摘要
地层学作为地质学的基础学科的内涵在于它起着联结地质科学其他分支学科的纽带作用。众所周知,地球发展历史过程中同时性事件的研究和系列发展阶段的建立是地质学的主要任务,当然,它们也应成为地层学研究的主要内容。在地层学发展的初始阶段,因受地区性的限制,在地层学研究范畴内,存在着不同术语和地层划分的不同标准,这些,或多或少地影响着地层学的进一步发展。随着科学的发展和地质学全球性研究的重要性被进一步认识,从而对地层划分和对比,提出了更高的要求。
Since Murchison (1841) named the Permian system but failed to make clear the base of the Lower Permian in the Perm Region of USSR, several problems on the placement of the CarboniferousPermian boundary have been raised. On the other hand, efficient conditions toward the solution for these problems have been created and provided by geologists and palaeontologists. The current C—P Boundary Working Group, which was reorganized by ICS in 1987, has also paid attention to the placement of this boundary, and called on the membership of the group to make contributions to this issue after studying it from different place. In order to carry on this work more efficiently, the Working Group held a meeting in Washington, D. C., 1989 to discuss and select the better position of the boundary that would be more acceptable. Sixteen voting and corresponding members participated in the meeting, with the proposal of three well dentified boundary levels from the current viewpoints on all of the boundary levels throught the world. They are: the base of the Daixina bosbytanensisD. robusta Zone; the base of the Schwagerina fusiformis-S, vulgaris Zone and the base of the Schwagerina moelleri-Pseud of usulina fecunda Zone together with their respective equivalents. After a straw voting, most members were inclined to take the third level as the International Carboniferous-Permlan Boundary position. Participants in the meeting also stressed that it is necessary to prove the benefits of this boundary position through practical work. Actually, those different viewpoints have arisen from the, definition of the Lower Permian. In this regard, Dr. Ross proposed that the first occurrence of the species Pseudoschwagerina uddeni, P. texana and P. beedei should be taken as the base of the Permian; Dr. Wang Zhihao holds the same view but particularly on the first appearance of the conodont Streptognathodus barskovi which is nearly corresponding to the species Pseudoschwagerina uddeni.It is believed that in consequence this basal level will be efficiently worked by the Working Group in the near future.
出处
《古生物学报》
CAS
CSCD
北大核心
1991年第1期1-5,共5页
Acta Palaeontologica Sinica
基金
国家自然科学基金
中国科学院院长基金
