Study On The Lithofacies Palaeogeography Of The Mesozoic And Cenozoic In Arabian Plate And Adjacent Areas

In this paper,using the basin data of the IHS database and a large number of published literatures,using the theory of plate tectonics and sedimentology,the Mesozoic and Cenozoic geological records of the 53 basic tectonic units of the Arabian plate and its adjacent areas are merged into 15 types of lithofacies assemblages and 8 palaeogeographic types,fill in the different basic tectonic units of ArcGis attribute table in different periods,and compile the lithofacies palaeogeographic maps of the six key periods of the Mesozoic and Cenozoic,revealing the lithofacies and Paleogeographic characteristics and evolution law of the Arabian plate and adjacent areas.The 15 types of lithofacies assemblages are mudstone,sandstone + mudstone,conglomerate + sandstone + mudstone,sandstone + mudstone + carbonate rock,carbonate rock,evaporite,evaporite + carbonate rock,evaporite + debris rocks,coal-bearing rock series,volcanic rocks,volcanic rocks + clastic rocks,volcanic rocks + carbonate rocks,metamorphic rocks,metamorphic clastic rocks and orogenic complexes.The 8 paleogeographic types are island arc,alluvial area,bathyal area,shallow sea area,coastal shallow sea area,littoral shallow sea + salt marsh area,lake area and uplift and erosion area.During the Triassic period,uplift and erosion area covered the largest area in the Arabian Plate and its adjacent areas,littoral shallow sea + salt marsh and evaporite developed in the Zagros basin and its southeastern region,shallow sea developed in the central and eastern Iran,and alluvial area developed in the Central Iran basin.During the Jurassic period,littoral shallow sea + salt marsh area expanded,uplift and erosion area decreased relatively,island arc appeared in the central Iran,forming abundant volcanic rocks.During the Early Cretaceous and Late Cretaceous period,the Arabian Plate and its adjacent areas were dominated by shallow sea and bathyal area,there were extensive island arcs in the northeastern of the Zagros Basin.During the Paleogene period,the shallow sea area covered a wide range in the Arabian plate and adjacent areas.The Red Sea basin and its surrounding areas were littoral seas & salt marshes,and the Iranian microplates developed island arcs.During the Neogene period,littoral shallow sea + salt marsh expanded.The alluvial area covered the largest area,and the northern part of the Arabian platform and the Iranian micro-plate area were alluvial areas.The paleogeographic characteristics and its evolution of the Mesozoic and Cenozoic in the study area are closely related to the opening and closing of the Tethys Ocean.During the Triassic period,the Mid-Tethys Ocean between the Sanandaj-Sirjan block and the central Iranian block rapidly expanded and began to subduct to the north side of the block.During the Middle Triassic,the central Iranian block,Alborz block and outer Caucasus block collided and formed a metamorphic basement.During the Jurassic period,the Mid-Tethys Ocean expanded rapidly and subducted northward,and the northern terrain collided in the early stage developed back-arc extension and formed a number of small ocean basins,in the early Cretaceous,the ocean basin expanded rapidly to the peak.In the late Cretaceous,the Mid-Tethys Ocean and the back-arc Ocean Basin gradually shrank.During the Paleogene period,the ocean basins gradually closed,and land-land collisions began,accompanied by magma activity.Since Paleogene,the Arabian plate continued to move slowly to the Eurasian plate in the northeast direction,resulted in fold and fault increased in the Zagros region.