露头碳酸盐岩旋回层序的识别与划分

Recognition and division of carbonate cyclic sequence in outcrops.

在海相碳酸盐岩新区勘探中，露头层序地层学是一种重要的勘探手段。归纳了露头碳酸盐岩米级旋回层序的识别特征和划分依据，识别和测量了北京西山丁家滩剖面的米级旋回层序，并分析其垂直叠加型式，划分了长周期旋回层序。结果表明，通常是４～６个向上变厚并变浅的米级旋回层序构成一个五级旋回层序；４个总体向上变厚并变浅的五级旋回层序构成一个四级旋回层序；３～５个四级旋回层序构成一个更大级别的总体向上变厚变浅的序列。图１表１参６（邹冬平摘）

Sequence stratigraphy in outcrop is important for the exploration in new area of marine carbonate. Based on correctly recognizing and surveying meter scale cyclic sequences and analyzing their vertical stacking pattern, this paper recognized and divided the long term cyclic sequences of Dingjiatan profile in Beijing by analyzing their vertical stacking pattern. In general, four to six thickening and shallowing upward meter scale cyclic sub sequences make up a fifth order cyclic sequence, four fifth order cyclic sequences shallowing upward make up a fourth order cyclic sequence, and three to five fourth order cyclic sequences make up a third order cyclic sequence overall shallowing upward.