苏北盆地早第三纪海侵析疑

A DISCUSSION OF THE PALAEOGENE TRANSGRESSION IN NORTH JIANGSU BASIN

本文根据化石的生态习性、属种分异度、韦度、共生化石等说明苏北盆地发现的生物化石具一定海相性或与海有关,为生活于半咸水的广盐性属种;本文还论证了岩矿标志和地球化学参数在古环境解释中的多解性和区域局限性,说明水介质中盐度的分析不能作为区分海、陆相的依据;从地质背景阐明苏北盆地早第三纪未经历海侵或海泛沉积,属陆相湖盆,在阜二段和阜四段时期湖水曾一度咸化。

In the present paper, the author uses the ecological habit, diversity of organism genus or species, abundance of and associated fossil to explain that the discovered marine property orsea related organisms are of euryhalinous genera or species. The nonuniqueness and local lim-itations of mineral marker and geochemical index in the explanation of paleoenvironment are proposed. It is shown that salinity can not be taken as the basis for a differentiation between marine and continental facies. The basin’s geological background indicates that no transgression or sea flood had taken place in paleogene in the basin. North Jiangsu Basin is a continental facies lacustrine basin. During the time when the 2nd and 4th members of Funing Formation were deposited, the lake was once saline in nature.