Abstract: A series standard of CAI of conodonts is established through heat tests and colour observations in the field. From determination of Ro% and colour observation of conodonts of a same rock sample, the relationship between CAI value and Ro% of vitrites is derived,which indicates that the CAI value may be used as one of the indices of maturity of organic matter.It has been identified that the colour of conodonts distributed in the Permian aud Triassic rocks in Hubei varies from place to place. The organic matter in the Permian and Triassic in Tianmen, Chenhu, Sangzhi, Xingshan etc., rauges from matured to highly-matured, giving a better oil and gas prospect; while those in Lichuan, Jiannan and eastern Sichuan are over-matured and good for gas generation only.

摘要： 通过对牙形石室内加热试验和对野外不同地区牙形石颜色的观察,建立了牙形石色变指标(CAI值)的标准系列。通过对同一岩样进行Ro%的测定及牙形石颜色观察,得出CAI值与镜煤反射率(Ro%)的规律性关系,证明CAI值作为有机质成熟度的指标之一是可行的。在此基础上对湖北二、三迭系牙形石颜色观察鉴定,发现牙形石颜色分布有明显的分区性。湖北二、三迭系在天门、沉湖等地有机质成熟度属成熟—高成熟区,含油气远景较好,利川建南及川东地区属过成熟区含气远景较好。