). This ceramic style has recently been investigated in detail by Wernke as part of his elaboration of the Colca valley ceramic sequence (Wernke 2003: 466-477). Other Wari-influenced sites in the Colca Valley include a large, recently located site in on the north side of the Colca river named Charasuta close to the town of Lari (Doutriaux 2004: 212-223) and the site of Achachiwa near Cabanaconde (de la Vera Cruz 1987;de la Vera Cruz 1988;Doutriaux 2004: 202-207). Curiously, Chivay obsidian is not known to have circulated in the Wari sphere at all despite the proximity of these sites to the Chivay source.

In the main Colca Valley, indications of Wari ideological and stylistic influence are the strongest evidence for external links during the Tiwanaku Horizon. In addition to Wari influences at Chijra and Charasuta, the site of Achachiwa provides intriguing evidence of exotic obsidian intruding into the Colca valley. Achachiwa is a large site adjacent to the modern town of Cabanaconde that has a large Middle Horizon component that appears to be Wari influenced, as well as components belonging to a the local LIP occupation and an Inka occupation (de la Vera Cruz 1987;de la Vera Cruz 1988;Doutriaux 2004: 202-207). Brooks reports that she collected seven obsidian flakes for analysis from Achachiwa that were visually distinct from obsidian she had encountered elsewhere in the Colca (Brooks 1998: 447). Of these seven flakes, none were of Chivay type obsidian although the site is only 46 km downstream of the source. Her analysis showed that six of the flakes were from the Alca source (96 linear km away) and one was from the Quispisisa source (300 km away), a strongly asymmetrical pattern that is non-the-less consistent with Middle Horizon obsidian distributions in southern Peru.

Discussion

Chivay obsidian distributions during the Tiwanaku period are somewhat of an enigma. As Tiwanaku persisted for longer than Wari one might expect Tiwanaku evidence at the Chivay source either preceding or simultaneous with Wari presence in the Colca valley. However, the nature of procurement and distribution of Chivay obsidian during the Tiwanaku period was such that diagnostic materials from the consumption zone do not appear at the Chivay source. There appears to have been considerable nuance in the relationships between state leaders, corporate integration, and ethnic local kin-based groups during the period of Tiwanaku hegemony. Groups living in the Tiwanaku peripheral areas were perhaps consistent with Dillehay's characterization as"…a patchwork of overlapping, geographically disparate, and apparently politically semi-autonomous core valleys, oases, and plateaus or foci of cultural development, each of which primarily exploited its own immediate peer area"(Dillehay 1993: 247). Along these lines,Stanish (2002: 188) notes that early states appear to have "selectively incorporated certain areas around the basin" rather than attempt comprehensive control. John Janusek summarizes a variety of evidence demonstrating that "Tiwanaku was an incorporativemore than it was a transformativestate, simultaneously employing multiple strategies of regional control and influence" (Janusek 2004: 162), along the lines of corporate political strategies described by Blanton et al.(1996). Accordingly, a direct correlation between the predominance of Chivay obsidian in the Tiwanaku economy and clear, material evidence of incorporation in the archaeological remains of communities in the Chivay source area should not be expected. The political affiliation of Colca valley communities was probably made more complex due to the presence of the Wari frontier during the Middle Horizon.

The asymmetrical, export-only exploitation is consistent with a pattern that has been observed at a number of prehispanic obsidian sources in the Andes. Obsidian sources generally have few diagnostic artifacts or architecture in association with quarrying. It was mentioned earlier that Formative distributions of Alca obsidian were strikingly asymmetric with export to long distance consumption sites but no corresponding diagnostics from those consumers back at the Alca source (Burger, et al. 2000: 314, 323). Similarly, the Quispisisa source has little diagnostic evidence the immediate vicinity linking the source to Wari or any other known group, despite the long history of use of that obsidian type in Wari sites (Burger and Glascock 2000;Burger and Glascock 2002). The asymmetrical nature of Chivay obsidian use during the time of Tiwanaku and Wari is, therefore, consistent with a pattern apparent at raw material sources elsewhere in the Andes where obsidian procurement does not involve reciprocation or discard of diagnostic artifacts from the consumption zone.

Late Intermediate Period (AD1100 - 1476)

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

Chivay obsidian during the LIP

In a review that considers the LIP and Late Horizon together in one discussion, Burger et al.(2000)note the declining presence of obsidian in most LIP and LH contexts in the region. Many of the chemically provenienced obsidian samples from the Titicaca Basin come from surface contexts with either LH or LIP associations, and the pattern revealed in the Titicaca Basin from these samples is one of almost exclusive use of Chivay type material. One of the reasons for the strong presence of Chivay obsidian over Alca obsidian may have resulted from cultural affinities between Aymara groups(Browman 1994). The Colla in the North Titicaca Basin and the Collagua in the upper Colca area share many traits including the construction of pukaras(Wernke 2003: 262-263), mortuary features including chulpaburial structures and fiber-wrapped mummy encasings(de la Vega, et al. 2005;Wernke 2003: 225-234), and other commonalities.

In the northern Lake Titicaca Basin, Arkush(2005: 247)notes that two-thirds of the occupied pukaras throughout her survey area contained obsidian on the surface, and that chert flakes and blades are common. In one instance, at Calvario de Asillo (AS1) prepared obsidian cores and a concentration of flakes was encountered. Obsidian projectile points were small, triangular base-notched points (series 5), consistent with the Klink and Aldenderfer point typology for the Terminal Archaic and onwards(Arkush 2005: 709-711). Metal objects are common as well, with copper and copper-alloy pendants and tupus(long pins) frequently found at pukaras.

Six obsidian samples from the mesa-top pukaraand chulpaburial tower complex of Cutimbo were analyzed by Frye et al.(1998)and the samples were 100% from the Chivay source. Burger et al.(2000: 343-344)indicate that one obsidian sample from the renowned chulpacomplex of Sillustani was also from the Chivay source. Burger et al. observe that while a single Alca flake was excavated at Taraco from an LIP context, and another was found on the surface at the LIP or LH site of Kolkeparke near Ayaviri(Burger, et al. 2000: 343), the Titicaca Basin is otherwise entirely supplied from the Chivay source during the LIP.

At the rock shelter of Qillqatani (SectionX3.4.2X) a large percentage (15.4%) of the tools from LIP levels were made from obsidian, although the count is very low (n = 2) and the tools were extremely small. The single obsidian sample that was analyzed proved to be from the Chivay source.

In the south-western Lake Titicaca area, Hyslop(1976: 118-119)found that the Lupaqa sites he encountered in the course of his road system survey contained primarily basalt and quartzite flaked stone. More recent survey work in the Ilave and Huenque drainages(Klink and Aldenderfer 1996)found that high-quality cherts are abundant in the region, which suggests that the prominent use of basalt at the sites Hyslop encountered was by choice, not by necessity, and was perhaps a reflection of lakeshore agricultural activities.

Late Horizon (AD1476-1532)

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

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

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

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

Discussion and review of "Late Prehispanic" obsidian

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