陕南早寒武世宽川铺生物群沉积环境及埋藏机制研究

DEPOSITIONAL ENVIRONMENT AND BIOSTRATINOMIC MODEL OF THE EARLY CAMBRIAN KUANCHUANPU BIOTA FROM SOUTHERN SHAANXI

陕南早寒武世宽川铺生物群三维立体保存了大量结构精美的磷酸盐化胚胎及小壳化石,为后生动物演化及化石胚胎学的研究提供了珍贵的实证材料。目前的研究主要集中在化石分类学及演化生物学上,而对沉积环境及埋藏机制的研究却很少涉及。文中通过对大量野外岩石照片、岩石薄片、小壳化石SEM照片的综合研究后认为,宽川铺生物群不是原地埋藏的产物,而是事件沉积的结果。该研究对于探讨宽川铺生物群化石的埋藏环境及保存机制具有一定的意义。

The Early Cambrian Kuanchuanpu biota from southern Shaanxi of South China yielded a large number of three-dimensionally phosphatized animal embryos and Small Shelly fossils.These exceptionally preserved fossils have provided very important paleobiological insights into the study of metazoan evolution before the Cambrian explosion.Previous work on this biota mainly focused on systematic taxonomy and developmental biology,while the depositional environment and taphonomy of this biota has been largely ignored.In this paper,two taphonomic models are proposed：1） Chemical deposition;2） Mechanical dynamic winnowing.We suggest that the Kuanchuanpu fossils are allochthonously preserved.