Raichur Doab constitutes land between the rivers of Krishna and Thungabhadra confluence; constituting approximate area of 22,000 km2. The Doab is characterised by two different physiography, west and east. The western portion is a terrain and the eastern portion is relatively plain. This is a semi-arid region with a dry deciduous forest with often tree scrubs, grasslands and very sparse vegetation, sometimes barren on the stony waste/ low land denudations. The current research is confined to northwestern portion of the Doab, bordering with 65 km discharge of Krishna (south bank only) to 35 km down south where there are series of granitic valleys with intrusive dykes. The study area is of about 1300 km2 including valleys of both densely vegetation-covered and very sparsely covered Dharwars, intrusive dyke valleys, granodioritic inselbergs and knobs of residual characters, granitic stony waste/ low land denudations covering a major portion of the study area.
This research continues the works of Foote (1916), Munn (1935), Allchin (1954), Sundara (1969) and Korisettar (1979). Their expeditions during the span of 1880 to 1980 have exposed Middle Palaeolithic, Neolithic and Iron Age sites and their publications have contributed towards temporal and spatial gaps in the archaeology of Raichur Doab (Chapter 1). Therefore, the present explorations aim at exploring unexplored areas and make a detailed reporting and documentation in addition to a systematic reconnaissance at reported sites in the background of landscape, site land use and settlement pattern, sampling cultural materials and archaeological features. Likewise, the author has studied twenty-four sites including thirteen newly discovered (Chapter 2), and statistical and attribute analysis were conducted on the sampled artefacts and archaeological features (Chapter 3).
As the geography of the study area is diverse, this study finds the scope of landscape and their implication on cultures to flourish in dynamic ways. Yet, the sites are interconnected with irrespective kinds of landscape and depended on the common resource availabilities. Such as, High Level Gravels on the bank of Krishna and intrusive dykes in the valleys are chief resources for the lithic tool production. The former being exploited since Middle Palaeolithic to Iron Age, and the latter is a novel material for Neolithic celt production, probably continued even during Iron Age. Longitudinally, the gravels have been carried to many of the multiperiod sites associated with granodioritic valleys ranging from a distance of 1km to 35 km further south. Neolithic sites are closely located with dyke valleys, and material for their dolerite celt production is more closely available than for their microliths.
The hunting-gathering economies such as Middle Palaeolithic and microlithic/ Mesolithic sites are associated with the high-level gravels on the riverbank. Such sites are Anchesugur, Anjal, Gopalapura and Nilavanji. Middle Palaeolithic sites are completely absent in the interior valleys and are only confined to the river environ; suggests the implications of gravel as a material for lithic production, and suitability of forest in the plains and aquatic faunal availabilities for their subsistence. Microlithic industries, such as Bairappamaradi site complex and Shambulingeshwaragudda in the very dry denudational landscapes, away from the riverbank indicates the catchment range for gravels and exploring valleys for their diet. The emergence of agro-pastoral economies, i.e. Neolithic culture confined to the residual hills catered with natural springs and rock shelters for sustaining both life and cultures.
Sites such as Wandalli, Goudur, Bassapura and Chikka Hesaruru are located in the high-density vegetation landscapes of granitic and Dharwar schist valleys that are ideal for grazing cattle, which was a chief subsistence economy as indicated by the massive dimension of ashmounds and extensive number of cattle motifs in the settlement sites elsewhere. Multi-period settlement sites such as Bilamrayanagudda, Anandgal, Harvapura, Kotekal, Watgal and Maladkal range in periods from Pre-Neolithic, Neolithic, Iron Age and Early History. These sites have sheltered the above cultures for not less than 3000 years considering time bracket of 3000 BC to 300 AD for Neolithic – Early History.
Irrespective of four major kinds of landscapes (riverine, denudational, Dharwars, granodiorite/ dolerite on the younger granites) across northwestern part of Raichur Doab were explored and exploited during different cultural phases of Pleistocene and Holocene. The earliest to occupy was Middle Palaeolithic, the earliest to explore wider range of landscape was during Microlithic/ Mesolithic. Hunter-gathers of the Microlithic/ Mesolithic phase seem to have better advantage of various combinations of landscapes. But for a settled agro-pastoral group, one such landscape that supported their occupation in a long run was granodiorite and dyke valleys. Such landscapes have catered to their pastoral, agricultural, lithic tool needs and given a feeling of secure shelter in the summits. The scope of such landscapes is attested further by repeated reoccupation of the sites by Iron Age (and even continued during Early History); new iron technology and improvised political ideas might have better adapted to such landscapes.