1.Earth and Space Sciences|Peking University|Beijing |100871； |2.Nanjing Institute of Geology and Palaeontology|Chinese Academy of Sciences|Nanjing |210008； |3.Exploration and Development Research Institute|Tarim Oilfield Company|Korla|Xinjiang |841000
Unconformably contact between the sandstonesiltstone of the Sangtamu Formation and limestone of the Lianglitag Formation in Ordovician，Kaitian，exists in the Tazhong High，central Tarim Platform. It distinctively indicates a regional tectonic uplift event happened with duration of about 1 Ma. A suite of coalesced，collapsedpaleocave sediment occurred from the 4 125.6～4 133.9 m drilling core of the well Zhonggu 31 is assigned to the Member 3 of the Lianglitag Formation. The depth between the caveceiling and the top of the Lianglitag Formation is about 190 m. The sedimentfill facies mainly consist of chaotic breccias sourced from the cavewall，which the latter had been reefal rocks originally. Centimeters thick of laminated silciclastic debris implicates hidden river facies. Sediment of noKaitian time has not been found. Such a case implies that the formed and filledprocessions of the paleocave was consistent to the timeinterval between the postLianglitag Formation and preSangtamu Formation timely. The depth of the vadose with dissolutional excavation was generally not lower than its surrounding sealevel. Even though the unremained thickness of the Member 1 of the Lianglitag Formation，which had been eroded by karstfication of the earth surface in advance of a new cycle transgression of the Sangtamu Formation could be negative，the exposed part of the Lianglitag Formation above the sealevel was minimal of 190 m at least. Reefal rocks of the cavewall were formed at a depth about 30 m of the seafloor. Thus，the sum of the exposed high plus the reef community depth results the amplitude of the uplift.