Flint procurement strategies of the early hunter-gatherers of eastern Uruguay

Proceedings of the 2nd International Conference of the UISPP

Commission on Flint Mining in Pre- and Protohistoric Times (Madrid, 14-17 October 2009)

Edited by

Marta Capote Susana Consuegra Pedro Díaz-del-Río

Xavier Terradas

BAR International Series 2260 2011

Published by Archaeopress Publishers of British Archaeological Reports Gordon House 276 Banbury Road Oxford OX2 7ED England [email protected] www.archaeopress.com BAR S2260 Proceedings of the 2nd International Conference of the UISPP Commission on Flint Mining in Pre- and Protohistoric Times (Madrid, 14-17 October 2009) © Archaeopress and the individual authors 2011 ISBN 978 1 4073 0831 9 Cover figure: Last mining event at Casa Montero, Madrid (c. 5200 cal BC). Illustration by Juan Álvarez-Cebrián Printed in England by Blenheim Colour Ltd All BAR titles are available from: Hadrian Books Ltd 122 Banbury Road Oxford OX2 7BP England www.hadrianbooks.co.uk The current BAR catalogue with details of all titles in print, prices and means of payment is available free from Hadrian Books or may be downloaded from www.archaeopress.com

291

1. Introduction

Evidence of early human occupation (Pleistocene-Holo-cene transition) of South America comes from different archaeological regions, including the Andean ranges, the Caribbean and Pacifi c coasts, Patagonia and the Pampa (Dillehay 2000; Politis et al. 2004). Over recent years, an increasing amount of data has been collected in Uruguay (30º-35ºS to 58º-54ºW) from archaeological sites loca-ted near important watercourses (e.g., the Negro, Uru-guay and Tacuarembó rivers and their tributaries), and from hills and lagoons near the Atlantic coast (Suárez and López Mazz 2003). These early Americans lived in small groups and covered long distances over the cour-se of the year (Dillehay 2000). The early settlements of southeastern Uruguay are located on a Quaternary coastal plain home to landscape features such as coastal lagoons, lowlands, mid-altitude plains and the seashore itself, the origin of which lies in changes in the sea level during the Pleistocene-Early Holocene (Bracco 1995; Martin and Suguio 1989).

This paper discusses the petrographic information pro-vided by lithic material produced by ancient settlers (c. 9300-7600 years BP cal) and recovered from the Rincón de Los Indios archaeological site (López Mazz 2001), and assesses organisational models of lithic production and strategies of fl int procurement. Models of lithic technolo-

gy require data regarding distances to quarries; the present work provides information in this respect.

Knowledge of the area’s lithic economy enables discus-sion regarding the type of societies to which its early hun-ter-gatherers belonged. They appear to have made use of a wide range of animal resources, including fi shes, rodents and deer, and made many products from the native palm tree Butia capitata (López Mazz 2001). The most impor-tant feature of the lithic technology of these groups was the production of projectile points, bifacial tools, unifacial tools, fl akes and grinding stones (Gascue et al. 2009a; Ló-pez Mazz et al. 2009).

2. Early South American hunter-gatherers

The fi rst Americans to arrive in the Far South did so be-fore the raising of the La Plata River to its present level (c. 14,000-9000 years BP), possibly attracted by the high productivity of the coastal wetlands and lagoons of the ancient Palaeo-Paraná delta (now underwater) (Dillehay 2000; López and Gascue 2007; Politis et al. 2004). These peoples developed a wide-spectrum hunting technology focused on the fauna of open environments. The variabili-ty of projectile points and bolas (polished stones for use in a bolas sling) show that large, medium and small animals

Flint procurement strategies of the early hunter-gatherers of eastern Uruguay

José LÓPEZ MAZZ, Andrés GASCUE and Gustavo PIÑEIRO

AbsractThe southeastern area of the American continent was probably fi rst populated because of the high productivity of its coastal wetlands and lagoons. These small groups had a high mobility pattern, covering considerably long distances over the course of the year, and developed a wide-spectrum hunting technology. Essential to this technological system was the supply of quality raw material for fl aking. This social and economic mobility is key in order to understand these prehistoric production systems. In this paper we present petrographic information of lithic remains produced by the ancient settlers of the the ‘Rincón de Los Indios’ archaeological site (9300-7600 cal BP). We discuss organizational patterns of lithic production and strategies of fl int procurement.

