Abstract:

In accordance with the recent results of several seismic sections accross Takli-makan Desert in length and breadth made jointly by Sino-American geophysicis-ts,the tectonic evolution and division of Tarim Basin have been studied andpresented here.It is considered that three stages in the basin's evolution process may be divided,i.e.,the formation of geosyncline and platform basement during Archaeozoic;the formation of sedimental blanket of platform during Sinian-Paleozoic and the formation of a continental sedimentary basin of Meso-Cenozoic.Among them,the last stage can be further subdivided intoTriassic-Jurassic faulted basin substage,the Cretaceous-Eogene faulted depression substage,the Neogene depression substage and the Quaternary depauperization substage.Thus the basin is recognized to be a superposed complex hydrocarbon-bearing basin with polycycles.According to its structural features,the basin can be divided into eleventectonic units of second-order,i.e.Central uplift,Tabei uplift,Baicheng depres-sion,North depression,Southwest depression and Southeast depression,and Qiemo-Ruoqiang,Kuruktag,Keping,Teklic and Altun faulted uplifts.Source rocksfrom Paleozoic to Tertiary system are well developd in this basin.Among thesetectonic units,Tabei uplift is the best in hydrocarbon potential,followed suc-cessively by Southwest depression,Baicheng depression,North depression,Central uplift and Southeast depression.Taking other hydrocarbon-bearing basinsinto account,Tarim is the fouth largest one in China.