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: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。
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 palaeostructures reflect that the palaeostructure was a steep slop in topographical during Yingtaogou period at Hujitai.
出处
《海相油气地质》
2010年第2期14-19,共6页
Marine Origin Petroleum Geology
关键词
重力流沉积
贺兰山
拗拉槽
中奥陶统
鄂尔多斯盆地
Gravitational current deposit
Turbidity current deposit
Helan Aulacogen
Middle Ordovician
Ordos basin
