126-9 Islands of Anthropogenic Influence: Catena Analysis at Prehistorically Occupied (circa 3,000 BCE) and Unoccupied Residual Hills in Karnataka, South India.

Session: Geoarchaeology of Sites to Landscapes: Current Research on Long-Term Water and Soil Management and Maladaptation, Part II

Presenting Author:

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Abstract:

Over 5,000 years of human occupation and land use in North Karnataka, South India, clusters on and around granitic boulder hills that rise above a now largely agricultural plain. These slowly evolving, residual bedrock hills arose from a combination of deep chemical weathering and surface erosion of an etchplain or backwearing of a pediplain and occur throughout the tropics worldwide. Inselbergs or ‘island mountains’ are biodiversity hotspots offering unique microclimates due to their marked topographic difference from the surrounding plain. Recent research on Archean-aged hills in the region indicates a connection between erosion and relief with important feedback from fluvial incision on the plain (Gunnell et al. 2007) and that prehistoric human occupation more significantly correlates with denuded hills than slope and elevation factors (Bauer 2014). Though these hills formed over geological timespans, anthropogenic landform modifications since at least the Neolithic period (circa 3000 BCE) including terracing, water retention, and mound building has altered water flows, sediment transport, and pedogenesis. This geoarchaeological study will examine catenas at unoccupied and prehistorically occupied hillsites to examine differences in the timing, pace, and extent of erosional pulses and relate them to changes in local vegetation (i.e. plant cultivation and grazing) and social response (horizontal movement of occupation across the hills) over time. Sediment samples collected from profiles will be run through a variety of analyses to relate strata across the slope and characterize the nature of transport and/or soil formation. In a current landscape where these hills offer ecological and cultural refuge, grazing grounds for herds, and inputs to surrounding agricultural fields, an empirical understanding of accumulated human-soil/sediment histories is essential for assessing trajectories of present land use.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10205

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