0 geoarqueologia (grosjean y núñez)

Lateglacial, Early and Middle Holocene Environments, Human Occupation, and Resource Use in the Atacama (Northern Chile)

Martin Grosjean" Department of Soil Science, University of British Columbia, Vancouver, B.C., Canada V6TlZ4

Lautaro Nunez A. Instituto de Investigaciones Arqueolbgicos y Museo, Universidad Catdlica del Norte, San Pedro, Chile

Paleoenvironmental data from the Atacama Altiplano (21"-24"S) indicate that water, vegetation and animal resources were more abundant during lateglacial and early Holo- cene times than today. The rate of precipitation increased above 4000 m elevation to 400-500 mmlyr compared to the present 200 mm/yr. Dry conditions prevailed below 3500 m. Evidence of Paleoindian habitation is still missing, even though there is no evidence for environmental prohibitors during lateglacial time. The early Archaic hunters (10,820 yr B.P.-ca. 8500 yr B.P.) inhabited the Altiplano (high Puna) and its western slope, where water was available due to higher river runoff from the Altiplano, and the resources in different elevation zones were accessible. Natural resources decreased significantly during the middle Archaic period (8500-ca. 5000 yr B.P.). Lakes receded to today's levels, pedogenesis in the Altiplano terminated, and human activities were restricted to the most stable sites in the Rio Lao and the Rio Purifica catchments north of 23"s. The less stable oases south of 23"s (Salar de Atacama and Punta Negra) were abandoned. The climatic changes are best explained by shifts of the (sub)tropical circulation. Q 1994 John Wiley & Sons, Inc.

INTRODUCTION In areas with marginal food and water supplies, the rapid and fundamental

environmental changes were primary driving forces in the subsistence of hunting and gathering cultures. Their capacity for buffering the fluctuations in the potential natural resources was limited. In this context, the Atacama desert provides with its former lakes, peat bogs, glacial deposits, paleosols and archaeological sites a variety of archives to study the interaction between man and his environment since the first human habitation about 10,800 yr B.P.

* Present address: Department of Physical Geography, University of Berne, Hallerstrasse 12,3012 Berne/Switzerland.

Geoarchaeology: An International Journal, Vol. 9, No. 4, 271-286 (1994) 0 1994 by John Wiley & Sons, Inc. CCC 0883-6353/94/040271-16

HUMAN OCCUPATION IN THE ATACAMA, NORTHERN CHILE

Today, this extremely dry area is located between the tropical and extratropi- cal circulation belts, and is, therefore, most sensitive to climatic changes. Even the smallest shifts in the precipitation regime effected significant changes in the water budget of lakes, and in pedogenesis, vegetation, and animal resources. Under the current, hostile climatic conditions, all lakes are dry or highly saline (Salars), vegetation is too scarce to initiate any substantial pedogenesis, groundwater recharge is limited, and there are no glaciers even in the continuous permafrost belt above 5800 m elevation.

Rapid and fundamental changes took place in the Central Andes during the transition from Pleistocene to Holocene. Glaciers retreated (Seltzer, 19901, vegetation began to regroup (Fernandez et al., 1991), animal extinction rate increased, and man began to occupy the dry Andes in Peru, Southern Chile, and Patagonia (12,560 yr B.P. Guitarrero Cave, 12,600 yr B.P. Los Toldos Argentina; and 12,000-13,000 yr B.P. Monte Verde; Lynch et al., 1985). As in other mountains of the world, the vertical zonation and the strong interaction between climate and topography determined the pattern of human resource use. Vertical gradients dominate the climate, vegetation, hydrology, etc., and therefore a broad variety of ecotopes was accessible within a short distance. This is one important key to understanding the very efficient, seasonal, and vertical transhumance in the past, including the high Puna and the dry, western foot zone. This system persists today in some areas of Bolivia (Lauer and Erlenbach, 1987), Peru (Lynch, 1973) and northern Chile (Nuiiez, 1992).

Whereas human habitation on the western slope of the Atacama Altiplano is relatively well known (Ntinez and Santoro, 1988,1990; Lynch, 1990; Nufiez, 1992) detailed information about the paleoclimatic conditions since lateglacial times is sparse. The environment during habitation had to be inferred from the adjacent areas in Bolivia, Argentina (Fernandez et al., 1991), or semiarid Chile (Veit, 1991). Recent paleoenvironmental studies in the interior of the Salar de Atacama (Figure 1) have brought some insight into the dynamics of natural resources in space and time with the respective paleoclimatic implications (Grosjean et al., 1991; Messerli et al., 1993; Grosjean, in press).

