西北地质2024，Vol.57Issue(6)：95-112,18.DOI:10.12401/j.nwg.2024075
中亚造山带南缘晚石炭世—早二叠世碳酸盐岩台地的建立和消亡
Formation and Demise of Late Carboniferous to Early Permian Carbonate Platforms on the Southern Margin of the Central Asian Orogenic Belt
摘要
Abstract
Carbonate platforms have significant implications for the ancient marine environment.During the Late Carboniferous to Early Permian,continuous deposited carbonate strata were widely distributed on the southern margin of the Central Asian Orogenic Belt.However,these rock units lack precise age constraints and systematic correlation,thus limiting further discussions on their paleogeographic and paleoenvironmental signif-icance.This study reports the stratigraphic sequence of the"Amushan Formation"measured sections on the northern margin of the Alxa Block and provides zircon U-Pb isotope ages from volcanic intercalations,precise-ly constraining the age and distribution of the carbonate platforms.The results indicate that the"Amushan For-mation"north of the Engerwusu Fault Zone should be revised to the"Gegenaobao Formation,"which is domi-nated by clastic rocks and dates to the Kasimovian to Asselian(＜296.1 Ma).South of the fault zone,the car-bonate platform of the Amushan Formation is characterized by continuously deposited and fusulinid-rich lime-stone with ages from the Gzhelian to Asselian(303.2～295.3 Ma).Based on high-resolution stratigraphic corre-lations with areas such as Beishan in Gansu and central Inner Mongolia,this study proposes that the carbonate platforms at the southern margin of the Central Asian Orogenic Belt were a product of global Late Carbonifer-ous transgression and the subtropical climate of the southern margin of the Paleo-Asian Ocean.The rifting dur-ing the Early to Middle Permian was the primary reason for the demise of these carbonate platforms.关键词
阿拉善地块/古海洋/碳酸盐岩台地/同位素年代学/晚石炭世—早二叠世Key words
Alxa Block/carbonate platform/isotopic chronology/Late Carboniferous-Early Permian/pa-leo-ocean分类
天文与地球科学引用本文复制引用
牛亚卓,史冀忠,赵国春,牛文超,陈高潮,宋博..中亚造山带南缘晚石炭世—早二叠世碳酸盐岩台地的建立和消亡[J].西北地质,2024,57(6):95-112,18.基金项目
国家自然科学基金面上项目"中亚造山带北山北部石炭系火山-沉积层序及其对古地理重建的时空制约"(42072132),中国地质调查局项目"氦气资源调查评价与示范"(DD20221665)联合资助. （42072132）
