赣西北莲沱组较深浅水沉积类型的发现及其地质学意义

THE DISCOVERY AND GEOLOGICAL IMPLICATIONS OF THE DEEPER SHALLOW-MARINE SEDIMENT TYPES IN THE LIANTUO FORMATION,NORTHWESTERN JIANGXI.

本文论述了赣西北莲沱组小规模重力流出现，不仅仅是一种沉积环境改变，而是一种事件沉积作用，其在地质学上的意义十分巨大。它不仅仅具良好的相分析、层序地层配套以及对其上的南沱组成因地层分析具重要作用，而且更为重要的是具良好的构造古地理、板块活动标志．

The small-scale gravity-flow deposits considered as the event sediments at the upper-most part of the Liantuo Formation,northwestern Jiangxi indicate a progressively increas-ing depth of sedimentary environments rather than a simple terrestrial-marine transition.The retrogradational sediments from continent to foreshore to shelf produced by increasingexpansion of transgressions in the early and middle stages of the deposition of the LiantuoFormation show a gradually deepening of sea water,whereas the intercalations of the sea-ward progradational small-scale gravity flow sediments and thick massive non-gravity flowsediments generated during the late stage of it represent relatively complicated sediments,The small-scale gravity-flow sediments in the study area may not only play an impor-tant part in facies analysis,sequence stratigraphic analysis and genetic analysis of the grav-el-bearing tillites overlying the Nantuo Formation,but also serve as good indicators for thereconstruction of tectono-palaeogeography and plate tectonics.