The aim of this study is to present a synthesis of the lateglaciallearly Holo- cene environmental conditions and to discuss the man-environment relation- ship for the early Archaic period (10,800-8500 yr B.P.) in the light of these new data. Earlier studies in the same area (Lynch, 1986, 1990; Lynch and Stevenson, 1992) are supported and/or modified. The scope of our study is determined by two key questions: (1) Why is there no Paleoindian occupation associated with late Pleistocene fauna despite humid lateglacial conditions in the Altiplano?, and (2) Why were the early Archaic sites in the Salar de AtacamalPunta Negra catchment (Tuina, Tul An, and Punta Negra) abandoned during the middle Archaic period (“Silencio archeol6gico”)? And why, in contrast, did human occupation persist further north in the Rio Loa valley? Were the environmental conditions in the Atacama basin during middle Holocene so hostile that they limited human occupation?

272 VOL. 9, NO. 4


Figure 1. Map showing the research area and the archaeological sites mentioned in the text.

METHODS In reconstructing the paleoenvironment in this dry and cold environment,

emphasis was put on the chronological control and on cross-correlations of hydrological, limnological, pedological, palynological, and glaciological proxy- data. This multiproxy mapping was carried out in different altitudinal belts from the Salar de Atacama (2400 m) to the Altiplano (4500-6700 m) in order to evaluate vertical gradients in the environment.

Paleohydrological information was obtained from water budgets of paleo- lakes in the Altiplano, where fossil shorelines were mapped and correlated

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL 273


with key sediment strata and facies of known age. A water and energy budget model was used to derive paleoclimatic scenarios from the history of the lake levels in the case study catchment of the Laguna Lejia (Grosjean, in press). Pollen, ostracode, and diatom data from lake sediments (Messerli et al., 1993; Grosjean, in press) provided information about local vegetation, long distance transport of pollen, and paleolimnological data. Radiocarbon dating was used on aquatic organic matter (total organic fraction with accelerator mass spec- trometry AMS) and on inorganic carbonates. Thermoluminescence dating was used on the 4-12 pm polymineral fraction of volcanic ash layers and slope debris (Burgi, 1992). The spatial distribution and development of the early Holocene paleosol was mapped in vertical transects on the western slope of the Altiplano (Schreier et al., in prep.). This brought insight into the regional, long-term climatic pattern and the vertical shifts of the vegetation belts, as manifested in the degree of physical and biological weathering.

The archaeological investigation included the Altiplano, its western slope, and the Atacama basin. Emphasis was put on a transect in the Quebrada Tu lh , where the Atacama basin and the adjacent Altiplano are connected by a series of sites. The radiocarbon dates cover a subregional, Archaic sequence from 10,820 14C yr B.P. to 4050 14C yr B.P. Information about the pattern of mobility, the subsistence mode, and the adaptation to resources in space and time was obtained by petrographic and functional analysis of artifacts, bones, macroscopic organic remains, and various chronostratigraphic tests.

LATEGLACIAL ENVIRONMENT, PALEOINDIAN PERIOD (CA. 17,000-CA. 11,OOO YR B.P.)

(See also synthesis in Figure 5. ) The lateglacial time was characterized by moist and cool climatic conditions.

Kessler (1991) and Markgraf (1989) proposed a southward shift of the tropical (summer) circulation to explain the wet conditions in the Central Andes. This is in agreement with paleoecological evidence between 21" and 24"S, where precipitation rates of up to 400-500 mm/yr (compared to <200 mm/yr today) is inferred from former lake levels of the Laguna Lejia in the Altiplano (Gros- jean, in press). Three independent energy and water budget models (Hastenrath and Kutzbach, 1985; Kessler, 1985; Grosjean, in press) suggest that the large lakes were not merely the result of a temperature depression or of melt water due to rapid deglaciation. An increase in the precipitation rate in the order of 200-300 mmlyr and a reduction of the evaporation rate due to higher cloudiness was necessary. Studies on the Pleistocene snowline between 25" and 27"s (Fox and Strecker, 1991) and on lateglacial paleosols in semi-arid Chile (Veit, 1991) coincide with paleolimnologic, glaciologic and pedologic evidence from the Ata- cama Altiplano at 21"-24"s (Messerli et al., 1993): It is suggested that the westerly stormtracks remained stable at 27"-29"s whereas the tropical, monsoonal summer circulation shifted southward at least as far as 24"s. These

274 VOL. 9, NO. 4

HUMAN OCCUPATION IN THE ATACAMA. NORTHERN CHILE

Table I. Current and lateglacial maximum lake surfaces. Data from digital elevation models (aero photogrammetry), Pampa Punta Negra: Topographical map 1 : 50,000.

Lake Surface Lejia Tuyajto Miscanti/Mixiiques/ Pampa Aguas [km*, mas11 4325 4040 Varela Punta Negra Calientes 1

4150 4350 4200 Present 1.9 2.7 14.0 Lateglacial 10.8 14.6 35.6

- 2.5-6.7 <6 28.8*

Maximum Factor: 5.7 x 5.4 2.3 4.3-11.5

* Spillway into Salar Quisquiro.

new data support the reinterpretation of the lateglacial wet phase in the Salar Punta Negra (Lynch, 1990).

