东海西湖凹陷渐新统花港组海绿石的发现及其意义

在西湖凹陷渐新统花港组中首次发现非正常海相海绿石。可分为三种类型:即团粒状海绿石、胶结物海绿石和碎屑假象海绿石。前两者属沉积过程或成岩初期的产物。通过沉积学研究，结合微量元素及介质条件分析认为，花港组总体为滨岸湖泊三角洲－河流体系，但是曾程度不同地受到海水或咸水-半咸水影响。花港组的时代就可能归属为始新统。这一认识上的突破除了花港组年代地层的对比意义以外，还将引起对盆地演化阶段、沉积体系空间配置及油气有利相带预测等问题的重新认识。

The Discovery and Significance of Glauconites in the Huagong Formation of the Oligocene ,Xihu Depression,East China Sea

The glauconite formed in the abnormal marine environment was found firstly in the Huagong Forma-tion of the Oligocene ,Xihu Depression,East China Sea.It can be divided into three types as follows:granule glauconite,cemented glauconite and clastic pseudomorph glauconite.The first two types were formed during the sedimentation and the beginning of diagenesis.It was thought by the sedimentary studies that the Huagong Formation was generally formed in the shoreline lacustrine delta fluvial depositional systems.But the formation was influenced by marine water or salt semisalt water in some degree.The re depositional fossil in the formation,at least a part of it was probably developed and preserved at the same place.Con sequently,the age of the Huagong Formation would be probably taken as the Eocene Epoch.Besides the chronos tratigraphy,the idea would lead to re analysis for the problems about the evaluating stages,dimensional dis tribution of sedimentary systems as well as the prediction of favorable facies belts for oil and gas.