焦作地区太原组介形动物群——兼论石炭——二叠系界线

OSTRACODES FAUNA FROM THE TAIYUAN FORMATION OF JIAOZUO AREA WITH COMMENTS ON THE CABONIFEROUS-PERMIAN BOUNDARY

本文介绍了对焦作地区太原组介形类的研究成果,共获24属46种,可分为两个组合.下组合为Cryptobairdia xiaodonggouensis-Lobobairdiaventiconcava—Rectobairdia(L_1-L_5);上组合为Orthobairdia chasae-Amphissites-Discoidella(L_6-L_9)。上、下组合介形类的特征和生活习性均有明显的差异。文章并分析对比了该区太原组介形类、牙形刺及蜓类组合变化的界线和介形类、蜓类、珊瑚、腕足类的形态特征及生态习性的变化趋势及其与太原组沉积期海面变化事件的关系,从而为石炭—二叠系界线的确定提供新的依据.

The Taiyuan Formation exposed in Jiaozuo area contains abundant fossil ostracodes comprising 24 genera and 46 species with 1 new species.They can be grouped into two assemblages in ascending order as follows:1. Cryptobairdia xiaodonggougensis-Lobobairdia ventriconcava-Rectobairdia Assemblage (L_1—L_5)2. Orthobairdia chasae—Amphissites—Discoidella Assemblage (L_6—L_9)The two assemblages are quite different in morphological features and ecological habits.This paper has also deal with the features and the boundary of assemblages of ostracodes, conodonts and fusulinids as well as the morphology and ecological trends of ostracodes,fusulinids,coral and brachiopods.It is suggested that the variations in morphology and ecology of these fossils may related to the events of sea level changing during the sedimentary period of Taiyuan Formation.This is could be a new evidence for determining the boundary of Carboniferous and Permian.