The increased precipitation rate and the reduced evaporation rate due to higher cloudiness produced large freshwater lakes (“lake phase”) with sediment deposits in the presently arid Altiplano above 4000 m. No comparable lake sediments could be found below 3500 m in the Salar de Atacama/Punta Negra depression. Several high elevation basins with similar catchment parameters to the Laguna Lejia show a similar lake evolution. The water surfaces of these lakes were up to 6 times greater during the maximum stage than at present (Table I). This suggests that the lake phase was of regional significance for the Altiplano between 21”-24”S, synchronous and genetically related to the Tauca phase in Lake Titicaca.

The up to +25 m higher lake levels in the Laguna Lejia lasted throughout lateglacial times, bracketed by 16,715 2 195 14C yr B.P. (Hv-17806, carbonate fraction interpreted as maximum age) and 11,700 f 110 14C yr B.P. (ETH- 61791, total organic fraction). In other lakes, the highest shorelines are marked by stromatolites, giving ages for the maximum lake phase of 13,160 80 14C yr B.P. (Beta-63356, Salar Aguas Calientes I) and 11,300 * 70 14C yr B.P. (Beta-63353, Salar Ollagiie at 21”s). Laminated carbonates were still being precipitated in the Salar Aguas Calientes I after 10,400 * 75 14C yr B.P., suggesting persistently high lake levels during ca. 3000 years. The basal deposits in the Salar de Tuyajto (12,020 t 95 14C yr B.P. UZ-2667/ETH-7371) also confirm the lateglacial age of the lake phase. Based on these features, we conclude abundant water resources in the Altiplano with larger river discharge to the foot zone, higher groundwater tables and some open-water bodies in adjacent basins on the western slope. This is in agreement with earlier studies on lateglacial groundwater formation in the Atacama basin and in the Pampa de Tamarugal (Fritz et al., 1979). We found no evidence, however, for the lateglacial age of the large lakes in the Salar Punta Negra depression as described by Lynch (1986).

Due to their water storage capacity, glaciers played a major role in buffering the short-term fluctuations in the water budget. Direct ages for the widespread



3 Q r.

S.OC0EZ I

-1

I S.OC"cZ

S.OE cz

I I S.OC,,EZ

S.OCeEZ

I I

-1

Q 0

5 In 0 Y m -

I

276 VOL. 9, NO. 4


glacial features in the Altiplano are not yet available. We believe that they are related to more humid conditions under tropical influence during lateglacial times. This is based on the following considerations: (1) Glaciers in permafrost environments like the high Andes are most sensitive to changes in precipitation, (2) the lowest moraines descend equatorward from 4900 m at 24"43'S to 4200 m at 22'23's (Messerli et al., 19931, (3) widespread Pleistocene glaciation in the Ojos del Salado area at 27% is lacking, and (4) there are lateglacial glacier advances further north (Clapperton, 1990; Seltzer, 1990). The equilibrium line, which no longer exists, was as low as 4650 m (Co. Pajonal, 22'30'S, Messerli et al. 1993) in the Atacama area, suggesting that most of the volcanoes were covered by ice. This considerable volume of water in frozen storage may have provided the lowlands with a stable water supply. Such a supply would have been of extreme importance for any human inhabitants.

Lateglacial vegetation cover was scarce in the Altiplano. Increasing amounts of Gramineae, Compositae and Chenopodiaceae pollen were found in the sediments younger than ca. 15,000 yr B.P. in the Salar de Tuyajto and Laguna Lejia (Graf, 1992; Messerli et al., 1993). This suggests temperatures slowly increasing after the last global cold maximum. Evidence for persistently cool conditions is also found on the eastern slope of the Altiplano at Barro Negro (23'S/65'37W/3820m; Fernandez et al., 1991), which was probably the main constraint for dense vegetation in the Altiplano. Records for vegetation cover in the foot zone are still scarce. But in light of the regional water budget with higher river discharge and shallow groundwater tables, vegetation in the Atacama depression (Prosopis juliflora and Geoffrea decorticans; Ochsenius, 1986) was probably abundant and was a sustainable fodder supply for the Pleistocene fauna (Table 11).

The lack of human Paleoindian occupation associated with Pleistocene fauna in the Atacama (Nunez, 1983; Lynch, 1990; Nuiiez and Santoro, 1990:88) is still puzzling. As discussed before, there is no evidence for hostile environmental conditions in the subtropical Andes, and the concentration of Pleistocene fauna in areas of higher elevation must have been considerable (Phillippi, 1893; Casamiquela, 1969-1970; Ochsenius, 1986; Fernandez et al., 1991). However, the discovery of a few lithic artifacts (Fig. 4 in Nunez, 1983) still leave open the possibility of Paleoindian occupation in the Atacama. But these finds have not been documented as well as in the central-south Andean area (Nuiiez and Santoro, 1990; Lynch, 1990).