KeywordsSouth America. Prehistoric quarrying. Petrography. Hunter-gatherer mobility.

292

Proceedings of the 2nd Conference of the UISPP Commission on Flint Mining...

Figure 1. Site location and sources of the analysed raw materials.

293

J. López Mazz et al.: Flint procurement strategies of the early hunter-gatherers...

were hunted. Essential to this technological system was the supply of good quality raw material for fl aking (López Mazz et al. 2009; Gascue et al. 2009a).

3. The Rincón de Los Indios archaeological site

The Rincón de Los Indios archaeological site is a multi-mound, multi-component site located on a peninsula-sha-ped area surrounded by the Las Maravillas swamp. The occupation process dates between 9300 years BP to the period of contact with European conquerors. The site was excavated between 1995 and 2010; current evidence su-ggests that it was an area of logistic use in the lowlands close to the sea (Figure 1).

The oldest level of the site shows that it was occupied bet-ween 9300 and 7700 BP. The site is located at a strategic point for hunting and fi shing activities as well as for intra-regional communication. The formation processes of the site are related to intensive human occupation (longue durée) and the changing lowland environments of the Early Holo-cene (López Mazz 2001). Lithic material recovered in ex-cavations shows the use of different technologies with each

Figure 3. Sources the geological samples and their classifi cation.

Figure 2. Macroscopic classifi cation of raw materials from the Rincón de Los Indios site.

Resources %

Quartz 52.4

Quartzite 20.4

Chalcedony 14.6

Rhyolite 2.8

Microgranite 2

Granite 1.8

Slates 1.2

Silicifi ed limestone 0.8

Other quartz-rich rocks 0.6

Other suitable for polishing rocks 0.5

Ochre 0.1

N/I 2.7

ID Source Location Origin

LN MG2 Secondary Northern coast, Negra Lagoon Local

LN MG10 Primary Northern coast, Negra Lagoon Local

PG MG1 Primary Potrero Grande Local

LN MG11 Primary de los Difuntos Hill Regional

Blanq MG1 Primary de los Difuntos Hill Regional

Moza MG9 Primary Santa Teresa Headland, Atlantic coast Regional

Moza MG7 Primary Santa Teresa Headland, Atlantic coast Regional

CV MG8 Primary Cerro Verde Headland, Atlantic coast Regional

SM MG1 Primary San Miguel Hill Regional



AGDE MG1 Primary Mouth of the Río Grande (Paso de Lugo) Extra-regional

Yaguarí D’ Secondary Río Yaguarí (Paso Casildo) Extra-regional

294


ID Macro classification

Minerals Structures

Moza MG 9Brown opaque chalcedony

Porphyroclasts and porphyroblasts of quartz. 50%matrix of fi ne-grained quartz and Fe oxide. Chalcedony in voids.

Microcracks and transgranular fractures Voids cemented with quartz.

PG MG1 QuarziteQuartz deformed and fractured – Chalcedony layers and quartz in voids.

Microcracks and transgranular fractures

Blanq MG1 QuarziteQuartz + K feldspar+ chlorite+ crystal pseudomorphs. Chalcedony layers in voids.

Microcracks and transgranular fractures

LN MG 11 Quarzite Qz + opaque minerals + Fe-oxides Stockwork

LN MG 2 White quartz Qz with undulose extinction + K feldspar+ garnet Microfaults/ mineral cracks

SM MG1 Rhyolite Tabular sanidine, quartz, isometric magnetite, apatite Massive

SM MG2 Basalt Pg + Px + opaque minerals Massive

SM MG3 Opal Qz with undulose extinction + brown microcrystalline minerals Faults, cracks, voids

CV MG 8 Smokey quartz

Quartz + albite + K feldspar +epidote Perthites / displaced fractures fi lled with quartz

Moza MG7 Smokey quartz

Quartz + albite + turmaline + biotite + epidote Perthites /fractures

LN MG 10 Micro- crystalline quartz

Two grain size generations of microcrystalline quartz Ribbon quartz / strained quartz veins/fractures

Yaguarí MG D

Chalcedony layers (agate) Chalcedony fi bres. Lengthfast. Layers of twisted-untwisted quartz fi bres

A GDE MG 1

Red Silicifi ed Limestone

Chalcedony + calcite + opaques + Qz + Fe-oxides Gastropods/ charophytes

Figure 4. Petrography of sampled outcrops and potential quarries.

