Excavation of an Acheulian Workshop at Isampur, Karnataka (India)

Article excerpt

Isampur is one among a remarkably dense concentration of 200 Acheulian sites of the Lower Palaeolithic stage located in the Hunsgi and Baichbal valleys of peninsular India. The two valleys constitute an amphitheatre-like erosional basin (about 500 sq. km in extent) of Tertiary age and are enclosed by shale and limestone flatlands or low hills of schist and granite. Paddayya's research over quarter-century (foot-surveys and excavations) has revealed much data on depositional, spatial and cultural contexts of the Acheulian sites: one of their special features concerns the use of limestone as the principal raw material for tool making. Radiometric dates suggest that the age of the sites ranges from 200,000 to beyond 350,000 years. From field data combined with observations from experimental and ethnoarchaeological approaches, Paddayya (1982; 1991) has reconstructed the Acheulian culture from a settlement system perspective.

The site of Isampur (16 [degrees] 30'N; 76 [degrees] 29'E) is located in the northwestern corner of Hunsgi valley. It was discovered in 1983 when much of the 1-1.5-m thick brown/black silt cover overlying the cultural level was quarried away by the Irrigation Department, leaving a remnant of 10 to 60 cm cover. Our geoarchaeological research showed that the site was located on the limestone-strewn outer edge of an ancient drainage tract (3-4 m deep) where water was assured, and forming part of the undulating erosional topography of the valley floor.

The recent soil quarrying, farming activities and soil deflation have exposed the surface of rich Acheulian cultural material lying directly on the limestone bed of the valley floor. The site covers c. 0.75 ha and consists of an eroded outcrop of limestone blocks. In addition to a secure source of water, the availability of limestone blocks of suitable sizes (30-40 cm across and 10-15 cm thick) for purposes of flaking was a major factor influencing the selection of the spot by hominids.

The distinctive topographical context (located in a valley setting but away from a river) means the site is free from disturbances like flooding or erosion commonly noticed at Palaeolithic sites in India. Four seasons of excavation from 1997 to 2000 have resulted in five regular trenches, covering a total area of 159 sq. m (FIGURE 1). Most of the exposed Acheulian cultural material is in primary context, and is 20-30 cm thick. It consists of limestone blocks (some already altered to form cores), artefacts in various stages of working, debitage of various size ranges, and hammerstones of basalt, chert and quartzite, all set in a hard matrix of brownish calcareous silt. The fresh physical condition of artefacts confirms that the material remains in situ (FIGURES 2 & 3).

[Figures 1-3 ILLUSTRATION OMITTED]

The authors propose that the Isampur site was essentially a workshop (Paddayya et al. 1999; Petraglia et al. 1999). The site's location, on a geological outcrop of raw material (limestone), and the presence of hammerstones, as well as cores and artefacts in various stages of manufacture or reduction, various classes and kinds of waste products and the low proportion of finished tools like handaxes and cleavers as compared to cores and debitage, all support this proposition. …