EARLY HOLOCENE ENVIRONMENT, EARLY ARCHAIC PERIOD (11,000-8500 YR B.P.)

(See also synthesis in Figure 5.) Humid conditions prevailed in the Altiplano during early Holocene times

with up to 400 mm/yr summer precipitation compared to 200 mm/yr today (Grosjean, in press). High lake levels are reported for the Salar Aguas Calientes I, where laminated carbonates were still being precipitated after 10,400 ? 75



Table 11. Pleistocene fauna in North-Central Chile and adiacent areas. ~

Site ~ ~

Time Species 14C yr B.P.

~~

Reference

Pampa de Tamarugal Late Pleistocene Megatherium Scelidon Macroauquenia Equus

Barro Negro 3820 m 12,530 f 160 Hippidion sp. 10,200 * 140 Hippidion sp.

Quereo 11,400 2 155 Mastodont (Cuvieronius sp.)

Equus sp. Ciervo (Antifer sp.)

Camelidae Mylodon sp.

Ciervo (Antifer sp.)

(C. humboldti)

Tagua Tagua 11,000 f 170 Mastodont, Equus

10,120 * 130 Mastodont

Casamiquela, 1969-1970 Casamiquela, 1969-1970 Casamiquela, 1969- 1970 Casamiquela, 1969-1970 Fernandez et al., 1991 Fernandez et al., 1991 Nufiez et al., in press

Nufiez et al., in press Nufiez et al., in press

Nufiez et al., in press MontanB, 1972 MontanB, 1972 Ndfiez et al., 1992

14C yr B.P. (carbonate fraction interpreted as maximum age due to hardwater effect). But the diatom assemblages in the sediments of Laguna Lejia suggest increasingly saline water due to high evaporation and long-term enrichment processes in the still large water body.

An early Holocene paleosol on the eastern slope of the Atacama basin between 4000 and 4800 m is interpreted as additional evidence for stable, humid conditions in the Altiplano. The paleosols above 4000 m show a higher concentration of active FecBD, a slightly different clay mineralogy, a more advanced development of soil horizons, and a very weak Ahb horizon. These indicate dense vegetation and considerable biological and physical weathering (Messerli et al., 1993; Schreier et al., in prep.). The best soil development is found at 4500 m, i.e. 500 m above the current maximum vegetation line. Given the humidity control of the lower limit of the vegetation belt, the temperature control of the upper limit of the vegetation belt, and a temperature gradient of 0.7"C/lOO m, we suggest a (summer) temperature increase of about 3.5"C. Regarding the age of the paleosol, only indirect dating has been successful so far: The pedogenesis is postglacial and terminated prior to ca. 7400 yr B.P. (Schreier et al., in prep.). Moreover, the I1 B, horizon is related to the uppermost, early Holocene lake terrace and is associated with early Archaic artifacts (Figure 3). Therefore, we conclude an early Holocene age of pedogenesis. Again, the vertical distribution of these soils indicates that the high Andes were an area with optimum environmental conditions for human habitation. This coincides with early Holo- cene groundwater formation as reported for San Pedro (Fritz et al., 1979540). The contribution of large, melting permafrost bodies to the regional water supply during the temperature increase is still a matter of debate.

278 VOL. 9, NO. 4

A

23O

4O.s

43

50

m

23O

42.S

-

7

67O

28'W

67

O26

'W

late

gla

cia

l la

ke

su

rfac

e

tria

ng

ula

r IC

- a

rte

fac

ts -bl

B

I

+B,h

ori

zon

4

I

max

imu

m la

ke

leve

l

earl

y H

olo

ce

ne

wat

er le

vel

I &.

. . . * - .

. . . . .

. . . . . . -

- - . . . . J

Figure 3. L

ateg

laci

aVea

rly H

oloc

ene

lake

Pam

pa P

unta

Neg

ra a

nd p

rofil

e sec

tion

with

pal

eoso

l Bm

and

lith

ic a

rtifa

cts o

n th

e up

perm

ost t

erra

ce.


P

- 5000- -

6000 - al 5

7000-

8000-

- y

-

z 9000-

>. b D 10.000

g

11,000-

y, B.P. I Atacama Basin

- I m a .- L

i **

'Silencio Arqueologico'

I

Loa/Puripica - i I I i i

a n .- .-

Figure 4. Chronosequence of archaeological sites in the Rio Loa and Atacama basin between 11,000 and 4000 yr B.P.

