Permian climatic and paleogeographic changes in Northern Gondwana: the Khuff Formation of Interior Oman

Detailed stratigraphic, paleontologic, and petrographic data from the Middle Permian Khuff Formation exposed in the Haushi-Huqf area of Interior Oman provide new insight into the Permian climatic evolution of the northern Gondwana margin, and on the still debated timing of Neotethys opening between Gondwana and the Cimmerian blocks. The Khuff Formation is interpreted to record a major transgression of Neotethyan waters in Wordian times (Middle Permian), at a stage of full oceanization and tectonic quiescence, when thermal subsidence caused final drowning of rift shoulders and deposition of marine carbonates onto vast portions of stable Arabia. The petrographic composition of Middle Permian sandstones indicates a post-rift stage, and documents a long-term increase in mineralogic stability ascribed to a shift toward warm-humid climatic conditions, coupled with reduced relief and longer transit times of detritus from source to basin. Raising temperatures and northward latitudinal drift towards lower tropic latitudes throughout the Permian are fully documented by rich transitional marine faunas and available paleomagnetic evidence.