通过对江苏下扬子地区笔石反射率的研究，发现随埋深增加笔石反射率增高，并建立了笔石反射率与牙形刺色变指标的对应关系，又以牙形刺色变指标与镜质体反射率之间的对应关系为“桥梁”，进一步建立了笔以射率与镜质体反率的对应关系，从而为下古生界烃源岩有机质成熟度的评价提供一项新的可靠的评价指标。

Graptolite reflectance increases with the increasing of depth according to the study graptolite reflectance of Lower Yangtze Region in Jiangsu Province, E China. The correlation between graptolite reflectance and conodont Color Alteration Index (CAI) is established. Further more, the correlation between graptolite reflectance and vitrinite reflectance is established by using the correlation between CAI and vitrinite reflectance. It provides a new and reliable scale for evaluating the organic maturity of the Lower Plaeozoic rocks.

Q91－3