宁夏北部沙巴台地区太原组沉积层序及其年代地层对比

宁夏北部沙巴台地区的太原组为海陆交互相和三角洲相沉积 ,可划分为 2个三级层序、 4个副层序组和 1 8个副层序。与华南海相沉积层序的对比表明太原组属晚石炭世 Gzhelian晚期至早二叠世 Artinskian中期。下二叠统 Asselian阶的底界 (即 C/P界线 )大体与太原组下部层序的初始海泛面一致 ,可广泛对比。

SEQUENCE STRATIGRAPHY OF EARLY PERMIAN TAIYUAN FORMATION IN SHABATAI AREA,NORTHERN NINGXIA AND ITS CHRONOSTRATIGRAPHIC CORRELATION

The Taiyuan Formation in the Shabatai area,northern Ningxia,is characterized by the alternative deposits of shallow marine and non- marine facies,shifting mainly between neritic and deltaic environments. The presentstudy showsthatthe Taiyuan Formation consistsof1 8upward- shallowing parasequences,which can be grouped into4 parasequence sets and further into2 third- order sequences.The correlation of these depositional sequences with those recognized in the marine sediments of southern Guizhou,SW margin of the South China Plate,suggeststhatthe Taiyuan Formation,which waspreviously assigned to Late Carboniferous is largely Early Permian in age,extending from late Gzhelian to middle Artinskian.The boundary between Carboniferous and Permian is in well accordance with the FFS of the lower sequence in the Taiyuan Formation.