An Encyclopaedia of Indian Archaeology v1.c14.s2.11

v1.c14.s2.11

Between 1971 and 1976 a team consisting of B. Allchin of Cambridge Univ., A.S. Goudie of Oxford Univ. and K.T.M. Hegde of M.S. Univ. of Baroda carried out extensive field and laboratory studies for reconstructing the palaeoclimatic and archaeological history of the desert. Though they explored widely, their work was mainly concentrated on the dune sites at Pavagarh e. of Baroda, Budha Pushkar near Ajmer and Benara, e. of Jaipur. The major conclusions of their study are: (1) The active dunes today occur in Rajasthan only in the w. and n. Dts, w. of the 250 mm isohyet. Therefore the dunes are formed in a climate with annual rainfall of 250 mm or less. (2) Fossil dunes on the other hand occur over a much larger area, their e. limit defined by a line running from Pavagarh in the s., through Budha Pushkar and Benara in the centre to Hissar in the n., the annual rainfall along this line being roughly 900 mm at Pavagarh, 600 mm at Jaipur and 400 mm at Hissar. It follows therefore that in the past the rainfall along this line was 250 mm or less when the dunes were formed here. (3) There are two major phases of dune activity in the area, the first one occurring during the earlier part of the Upper Pleistocene [9.8.2], followed by a period of increased rainfall when the dune surfaces were deeply weathered to a brown colour by complete leaching of calcium carbonate. Middle Palaeolithic [4.3] man occupied this weathered surface in the Budha Pushkar basin. (4) This was followed by a second arid phase when fresh dunes were formed that covered the older weathered surface. The surface of these later dunes is covered with carbonate nodules and root casts formed by leaching due to increased rainfall after the dunes were formed. On this surface microlithic industries occur widely suggesting increased human occupation in response to an improved climate.