四川盆地龙马溪组笔石组合特征与沉积环境关系探讨

he graptolite in Longmaxi group in Sichuan basin is well-preserved, wide-spreading, fast-evolution and its distinct characteristic. In this paper, according to previous data and the specimen of the study area, I carry on a research at subordinate species identification, graptolite zone division, sedimentary facies analysis and so on. In the study area, the Longmaxi group is divided into six Graptolite zones, the abundance, diversity and morphology of graptolite have changed a lot. The sedimentary environment changed from deep shelf to shallow shelf, which have an importance influence to the assemblage characteristics of graptolite.