自贡大山铺恐龙动物群埋藏环境及集中埋藏原因分析

An analysis of the taphonomic environment of dinosaur faunae in Dashanpu of Zigong City and the cause of their concentrative burial

四川自贡大山铺以其集中埋藏数量众多的恐龙化石而闻名于世,恐龙化石集中埋藏的原因一直是人们关注的焦点问题之一。笔者在对自贡恐龙博物馆内及其附近地层剖面调查的基础上,根据对该处埋藏恐龙化石地层的岩相、沉积构造、砂体形态特征以及沉积背景的分析,认为恐龙化石的埋藏环境为湖泊三角洲,恐龙由于某种原因死亡后,经过河流搬运埋藏于湖泊三角洲前缘的河口砂坝之中,而非由于中毒异常死亡原地埋藏。

Dashanpu of Zigong City in Sichuan Province is world-wide famous for its dinosaur fossils, particularly the concentrative burial of a large quantity of dinosaurs. The cause of their concentratrative burial remains a problem of much controversy. Based on an analysis of such characteristics of the strata in the Zigong Dinosaur Museum and its surrounding areas as the lithofacies, depositional environment, shape of sandstone, and deposition background, this paper deals with the taphonomic environment of dinosaur faunae in Dashanpu and the cause of their concentrative burial. The authors consider that dinosaur remains were buried in frontal river mouth sand bar of lacustrine delta after their depth due to an unknown cause and river transport of their bodies instead of being buried in situ after their death due to poisoning.