Temporal- spatial analysis of sedimentary environments of the Upper Cretaceous carbonate deposits in the Bajestan area (North of Lut Block)

In this study, microfacies, sedimentary environment and sedimentary model of the Upper Cretaceous carbonate deposits in the Bajestan region were studied and analyzed in four sections Chachool, Shahrak Sanati, Mazar and Bahabad. These deposits are exposed in different sections with different thicknesses. Based on sedimentary texture, petrographic and biotic evidences, 6 carbonate microfacies belonging to three facies belts of lagoon, shoal and shallow open marine located on the inner ramp were identified in these deposits. Comparison of microfacies and facies zones of different sections show a slight and gradual increase in the depth of Cenomanian and a significant increase in Santonian- Early Campanian relative to Cenomanian. Furthermore, the depth of these sediments in Chachool and Shahrak Sanati sections is almost similar and shallower than the others, while Mazar and Bahabad sections represent deeper environment. Accordingly, the approximate coastline trend seems to be east, northeast- west, southwest. However, the presence of different amounts of siliciclastic sand in some facies could be related to the tectonic activity along the basement faults in the area.