上扬子区下寒武统的层序地层格架及其形成的古地理背景_梅冥相.pdf

20　 2 　　　 Vol.20　No.2 2006 6 GEOSCIENCE Jun.2006 1, 2 1, 2 1, 2 1, 2 1, 2 梅冥相 , 张　丛 , 张　海 , 孟晓庆 , 陈永红 (1. , 　100083; 2. 、 , 　100083) :, , 。, , 5, —;, , “ (CS) + (HST)” “ (TST) + (CS) + (HST)”, , 。, , , 。——— “ ”, “”。, ;, 。, , 。 :;;; :P539.2　　　　:A　　　　:1000 - 8527(2006)02-0195 - 14 Sequence-Stratigraph ic Fram eworks and Their Form ing Backgrounds of Paleogeography for the Low er Cambrian of the Upper-Yangt e R egion 1, 2 1, 2 1, 2 1, 2 1, 2 EI ing-xiang , ZHANG Cong , ZHANG Hai , ENG Xiao-qing , CHEN Yong-hong (1. S tateK ey Laboratory of GeologicalProcesses andM ineralR esources, China University of Geosciences, B eij ing　100083, China; 2. Key Laboratory of Lithosphere ectonics and Lithoprobing echnology of M inistry of Education, China University of Geosciences, Beij ing　100083, China) Abstract:In theUppe-rYangtze region, especially inGuizhou Province and its adjacentareas, theLowerCam- brian iswelldeveloped and ismarkedby a succession from black shale to carbonate rocks. And this stratigraph- ic successionmakes up a complex and regular sequence-stratigraphic framework. The Lower Cambrian in the study area constitutes a second-order sequence that can be further subdivided into five third-order sequences, and form a regularly cyclic succession of the transgression-regression. There is a regularly verticalstacking pa-t tern for the third-order sequence in the second-order sequence. From the bottom to the top, third-order se- quences that are characterizedby the succession of “the CS (condensed section)+HST (high-stand system tract)”are changed into those marked by the succession of “the TST (transgressive system tract) +CS+ HST”, c