北京十三陵元古宙大红峪组含事件信息的沉积岩研究

A Study of Event Message-bearing Sedimentary Rocks of the Proterozoic Dahongyu Formation from the Ming Tombs District, Beijing

北京十三陵元古宙大红峪组在不足 4km的距离内岩相急剧变化 ,实为国内外罕见。从东至西 ,泰陵剖面由灰色角砾硅化岩 +黑色粉砂凝灰页岩 +黄色含长石石英砂岩组成 ,山顶剖面由不纯砂岩 +泥质白云岩组成 ,德胜口剖面由泥质白云岩 +石英砂岩 +层凝灰岩组成。本文仅对泰陵剖面大红峪组的三种岩石进行系统研究。宏观、微观特征、地球化学和同位素地球化学分析数据表明 :泰陵剖面大红峪组的灰色角砾硅化岩和黑色粉砂凝灰页岩是受火山 -地震事件影响形成的沉积岩 ,而覆盖其上的黄色含长石石英砂岩形成于正常滨海环境中。最后提出大红峪组含事件信息的沉积岩形成模式图。

The drastic lithofacies change of the Dahongyu Formation in less than 4 km within the Ming Tombs District of Beijing is a phenomenon rarely seen both in China and abroad, From east to west, there are Tailing section composed of grey brecciated silicified rock+black silty tuffaceous shale +yellow feldspar_bearing quartz sandstone, the hill top section consisting of impure sandstone + muddy dolostone, and the Deshengkou section comprising muddy dolostone + quartz sandstone + tuyffite. As the last two sections have been discussed before, this paper deals mainly with the Tailing section. According to macroscopic, microscopic, geochemical, and isotopic geochemical data, the authors hold that the grey brecciated silicified rock and black silty tuffaceous shale were formed under the influence of volcano_seismic event, thus serving as a kind of event message_bearing rock, whereas the overlying yellow feldspar_bearing quartz sandstone was formed in a normal littoral environment. A model for the event message_bearing rocks of the Dahongyu formation is advanced in this paper.