河流层序地层学研究现状与存在的问题

Review and Problems of Fluvial Sequence Stratigraphy

河流层序地层学为河流沉积学研究注入了活力,但已有的河流层序地层模式还存在不少问题。在回顾已有河流层序地层模式的基础上,从河流层序的主控因素、层序内部的等时对比和体系域特征的描述3个方面分析了已有模式中存在的问题,并提出从河流阶地的成因入手分析河流层序的主控因素,基于河流形成过程划分体系域和进行等时对比,并从砂泥比、砂地比、砂体切割程度、微相类型的垂向变化、单层砂体平均厚度、砂体钻遇率等方面对体系域进行客观的描述,最后指出了河流层序地层学研究的发展趋势。

Fluvial sequence stratigraphy has brought enormous vitality to the study on fluvial sedimentology,but at the same time,there are some problems from the fluvial sequence stratigraphy models built.This paper analyses the main controlling factors of fluvial sequence,discusses the isochronism of sequence interior,and describes items about systems tract on the basis of reviewing all models about fluvial sequence stratigraphy.It proposes that the controlling factors should be conceded based on origins of the fluvial terrace sediments,that dividing systems tracts and isochronism stratigraphic correlation should be depended on the fluvial forming processes,and that systems tracts should be objectively described by sandstone/mudstone ratio,sandstone/strata ratio,incision degree among sand bodies,microfacies change in vertical direction,average thickness of single sand body,and drill encounter rate of sand bodies.At last,it presents the development tendency about fluvial sequence stratigraphy.