江苏下、中三叠统牙形刺生物地层的研究

Study of the Middle and Lower Triassic conodonts biostraugraphy Jiangsu

江苏下、中三叠统分布于郯庐断裂东侧,响水—淮阴一线东南,主要出露于宁镇、茅山山脉、溧宜山区,苏锡地区亦有零星分布。在常州、江阴、苏州、句容、南通、启东、黄桥等地钻井中也揭示了三叠系地层。 从1924年以来,不少地层工作者对本区下、中三叠统地层提出不同的划分意见。本文主要以牙形刺为依据,参照头足类、瓣鳃类化石,结合岩性、电性特征综合分析研究。

Triassic strata are widely distributed in Jiangsu Province. Many geologists have made a great number of geological investigations and biostratigraphic studies of these strata, but up to now, there are many different opinions about the stratigraphic classification and correlation. The conodonts from Suzhou, Wuxi, Changzhou, Zhenjiang, Nanjing and Subei Basin are studied systematically by the author, and 7 conodont assemblage-zones are established. According to the conodont assemblage-zones, the lithologic and electronic characters, the Middle and Lower Triassic rocks, from bottom to top, are divided into the Lower Series: Lower Qinlong Formation (1-2 members), Upper Qinlong Formation (1-2 members); the Middle Series: Zhouchongchun Formation (1-2 members). These formations and members are correlative with the concerned ones internally and externally.