豫西鲁山地区新元古界罗圈组沉积环境分析  

SEDIMENTARY ENVIRONMENT ANALYSIS OF NEOPROTEROZOIC LUOQUAN FORMATION IN LUSHAN AREA, WESTERN HENAN PROVINCE

作　　者：张碧云 郑德顺[1] 刘仰光 ZHANG Bi-yun;ZHENG De-shun;LIU Yang-guang(School of Resources and Environment^Henan Polytechnic University,Jiaozuo 454000)

机构地区：[1]河南理工大学资源环境学院

出　　处：《地层学杂志》2019年第4期417-424,共8页Journal of Stratigraphy

基　　金：国家自然科学基金项目(41872238)资助

摘　　要：华北板块南缘新元古界罗圈组为一套特殊的杂砾岩层,其是否为冰川成因对于新元古代冰期的研究具有重要意义。在野外实测剖面的基础上,本研究对鲁山地区罗圈组岩性、岩相特征及冰蚀遗迹进行探索,恢复其沉积环境,结果显示:罗圈组底部存在冰溜面,主体为块状杂砾岩,砾石砾径差异较大,呈棱角及次棱角状,地层中含有砂岩透镜体及出现坠石构造;镜下观察砂岩分选磨圆差、颗粒支撑。上述特征说明豫西鲁山地区罗圈组为冰川成因,推断其为陆相冰磧岩及冰水环境形成的产物。本文建立了罗圈组冰川相、冰水相的沉积模式,对于确定该地区古环境、古地理及新元古代冰川发育范围具有一定的参考价值。The Neoproterozoic Luoquan Formation in the southern of North China is a special set of diamictite layers,the origin of which is of great significance for the study of the Neoproterozoic Glaciation.Based on the measured sections in the field,the lithology,lithofacies characteristics and glacial relics of the Luoquan Formation were studied to restore their sedimentary environment.The results show that there are glaciated pavements at the bottom of the Luoquan Formation,the main bodies of which are massive diamictite with gravels and clasts of different diameters which are angular and sub-angula匚The stratum contains sandstone lens body and dropstone structure.Petrographic analyses revealed that sandstone has poor sorting and psephicity showing particle support.The above characteristics indicate that the Luoquan Formation in the Lushan area is glacial origin;therefore,it could be deduced that the Luoquan Formation was the product of terrestrial glacial moraine and shallow water environment.Finally,the sedimentary model of glacial facies and glaciomarine of the Luoquan Formation was established.This study has certain reference value for determining the paleoenvironment,paleogeography and the development range of the Neoproterozoic glacier in the region.

关 键 词：罗圈组 杂砾岩 成因 沉积环境 豫西鲁山 

分 类 号：P534.3[天文地球—古生物学与地层学]