Despite warmer and moister conditions, tree growth was limited to lower elevations in the Atacama depression. There is no evidence for Prosopis sp. and Geoffrea juliflora in quebradas above 3000 m.

The early Holocene warm/moist conditions seem to be linked to the southward shift of the tropical circulation with summer rainfall. Most likely, this was concomitant with the southward shift of the Panamic Province in the east Pacific (Rollins et al., 1986), which brought warm tropical waters as far south as Antofagasta between 9680 5 160 14C yr B.P. and 9400 +_ 160 I4C yr B.P. (Llagostera, 1979:314).

As shown in Figure 4, the earliest clear evidence for Archaic human occupation is found in Tuina-l(10,800 yr B.P.), San Lorenzo (10,400 yr B.P.), Chulqui- 1 (9600 yr B.P.), TulAn-68 (9300 yr B.P.), Tambillo-1 (8870 +_ 70 14C yr B.P., Beta-63365), and Salar Punta Negra (Sinclair, 1985; Nude2 and Santoro, 1988; Lynch, 1990; Lynch and Stevenson, 1992; Nufiez, 1992). Summer precipitation and warmer temperatures were favorable for animal life, and consequently, the Altiplano provided excellent conditions for seasonal hunting of modern camelids, birds, and rodents. River runoff and groundwater supply provided living, gathering, and hunting space in the quebradas and the oases of the foot zone during the winter. Although there are still no radiocarbon ages available for human occupation in the Altiplano, the association of high early Holocene lake levels, soil formation and early Archaic human occupation is obvious:

280 VOL. 9, NO. 4


Typical, early Archaic, triangular, lithic artifacts and soil formation (I1 B,) are only found on the uppermost lake terrace, whereas there is no evidence for these features below the early Holocene water line. For example, Figure 3 shows the present day dry basin of the Pampa Punta Negra. The same pattern is found in the Laguna Lejia, Salar Aguas Calientes I, and Lagunas Miiiiques/ Miscanti.

Almost identical, triangular, lithic artifacts in the Altiplano, in the adjacent Quebradas and in the Atacama basin (eg. Aguas Calientes I at 4100 m and Tambillo at 2400 m) are evidence for seasonal, vertical mobility of early Archaic societies. Primary lithic material is found on the entire transect. This shows that shifting areas of resource use was the principal strategy for subsistence during early Holocene. In summertime, fresh and dried meat was transported from the Altiplano (4500 m) down to lower quebradas and the Atacama basin (2400 m), where cactaceae and trees provided complementary food resources, and where alternative and additional pasture was available for camelids during winter (Nufiez, 1992). The beginning of human occupation in the Atacama was contemporaneous with the first dated lithic artifacts in the adjacent areas at Inca Cueva and Huachichocana (Aschero, 1983; Fernandez-Distel, 1974) where the subsistence mode was similar to that of Tuina involving seasonal circum- puna transhumance (Yacobaccio, 1983). In all of these sites, there is only evidence for modern fauna (mainly camelids). This suggests that the Pleisto- cene fauna had already disappeared. Whatever the reason for their disappear- ance, there is evidence for a relation between extinction of fauna and fundamental changes in the vegetation at the end of the Pleistocene, as reported from Barro Negro in NW Argentina (Fernandez et al., 1991).

MIDDLE HOLOCENE ENVIRONMENT, MIDDLE ARCHAIC PERIOD (SILENCIO ARQUEOLdGICO) 8500-5000 YR B.P.

(See also synthesis in Figure 5.) The Aguas Calientes I lake receded to today’s level at about 8400 yr B.P.

(Grosjean, in press), slightly earlier than the attainment of low lake levels in Lake Titicaca at 7700 yr B.P. (Wirrmann and De Oliveira Almeida, 1987). Soil formation was terminated before ca. 7400 yr B.P. (Schreier et al., in prep.; Messerli et al., 1993). These findings suggest a shift to generally drier conditions with decreasing water, vegetation, and animal resources towards middle Holocene. Evidence for episodic, fluvial-torrential sedimentation is found in the Quebrada Puripica, north of the Salar de Atacama: More than 20 middle Archaic fireplaces between 6460 ? 230 14C yr B.P. (Beta-63366) and 5300 ? 100 14C yr B.P. (Beta-63360) are embedded in clastic sediments that represent single storm events. This in turn suggests generally dry conditions, with heavy and highly variable rainfall and poor erosion control on the adjacent slopes. These storms may also have caused the temporal floodings in the dry Salar de Atacama. Radiocarbon-dated charcoal in clayhilt deposits in a profile pit

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL 28 1


Figure 5. Environment and human occupation on the western slope of the Atacama Altiplano (22”-23”S) during lateglacial, early, and middle Holocene.

between San Pedro and Tulor yielded an age of 5605 2 65 14C yr B.P. (ETH- 58481, which fits well to the episodic deposits in the Quebrada Puripica.

