Discovery and geologic significance of paleokarst unconformity between Changxing Formation and Feixianguan Formation in Shunan area of Sichuan Basin
2010; Science Press; Linguagem: Inglês
ISSN
2095-8927
Autores Tópico(s)Paleontology and Stratigraphy of Fossils
ResumoThere exists a long-time dispute for the contact relation between the Permian and the Triassic in Shunan area of Sichuan Basin.The drilling break phenomenon commonly occurred during the drilling process,and a great quantity of karrens,dissolved fractures,caves and karst breccia were found in the rock cores.The comprehensive analysis shows that there is not the successive sedimentation between Changxing Formation and Feixianguan Formation in the Shunan area of Sichuan Basin.The paleokarst in Changxing Formation is highly-developed and causes the paleokarst unconformity at the top of Changxing Formation.The Luzhou palaeo-high embryo and the exposed corrosion due to a major regression at the end of the Permian are the key factors to form and develop paleokarst.Actually,the paleokarst can optimize the hydrocarbon accumulation capacity in carbonate rocks.The uncomfortable surface can be taken as the high-quality channel of the long-distance hydrocarbon migration.The discovery of the paleokarst unconformity at the top of Changxing Formation proved the existence of the uncomfortable contact relation between the Permian and the Triassic.The further exploration of biothermal limestone in Changxing Formation of Sichuan Basin was presented.
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