Analysis Of Continental Collition Kinetics And Basin-Mountain Coupling Relationship In The South Yellow Sea Basin Of Lower Yangtze Sea Area

Studies have shown that the Sulu orogenic belt formed in Triassic by thesqueezing process of the Yangtze block and North China Craton,which is also thecause of the foreland basin of the South Yellow Sea. The evolution of the Sulu orogentectonic directly controls the South Yellow Sea foreland basin sedimentary evolutionTherefore, this study is of important theoretical significance by focusing on Suluorogenic belt, especially Qianliyan which is formed due to continent-continentcollision and the basin-mountain coupling relations between the Qianliyan uplift andthe South Yellow Sea Basin, can reveal the kinetic mechanism of the continent-continent collision of North China and Yangtze plate which determines the nature ofthe Mesozoic-Paleozoic basins of the South Yellow Sea, and also guide the oil andgas exploration, evaluation and research.However, so far, previous studies mostly concentrated in the foreland basin ofthe land area and the Sulu UHP metamorphic belt.The sduty of the continent-continent collision dynamics of the South Yellow Sea Basin in the Lower Yangtzewaters and the foreland basin is relatively limited.A variety of subduction exhumationmodels based on the Sulu ultrahigh-pressure metamorphic belt is applicable to watersalso needs further study to verify.On the basis of previous research, integrated use of petrography, isotopegeochronology, structural geology, geophysics methods, Especially use the methodsand means of the foreland basin in the petroleum geology, we study the microscopicidentification of characteristics of eclogite from Yangkou in Qingdao and QianliyanIsland in Haiyang. We collect a large number of the Sulu UHP metamorphicchronological data and redetermine the protolith age and metamorphic age of UHPmetamorphic rocks. Finally,based on2D seismic data and the latest interpretation ofseismic profiles, we study the foreland basin system in the South Yellow Sea andanalysis the coupling between the ancient collision orogenic belts and sedimentarybasins in Qianliyan uplift first-line,and the dynamics of the Lower Yangtze waters ofthe South Yellow Sea Basin continent-continent collision, obtain the followingunderstanding. (1) The Qianliyan Island eclogite has weak tectonic deformation and strongretrograde metamorphism.Most of the eclogite change to the garnet amphi-bolites,which similar to the CCSD-MH retrograde eclogite characteristics,but unlikethe southwest Tianshan eclogite which change into the glaucophane schist.TheYangkou eclogite has strong tectonic deformation and weak retrograde,which isdifferent from the eclogite from China Continental Scientific Drilling Project mainhole in Donghai County and southwest Tianshan.(2) The Sulu UHP metamorphic rocks are mostly formed in Neoproterozoic(750-800Ma),Small part formed in the Paleoproterozoic-Mesoproterozoic (1001-2530Ma);Sulu ultrahigh-pressure metamorphism began in the Middle Triassic (-249Ma),about249-219Ma for the ultrahigh-pressure metamorphic stage,About219-201Ma age of retrograde metamorphism of UHP metamorphic rocks.(3) The UHP metamorphic belt experienced a complex dynamics process withmultiplicity subduction and multi-stage exhumation. Therefore,based on the previousstudies of continent-continent collision evolution model,we propose the continent-continent collision evolution model of the Yangtze/North China plate in SouthYellow Sea Basin of the lower Yangtze Sea.(4) We think that the foreland basin of the South Yellow Sea includes the threeparts of the wedge top, foredeep, forebulge.The wedge are Qianliyan thrust belt andimbricate thrust belt in the northern basin. The foredeep include Northeast depressionand northern depression.the forebulge including most of the uplift and slope areas inthe south of Northern depression and Northeast depression in South Yellow Sea Basin.We further proposed the establishment of a model of the foreland basin system of theSouth Yellow Sea,and basin-mountain coupling model which is a relationshipbetween the foreland basin of the South Yellow Sea and the Sulu orogenic belt.(5) The drilling data and seismic data reveal the relationship of basin-mountaincouplingbetween the foreland basin of the South Yellow Sea and the Sulu orogenicbelt. The thrust nappe structure of the Sulu orogenic belt directly controls the sedi-mentary filling of the foreland basin of the South Yellow Sea.