Study On Lithofacies-palaeogeography Of The Mesozoic And Cenozoic In The Caribbean Tectonic Region Of The Tethys

This paper is based on published literature and IHS database.Combined with a small amount of seismic and drilling data,using the theory of plate tectonics,petrology and lithofacies paleogeography and other related theoretical knowledge.The structural stratigraphic zone of the Caribbean tectonic region of the Tethys is divided.The geological records of the main structural units are studied,and the lithofacies paleogeographic maps of the Triassic,Jurassic,Upper Cretaceous,lower Cretaceous,Paleogene and Neogene are compiled.The distribution and evolution of lithofacies palaeogeography of the Mesozoic and Cenozoic in the Caribbean tectonic region of the Tethys are revealed.The Caribbean tectonic region of the Tethys can be divided into five tectonic-stratigraphic zones:(1)Basins on the southern margin of the North American continent.(2)The Neoproterozoic-Palaeozoic deformation zone on the southern margin of North America and the Mesozoic and Cenozoic Mexico Ocean Basin.(3)Cordillera-Caribbean Mesozoic and Cenozoic deformation zone and ocean basin.(4)Mesozoic and Cenozoic deformation zone in the northwestern margin of South America.(5)Sedimentary basins in the northwestern South American Craton.The basement and sedimentary cap layer of different structure-stratigraphic zones are obviously different.The basins on the southern margin of the North American continent are generally based on the Precambrian,with the Paleozoic-Cenozoic as the capping layer.Paleozoic is widely distributed,mainly shallow marine facies,Mesozoic and Cenozoic shallow marine facies,lacustrine facies,alluvial facies and uplift areas coexist;The Neoproterozoic-Palaeozoic deformation zone on the southern margin of North America mainly develops Mesozoic and Cenozoic neritic carbonate rocks on the Paleozoic basement,with mudstones,sandstones and evaporites locally;The basement of the Cordillera-Caribbean Mesozoic and Cenozoic deformation zone changes southward,and the caprock is dominated by neritic carbonate rocks;The Mesozoic and Cenozoic deformation zone in the northwestern margin of South America is based on the Paleozoic and mainly developed Mesozoic and Cenozoic sandstone,mudstone,and carbonate neritic facies;The sedimentary basin in the northwestern part of the South American Craton is the basement of the Precambrian.The Paleozoic is discontinuous,dominated by neritic sandstones and mudstones,partially carbonated.The Mesozoic and Cenozoic are mainly neritic-alluvial sandstone and mudstone.There are 13 lithofacies assemblages and 8 paleogeographic units in the Mesozoic Cenozoic in the Caribbean tectonic region of the Tethys.The western margin of North America is dominated by sandstone,mudstone and carbonate rocks in shallow sea area,while the south side of North America and part of South America are dominated by conglomerate,sandstone and mudstone in alluvial area.In Jurassic,the Mexican ocean basin appeared,and the shallow sea area and coastal shallow sea salt marsh area developed around it.In the early Cretaceous,the Mexican ocean basin was formed and the shallow sea area expanded.Only in North and South America,there were alluvial conglomerates,sandstones and mudstones,and the Mayan block was a salt marsh.In the late Cretaceous,the Caribbean ocean basin was formed,the shallow sea area was expanded,and the island arc was most developed.The Paleogene basically inherited the lithofacies paleogeographic pattern of the late Cretaceous,and the main changes were the decrease of island arc and the slight increase of continental lake area.The Neogene inherited the Paleogene lithofacies palaeogeographic pattern,the main change is that the oxquia block became a uplift area,and the northern margin of South America continent evolved mainly from alluvial sandstone and mudstone.The Mesozoic Cenozoic lithofacies paleogeographic distribution and evolution process of the Caribbean tectonic region of the Tethys are obviously affected by multiple factors,such as the separation of the North American continent,the South American continent,the intermediate block,the formation of the ocean basin between them,and the subduction of the ocean crust to the South American plate.