摘要
瓜德鲁普统与乐平统的全球界线层型剖面—蓬莱滩剖面及其辅助剖面—铁桥剖面位于广西来宾地区,两剖面沿红水河两岸连续出露,是开展沉积相和层序地层研究的理想剖面。在两剖面的瓜德鲁普统茅口组与乐平统合山组中共识别出14种沉积相,组成4类沉积相组合,分别为盆地相、下斜坡相、上斜坡相和台地边缘相。依据这些沉积相及相组合垂向演化样式和横向分布特征,识别出6个主要的海侵—海退层序(TR),并具有高分辨率牙形石带的约束,分别为:TR1(J.nankingensis zone)、TR2(J.aserrata to J.shannoni zone)、TR3(J.shannoni zone to early C.p.postbitteri zone)、TR4(C.p.postbitteri zone to early C.transcaucasia zone)、TR5(C.transcaucasia zone to C.orientalis zone)和TR6(C.orientalis zone to C.inflecta zone)。基于两剖面的海侵—海退层序,开展了本地区高分辨率(等时)层序古地理恢复,这对厘定这一时期海平面下降、峨眉山玄武岩喷发、生物灭绝等重要事件之间联系可能具有重要的指示意义。
Two sections,at Penglaitan and Tieqiao,where the global stratotype sections for the boundary between the Guadalupian and Lopingian are located in the Laibin area of Guangxi province,respectively,are extensively eposed along the two banks of the Hongshui River and are chosen for analyses of facies and sequence stratigraphy.At the two sections,fourteen facies are recognized in the Maokou(Guadalupian) and Heshan(Lopingian) Formations,and these facies are further grouped into four main facies associations,which are basin,lower slope,upper slope and platform margin.Based on these facies,their vertical stacking patterns and the lateral distribution of facies associations,six transgressive-regressive(TR) sequences,TR1 to TR6,are identified and well correlated by detailed conodont zones.They are the TR1(J.nankingensis zone),TR2(J.aserrata to J.shannoni zone),TR3(J.shannoni zone to early C.p.postbitteri zone),TR4(C.p.postbitteri zone to early C.transcaucasia zone),TR5(C.transcaucasia zone to C.orientalis zone) and TR6(C.orientalis zone to C.inflecta zone).Based on the transgressive-regressive sequences of the two sections,(high-resolution) sequence-based lithofacies and paleogeographic evolution in the study area were carried on,which provides important implications for the relationship among some events during this time,such as the global regression,the Emeishan volcanism and the endGuadalupian mass extinction.
出处
《沉积学报》
CAS
CSCD
北大核心
2014年第3期429-441,共13页
Acta Sedimentologica Sinica
基金
国家科技重大专项(编号:2011ZX05001
2011ZX05008)
中石油重大科技专项"第四次油气资源评价"(编号:2013E-0502)联合资助
关键词
界线层型剖面
蓬莱滩
铁桥
沉积相
层序地层
the global stratotype section
Penglaitan
Tieqiao
facies
sequences stratigraphy
