巢湖地区五通组砂岩岩石学特征  

Petrologic Features of Wutong Formation Sandstone in Chaohu Area

作　　者：宋佳伟[1] 赵鲁阳[1] 吕大炜[1] 

机构地区：[1]山东科技大学地球科学与工程学院,山东青岛266590

出　　处：《中国煤炭地质》2016年第4期41-44,共4页Coal Geology of China

基　　金：国家自然基金项目(41202070);山东省自然科学基金(ZR2015JL016)共同资助

摘　　要：巢湖地区广泛发育泥盆系五通组砂岩,砂岩的岩性变化较大,其岩石学特征也比较复杂。在前人研究成果和野外实测的基础上,采用沉积学和地层学的方法,结合镜下鉴定和手标本颗粒粒度分析的方法,对砂岩的岩石学特征进行分析。区内五通组根据岩性特征自下而上可划分为三个岩性段,下部由粒径大于5 mm的砂砾岩组成,底部砾石高度发育,含量高达70%为砂砾岩;中部石英砂岩部分被铁质胶结,砂岩中含有少量重结晶,成团粒状分布的石英颗粒;上部见粒径较小的石英粉砂岩和砂岩,粒径在0.05~0.15 mm,磨圆度较差;砂岩的频率曲线呈现对称一正偏,偶有负偏,尖度为中等到尖锐,偶有平坦。砂岩中板状交错层理、平行层理,波痕等构造常见。Devonian Wutong Formation sandstone is widely developed in the Chaohu area. Its lithologic character is rather complex.Based on previous research results and field measurement, through sedimentologic and stratigraphic methods combined with microscopic identification and hand specimen granulometric analysis carried out sandstone lithologic character analysis. Lithologic features of Wutong Formation in the area can be partitioned into 3 lithologic sectors from bottom to top. Lower sector is composed of sandy conglomerate with grain size 5mm, bottom part pebbles are well developed, when pebble content is higher than 70%, then can be called as sandy conglomerate. In middle sector, a part of quartzose sandstone is ferruginous cemented with light recrystallization, quartz particles aggregated into crumbs. Upper sector is composed of quartzose siltstone and sandstone with smaller particles, grain size 0.05~0.15 mm and poorly rounded. Sandstone frequency curves present symmetry to positive bias, and occasionally negative bias; sharpness is medium to sharp, smooth occasionally; tabular cross-bedding, parallel bedding and ripple marks are common.

关 键 词：五通组砂岩 岩性特征 粒度特征 沉积特征 

分 类 号：P588.212.3[天文地球—岩石学]