摘要
贵阳地区早、中三叠世位于台地边缘剧烈相变地带,在海平面变化由快速上升、缓漫下降到突然下降的变化过程中,形成了一套发育于二叠纪末、三叠纪初的淹没事件所形成的凝缩序列为基底的碳酸盐台地沉积体系。包括了三套具有密切成因联系且富有规律性的岩石地层系统。
Three sets of genetic lithostratigraphical systems of Early-Middle Triassic in Guiyang area are respectively development platfrom, platform margin and platfrom margin slope, which belong to the tectonic setting of passive continental margin.
The stratigraphical system belonging to platform facies includes the following formations: 1. Dayie Formation (limestone and shale beonging to platform low slope facies); 2. Anshun Formation (dolomite belonging to lagoon facies behind reef); 3. Guanling Formation and Yangliujing Formation (dolomite belonging to lagoon facies behind carbonate reef); 4. Gaicha Formation (dolomite and sand-shale stone belonging to littoral-platform facies).
The lithostratigraphical system belonging to platform margin facies contains the following formations: 1. Dayie Formation (limestone and shale belonging to platform low slope facies); 2. Anshun Formation (limestone and dolomite belonging to beach fa-ciees); 3. Poduan Formation and Longtou Formation (limestone and dolomite belonging to reef facies); 4. Gaicha Formation (dolomite belonging to reef top facies).
The lithostratigraphical system belonging to platform margin slope facies includes the following formations: 1. Lulou Formation (shale and limestone belonging to shelf facies ); 2. Zhiyun Formation and Qinyan Formation (shale and breccia belonging to platform margin slump slope facies); 3. Bianyang Formation (shale and limestone belonging
to shelf facies).
The lithostratigraphical system of this area is formed in four developing periods of carbonate platform margin: the first period characterized by carbonate platform low slope, the second period by depositional margin of carbonate beach-falling accumulation type, the third period by depositional margin of carbonate reef-falling accumulation type and the fourth period by platform margin of carbonate beach-sedimentation type. All of them belong to a set of carbonate strata formed in the process of sea level changes : rapid rising (Ind. ), slow rising (Olk. and Ans. ), gradual falling (Eariy Lat. ), slow falling (Late Lat. ) and rapid falling (the end of Lat. ). The evolution and development of carbonate platform that is composed of these strata has undergone four periods: starting period, catchingup period, keeping period and dying period.
出处
《贵州地质》
1992年第3期269-278,共10页
Guizhou Geology
