青海南部治多-杂多-带下石炭统杂多群

在青海南部治多-杂多-带1／25万地质填图中，对杂多群进行了重新划分，自下而上分为下碳酸盐岩组、碎屑岩组和上碳酸盐岩组。下碳酸盐岩组为深灰色中层状生物屑灰岩、鲡粒灰岩夹泥岩、细粒石英砂岩，属于台地边缘浅滩相；碎屑岩组为灰色中层状细粒石英砂岩、泥岩夹灰岩、玄武岩，属于三角洲相、陆棚相和台地边缘浅滩相；上碳酸盐岩组为灰色中厚层状生物屑灰岩，见燧石结核和条带，为陆棚相和台地相沉积。丰富的筵类、非筵有孔虫、珊瑚化石，表明杂多群地质时代为早石炭世大塘期-德坞期。根据岩性组合、生物群面貌杂多群与青海南部杂多-囊谦地区杂多群、西藏东部昌都地区马查拉群可很好地对比。

LOWER CABONIFEROUS ZADOI GROUP IN THE ZHIDOI AND ZADOI AREA, SOUTHERN QINGHAI

The Zadoi Group in the Zhidoi and Zadoi area, southern Qinghai, was subdivided into the Lower Carbonatite Formation, Clasolite Formation and Upper Carbonatite Formation in ascending order. The Lower Carbonatite Formation consists predominantly of grey, medium-bedded bioclastic limestone, oolitic limestone, interbedded with mudstone, fine-grained quartzose sandstone, and it was the representative of the carbonate platform marginal riffle. The Clasolite Formation was composed mainly of grey, mediumbedded, fine-grained quartzose sandstone, mudstone and intercalated with limestone and basalt,belonging to delta, shelf and platform margin riffle environment. The Upper Carbonatite Formation consists chiefly of grey, medium- to thick-bedded bioclastic with limestone with nodular or stripped chert, being the continental shelf and platform deposits. Abundant faunas occur in limestone, such as fusulinid Eostaffella assemblage, non-fusulinid foraminifera Endothyra-Mediocris-Archaediscus and Bradyina-Endothyranopsis assemblages, coral Siphonodendron scitulus-Lithostrotionella zadoensis and Lithostrotion decipiens-Kueichouphyllum sinense-Siphonodendron irregulare asiaticum assemblages, indicated the the Zadoi Formation to be Datangan to Dewuan Zadoi Group in the Zhidoi and Z Nangqen, southern Qinghai and Early Carboniferous in age. Lithologic character and fauna from the oi area may be correlated with those of the Zadoi Group in Zadoi and achaia Group in the Qamdo area, eastern Tibet.