Integrated Foraminiferal and Ammonoid Biostratigraphy of Jurassic Sediments in Jaisalmer Basin, Rajasthan

In the Post-Vindhyan times, major marine transgressions covered the areas of Kutch and Rajasthan, including the Jaisalmer Basin during Jurassic, although minor Permian transgressions are also known. These events could be documented from the well known exposures of Kutch and Rajasthan which entombed classic Cephalopod fauna. The foraminiferal components of Kutch Mesozoic were catalogued by Pandey and Dave (1993), recognizing 13 benthic foraminiferal biozones, establishing 8 chronostratigraphic units (stages). Within the outcropping marine Middle-Upper Jurassic succession of Jaisalmer, seven benthic foraminiferal zones have been recognized and correlation with Kutch Mesozoic established. However, the succession is interrupted by five hiatuses during - (1) Upper Bathonian, (2) Upper Callovian - Lower Oxfordian, (3) Upper Oxfordian - Lower Kimmeridgian, (4) Middle Kimmeridgian and (5) Upper Kimmeridgian - Lower Tithonian. Trangressive events during Lower Bathonian, Lower Callovian, Middle - Upper Oxfordian and Lower Kimmeridgian with intervening regressive pulses are also recorded. Badian, Charian, Dhosaian, Katrolian and Umiaian stages of Kutch ranging in age from Bathonian to Tithonian are recognized.