【作者】 李朋；

【导师】 华洪；

【作者基本信息】 西北大学 ， 古生物学与地层学， 2008， 硕士

【摘要】 埃迪卡拉生物群是目前已知最早、较为可靠的后生动物化石,它为早期生命研究提供了非常重要的化石证据.高家山生物群作为埃迪卡拉生物群晚期主要代表,其埋藏学特征与世界范围内广泛分布的埃迪卡拉型化石库存在很大的差异,因此,对高家山生物群沉积环境的研究可以为整个埃迪卡拉型化石库埋藏学的研究提供新的线索和思考,产生重要研究意义.埃迪卡拉生物群生物分异度低,分类位置不明确,具有明显的地方特色,导致了显生宙的生物地层学划分方法,在埃迪卡拉生物群难以适用.当前的首要任务,是要建立一个高分辨率的埃迪卡拉纪地层系统,但是,由于种种原因,高家山生物群的化学地层学的研究相对局限,为了使高家山生物群能更好的与全球其他埃迪卡拉纪生物群对比,迫切的需要对高家山生物群碳同位素地球化学作系统的研究.本文通过野外沉积特征、室内岩石薄片特征(8个剖面)以及同一区域不同剖面(19个剖面)碳同位素地球化学对比等方法对高家山生物群的沉积环境以及碳同位素地球化学特征进行了重点研究.根据风暴沉积的特征,对高家山生物群的沉积环境进行了详细的划分.与华南地区埃迪卡拉系碳同位素对比以及华南地区碳同位素合成剖面,构建了华南地区埃迪卡拉系碳同位素地球化学剖面.并总结了其特征,并在此基础上尝试解释了其形成原因.并总结了宽川铺生物群的属种,提出了2种沉积模式.更多还原

【Abstract】 The Ediacaran Biota, known as the earliest and reliable metazoan, provids indispensable evidence for the study of early life. The Gaojiashan biota is of the Late Ediacaran in age and typically yields Nama-type fossils, and differs a great deal with the word-wide Ediacaran-type biotas in taphonomic feature. Therefore, the study of sedimentary environment of the Gaojiashan Biota can provide new clues and perspectives for the taphonomy of Ediacaran-type biotas. Unfortunately, biostratigraphy, a principle tool for subdivision and correlation of richly fossiliferous Phanerozoic strata, is of limited usefulness in developing a global time scale for the Ediacaran System, the difficulties being related to the low species diversity, taxonomic uncertainty, and the sporadic and endemic palaeogeographic distribution of Ediacaran fossils. Thus, a critical task of establishing a high resolution, globally applicable Ediacaran chemostratigraphy has become the primary objective of the International Subcommission on Neoproterozoic Stratigraphy of the ICS. However, chemostratigraphy of the Gaojiashan Biota is of relatively weak and still waiting to be corroborated.The purpose of this paper, therefore, will focus on the sedimentary facies and paleoenvironment as well as carbon isotope stratigraphy of the Gaojiasha Biota, with particular references to the sedimentary, petrological （8 reference sections） andδ¹³C chemostratigraphy correlation of different sections （19 reference sections） in South China. The sedimentary environments of the Gaojiashan Biota are elaborated mainly based on the different features of storm deposits. A compositeδ¹³C profile of the Dengying Formation in South China is provided and carbon isotopic oscillations from Gaojiashan section are correlated with the reference curves for South China. In addition, Small Shell Fossils from the Early Cambiran Kuanchuanpu Formation are rectified, including 14 genuses, 22 species, and two sedimentary models of the Kuanchuanpu Biota are reconstructed.更多还原