滇黔桂地区晚古生代至三叠纪层序地层序列及沉积盆地演化

SEQUENCE-STRATIGRAPHIC SUCCESSION AND SEDIMENTARY-BASIN EVOLUTION FROM LATE PALEOZOIC TO TRIASSIC IN THE YUNNAN-GUIZHOU-GUANGXI REGION

志留纪末期的加里东运动使扬子板块与华夏板块基本上连接成一个统一的华南板块,在这个较为稳定的构造背景下,从晚古生代至三叠纪滇黔桂地区经历了一个较为复杂的盆地演变过程,形成了一个复杂而有序的层序地层序列。晚古生界可以划分为25个三级沉积层序,三叠系大致可以划分为10个三级沉积层序;35个三级沉积层序又大致可以归并为8个二级构造层序。从三级沉积层序到二级构造层序的归并,代表了滇黔桂地区从晚古生代的"滇黔桂盆地"演化为早、中三叠世的"南盘江盆地"、最后在晚三叠世早期结束海相沉积历史的沉积学和地层学响应过程,为在层序地层学框架内理解复杂的地质演化历史提供了一个较为典型的实例。

The Caledonian orogeny that occurred at the turn between the Silurian and the Devonian led the Yangtze Plate and the Huaxia Plate to merge into one plate, i.e.South China Plate. In this relatively stable background, the Yunnan-Guizhou-Guangxi region had undergone a sophisticate evolutionary process of sedimentary basin from the Late Paleozoic to the Triassic, which formed a complex and regular sequence-stratigraphic succession. In this succession, the Late Paleozoic can be subdivided into 25 third-order sedimentary sequences, and the Triassic can also be divided into 10 third-order sedimentary sequences, and these 35 third-order sedimentary sequences can be grouped into 8 second-order tectonic sequences. The division of sedimentary third-order sequences and the incorporation of the second-order tectonic sequences, represent a sedimentological and stratigraphic response process from the Late Paleozoic Dian-qian-gui Basin to the Triassic Nanpanjiang Basin and the end of marine sedimentation within the early of the Late Triassic in the study region. Thus, the sequence-stratigraphic succession from Late Paleozoic to Triassic in the study region provides a typical example to understand complicate geological-evolution history in the sequence-stratigraphic framework.