京西下苇甸地区寒武系岩石特征及沉积环境研究  

Study on Cambrian Petrology and Sedimentary Environment in Xiaweidian Area, Western Beijing

作　　者：康世龙[1] 邵龙义[1] 易琦[1] 赵晓峰[1,2] 许文茂 鲁静[1] 

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]中国科学院地理科学与资源研究所,北京100101 [3]中国地质大学(北京)能源学院,北京100083

出　　处：《中国煤炭地质》2016年第6期1-8,共8页Coal Geology of China

基　　金：国家科技重大专项(编号:2016ZX05009002)资助;中国矿业大学(北京)2013年度"大学生创新训练计划"

摘　　要：北京西山下苇甸地区寒武系为典型的华北型地层,常见的岩石类型为亮晶鲕粒灰岩、亮晶内碎屑灰岩、泥晶鲕粒灰岩、泥晶内碎屑灰岩、泥晶-微晶灰岩、晶粒灰岩、白云岩、粉砂岩及钙质泥岩。该区碳酸盐岩中的颗粒主要为鲕粒、内碎屑及生物碎屑,所见生物碎屑以三叶虫、介形虫、海百合茎等为主。昌平组以角砾灰岩、核形石灰岩、豹皮灰岩以及白云岩为主,形成于潮坪-潟湖环境;馒头组和毛庄组以紫红色泥岩为主,沉积于萨勃哈及潮坪环境;徐庄组和张夏组以厚-巨厚层状鲕粒灰岩夹条带状灰岩及粉砂岩为主,沉积于高能浅滩环境;崮山组以泥质条带灰岩夹鲕粒灰岩为主,沉积于滩外中缓坡环境;长山组和凤山组以泥质条带灰岩和砾屑灰岩为主,形成于中缓坡-外缓坡环境。总体上,下苇甸剖面碳酸盐岩发育匀斜缓坡沉积模式。研究区在寒武纪经历了昌平组沉积期到长山组沉积期的逐渐海侵过程及凤山组沉积期的逐渐海退过程。伴随着海平面的升降,该剖面形成了整体处于二级海侵背景下的11个三级海侵-海退旋回序列。The Cambrian System in the Xiaweidian area, Beijing Western Hills belongs to typical North China type lower Paleozoic strata, common rocks have oosparite, intrasparite, oomicrite, intramicrite, micritic, crystalline limestone, dolomite, siltstone and calcilutite. Grain types of carbonate rock in the area have mainly ooid, intraclast, and bioclast. Appeared bioclasts have mainly trilobites, ostracodes and crinoids etc. Rocks in the Changping Formation have mainly brecciola, oncolitic limestone, mottled limestone and dolomite deposited in tidal flat and lagoon environments. In Mantou and Maozhuang formations have mainly purplish red mudstone and formed in sabkha and tidal flat environments. In Xuzhuang and Zhangxia formations have mainly thick to extremely thick oolitic limestone intercalated with banded limestone and sihstone, deposited in energetic shoal environment. In Gushan Formation has mainly pelitic banded limestone intercalated with oolitic limestone, deposited in off-beach medium slope environment. In Changshan and Fengshan formations have mainly pelitic banded limestone and calcirudite, formed in medium slope to outer gentle slope environments. Generally, carbonate rocks on this section have developed a uniform inclined gentle slope model. During the Cambrian Period the study area had experienced from Changping Formation to Changshan Formation sedimentary stages gradual transgression process and Fengshan Formation sedimentary stage gradual regression process. Along with eustatic movement, 11 third-order transgression-regression cyclic sequences can be seen on the section.

关 键 词：下苇甸剖面 寒武系 岩石学特征 沉积模式 

分 类 号：P581[天文地球—岩石学]