摘要
本文以苏浙皖毗邻地区晚二叠世长兴期地层为岩石单元,该单元从研究区东南向西北依次划分为近滩潮坪相、浅水碳酸盐台地相、台前碳酸盐凹陷相及近台边缘硅质岩盆地相。对该岩石单元不同相带剖面牙形石产出量进行研究,用信息函数论方法对数据进行计算机处理,发现研究区不同相带牙形石产出频率、分异度、产出量、均衡度及牙形石种类和形态等与沉积相、共生矿物、水深、盐度水动力条件等有密切关系。通过综合研究得出:(1)最适合牙形石动物繁衍生息的环境是浅水碳酸盐岩台地相和台前凹陷相,尤以台前凹陷相最宜。(2)水体较浅的近滩潮坪相和水体较深的近台边缘硅质岩盆地相则不适宜牙形石动物生存。(3)广布的单分子器官属Neogondolella营浮游生态类型。分布局限的多分子器官属Prioniodella、Hibbardella、Enantiognathus,为底栖底游生态类型。
Abstract
The strata in the adjacent area of Su-Zhe-Wan (the provinces of Jiangsu, Zhejang, and Anhui) area dated from Changxing period of the late Permian are taken as a rock unit, which, from southeast to northwest of the study area, are successively divided into peri-beach tide-flat fades, shallow water carbonate platform facies, platform-front carbonate depression fades and peri-platform margin siliceous rock facies. The yields of conodonts from the sections of different facies belts are studied, and the data are processed on computer with the method of information functions. It has been found that the yield frequency,differential index,yields,isostatics, the species and forms of conodonts from different facies belts are all closely related to sedimentary facies, paragenetic minerals, water depthes,salinity and hydrodynamic conditions. The synthetical study shows that 1. the environments favourable for the breeding and living of conodont animals are shallow-water carbonate platform facies and platform front depression facies, especially the latter; 2. peri-beach tide flat facies with shallow water body and peri-platform margin siliceous rock basin facies with deeper water body are unfavourable for the living of conodont animals; 3.the extensively distributed monomolecular organs belong to the plankton ecological type of Neogondodella, while the limitedly distributed polymolecular organs belong to the benthic ecological type of Prioniodella, Hibbardella, and Enantiognathus.
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