沉积与特提斯地质2018，Vol.38Issue(2)：23-35,13.
羌塘盆地南坳陷古油藏带中侏罗统布曲组白云岩元素地球化学特征及意义
Trace element geochemical signatures and significance of the Buqu Formation dolostones in southern Qiangtang depression
摘要
Abstract
Based on the previous detailed petrological classification,the present paper focuses on the geochemical signatures and significance of trace elements in the carbonate rocks from the Buqu Formation in the southern Qiangtang depression. The results of research in this study are outlined in the following. (1)The carbonate rocks in the Buqu Formation have lower trace element contents,which are related to the rapid invasion of sea water in the Bangong Lake-Nujiang Ocean Basin and the lack of surface runoff compensation for terrigenous materials under hot, semi-humid and semi-arid conditions;(2)Na and K contents indicate that both of the primitive fluids resulting the formation of the dolostones retaining primordial compositions and structures of pioneer limestones and the primitive fluids resulting the formation of the crystal grain dolostones not retaining pioneer limestone primordial composition in the Buqu Formation are the seawater evaporated in the same periods,and the contents of Sr are generally controlled by the relative contents of calcite and dolomite in the rocks;(3)The transitional rocks experiencing incomplete dolomitization(RD5-1)were formed by incomplete replacement of pioneer limestones in the middle to late phases of medium to deep burial stages. Fine-to medium-sized crystalline,euhedral-subhedral dolomite fillings were formed by the recrystallization of micro-powder dolomite at the end of shallow burial stage;(4)The formation of saddle dolomite involves the participation of exotic high-temperature fluids,and genetic fluids have the characteristics of atmospheric fresh water and deeply-cyclic fluids flowing through clastic formations. The high temperatures are provided by the Cenozoic (78-64 Ma)tectonic thermal events,and the partial matrix dolostones are transformed by the high temperatures caused by tectonic thermal events.关键词
元素地球化学/白云岩/布曲组/南羌塘坳陷Key words
element geochemistry/dolomite/Buqu Formation/southern Qiangtang depression分类
天文与地球科学引用本文复制引用
万友利,王剑,付修根,王东..羌塘盆地南坳陷古油藏带中侏罗统布曲组白云岩元素地球化学特征及意义[J].沉积与特提斯地质,2018,38(2):23-35,13.基金项目
中国地质调查局项目《羌塘盆地金星湖-隆鄂尼地区油气资源战略调查》(No. 121201010000161110) （No. 121201010000161110）