295


Texture-fabric Matrix Secondary minerals Lithological classification

Oriented. Mosaic quartz Fine Fe oxide. Chalcedony rims PROTOMILONITE

Cataclastic / Fluidal Fine to medium Fe oxide. Chalcedony bands and rims QUARTZITE CATACLASITE

Cataclastic / fl uidal Fine to medium Disseminated Fe oxide. Chalcedony rims. QUARTZITE CATACLASITE

Cataclastic and grano-blastic Fine Fe oxide. Feldspar silicifi cation QUARTZITE CATACLASITE

Granoblastic to cata-clastic Very coarse Feldspar alteration (kaolinite?). QUARTZITE CATACLASITE

Micro porphyritic Very Fine Sanidine pseudomorphs. Fe oxide RHYOLITE

Intergranular Very Fine Clay transformation. Fe oxide. THOLEITIC BASALT

Microcrystalline Very Fine Brown microcrystalline minerals QUARTZITE BRECCIA

Pegmatitic Medium Epidote in feldspars. Mn oxides in cleava-ge fi losilicates. CATACLASTIC PEGMATITE

Pegmatitic Coarse Epidote in feldspars. Mn oxides in cleava-ge fi losilicates CATACLASTIC PEGMATITE

Granoblastic and mortar Very Fine Fe oxide in fractures QUARTZ VEIN

Fibrous sequence layers Very Fine Fresh CHALCEDONY LAYERS

Microcrystalline Very Fine Fresh SILCRETE

296


ID Macro classification Minerals Structures

iV_7-38 Brown opaque chalcedony Porphyroclasts and porphyroblasts of quartz. Fe oxides. Chalcedony in voids. Microcracks and transgranular fractures.

iV_6-9 Pale brown quartzite Porphyroclasts and porphyroblasts of quartz + epidote. Voids fi lled with undulose quartz. Ribbon quartz. Faults, microcracks.

iV 7-17 Pale brown quartzite Porphyroclasts and matrix of undulose quartz. Chalcedony. Stockwork

iV_6-4 Sedimentary quartzite Quartz porphyroclast. Matrix: quartz + epidote + opaques. Layers of ribbon and fragmented quartz.

iV_6-8 Brown opal Quartz and chalcedony; Fe oxide rims in voids Chalcedony in cracks

iV_6-5 Red rhyolite Tabular feldspar + porphyrocrystals of quartz. Matrix: quartz + amphibol Massive

iV_6-29 Reddish-brown rhyolite Tabular sanidine. Matrix; microcrystalline quartz + K feldspar + opaques Massive

iV_6-35 Pale brown quartzite Holocrystalline quartz Massive

iV_6-31 Translucid quartz Quartz (one crystal) Microcracks

iV_7-42 Quartz Quartz sacharoidal Faults, cracks

iV_7-14 Red quartzite Sacharoidal quartz vein in a garnet + epido-te + amphibol granite. Quartz veins in granite

iV_7-16 Chalcedony layers (agate) Cryptocrystalline and fi brous chalcedony Twisted layers of quartz fi bres. Cracks.

iV_7-37 Translucid chalcedony Chalcedony + opaques Bands, not always with orientated chalcedony

iV_7-33 Chalcedony layers Criptocrystalline chalcedony Layers / microcracks

iV_6-44 Red silicifi ed limestone Chalcedony + Ca-sparite + opaques + quartz

Gastropods / charophytes – Voids with chalcedony

iV_6-32 Orange silicifi ed limestone Chalcedony + Ca-sparite + opaques + quartz Veins and voids partially fi lled with chalcedony

iV_6-30 Gneiss Quartz + feldspars + amphibol Bedding (So) and foliation (S1)

iV_7-12 Quartzite Quartz + zoisite + opaques + albite + green - brown biotite + epidote + apatite + zircon Faults

iV_7-18 Quartzite Quartz + K-Feldspar Massive

Figure 5. Petrography of archaeological samples from the earliest layer of the Rincón de Los Indios site.

