贺兰拗拉槽胡基台地区中奥陶统樱桃沟组深海重力流沉积特征

作    者:许强,陈洪德,赵俊兴,陈安清,苏中堂,王峰
单    位:成都理工大学油气藏地质及开发工程国家重点实验室;成都理工大学沉积地质研究院
基金项目:
摘    要:
结合国际上深海沉积研究最新动态,分析了鄂尔多斯盆地西侧胡基台地区中奥陶统樱桃沟组野外剖面。认为该地层块状内部无层理砂岩为砂质碎屑流沉积而不是前人认为的浊流沉积。研究区发育有垮塌沉积、颗粒流沉积、砂质碎屑流沉积、浊流沉积等重力流沉积。该区樱桃沟组重力流沉积类型的总体分布特征是院下部发育钙屑浊流与 大规模灰岩垮塌沉积,见砂质碎屑流沉积;中部主要发育陆源碎屑浊流沉积,但在其下部有较为发育的颗粒流沉积;上部发育陆源碎屑浊流沉积。其中垮塌沉积和颗粒流沉积作为对古构造的沉积响应,反映了樱桃沟期该地区的古构造地形为陡坡。
关键词:重力流沉积;贺兰山;拗拉槽;中奥陶统;鄂尔多斯盆地

The Features of Middle Ordovician Yingtaogou Deep-seaGravitational Current Deposits at Hujitai area in the Helan Aulacogen, Ordos Basin

Author's Name: Xu Qiang, Chen Hongde, Zhao Junxing, Chen Anqing, Su Zhongtang, Wang Feng
Institution: Institute of Sedimentary Geology, Chengdu University of Technology
Abstract:
The massive unbedded sandstone is identified in the field cropout profile of Middle Ordovician Yingtaogou Formation at Hujitai in the western part of Ordos Basin and it is advanced that involving the latest international studies of deep sea depositions, the massive unbedded sandstone belongs to sandy debris current deposits but turbidity current deposits mentioned in literatures. Gravity current deposits including slump deposits, grain current deposits, sandy debris current deposits and gravity current deposits developed in this study area. The gravity current deposits are commonly characterized by: abundant calcarenaceous turbidite and a large scale of limestone slump deposits including limestone sandy debris currents in the lower part; massive turbidity current deposits deriving land in the middle part, and abundant of grain current deposits at the bottom of the middle part; a large scale of turbidity current deposits from land in the upper part. Slump and grain current deposits responsing to palaeostruc tures reflect that the palaeostructure was a steep slop in topographical during Yingtaogou period at Hujitai.
Keywords: Gravitational current deposit; Turbidity current deposit; Helan Aulacogen; Middle Ordovician; Ordos basin
投稿时间: 2009-06-17  
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