鲁西寒武系层序地层特征及在区调中的应用

SEQUENCE STRATIGRAPHIC CHARACTERISTICS OF CAMBRIAN IN WEST OF SHANDONG AND ITS APPLICATION IN REGIONAL GEOLOGICAL SURVEY

鲁西地区寒武纪地层发育较好，沉积记录具旋回性的特点。根据层序地层学的原理与方法，按照不同的层序界面类型、岩石组合特点及沉积相序叠置关系，在该区寒武系中识别出１５个三级层序界面，划分出１４个三级层序（—Ｃ１～—Ｃ１４）。这些层序的共同特点是海侵体系域和高水位体系域发育较好，而典型的低水位体系域则未见及。通过分析海平面的变化规律及其延续时限，它们被归并为两个中层序（ＭＳ１、ＭＳ２），分别对应于二级海平面变化旋回和碳酸盐台地的两个发育阶段。

Cambrian stratigraphy well developed in Luxi(west of Shandong),and their sedimentary records possesses cyclicity.According to the principles and methods of sequence stratigraphy,and on the basis of different sequence interface types,rock associations characteristics and sedimentary facies′ superimposed relations,15 thirdgrade sequence interfaces have been recognized and 14 thirdgrade sequences divided from Cambrian system.The common characteristics of these sequences is that incursion systemfield and hightide line system field developed well;on the contrary,typical lowtide line systemfield unfound.Through the analysis of the variation regularity of sea level and its lasting period,the sequences can be incorporated into two mediumsequences(MS 1,MS 2),equivalent to the variation cycle of secondgrade sea level and to the two developing stages of carbonate terrace.