OCCURRENCE AND ORIGIN OF GYPSUM DEPOSITS AT JAMSAR AND PALLU IN NORTHWEST RAJASTHAN

Surface and near-surface Quaternary gypsum deposits of lacustrine and pedogenetic origins are abundant in northwest Rajasthan. The lacustrin e forms are horizontally bedded gypsum deposits and pedogenetic crusts are massive, nodular and powdery pans. The lacustrine gypsum deposits are the locales of palaeolake basins and are in association with a se rir surface. The pedogenetic gypsum pans occur in pockets along the pa laeochannels, especially in the dune country. The influence of climati c variation and the control of tectonism are discussed on the basis of observations at Jamsar and Pallu in northwest Rajasthan.