SEDIMENTOLOGY AND PALEOGEOGRAPHY OF THE REGRESSIVE-TRANSGRESSIVE KURNUB GROUP (EARLY CRETACEOUS) OF JORDAN

The Early Cretaceous Kurnub Group of Jordan consists of three regressi ve-transgressive (fluvial-marine) depositional sequences in northern J ordan, recorded here for the first time, whereas continental clastics dominated central and southern Jordan. Deposition of the Kurnub Group started in the late Neocomian above st regional angular unconformity b y basal conglomerate and sandstone facies association of an alluvial b raidplain origin. During this time the Tethys Seaway was located to th e north and northwest of Jordan which afterwards, during the Barremian , advanced in a south-and southeastward direction flooding north Jorda n and giving rise to a tidal flat-coastal swamp sequence. Following a subsequent regression of the sea, unconfined braidplain deposits cover ed the area. The most extensive transgression of the Tethys inundated the region during the late Aptian and early Albian where a mixed silic iclastic-carbonate sequence with interbedded inner shelf carbonates an d tidal marsh-coastal swamp black shales and lignites was deposited. T he next and last regression took place in the middle Albian where a th in meandering river elastic sequence was deposited. Finally, shallow-m arine sedimentation resumed over the region during the remaining time of the Kurnub Group which at the same time prepared for the subsequent regional Cenomanian transgression. Upon comparison with global eustat ic curves, these three incursions of the Tethys sea in Jordan are to a great extent in accordance with the global sea-level fluctuations. Th e various formations of the Kurnub Group and their informal units that are established here for the first time can readily be correlated wit h equivalent deposits in adjacent countries. The distribution of the s horelines of the Barremian, Aptian and Albian on both sides of the Dea d Sea Transform offers new evidence for 100 km northward displacement of the Arabian plate against-the Sinai-Palestine plate.