桌子山地区中奥陶统乌拉力克组砾屑灰岩沉积特征及深水沉积模式研究

Sedimentary Characteristics and Sedimentary Model of Calcirudite in the Wulalike Formation of Middle Ordovician in Zhuozishan Area of Inner Mongolia

以桌子山地区中奥陶统乌拉力克组砾屑灰岩为研究对象,根据砾屑灰岩的发育规模、颗粒大小、磨圆、砾屑的主要成分等方面的差异,将砾屑灰岩分为小型砾屑灰岩、小型角砾化砾屑灰岩和大型角砾化砾屑灰岩3种类型,对其沉积特征及深水沉积模式进行了研究。结果表明,桌子山地区中奥陶统乌拉力克组小型砾屑灰岩、小型角砾化砾屑灰岩和大型角砾化砾屑灰岩这3种类型的形成均与碎屑流有关,所反映的碎屑流能量大小也有所差异;桌子山地区中奥陶统乌拉力克组砾屑灰岩沉积模式中,碳酸盐台地为砾屑灰岩提供物质来源,上斜坡一般不发生沉积,下斜坡处发育大型角砾化灰岩,盆地边缘处则沉积小型角砾化砾屑灰岩,深水盆地发育小型砾屑灰岩。

The calcirudite of the Wulalike Formation of Middle Ordovician in Zhuozishan Area of Inner Mongolia is the main object of study.Through the micromesh observation of core,particle size,grinding,the main component of sedimentary, construction background,lithology,structure and construction of the calcirudite,the calcirudite is divided into three types,include the small calcirrudite,the small brecciated calcirudite and the large brecciated calcirudite.Their formation is related to debris flow and they reflect different energy of debris flow.On this basis,the sedimentary mode is that carbonate platform provides material sources for calcirudites;there is no sediment on the upper slope;the large brecciated calcirudite is developed on the down slope;the small brecciated calcirudite is developed on the edge of basin;the small calcirudites is developed in the basin.