ass="MsoNormal" style="margin: 0cm 0cm 0pt">
an lang="EN-US">ace="Times New Roman">Based on the analysis of the tectonic deformation in the southern Tazhong Oilfield, the present study proposes for the first time a large kink structure as an essential controlling factor to explain sedimen- tary history and petroleum trap formation in Ordovician carbonates of the Tazhong area. This model is dif- ferent from previous models that focused on faults and related structures as the key tectonic control on sed- imentary sequences and trap formation. The result illustrates that at least three episodes of tectonic de- formation occurred in the Tazhong area during the Paleozoic time. The Ordovician sedimentary pattern was essentially controlled by the first episode of deformation that established a symmetrical conjugate chest-like anticline. The topography of the epeiric continental shelf was characterized by an isolated platform sur- rounded by two symmetrical slope-breaks to the south and north, although the two slope-breaks had differ- ent inclinations sloping angles. The platform margin carbonate reservoirs are juxtaposed with the slope source rocks. Such a tectonic setting maintained a balance of subsidence rate and sedimentary compensation rate, thus maintained a shallow marine carbonate platform during the Ordovician. The thick reef complex of the Late Ordovician Lianglitag Formation formed in platform margin. Karst-type reservoirs of the Low- er-Middle Ordovician Yingshan Formation in the northern slope and the Kaitian an>an style="font-family: 宋体; mso-ascii-font-family: ’times new roman’; mso-hansi-font-family: ’times new roman’">（an>an lang="EN-US">ace="Times New Roman">Upper Ordovicianan>an style="font-family: 宋体; mso-ascii-font-family: ’times new roman’; mso-hansi-font-family: ’times new roman’">）an>an lang="EN-US">ace="Times New Roman"> reef- complex Lianglitag Formation in the Slope-Break are both considered oil-gas exploration targets in theTazhong Low-Uplift.an>
