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C.), Special Publication of NCAOR, Goa, 2005, pp. 184–197. 23. Korisettar, R. and Ramesh, R., The Indian Monsoon: Roots, rela- tions and relevance. In Archaeology and Interactive Disciplines, Indian Archaeology in Retrospect, Vol. III (eds Settar, S. and Korisettar, R.), Indian Council of Historical Research, Manohar Publications, New Delhi, 2002, pp. 23–59. Received 23 June 2006; revised accepted 11 May 2007 Late Quaternary bedrock incision in the Narmada river at Dardi Falls Avijit Gupta 1 , Vishwas S. Kale 2, *, Lewis A. Owen 3 and A. K. Singhvi 4 1 School of Geography, University of Leeds, Leeds, LS2 9JT, UK 2 Department of Geography, University of Pune, Pune 411 007, India 3 Department of Geology, University of Cincinnati, Cincinnati, OH 45221, USA 4 Planetary and Geosciences Division, Physical Research Laboratory, Ahmedabad 380 009, India Fluvial incision in bedrock is common in many rivers of the Indian Peninsula. We investigated a site in the gorge of the Narmada river at Dardi Falls that displays geomorphic evidence of intense bedrock erosion. We report here a terrestrial cosmogenic radionuclide date from an eroded rock surface in Peninsular India. Ter- restrial cosmogenic radionuclide dating of the rock surface adjacent to the inner gorge indicated that the minimum age of the gorge is 40 ka. We suggest that the present gorge has developed in two phases, sepa- rated by a period of large-scale aggradation that filled the gorge with alluvium. Gorge formation is most likely associated with tectonic activity in the Son– Narmada–Tapi lineament zone. Erosion at this scale also requires large palaeodischarges with high unit stream power. This study illustrates the powers of combining newly developing geomorphic, DEM and geochronological methods to elucidate the dynamics and nature of landscape evolution. Keywords: Bedrock erosion, cosmogenic radionuclide dating, DEM, gorge, Narmada. THE erosion-dominant landscape of the Indian Peninsula is characterized by rivers downcutting into underlying bedrock. Many large rivers of Peninsular India flow through scablands, rock gorges and knickpoint-related waterfalls. However, the dates of such downcutting or rates of erosion are not known for any of the Peninsular rivers, with the exception of the pre-Holocene Tapi Gorge 1 and the histori- cal evidence of rapid bedrock erosion by the Indrayani river 2 . We report here a 10 Be terrestrial cosmogenic ra- dionuclide surface exposure age determination for the Narmada Gorge at Dardi Falls and discuss its significance in terms of regional geomorphology and bedrock erosion. The 1300-km long Narmada river in Central India flows through three major bedrock gorges separated by alluvial basins. In the downstream direction these are the Marble Canyon near Jabalpur, Punasa Gorge near Khandwa, and Dhadgaon Gorge west of Badwani 3 . The present study is on the Punasa Gorge, where at Dardi (22°18′49″N and 76°21′11″E) the Narmada river (Figure 1) has eroded a >100 m deep and 1–7 km wide gorge with an inner canyon 4 (Figure 2). A ca. 10-m high waterfall occurs at the head of the inner canyon. Thick (>50 m) alluvial deposits of late Quaternary age overlie the bedrock on the right bank (Figure 2 a), whereas the left bank rises to a set of strath terraces with abraded and water-polished rock surfaces. The back of the terraces is covered by riverine alluvium and soil. Similar rock surfaces are likely to extend below the alluvium that occurs on the top of the right bank. Quartzites of the Vindhyan Supergroup constitute the local bedrock. To the south, a major fault runs parallel to the Narmada river 5 (Figure 1 c). The river flows through the large tectonic feature of the Son–Narmada–Tapi (SONATA) lineament zone characterized by neotectonism, moderate seismicity 5–7 , and several longitudinal fault-bound blocks with an episodic history of vertical and lateral movements 6 . The resulting river morphology demonstrates tectonic and structural control as illustrated in Figure 1 c and d, which is a digital elevation model (DEM) of the Dardi Falls area