297


Texture-fabric Matrix Secondary minerals Lithological classification

Oriented. Fine Fe oxides. Chalcedony rims PROTOMILONITE

Cataclastic. Fine to medium Some Fe oxides. QUARTZITE-CATA-CLASITE

Cataclastic and granoblastic zones Very fi ne l to medium N/I QUARTZITE-CATA-CLASITE

Oriented. Granoblastic. Fine Epidote QUARTZITE-PROTO-MILONITE

Unequigranular xenomorphic Very Fine l Disseminated Fe oxides. Chalcedony rims. HORNFELS

equigranular to microporphyrytic Very Fine Feldspars pseudomorphs. TRACHITE

Porphyrytic Very Fine Fe oxide RHYOLITE

Granoblastic Very Fine Some Fe oxide METASEDIMENTARY QUARTZITE

Pegmatitic Very coarse N/I PEGMATITE

Pegmatitic Very coarse N/I PEGMATITE

Granoblastic coarse Fresh / some Fe oxide over cracks QUARTZ VEIN

Layered. Cracks. Very Fine Fe oxides rims CHALCEDONY LAYERS

Layered Very Fine Fresh CHALCEDONY LAYERS

Oriented fi bres. Very Fine Fe oxide dendrites. Opalescence of chalcedony

CHALCEDONY LAYERS

Microcrystalline. Very Fine Silicifi cation, Fe oxide. Quartz rims. SILCRETE

Microcrystalline Very Fine Silicifi cation, Fe oxide. Quartz rims. SILCRETE

Grano-nematoblastic Very Fine Defective section SLATE

Oriented. Very Fine Epidotized quartz MILONITE

granoblastic Medium Fresh ALCALI GRANITE

298


by the prehistoric populations of eastern Uruguay, b) to explore the petrographic characteristics that infl uenced the selection of raw materials, and c) to evaluate, using litho-logical data, the origin of the lithic resources used by the early inhabitants of the Rincón de Los Indios site.

4. Methods and Constraints

Moving to produce, is often an important strategy of the modern-day ethnographic societies of America (Politis 1996; López Mazz et al. 2009). Movement is part of hu-man life, but normally leaves no material trace. Movements made in the past are therefore very diffi cult to investigate (Close 2000). Nevertheless archaeology must attempt to measure the economic distances travelled if it is to explain social processes. Spatial analysis provides information on the economic organisation of prehistoric peoples, while the comparative petrographic study of lithic raw materials from outcrops and lithic artifacts provides a means of re-constructing their territoriality and circulation patterns.

This paper reports information generated by local, regio-nal and extra-regional geological surveys and technologi-cal lithic analyses of the artifacts from the Rincón de Los Indios site. The ethnographic defi nitions of Politis (1996) and López Mazz and Bracco (2010) used in this work, in-cluding defi nitions of scales of distance, are listed below:

- Local sources refers to quarries located at a distance of under 10km.

- Regional sources refers to quarries located between 10 and 100km away.

- Extra-regional sources refers to quarries located more than 100km away.

- Primary sources correspond to geological outcrops.

kind of raw material; Figure 2 shows a macroscopic classi-fi cation of these materials and their frequency of recovery.

Flint-knapped products of the early occupants of the Rin-cón de Los Indios site include fl aked instruments (unifa-cial and bifacial), cores, fl akes and debris, and projectile points made by uni- and bifacial reduction (Gascue et al. 2009a; López Mazz et al. 2009). The most important eco-nomic activities identifi ed at the site by the latter authors include the:

- gross transport to the site of different varieties of quartz, quartzite, rhyolite and microgranite.

- reduction of cores of the above raw materials by unipo-lar and bipolar knapping (mainly quartz), oriented towards the production of blanks for instrument-making (sensu Ini-zan et al. 1995).

- use of fl akes without modifi cation by retouching.

- production of tools by unifacial and bifacial knapping of good quality raw material.

- use of tools.

- production of projectile points from good quality raw materials.

- reactivation of projectile points.

- recycling of projectile points damaged by use.

- discarding of projectile points with irreparable damage or that required much repair.

- production of bolas from granite and rhyolites.

The aims of the present work were to a) verify the classical macroscopic classifi cation of the lithic raw materials used

Figure 6. Photomicrograph of pegmatite quartz: Cº Verde MG8 sample (left) and iV 7-42 (right). Scale x 100, cross-polarised light.

