云台山中元古界云梦山组红色砂岩特征及其环境意义

Characteristic of red sandstone and its environment significance in Yunmengshan Formation of Yesoproterozoic in Yuntai Mount

云梦山组红色石英砂岩形成的峡谷地貌是河南省云台山世界地质公园的主要景观之一.以云台山地区云梦山组红色石英砂岩为研究对象,从宏观和微观角度对石英砂岩的沉积特征及沉积环境进行分析,并利用扫描电子显微镜和能谱仪对云梦山组中上部的暗紫色和肉红色石英砂岩进行了元素成分分析,在此基础上探讨了其揭示的环境意义.研究结果表明,云梦山组石英砂岩形成于滨海海滩-潮坪环境,具有较高的成分和结构成熟度,暗紫色石英砂岩胶结物中Fe元素的含量明显高于肉红色石英砂岩中的含量,该现象是岩石圈-水圈-大气圈-生物圈共同作用的结果.该研究对于云梦山组沉积时期的环境分析具有重要意义.

Gorge topography constituted of the red sandstone of Yunmengshan Formation of Mesoproterozoic is one of main landscapes in the Yuntai Mount World Geopark. Taken the red sandstone as the object, its sedimentary characteristic and environment are analyzed from the macro and micro viewpoints and the elemental compositions of dark purple and yellowish pink sandstone in the middle and upper Yunmengshan Formation are tested using SEM and EDS. Based on the above, the environment revealed by the sandstone is discussed in this paper. The result shows that the quartz sandstone of Yunmengshan Formation forms in the beach and tidal flat sedimentary environments and has a high compositional and textural maturity. The weight percent of element Fe in the cement of dark purple sandstone is obviously higher than that in the yellowish pink one, which is the effect acted together by lithosphere, hydrosphere, atmosphere and biosphere. This result has the important significance to study on the environmental characteristic in the Yunmengshan Formation stage.