某些颗粒灰岩的成岩环境标志和成岩序次

追朔至19世纪,首次将成岩作用术语引入文献要推Moresby (1835)和Gumbeel (1868),后经Walther (1894)及其后很多学者研究才得以广泛使用。而有关碳酸盐成岩作用的专题研究仅是三十多年的历史。开始是成岩阶段分析,侧重在“时间”上研究成岩作用。本世纪五十年代以后,随着开展大量现代碳酸盐沉积工作,对碳酸盐矿物学和流体化学研究的日益深入,才从“空间”变化和分布上讨论碳酸盐成岩作用,即进行成岩环境研究。

The Evidences of Diagenetic Environments and Diagenetic Sequences of Grainstones

This paper deals mainly with oolitic limestones in the Zhangxia Formin the Tangshan area and other places. On the basis of the evidences of diagcnctic enviromas characteristics of cementation, the occurrence of dolomites, syntarial overgrowth of and micritization, it has been proposed that diagenetic sequences of the grain sediments dwith distinct sedimentary microenvironments, resulting in the occurrence of predictable superimposed diagenetic evidences and the understanding of the evolutionary law of the porosity. It is emphasized in the latter part of the paper that the grain cements are not only restricted to sparry calcite but also include the micritic cements in ncarshore environments. The microfcatures represented by both of them are obivously distinct.