The generally increasing aridity towards the thermal optimum is also con- firmed for Quereo (N~fiez et al., in press), for Barro Negro in NW Argentina (Fernandez et al., 1991) and in Lake Titicaca (Wirrmann and Oliveira, 1987). This seems, therefore, to be a regional phenomenon which was probably related to a northward shift of the (sub)tropical summer circulation (= monsoonal circulation), an increasing influence of the southeast Pacific anticyclone SPH, and the onset of the Humboldt current (Rollins et al., 1986; Enfield, 1989).

During these fundamental environmental changes, only the sites with the most stable water resources (e.g. Rio Loa, Rfo Puripica) show continuous, middle Archaic habitation. But most of the sites south of the Rio Loa were based on environmentally more sensitive resources, and were abandoned (Figure 4). So, there is evidence for the climatically induced “Silencio Arqueolbgico” in the southern part of our research area, i.e., in the Salar de Atacama (Nufiez, 1992) and in the Salar Punta Negra (Lynch and Stevenson, 1992). In the northern part, i.e., in the Rio Loa, Rfo Puripica, and in the Rio Toconce area, as well as in southern Peru (Aldenderfer, 1988), the middle Archaic habitation continued.

282 VOL. 9, NO. 4


Even in the northern part of the area, seasonal mobility was restricted to a few preferred pathways with isolated, but stable resources. This is the case between Chiuchiu at 2400 m, Puripica at 3400, and the upper Loa valley in the altoandean Puna (Druss, 1977; Nufiez, 1992). There is evidence for the beginning of domestication of camelids in the Atacama region after 4800 yr B.P. (Hesse, 1982a, b; Nufiez, 1989) and for the initial expansion of horticulture towards the end of the middle Archaic period (Yacobaccio, 1983). The subsistence economy was clearly oriented towards greater independence from short- term fluctuations in water, vegetation, and animal resources. Thus, the de- crease of natural resources can be seen as a major driving force for the transfor- mation of the early Archaic hunting and gathering society. Animal domestication, pastoralism, agriculture, and later ceramics were necessary adaptations to the harsh environmental conditions during the late Archaic reoccupation (phases Tuldn and Tilocalar).

SYNTHESIS AND CONCLUSIONS New data for the paleoenvironmental conditions in the Atacama indicate

the importance of the vertical zonation of natural resources. This was most important for human occupation and economic patterns during early Holocene time. While increased summer precipitation rates were spatially restricted to the Altiplano, the Atacama basin benefited from a higher river runoff and groundwater supply from the highlands. This highland-lowland interaction between several altitudinal belts formed the ecological base for the early Ar- chaic hunters. They settled exactly on those sites that provided easy access to various ecozones and resources in different seasons within a short distance between the Atacama basin and the Altiplano: Tuina and San Lorenzo, Toconce- Confluencia, Tambillo, and Tuldn.

Abundant water and animal resources were available at the end of the Pleistocene, and there is no evidence for an environmental prohibitor. There- fore, the lack of Paleoindian human occupation is enigmatic and remains the subject of further inquiry.

The impact of the changing environment on the interaction between man and nature at the end of the early Archaic period is evident. Technologies and strategies were not yet available to sustain or to adapt to a crisis in natural resources. Consequently, human occupation continued only in the most stable oasis north of the Salar de Atacama, whereas other early Archaic sites south of 23"s were abandoned. This resulted in a regional, temporary hiatus until ca. 4800 yr B.P., when domestication of camelids became common and fluctuations in resources could be buffered.

In the context of climatic changes, we emphasize the role of the monsoon circulation in subtropical areas. With our present knowledge, the tropical precipitation belt shifted south about 8"-10" latitude. For example, the 400 mm/yr isohyet that is presently located at Lake Titicaca (ca. IS'S), moved as far as 24"s during lateglacial and early Holocene times. This in turn produced



the favorable, moist conditions in the Altiplano, and provided living space for the early Archaic hunters. If this were the case, then it was also the northward retreat of the monsoon circulation to its present position that produced the unstable conditions with the “Silencio Arqueolbgico” in the fragile south. In this area, resource response to changing climate was particularly sensitive. And in contrast to the higher latitude areas, where changes in temperature were dramatic over time, it seems to be the change in precipitation which is critical in the (subltropical areas. The last word in the interpretation of the paleocirculation has not yet been spoken. Although the data from all the different archives become increasingly consistent, a detailed chronology with knowledge of the spatial extent and the rates of the changes is still lacking.

This article is a fist synthesis of the Swiss National Science Foundation project (NF 21-27 824.89) and the Chilean Science Foundation project (FONDECYT No. 1930022). We especially thank the members of our multidisciplinary team, who contributed their results and helped to synthesize the data: B. Messerli, M. A. Geyh, K. Graf, K. Ramseyer, U. Schotterer, H. Schreier, M. Vuille. We thank Sylvia Welke, Thomas, and Christina for field assistance. Logistical support and research permission was kindly provided by Willi Egli, Hugo Romero A., and Marcela Espinoza N. (DIFROL).