299


Figure 7. Photomicrograph of quartzite cataclasite: PG MG1 sample (left) and iV 6-9 (right). Scale x 100, cross-polarised light.

bias, and the natural variation of both the geological and archaeological materials may have had some infl uence on the results obtained. However, in almost all cases, a number of well known textural features (e.g., chalcedony bedding, saccaroidal and porphyritic texture, volcanic voids) easily linked the geological and archaeological materials.

5. Results

The petrographic features observed in some of the mate-rials making up the regional and extra-regional offer of potential lithic resources (Figure 4) are described analyti-cally and graphically. Others materials seen to have been used by the early inhabitants of the Rincón de Los Indios site are also described (Figure 5). The analysed geological sample was composed of 31.1% variable-genesis quartzi-te, 18.8% quartz and pegmatite dikes, 12.5% banded chal-cedony, 9.4% silcretes (silicifi ed limestone), 9.4% mylo-nites or protomylonites, 12.5% volcanic rocks and 6.3% other materials (microgranite and metapelite).

Petrography of the geological samples

Siliceous metamorphic rocks such as quartz-breccia, quar-tzites-cataclasites and protomylonites made up the largest group of materials. Subvolcanic (dikes and pegmatites) and volcanic rocks of local and regional origin, and sili-cifi ed limestone and banded chalcedony of extra-regional origin, were also identifi ed.

Figure 4 shows that the geological samples near the ar-chaeological site are affected by dynamic metamorphism, even samples previously classifi ed macroscopically as quartz dikes. This is refl ected by the presence of quartz veins (ribbon quartz-type), faults and cracks, strained crys-tals and the frequent dispersion of the extinction angle of the quartz crystals. The dominant dynamic metamorphism type seems to be characteristic of shear zones from eastern

- Secondary sources correspond to sedimentary deposits.

- Quarrying strategies (sensu lato) imply the work of se-lection, exploitation and transportation of the geological material to the hunter-gatherer system point of production.

Materials examined

Petrological thin sections of 19 archaeological materials from the earliest level of the Rincón de Los Indios site, and 13 geological materials from quarries and potential quarries (here referred to as the geological sample) were examined using a Leitz Wetzlar Laborlux 12 pol S model petrological microscope at 100-300X magnifi cation. The mineral iden-tifi cation criteria of Kerr (1965) and Mason’s classifi cation of metamorphic rocks (1990) were adhered to.

Samples of local fl int raw material were collected from quartz veins and rhyolithic rocks in outcrops in the nearby hills of La Blanqueada, Potrero Grande, De Los Difun-tos and San Miguel, from siliceous rocks on coastal head-lands, and from coastal gravels (northern coast of the Ne-gra lagoon, the Atlantic coast, and the La Moza and Cerro Verde outcrops). One sample taken from an extra-regional archaeological quarry – a Palaeocene silcrete here refe-rred to as silicifi ed limestone – was collected from the Rió Grande in western Uruguay. Another extra-regional sam-ple (banded chalcedony) was collected from north-central Uruguay (Río Yaguarí gravel deposits); this material origi-nated in vesicles within tholeitic basalts (see Figure 1 and Figure 3 for location).

The archaeological samples were selected from among the most common (near 90%) fl int-type lithic materials found at the Rincón de Los Indios site, i.e., quartzite, quartz and chalcedony. However, some mistakes in the classifi cation of the fl int-like material of the archaeological elements are to be expected given the lack of important structural and contextual geological information. The selection of the geological samples may have involved some subjective

300


Uruguay (Sánchez-Bettucci et al. 2001). The rhyolites, trachytes and acidic subvolcanic rocks are characteristic of the Cretaceous extensive margins of the Merin Lagoon and St. Lucia basins.

The silicifi ed limestone sample from western Uruguay is cha-racterized by the presence of fossils of pulmonate gastropods and charophytes (according to the description of Martínez et al. [1997] and Tófalo and Pazos [2009]). The reworked sample of banded chalcedony originated within the basalt vesicles and cavities of the centre-north of the country, and is composed of monomineral banded chalcedony layers asso-ciated with quartz, chlorite and calcite minerals.

Petrography of the archaeological samples

The archaeological samples are composed of several fl int-like lithologies (micro-crystalline quartz, hydrothermal quartz, banded chalcedony and silicifi ed limestone) fo-llowed in smaller proportion by microgranites and acidic volcanic rocks (see Figure 5).

