龙门山甘溪泥盆系生物骨架富集层成因机制  

Genetic mechanism of Devonian skeletal concentrations in Longmenshan area,Sichuan,China

作　　者：李凤杰[1,2] 荆锡贵 张昊[2] 徐文礼[2] 

机构地区：[1]成都理工大学油气藏地质及开发国家重点实验室,四川成都610059 [2]成都理工大学沉积地质研究院,四川成都610059

出　　处：《地学前缘》2017年第6期322-332,共11页Earth Science Frontiers

基　　金：国家自然科学基金项目"龙门山地区泥盆纪土桥子组高频韵律旋回成因及古气候意义研究"(41172100);四川省教育厅自然科学重点项目"龙门山地区泥盆纪风暴沉积及其地质意义"(12ZA012)

摘　　要：四川龙门山泥盆系显著特征是地层中广泛发育类型多样的生物骨架富集层。依据生物类型和几何形态,将生物骨架富集层综合划分为两大类13种。富集层中生物类型、排列方式、埋藏特征和厚度特征是恢复富集层成因过程的重要标志,据此将龙门山泥盆系生物骨架富集层分为6种成因类型:机会种簸扬富集层、风暴簸扬富集层、近源风暴岩、远源风暴岩、基本生物成因富集层和凝聚型富集层。建立了龙门山泥盆系各种生物骨架富集层成因类型的分布模式,从近岸到远岸依次分布风暴簸扬富集层、近源风暴岩、远源风暴岩、机会种簸扬富集层和凝聚型富集层成因模式,而基本生物成因富集层成因模式则分布广泛,从近岸到远岸均有分布。生物骨架富集层的形成受生物、沉积和水动力及其相互作用的制约,分布于不同的沉积环境,是沉积环境分析的有用工具。Skeletal concentrations are common and conspicuous features of the Devonian strata in the Longmenshan area. Based on the types of skeletal and geometrical morphology of concentrations, the skeletal concentrations are divided into two categories and thirteen types. The dominant characteristics, including the type and arrangement mode of skeleton, and taphonomic signature and thickness in concentrations, are important markers showing the resumption of the genetic process. According to these markers, six genetic types of the various skeletal concentrations are identified, and the genetic distrihution model is built in the Devonian strata of the Longmenshan area. It was found that the genetic types of the storm winnowed concentration, proximal tempestites, distal tempestites, opportunistic species winnowed concentration and condensed concentration distributed along an onshore-offshore area; whilst the primary biogenic concentration distributed in a broad range from onshore to offshore Furthermore, the formations of skeletal concentrations were restricted by organism, sediments, hydrodynamic force and interactions among these factors. Since skeletal concentrations are present in various depositional environments, they are useful tool for studying depositional environment.

关 键 词：生物骨架富集层 埋藏特征 分布模式 泥盆系 龙门山 

分 类 号：P534.44[天文地球—古生物学与地层学] Q911.6[天文地球—地质学]