REFERENCES Aldenderfer, M. (1988). Middle Archaic Period Domestic Architecture from Southern Peru. Science

241,1828. Aschero, C.A. (1983). El Sitio ICc-4: Un Asentamiento Precerhmico en la Quebrada de Inca Cueva

(Jujuy, Argentina). Estudios Atacamefios 7, 62-72. Biirgi, A. (1992). Aufbau und Betrieb eines Thermolumineszenz-Labors zur Datierung quartar-

geschichtlicher Proben. Ph.D. Dissertation, Bern: University of Bern. Casamiquela, R. (1969-1970). Primeros Documentos de la Paleontologia de Vertebrados para un

Esquema EstratigrAfico y Zoogeogrhfico del Pleistoceno de Chile. Boletln Prehistorfa de Chile

Clapperton, C.M. (1990). Quaternary Glaciations in the Southern Hemisphere. Quaternary Science

Druss, M. (1977). Computer Analysis of Chiu-Chiu Complex Settlement Pattern. El Dorado 2,

Enfield, D.B. (1989). El Nifio, Past and Present. Review ofGeophysics 27, 159-187. Fernandez, J., Markgraf, V., Panarello, H., Albero, M., Angolini, F., Valencio, S., and Arriaga,

M. (1991). Late Pleistocene/Early Holocene Environments and Climates, Fauna and Human Occupation in the Argentine Altiplano. Geoarchaeology 6, 251-272.

Fernandez-Distel, A. (1974). Excavaciones en las cuevas de Huachichocana, Dep. de Tumbaya, Prov. de Jqjuy. Relacwnes de la Sociedad Argentina de Antropologfa 7,101-127.

Fox, A.N., and Strecker, M.R. (1991). Pleistocene and Modem Snowline in the Central Andes (24-28”s). Bamberger Geographische Schriften 11,169-182.

Fritz, P., Silva, C.H., Suzuki, O., and Salati, E. (1979). Isotope Hydrology in Northern Chile.

Graf, K. (1992). Pollendiagramme aus den Anden. Eine Synthese zur Klimageschichte und Vegeta- tionsentwicklung seit der letzten Eiszeit. Schriftenreihe Physische Geogruphie 34,l-138. Uni- versitat Zurich.

Grosjean, M., Messerli. B., and Schreier H. (1991). Seenhochstande, Bodenbildung und Vergletsch- erung im Altiplano Nordchiles: Ein interdisziplinarer Beitrag zur Klimageschichte der Ata- cama. Erste Resultate. Bamberger Geogruphische Schriften 11,99-108.

2-3(2), 65-73.

Reviews 9, 121-304.

51-73.

IAEA-SM-228/26,525-543.

284 VOL. 9, NO. 4


Grosjean, M., (in press). Paleohydrology of the Laguna Lejia (Northern Chile) and Climatic Implica-

Hastenrath, S. and Kutzbach, J.E. (1985). Late Pleistocene Climate and Water Budget of the

Hesse, B. (1982a). Animal Domestication and Oscillating Climates. Journal of Ethnobiology 2,

Hesse, B. (198213). Archaeological Evidence for Camelid Exploitation in the Chilean Andes. SLiuge- tierkundliche Mitteilungen 30, 201-211.

Kessler, A. (1985). Zur Rekonstruktion von spatglazialem Klima und Wasserhaushalt auf dem peruanisch-bolivianischen Altiplano. Zeitschrift fur Gletscherkunde und Glaziologie 21,

Kessler, A. (1991). Zur Klimaentwicklung auf dem Altiplano seit dem letzten Pluvial. Freiburger Geographische Hefte 32, 141-148.

Lauer, W. and Erlenbach, W. (1987). Die tropischen Anden. Geookologische Raumgliederung und ihre Bedeutung fur den Menschen. Geographische Rundschau 39,86-95.

Llagostera, A.M. (1979). 9,700 Years of Maritime Subsistence on the Pacific: An Analysis by Means of Bioindicators in the North of Chile. American Antiquity 44, 309-324.

Lynch, T. (1973) Harvest Timing, Transhumance and the Process of Domestication. American Anthropologist 75, 1254-1259.

Lynch, T.F. (1986). Climate Change and Human Settlement around the Late-Glacial Laguna de Punta Negra, Northern Chile: The Preliminary Results. Geoarchaeology 1, 145-162.

Lynch, T.F. (1990). Quaternary Climate, Environment, and the Human Occupation of the South- American Andes. Geoarchaeology 5, 199-228.

