摘要
在沉积学、生物地层学研究之基础上，结合沉积地球化学资料，对龙门山马角坝地区石炭系进行了露头层序地层学研究。首次识别出９个三级层序和若干个四至五级高频层序。在三级层序中，岩关组２个、大塘组３个、威宁组２个、马平组２个，它们均可作区域性对比。其中，四个层序分别与冈瓦纳大陆晚古生代五次冰川事件中四次间冰期－冰期旋回相对应，表明其成因与冰川型全球海平面变化有关。显然，研究区石炭纪层序主要受控于全球海平面升降旋回，具有全球对比意义。
Based on key boundaries,systems tracts and stacking patterns,in conjunction with regional geological and biostratigraphic data,the Carboniferous carbonate strata in the Majiaoba district, Sichuan are grouped,for the first time,into nine third-order sequences:two in the Yanguan Formation, three in the Datang Formation, two in the Weining Formation and two in the Maping Formation,all of which, in turn, may be subdivided into a number of the fourth-or fifth-order high-frequency sequences or parasequences.The time intervals of individual third-order sequence range between 2 and 11.5 Ma.And the differences of these sequences are attributed to the variations in periods of relative sea-level rises or falls,amplitudes of tectonic subsidence,rates of carbonate production and modes of sediments supply in the study area.
基金
成都理工学院青年科学基金
关键词
层序地层学
海平面变化
石炭纪
龙门山地区
四川
sequence stratigraphy
sea-level change
Carboniferous
Majiaoba district in the Longmen Mountain area
glacio-eustatic change
