豫皖地区平顶山砂岩段地质时代的探讨

AGE ASSIGNMENT OF THE PINGDINGSHAN MEMBER IN HENAN AND ANHUI PROVINCES

欧阳舒 王仁农

Ouyang Shu Wang Rennong

中国科学院, 南京地质古生物研究所 2. 煤炭部, 一四七地质勘探队

Nanjing Institute of Geology and Palaeontology, Academia Sinica 2. 147 Geological Prospecting Team of Coal Ministry

平顶山砂岩段是指广布於豫西等地的石千峰组(相当狭义的孙家沟组)内的次一级的岩石地层单位,是豫西等地寻找石炭三叠系煤系的重要标志。自1955年平顶山地质队创名以来,地质部、煤炭部、中科院所属所、队及大专院校等单位地质工作者对该段地层曾多次描述命名(平顶山砂岩、组、段、马头山组,石千峰一段,土门组等),其时代归属(P21—P22—T1?亦较乱。为统一该段地层名称,划定其上、下界限及时代归属,具有一定的实际意义。煤炭部129队在豫西平顶山一带使用绳索钻具钻进,岩芯采取率较高,为研究该段地层提供了良好的素材。采统地采集了孢粉样,在地层的顶底部(相隔为102.20米)发现了颇为丰富的孢粉化石组合,包括一般认为属於浅海浮游藻类的少量疑源类,为探讨地质时代提供了有利的证据。

Pingdingshan Member,which was named Pingdingshan Sandstones in 1955 is a litho-stratigraphical unit that is widely distributed over the area of Henan,Anhui,northwestern Jiangsu and southern Shandong provinces.lt consists mainly of light gray,greyish white,purplish green and grey sandstones intercalated with,siltstones and sandy marls,with a thickness up to 60-120m.The Pingdingshan Member rests conformably upon the Shiqianfeng Formation (Upper Shihetze Formation).The geological age still is a problem unsolved.(P21—P22—T1?) According to the preliminary identification,the Pingdingshan Member should be Late Permian in age,and stratigraphically it can be roughly correlated with the lower part of the Shiqianfeng Formation in northern China.

https://doi.org/10.11781/sysydz198502141