Study On The Silurian Sedimentary Environment And Facies Of Clastic Rocks In The Eastern Tarim Basin

The eastern Tarim Basin located in the eastern Tarim Basin, stretched12millionsquare miles, is rich in hydrocarbon resources, low degree of prospecting and high potentialfor exploration. The previous studies just focused on the periphery of Manjiaerdepression,Tazhong area and the south slope of tadong areas, The view of thesource direction， the division of sequence and the type of sedimentary facies are notuniform due to the lack of an overall study and the limit of the data. In this paper, through theanalysis of the rock constituents, heavy mineral data, maturity and cathodoluminescence data,finaliy found out the tectonic setting of the provenance，the type of the parent rock and thesource direction; Used plentiful geological and geophysical data, and based on thefundamental principles of sequence stratigraphy, the isochronal framework of sequencestratigraphy were established. Based on the identification of facies markers in core，log andseismic，the types and distribution of the sedimentary facies under the isochronal frame ofsequence stratigraphy were discussed. The research has acquired following results:(1) The tectonic setting in source areas of Silurian is the recycled orogenic zone andvolcanic island arc. The main parent rock is the metamorphic rock, then the Plutonic andvolcanic rock. The southeast is the main source direction.(2) Based on the division of sequence stratigraphic boundary, all the sequences and theirboundaries of the Silurian were decentralized. The Silurian can be subdivided into2second-order sequences,5third-order sequences with15fouth-order sequences. Throughsequence stratigraphic subdivision and correlation of key wells and seismic sections，thesequence stratigraphic framework and sedimentary system models were established.(3) Integrated core facies, particle size analysis, log facies, seismic facies identificationand seismic attribute analysis, tideland facies, littoral facies, braided river delta facies andneritic shelf have been identified. and further subdivided into foreshore, offshore, shelf andsand flat etc. And combined with the formation thickness and the result of the clusteranalysis of seismic attributes, finally the plane distribution features of sedimentary faciesare analyzed under the sequence stratigraphic framework.