An Encyclopaedia of Indian Archaeology v2.c46.117

v2.c46.117

The c. Tapti valley has preserved lacustral and fluvial deposits the maximum thickness of which is around 300 m in the piedmont zone of the Satpuras. At certain places bed-rock basalt is present 90 m below mean sea level. It appears that during the early Tertiary times there existed a semimarine environment which was gradually replaced by low-energy fluvio-lacustral conditions in the later Tertiary. High-energy fluvial conditions of the Pleistocene [ 9.8.2] are represented by alternations of gravels, sands and silts in the upper 100 m portion of the alluvium. The exposed (about 30 m) alluvium consists of calcreted, brownish silts, sands and cobbly pebble gravels. Two cut-and-fill terraces are commonly seen in the entire valley. The older fill forms a conspicuous surface at elevations ranging in height from 15 to 25 m above the modern bed level. The younger fill is inset into the older fill. A few fossil bones of *Bos*. sp. along with the Middle Palaeolithic [4.3] tools found in the calcreted gravels suggest a late Pleistocene age for the major portion of the exposed older alluvium of the river.