Protomylonitic textures are the most frequent and, except for the pegmatites and quartz veins, the crystal size is fi ne to very fi ne (<0.1mm), particularly for the banded chalce-dony, silicifi ed limestone material and some of the volca-nic and metamorphic materials.

6. Discussion

The acidic composition of the geological and archaeolo-gical samples analysed, a consequence of the dominance of varieties of quartz and alkaline feldspars, dictated their aptitude (i.e., concoidal fracturing and hardness) for knap-ping. The grain size of the archaeological samples was not as fi ne as expected, suggesting that coarse-grained quartz (i.e., pegmatite quartz) and single crystal were commonly used for knapping. Some authors (Crabtree 1975; Gil Se-villano 1997; Ratto 1988) confi rm wear and tear resistance of some varieties of coarse-grained quartz to be desirable for tools to be subjected to rigorous use.

The distinctive textures of dynamic metamorphism of the region (cataclastic to mylonitic) do not appear to have compromised the use of the above materials, since they are well represented in the archaeological sample. Howe-ver, the use of such resources is generally limited to the manufacture of quickly made, non-standard instruments (Gascue et al. 2009a).

The macroscopic description of the samples made during the technological analysis sometimes did not fi t the obser-ved petrography (Figure 5). Petrographic analysis provi-ded important information for establishing that the percen-tage of massive chalcedony (14%) was much more than suggested by macroscopic analysis (see Figure 5, sample iV_7-38). Previous authors have warned that the strong

presence of chalcedony at the site refl ects an extra-regio-nal resource (Gascue et al. 2009a).

The data obtained showed that some archaeological lithic remains identifi ed as chalcedony are in fact other very homogeneous lithologies of excellent quality for knap-ping, and which are available at a regional scale (e.g., protomylonites). However, the presence of chalcedony in voids in the geological sample of protomylonite from the Atlantic coast (Moza MG9, Figure 4) reinforces the hypothesis that this chalcedony comes from a small regio-nal resource. A resource of excellent quality for knapping, present in the San Miguel Hills and traditionally identifi ed as ‘San Miguel Opal’ (Curbelo and Martinez 1992), is ac-tually a very fi ne-grained brecciated quartzite.

The results show that the present analytical method is useful for improving the identifi cation of exploited lithic resources, and suggests that the fi rst occupants of the Rin-cón de Los Indios site made use of a greater diversity of raw materials than originally identifi ed at the macrosco-pic level (Gascue et al. 2009a). This diversity covers tra-chytes, pegmatites (igneous) and metamorphic rocks such as mylonites and metapelites.

The results of the petrographic analysis tend to confi rm some of the hypotheses expressed earlier regarding the lo-cation of sources of some varieties of quartz and quartzite, banded chalcedony and silicifi ed limestone present in the Rincón de Los Indios archaeological record. The geolo-gical origin of the ochre component of the lithic mate-rials from the site is not discussed in this paper. However, sesquioxide enrichments can be recognised around stoc-kwork-type outcrops with ferro-siliceous near-extensional plains, and in some residual weathering deposits.

Local and regional mining activities

The great petrographic similarity between samples Moza MG9/iV 7-38, Moza MG7/iV 6-31 and Cº Verde MG 8/iV 7-42 (Figures 2, 4 and 5) confi rms that the early occupants of the Rincón de Los Indios site undertook displacements to the Atlantic coast to acquire pegmatite quartz and protomylonites.

In turn, the similarity of some geological and archaeolo-gical samples of quartzite (PG MG1/iV 6-9 and LN 11/iV MG 7-17; Figure 7) supports the assertion of both lo-cal and regional exploitation of this resource in the nearby hills of la Blanqueada, de Los Difuntos and Potrero Gran-de. Finally, it is confi rmed that the rhyolite of San Miguel was truly a resource exploited by the peoples in question (see samples iV 6-29 and SM MG1, Figures 4 and 5).

