江汉盆地早寒武世生态地层及生物古地理特征

EARLY CAMBRIAN ECOSTRATIGRAPHY AND PALAEOBIOGEOGRAPHY OF THE JIANGHAN BASIN

本文通过对江汉盆地6个地区早寒武世地层剖面古生态研究,建立了23个化石群落,通过群落生境型的分析,揭示了江汉盆地早寒武世海平面及古地理特征的演变,并将研究区早寒武世生态体系的演化划分8个阶段。通过对江汉盆地早寒武世生态地层的研究,本文建立了该盆地生态地层系统,其中包括23个群落带和11个群落组,并阐述了各群落组的分布、组成、生态环境特征和顶底界线以及各群落组与油气的关系。古生物地理特征分析表明,研究区西南缘石门杨家坪地区早寒武世早沧浪铺期之前属过渡区系,自晚沧浪铺期开始隶属于扬子生物区系。最后对过渡区与扬子区的界线进行了初步探讨。

Based on a study of the Early Cambrian paleoecology and an analysis of the community habitat type, the Early Cambrian sea-level change and paleo-geographical evolution in the study area are suggested and the Early Cambrian ecologic system is divided into eight stages in this paper. The authors establish the Early Cambrian ecostratigraphic system of the study area, which contains twenty-three community zones and eleven community Formations. Besides the distribution, composition , ecologic environment evolution and top and bottom boundary lines of these community Formations are expounded in this paper. According to a paleobiogeographical analysis, the Yangjiaping area on the southwest margin of the Jianghan basin belonged to a transition region befores the early Canglangpu stage and to the Yangtze region from the late Canglangpu stage on.