贵州早寒武世早期黑色页岩中生物化石保存及生态学研究

早寒武世早期黑色页岩中以前只发现少量的海绵骨针,但随着研究的深入,各类动物化石被发现。最近,贵州早寒武世早期黑色页岩中发现碳质和薄膜型化石,它们包括大量的简单线状遗迹、碳质膜状高肌虫、完整海绵动物、管虫、薄壳双壳动物、碳质膜状软舌螺以及一些圆形膜状化石等。通过对黑色页岩的粘土矿物定量和定性分析,结合地球化学特征,认为早寒武世早期小壳动物繁盛期之上有一个大型动物繁盛期,随后由于地壳拉张作用,大规模的海底热液和火山喷发作用的加强,海洋环境变成酸性环境,不利于生物生存,发生生物绝灭作用,随后海洋环境逐渐趋于碱性,大量的生物又开始繁盛。

Fossil Preservation and Palaeoecological Research in Early Cambrian Black Shale

Few fossils were found previously in early Early Cambrian black shale, such as sponges. With the deepening of the research, many phyla have been discovered recently. A lot of carbon fossils were found in early Early Cambrian black shale of Guizhou Province, south China, and they are simple trace fossils, carbon Phyllocarida, complete sponges, Platysolenites, Bivalvia, carbon Hyolitha, "Worm", bryozoa like animal fossil and membrane discus fossils. Mineral composition of the black shale in the base Cambrian, Kaiyang County, Guizhou, China was analyzed by XRD analyses, according to the change of mineral composition of black shale and geochemical character in Kaiyang section, authors suggest that a prosperous period of large animal between small shell animal and the Chengjiang fauna was present, this animal assemblage disappear as crustal expansion, mass submarine hydrothermal event and volcanic eruption, the early Early Cambrian seawater changed from the weak alkalinity to weak acidity, animal did not live at the weak acidity, so large animals between small shell animal and the Chengjiang fauna disappeared. With the recovering of weak alkalinity of the seawater, a prosperous period of animal, the Chengjiang fauna was present.