Extra-regional mining activities

The great petrographic similarity of the sample of silicifi ed limestone from the Río Grande with the entire archaeo-logical sample confi rms the extra-regional origin of this resource (Figure 8). However, given the spatial dispersion

301


of this resource (Calizas del Queguay formation) the cat-chment area may have been the coastal region of the Río Uruguay, the north and south of the Río Negro (Bossi et al. 1998; Florines 2004; Gascue 2009; Tófalo and Pazos 2001), and even the Santa Lucia river basin (Martínez et al. 1997; Beovide 2004). It is diffi cult to determine the exact origin for this raw material since the elements considered diagnostic (fossils and mineral composition) are shared by the brecciated facies of the silcretes in the mentioned areas (Martínez et al. 1997; Tófalo and Pazos 2009). Similarly, comparison of the geological sample of banded chalce-dony with the three samples recovered from the Rincón de Los Indios site (MG Yaguarí D ‘/ iV iV 7-16 7-37 7-33 iV) confi rms that this raw material comes from northern Uru-guay. The nearest source is located in the pebble alluvial beds of the Río Negro (Gascue et al. 2009b), although an abundant primary source is located over 400 km away in northern Uruguay and southern Brazil (Arapey Formation; Bossi et al. 1998).

7. Conclusions

The lithic material from the oldest level of the Rincón de Los Indios archaeological site represents the dominant pattern of early South American technology and raw ma-terial use (Suarez and López Mazz 2003). Early South American knappers may have obtained the good quality raw material they used via networks of exchange. In any event, fl int procurement strategies would have had to be combined with residential and economic mobility.

The technological organization of the early inhabitants of eastern Uruguay involved the acquisition of a variety of local, regional and extra-regional mineral raw materials from primary (geological outcrops) and secondary (fl u-vial and coastal gravels) quarries. These groups undertook

Figure 8. Photomicrograph of silicifi ed reddish limestone showing a section of a pulmonate gastropod shell replaced by chalcedony: A GDE MG 1 sample (left) and iV 6-44 (right). Scale x 100, cross-polarised light.

signifi cant movements across the region to acquire good quality rocks, showing them to be hunter-gatherers with high residential mobility able to exploit a diversity of en-vironments over the year. They developed a conservative technology (sensu Binford 1998) using good quality extra-regional raw materials. The extra-regional silicifi ed limes-tone and chalcedony brought from the west and north of Uruguay was exclusively used for the production of pro-jectile points and underwent different recycling processes. Currently it remains unknown how these raw materials were circulated. The bolas recovered were made from lo-cal and regional materials (granite and rhyolite). Howe-ver, some bolas made from raw materials from northern outcrops have been found in early settlements in southern Uruguay.

References

Beovide, L. 2004. Recursos y Organización del espacio prehistórico costero, Uruguay, in L. Beovide, I. Barreto y C. Curbelo (eds.), X Congreso Uruguayo de Arqueología: La Arqueología Uruguaya Ante Los Desafíos Del Nuevo Siglo. Montevideo, Uruguay. Montevideo, CD-ROOM edition.

Binford, L. 1998. En busca del pasado. Barcelona. Crítica. 3ª ed.

Bossi, J., Ferrando, L., Montaña, J., Campal, N., Mora-les, H., Gancio, F., Schipilov, A., Piñeiro, G. and Sprech-man, P. 1998. Geocarta. Carta geológica del Uruguay - 1:500.000. Versión 1.01. Montevideo, Geoeditores S.R.L.

Bracco, R. 1995. Cronología de la Laguna de Castillos. In. J. Bossi, J. Montaña and, R. Bracco, Causas geológicas del paisaje rochense, 14-17. Montevideo, Uruguay.

302


Close, A. 2000. Reconstructing Movement in Prehistory. Journal of Archaeological Method and Theory 7 (1), 49-74.

Crabtree, D. E. 1975. Comments on lithic technology and experimental archaeology. In E. Swanson (ed.), Lithic Te-chnology: making and using stone tools, 105-114. Chica-go, Mouston Publishers, The Hauge.

Curbelo, C. and Martínez, E. 1992. Aprovechamiento de Materias Primas Líticas para un Área Arqueológica Rela-cionada con la Sierra de San Miguel, Depto. Rocha. Edi-ciones del Quinto Centenario 1, 121-139.

Dillehay, T. 2000. The settlement of the Americas. New York, Basics Books.