Lynch, T.F., Gillespie, R., Gowlett, J.A.J., and Hedges, R.E.M. (1985). Chronology of Guitarrero Cave, Peru. Science 229,864-867.

Lynch, T.F., and Stevenson, C.M. (1992). Obsidian Hydration Dating and Temperature Controls in the Punta Negra Region of Northern Chile. Quaternary Research 37, 117-124.

Markgraf, V. (1989). Paleoclimates in Central and South America since 18,000 B.P. Based on Pollen and Lake-Level Records. Quaternary Science Reviews 8, 1-24.

Messerli, B., Grosjean, M., Bonani, G., Burgi, A., Geyh, M.A., Graf, K., Ramseyer, K., Romero, H., Schotterer, U., Schreier, H., and Vuille, M. (1993). Climate Change and Natural Resource Dynamics in the Atacama Altiplano in the last 18,000 Years. A Preliminary Synthesis. Moun- tain Research and Development 13, 117-127.

tions for Lateglacial Times. Palaeogeography, Palaeoclimatology, Palaeoecology.

South American Altiplano. Quaternary Research 24, 249-256.

1-15.

107-114.

Montane, J. (1972) Las Evidencias del Poblamiento Temprano de Chile. Pumapunku 5, 40-53. Nufiez, L. (1983). Palaeoindian and Archaic Cultural Periods in the Arid and Semiarid Regions

of Northern Chile. Advances in World Archaeology 11, 161-201. Nunez, L.A. (1989). Hacia la Producci6n de Alimentos y laVida Sedentaria,ln J. Hidalgo et al., Eds.,

Culturas de Chile. Prehistoria de Chile desde sus Origenes Hasta 1osAlbores de la Conquista, pp. 81-105. editorial Andres bello.

Nunez, L.A., (1992). Ocupaci6n Arcaica en la Puna de Atacama: Secuencia, movilidad y Cambio, In B.J. Meggers, Ed., Prehistoria Sudamericana. NuevasPerspectivas, pp. 283-307. Taraxacum, WA.

Nufiez, L., and Santoro, C.M. (1988). Cazadores de la Puna Seca y Salada del Area Centro-Sur Andina (Norte de Chile). Estudios Atacamerios 9, 11-60.

Nufiez, L., and Santoro, C.M. (1990). Primeros poblamientos en el con0 sur de America (XII-IX milenio A.P.). Revista de Arqueologla Americana 1, 91-139.

Nunez, L.A., Varela, J., Casamiquela, R. and VillagrBn C. (in press). Reconstruci6n Multidisciplina- ria de la Secuencia Prehistorica de Quereo (Centro No& de Chile). Latin American Antiquity.

Ochsenius, C. (1986). La Glaciacidn Puna durante el Wisconsin, Deglaciaci6n y MBximo Lacustre en la Tradici6n Wisconsin-Holoceno y Refugios de la Megafauna Postglaciales en la Puna y Desierto de Atacama. Revista de Geografla Norte Grande 13, 29-58.

Phillippi, R.A., (1893). Noticias Preliminares sobre 10s Huesos F6siles de Ulloma. Anales de la Universidad de Chile 82, entrega 9.



Rollins, H.B., Richardson 111, J.B., and Sandweiss, D.H., (1986). The Birth of El Nino: Geoarchaeo- logical Evidence and Implications. Geoarchaeology 1, 3-15.

Schreier, H., Grosjean, M., Lavkulich, L., and Messerli, B. (in prep). Paleosols in the Atacama Altiplano: Indicators for Early Holocene Climate Change. Manuscript to be submitted to Catena.

Seltzer, G.O. (1990). Recent Glacial History and Paleoclimate of the Peruvian-Bolivian Andes. Quaternary Science Reviews 9, 137-152.

Sinclair, C.A. (1985). Dos Fechas Radiocarb6nicas del Alero Chulqui, Rio Toconce: Noticia y Comentario. Reuista Chungarci 14, 71-79.

Veit, H. (1991). Jungquartare Relief- und Bodenentwicklung in der Hochkordillere im Einzugs- gebiet des Rlo Elqui, Nordchile, 30"s. Bamberger Geographische Schriften 11, 81-97.

Wirrmann, D., and De Oliveira, L.F. (1987). Low Holocene Lake Level (7700 to 3650 Years Ago) of Lake Titicaca (Bolivia). Palaeogeogmphy, Palaeoclimatology, Palaeoecology 59, 315-323.

Yacobaccio, H.D. (1983). Explotacidn Complementaria de Recursos en Sociedades Cazadoras-Recol- ectoras surandinas. Cuadernos del Znstituto Nacional de Antropologia 10,493-514.

Received October 7 , 1993 Accepted for publication March 17, 1994

286 VOL. 9, NO. 4

0 geoarqueologia (grosjean y núñez)

Documents