【摘要】 鄂尔多斯地台南缘断续出露上元古界青白口系皇坪组,其上部为叠层石白云岩,叠层石大都已硅化,呈树枝状,有原地生长的,也有倒卧的,厚30～40m,为叠层石生物层。它们大致沿东西向构造线呈带状分布,延展近60km,其底部为角砾岩,角砾成分主要为燧石,其次为白云岩,燧石大都为薄板状。角砾为杂基支撑,定向排列,具粒序层理,系叠层石生物层崩塌而成的碎屑流。更多还原

【Abstract】 The stratigraphy of the late Proterozoic Qingbeikou system has been discovered intermittently on the southern margins of the Ordos Massif.The deposition at the upper-layer of the Huang-Ping formation is the stromotolitic dolomitite. Most of the stromatolites have been silicified and are three-branches in shape.Some of them grow-up intact and others sleep upside-dawn.The stromatolite strata are about 30-40m thick and may be classified into stromatolite biostrome, which rolls out 60km along a E-W structure line in zonal distribution.The main rock is breccia at the lower layer of the Hung-ping formation. The components of the gravels are mainly silex, and have a smallnumber of dolomitites. The main silexes are thin-bedded and silicified stromatolite chips. The gravels in the profile breccia arranged in set direction are kept by impure-components and have graded bedding. They are clastic-sediments of the debris-flowing on the edge of the biostrome.更多还原