The Middle and Late Jurassic Intrashelf Basin of the Eastern Arabian Peninsula

Book excerpt: This memoir provides a thorough review of the geology of the rimmed Arabian Intrashelf Basin, reconciling differing interpretations of lithostratigraphy, sequence stratigraphy and biostratigraphy. Variation of energy levels and facies due to its setting in the SE palaeotradewind belt are described. The roles subtle tectonism played in developing the basin and in the Late Jurassic creating restriction by uplift and exposure of the Tethys shelf are evaluated. The intrashelf basin formed during rising sea level as a single rimmed carbonate intrashelf basin. A possible global cooling phase resulted in a lowstand which restricted the basin, resulting in petrographically unique carbonate source rock facies dominated by cyanobacterial deposition. Two subsequent 3rd order carbonate sequences largely filled the basin. Eustatic change concomitant with uplift of the Tethys shelf resulted in alternation of carbonates and evaporites (gypsum-anhydrite) across the region. The end result was a sealed intrashelf basin which preserved early-formed porosity and confined generated hydrocarbons within the intrashelf basin facies.