Jurassic benthic foraminiferal diversity, bathymetry and paleoenvironment of the Jaisalmer Basin (Western India)

摘要

This contribution presents an ammonite age constrained benthic foraminiferal dataset based on a study of 77 samples spanning from Bajocian to Early Tithonian from Jaisalmer (Western India). Species distribution and diversity are documented and changes therein are interpreted in terms of inferred bathymetry, shifts in sea level and paleoenvironment. The similarity and dissimilarity of benthic foraminiferal species from the adjoining Kachchh Basin (Western India) is also discussed. Results indicate that at Jaisalmer, sea level influenced facies deposition and both in turn, in a shallow marginal epicontinental setting, governed the distribution of benthic foraminifera. Further, the observed diversity patterns recognized bed-by-bed are governed by local conditions of the basin but at the stage- and family-levels, are influenced by global eustasy. The strong species dissimilarity observed between adjacent Jaisalmer and Kachchh basins and of increasing similarity at the family-level is most likely a reflection of large-scale changes in global eustasy.