古地理学报2018，Vol.20Issue(2)：175-190,16.DOI:10.7605/gdlxb.2018.02.013
塔里木盆地良里塔格地区奥陶系生物礁的沉积特征和成礁模式
Sedimentary characteristics and reef-forming models of the Ordovician reefs in Lianglitage area, Tarim Basin
摘要
Abstract
The Ordovician reef reservoirs in the Tarim Basin have been receiving more and more attention.The present research describes the reefs in Lianglitage area,Tarim Basin:NYG-1 reef (at the top of Yingshan Formation) and NYG-2 reef (at the bottom of Yijianfang Formation).Biotypes,lithologies,and sedimentary facies units of these two reefs were detailed documented,using detailed field observations,measurements,and thin section identifications.The results suggest that reef-building organisms are mainly composed of calathiums and that lithology associated with reefs is bafflestones,boundstones,bioclastic wackestones,bioclastic packstones,intraclastic packstones,bioclastic grainstones,intraclastic grainstones,and peloidal grainstones.Facies units in the NYG-1 reef mainly contain reef base,reef core,reef top,reef flank and reef cap.However,the NYG-2 reef consist only of reef base,reef core and reef cap.The Yingshan Formation is rich in calathium-baffle reefs,while Yijianfang Formation is dominated by calathium baffle-binding reefs.Reefs in Yingshan Formation are in the shape of circle-like and intra-platform patches,without obvious directional anisotropies.Reefs in Yijianfang Formation,in contrast,contain platform margin reefs that extensively show the vertical migration characteristics.Both formations have experienced three phases of evolutions,namely colonization,vertical aggradation,and capping.The difference lies mainly in the capping phase.More specifically,during the deposition of Yingshan Formation,the rapid decrease of sea levels and the high water energy led to the perish of calathium and the formation of grainstones,whereas the rise of sea levels and the development of considerable planktonic algae organisms caused the suffocation of calathiums.To conclude,this research provides insights into building reefs depositional models of the Tarim Basin and exploring new methods of comparative study on outcrops and underground reefs.关键词
塔里木盆地/奥陶系/生物礁/成礁模式Key words
Tarim Basin/Ordovician/reef/reef-forming models分类
能源科技引用本文复制引用
孟苗苗,樊太亮,卫端,王珊珊..塔里木盆地良里塔格地区奥陶系生物礁的沉积特征和成礁模式[J].古地理学报,2018,20(2):175-190,16.基金项目
国家自然科学基金(编号:51574208),国家“973”项目(编号:2012CB214802)和国家科技重大专项课题(编号:2011ZX05009-002)联合资助.特别感谢国家留学基金委的资助与支持！Co-funded by the National Natural Science Foundation of China (No.51574208),the National 973 Program of China (No.2012CB214802),and National Science and Technology Major Project of China(No.2011ZX05009-002) （编号:51574208）
