黄陵背斜周缘早古生代有机壳化石的光学特性与有机质成熟度

The Optical Characteristics of Organic Shell Fossils and the Maturity of Organic Matter

本文主要研究扬子地台西部黄陵背斜周缘早古生代有机壳化石的特征、光学特性和有机质成熟度规律，同时较为详细地研究了有机壳化石反射率随热成熟度变化特点与镜质组反射率之间的关系。提出该区以有机壳化石反射率为主要指标的有机质成熟度划分方案。认为笔石、几丁虫和虫牙等有机壳化石在形态、结构和构造上具有各自的特征，并具有突起、反射色、显微结构构造、非均性、异向光性、反射率和双反射现象等光学特征。有机壳化石反射率与镜质组反射率一样，随着热成熟度增强而增大。利用牙形石ＣＡＩ值，有机壳化石反射率可以与镜质组反射率进行对比，从而在缺少镜质组分的早古生代地层和海相碳酸盐岩地区，用有机壳化石反射率代替镜质组反射率以研究有机质成熟度。

The Early Paleozoic organic shell fossils arround the Huangling anticaline,including graptolite,chitinozoan and scolecedont,have their own characteristics in composition,shape,texture and struc-ture as well as sallent,reflection color,micro-texture and feature,heterogeneity,incongrucus optics,reflectance,double reflection and so on. Follwing the inctreas in thermal matureity their opticalcharacteristics show regular variations.The organic shell fossils the more thermal maturity reflectance like the vitrinite reflectance in-creases along with.organic shell fossils reflectance can be compared with vitrinite reflectance accord-ing to the CAI of conedont.So it would be possible to classify organism maturity by using organic shellfossils reflectance instcad ofvitrinite reflectance. It means that we could use organic shell fossils re-flectance to study the maturity of organic matter in the areas of Early Paleozoic rocks and marine car-bonate rocks which ore poorin vitrinite.Finally three area of Early Paleozoic rocks with different maturities of organic matter arround theHuangling anticline are dislinguished,according to the reflectances of organic shell fossils and the CAIvalues of conodont in this paper.At the same time,the author points out that the oil-forming condi-tions in these area ore not quiet good,because the rocks are too old and their degree of thermal evolu-tion of organic matter is refatively higher.