羌塘盆地北部上侏罗统东湖剖面的划分与对比

Discussion on the stratigraphic classification of the upper Jurassic of Donghu Region in Qiangtang Basin

羌塘盆地北部自然条件恶劣 ,地层研究难度极大 ,层位的划分和时代归属仍存在争议 .以测制的羌塘盆地北部东湖剖面为依据 ,对上侏罗统进行了详细的岩石及生物地层研究 ,将其划分为两部分 ,下部灰岩层为索瓦组 ,含Radulopectenfi brosus-Gervillellaaviculoides组合 ,时限为牛津期 ;上部灰岩、碎屑岩互层为白龙冰河组 ,含Radulopectenscarburgensis,Euprionoc erassp .等化石 ,其主体时限为基末里期—提唐期 ,顶部已跨入早白垩世白里阿斯期 .

Qiangtang Basin is located in the north of Qinghai\|Tibet(Qingzang)Plateau. It is difficult to do geological work. There are many questions to the stratigraphic classification and correlation. This article discusses the rock and biohorizon of the upper Jurassic according to the data of Donghu section in the north of Qiangtang Basin. Based on the difference in bivalve, brachiopoda, anthozoa fossils and lithostratigraphic character, the section can be divided into two formations.The lower limestone is Suowa formation which consists of hydrocarbons with Radulopectenfibrosus\|Gervillella aviculoides assemblages and the geologic age is Oxfordian stage, while the upper one is Bailongbinghe formation which consists of hydrocarbons and fragments with Radulopecten scarburgens, Euprionoceras sp.The geologic age is Kimmeridgian\|Berriasion stage.