Technological characteristics of analysed samples

3.5.1.1. Samples from potential raw material sources (clay, sand and other mineral inclusion sources)

Figure 3.1 shows the sites in the Puna region and the mesothermal valley where clay deposits were sampled, from 1465 to 4200 m ASL. Raw material studies showed that:

(a) The nine clay deposits sampled in the Puna (3500–4200 m ASL) correspond to secondary clays, meteorized and/or transported and deposited according to the geomorphological and geological characteristics of the area. These clays are rare but have high plasticity and workability. Textural analysis showed high sandy fractions, without differences among basins. XRD showed 50% good quality clays for ceramic manufacture, low presence of clay fractions (10–25%), high presence of calcite and high to medium presence of feldspar.

(b) Clay deposits from the river Guanchín area (19 deposits) were sampled from 1500 to 3000 m ASL. Clays from higher altitudes have a high sandy fraction and low plasticity. On the contrary, the macroscopic characteristics of low altitude deposits are similar to those from the La Troya river area 25 km away.

(c) At the river La Troya and Quebrada (1500 m ASL), 17 clay deposits were sampled, showing secondary clays, meteorized and transported by fluvial agents in a sedimentary environment. Clays are common, have a low presence of sandy texture fractions, and have excellent properties regarding their plasticity and workability. XRD showed 100% good quality clays for ceramic

manufacture, a high presence of clay fractions (17–45% concentration values), a low presence of calcite and feldspar, and a high presence of quartz (24–45%).

(d) The four sampled deposits from the river El Puesto (1480 m ASL) and three from the river Colorado (1465 m ASL) presented macroscopic characteristics similar to those from the La Troya area, at distances of approximately 8 and 50 km, respectively.

3.5.1.2. Puna sherds (3500–4200 m ASL)

The ceramics are mainly found at the 4000 m level and are associated with archaeological sites with two types of architectural feature: complex peripheral rectangular rooms and poorly conserved circular rooms. Both types show evidence of having been reclaimed for a long time, and also, they are located on the banks of vegas associated with rocky formations [3.5–3.8]. Despite strong superficial evidence of the Incas, sherds from earlier cultural periods were recovered from the surface. The analysed sherds (N= 195) come from surface collection (N = 76) and systematic excavations (N = 119) and have been classified within the existing periods for the Argentine northwestern area [3.15] on the basis of their ceramic styles and/or their technological characteristics. In this way, surface sherds define a potential 2000 year palimpsest, as they represent different ceramic–agricultural periods: (a) early (300 B.C.–650 A.D.), (b) middle (650–850 A.D.), (c) late (850–1480 A.D.) and (e) Inca (1480 A.D. until the Hispanic presence). These temporal ranges should not be considered as absolute ones but as period models of macroregional scope.

Thermoluminiscence¹ dating of four ceramic samples classified as Ciénaga (two, early period), Aguada (one, middle period) and Inca (one, Inca period) covered a 765 year range for the occupation of the Puna at 4000 m ASL [3.8]. Table 3.1 presents the sample composition related to their site of recovery and chronological period. The mentioned sites are located within a range of approximately 7 km.

Sherds were mostly small, so that it was impossible in most cases to ascribe pot shapes and/or parts. Figure 3.2(a) shows the technological behaviour trend of Puna samples: illustrating the antiplastic portion of the matrix, its mineral composition, size and firing percentage in sherds classified into ceramic–agricultural periods (with the exception of an undetermined group of undecorated ordinary sherds). In general the temper shows the predominant presence of quartz whatever the temper grain size;

a predominant presence of calcite, rock fragments and mica can also be observed as a function of temper grain size. The sherds also present other inclusions in a low

1 Dating was done at the thermoluminiscence laboratory of the Universidad Católica de Chile. Dating results were: (a) UCTL 1305–1450 A.D., Inca pot; (b) UCTL 1306–1075 A.D., Aguada pot; (c) UCTL 1307–735 A.D. Ciénaga pot; (d) UCTL 1308–685 A.D., Ciénaga pot.

percentage (i.e. feldspar, ground sherds and glass). Medium and small antiplastic sizes prevail over coarse and very coarse, these being principally associated with ordinary sherds. For early period pots, reducing atmosphere firing is predominant.

Figure 3.2(a) refers to Puna surface samples as they have a wider diversity than those from systematic excavations. Most excavated sherds (N= 119) were classified as Inca type (75 of 119) with technological characteristics similar to those from the surface TABLE 3.1. PROVENIENCE OF PUNA SHERDS

Archaeological Period (northwestern Argentina)

site Provenance

Early Middle Late Inca Undetermined Total

Laguna Salada Surface 12 0 0 2 14 44

(3980 m ASL) dispersion

Excavation 11 1 4

San Francisco Surface 7 5 2 14 15 114

(4000 m ASL) dispersion

Excavation 0 0 0 67 4

Excavation 12 0 0 0 1 13

peripheral area (El Corral)

Las Coladas Surface 0 0 0 5 0 13

(4200 m ASL) dispersion

Excavation 0 0 0 8 0

Las Grutas Excavation 0 0 0 0 6 6

Alero 12 (Asociado Laguna Salada)

Las Cuevas Excavation 0 0 0 0 5 5

(Alero) (4030 m ASL)

Subtotal by period 42 5 3 96 49

Total number 195

of Puna sherds

120

Inca Late Middle Early Indeterminate Inca Late Middle Early Indeterminate

Inca Late Middle Early Indeterminate

Number of sherds Number of sherdsNumber of sherds

Number of sherdsMean sherd composition (%) Mean sherd composition (%)

(a) (b)

FIG. 3.2. Technological profiles of: (a) Puna sherds (N = 76 of 195), (b) mesothermal valley sherds (N = 113).

(Table 3.1). Those sherds classified as undetermined correspond to undecorated ones, both from surface collection and from excavation.

3.5.1.3. Mesothermal valley sherds (1500 m ASL)

Sherds (N = 113) were selected from among those coming from systematic collections at the Batungasta site ceramic dispersion area and from excavation outside adobe enclosures towards the east of the site. The Batungasta archaeological site is located on the right margin of the river La Troya (1500 m ASL). An area equivalent to 9000 m²was sampled using radial transects centred on the site. The area was selected on the hypothesis that the Batungasta site played a fundamental role in the past due to its strategic position in Quebrada La Troya as:

(a) The gateway for the economic exploitation of the Andean areas;

(b) A node in a network of goods, fuel and information circulation, pointing to the west and connecting valley areas on both sides of the Andes;

(c) A production and manufacturing site acting as a goods emission centre towards other areas and altitudinal levels (the mesothermal valleys of Abaucán and Chaschuil and their respective Puna and Altoandino domains).

The recovered sherds stemmed from all the ceramic–agricultural periods, with the highest proportion corresponding to the late period. Owing to the conditions of the material it was possible to classify it according to its stylistic and technological characteristics. These characteristics are presented in Fig. 3.2(b) considering the same variables as for Puna sherds (Fig. 3.2(a)) to facilitate comparison. In general, quartz prevails over other antiplastic mineral components, although at a lower proportion if compared with the quartz in Puna sherds and with smaller sizes.