Florines, A. 2004. Relevamiento Arqueológico de la Loca-lidad Rupestre del Arroyo Chamangá, Flores, in L. Beovi-de, I. Barreto y C. Curbelo (eds.), La Arqueología Urugua-ya Ante los Desafíos del Nuevo Siglo. AUA, CD-ROOM Edition, Montevideo.

Gascue, A. 2009. Tecnología Lítica y Patrones de Asenta-miento en la Cuenca de Arroyo Grande (Soriano), in J. M. López Mazz y A. Gascue (eds.), Arqueología Prehistórica Uruguaya en el Siglo XXI, 133-150. Montevideo, Biblio-teca Nacional and Facultad de Humanidades y Ciencias de la Educación.

Gascue, A., López Mazz, J. M., Villarmarzo, E., De León, V., Sotelo, M. and Alzugaray, S. 2009a. La organización de la tecnología lítica de los pobladores tempranos del este de Uruguay. Intersecciones en Antropología 10, 63-73.

Gascue, A., Baeza, J. and Bortolotto, N. 2009b. Arqueolo-gía del Valle del Río Negro. In II Jornadas de Investiga-ción, Montevideo, Facultad de Humanidades y Ciencias de la Educación.

Gil Sevillano, J. 1997. Lithic tool making by Amazonian palaeoindians: a case-study on materials selection. Journal of materials science letters 16, 465–468.

Kerr, R. 1965. Mineralogía Óptica. Madrid, Ediciones Castilla.

López Mazz, J. 2001. Las estructuras monticulares (ce-rritos) del litoral atlántico uruguayo. Latin American Ar-chaeology 12, 231-255.

López Mazz, J. and Bracco, D. 2010. Minuanos. Apuntes y notas para la Historia y la arqueología del territorio ge-noa-minuan (indígenas de Uruguay, Argentina y Brasil). Montevideo, Linardi y Risso.

López Mazz, J. and Gascue, A. 2007. El valle del arroyo Balizas: Estructuras monticulares y sitios superfi ciales del litoral atlántico uruguayo. Cazadores –Recolectores del cono Sur 2: 89-103.

López Mazz, J., Nadal, O., Suárez, X., De León, V. and Salvo, X. 2009. La gestión regional de los recursos mine-rales en las tierras bajas del Este: el espacio como variable de la producción lítica, in J. M. López Mazz y A. Gas-cue (eds.), Arqueología Prehistórica Uruguaya en el Siglo XXI, 85-100. Montevideo, Biblioteca Nacional - Facultad de Humanidades y Ciencias de la Educación.

Martin, P. and Suguio, K. 1989. International Symposium of Global Changes in South America during the Quater-nary. Special Publications 2, 8-12. Sao Paulo.

Martínez, S., Veroslavsky, G. and Verde, M. 1997. Pri-mer registro del paleoceno en el Uruguay: paleosuelos calcáreos fosilíferos en la cuenca de Santa Lucía. Revista Brasileira de Geociéncias 27 (3), 295-302.

Mason, R. 1990. Petrology of the Metamorphic Rocks. 2nd ed. New York, Routledge.

Politis, G. 1996. Moving to produce. Nukak mobitity and settlement patterns in Amazonia. World Archaeology 27, 492-511.

Politis, G., Messineo, P. and Kaufmann, C. 2004. El pobla-miento temprano de las llanuras pampeanas de Argentina y Uruguay. Complutum 15, 207-224.

Ratto, N. 1988. Efi cacia funcional y técnicas de caza. Shin-cal 1, 32-43.

Sanchez-Bettucci, L., Cosarinsky, M. and Ramos, V. A. 2001. Tectonic Setting of the Late Proterozoic Lavalleja Group (Dom Feliciano Belt), Uruguay. Gondwana Re-search 4 (3), 395-407.

Suárez, R. and López Mazz, J. 2003. Archaeology in the Pleistocene Holocene transition n Uruguay: an overview. Quaternary International 109-110, 65-76.

Tófalo, O. R. and Pazos, P. J. 2009. Paleoclimatic implica-tions (Late Cretaceous-Paleogene) from micromorphology of calcretes, palustrine limestones and silcretes, southern Paraná Basin, Uruguay. Journal of South American Earth Sciences 29 (3), 665-675.

Flint procurement strategies of the early hunter-gatherers of eastern Uruguay

Documents

Transcript of Flint procurement strategies of the early hunter-gatherers of eastern Uruguay