辽宁金县寒武纪早期生物矿化迹象

A TRACE OF BIOMINERALIZATION IN THE EARLY CAMBRIAN OF JINXIANG COUNTY,LIAONING PROVINCE

从地质背景、沉积环境模式、矿化部位的宏观特征、显微特征研究,扫描电镜描述、电子探针分析和X-光衍射分析等数据,总结了生物矿化及其演化过程。

In Jinxian County, Liaoning Province, the Early Cambrian sedimentary sequence was deposited on the erosion surface of the Sinian carbonate bed, forming two sets of regressive beds, i.e.the Gejiatun Formation of the lower part composed of shoal-lagoonal facies and the Dalinzi Formation of the upper part composed of sabkha-intertidal facies.The galena-pyrite biomineralization discussed in this paper is seen in the lower part of Gejiatun Formation.The authors have summarized the evolution of biomineralization based on geological setting, model of sedimentary environment, macroscopic features of biomineralization positions, scanning-electron microscopic description, electron microprobe analyses and X-ray diffraction determinations. The authors hold that two typical examples in China should be further studied, i.e.the biomineralization of galena in Tertiary pebbly coquina of Xinjiang formed by organic degradation of animal and the biomineralization of galena-pyrite in Cambrian of Liaoning formed by algal degradation.