华北地区奥陶纪牙形石色变和有机物质成熟度分区初步研究

A PRELIMINARY STUDY ON COLOR ALTERATION OF CONODONT AND DIVISION OF MATURITY OF ORGANIC MATTERS IN ORDOVIAN SYSTEM NORTH CHINA

包德宪 王元顺

Bao Dexian Wang Yuanshun

地质矿产部华北石油地质局

North China Bureau of Petroleum Geology Ministry of Geology and Mineral Resources

华北地区奥陶系沉积厚度大,分布广,以海相碳酸盐岩为主。本文所指范围北自河北平泉、山西浑源一带,南到豫西、淮南,西自太行山,东至郯庐断裂,约60余万平方公里。被覆盖的奥陶系分布面积约12万平方公里。笔者以20条露头剖面,26口钻井剖面,共计7845个牙形石标本的色变指数(CAI)值为基础,绘出《华北地区奥陶系牙形石CAI成熟度分区图》,指出有机物质的变质程度和有利于生成石油、天然的区域,为寻找石油、天然气提供可用的资料。

The essential that caused color alteration of conodonts throughout North China are the maxium palaeo-geotemperature controlled by principle tectonic framework, whereas local color alteration of conodonts in some areas was affected by factors as follows. 1) buried rock masses whichintensified the color alteration of conodonts; 2) activities of underground water which degraded the color alteration of conodonts; 3) tectonic movement which intensified the color alteration of conodonts. By analyzing the history of color alteration of conodonts from Ordovician system, it is inferred that organic matters in this sequence reached mature stage during the period from the end of Permian to the beginning of Yanshan movement. After Yanshan movement, organic matters could be transferred into petroleum secondarily within some plain areas where Cenozoic strata had deposited. The whole region of North China is then devided and evaluated in terms of maturities of organic matters.

https://doi.org/10.11781/sysydz198404311