辽西凌源地区雾迷山组硅质岩地球化学特征  

Geochemical Characteristics of Siliceous Rocks in Wumishan Formation of Western Liaoning Province

作　　者：郑秀才[1] 王正允[1] 陈梦蛟[1] 

机构地区：[1]长江大学工程技术学院,湖北荆州434023

出　　处：《石油天然气学报》2010年第5期73-78,共6页Journal of Oil and Gas Technology

基　　金：中国石油化工股份有限公司海相前瞻性研究项目(YPH08026)

摘　　要：辽西凌源雾迷山组发育的硅质岩属于低硅质硅质岩,其SiO2平均含量为75%。岩石相对富集Fe、Mn,而相对贫Al、Mg、Ti,富集微量元素Ba。Fe2O3/FeO、Al/(Al+Fe+Mn)、K2O/Na2O和Ba/Sr比值,Al-Fe-Mn、SiO2-Al2O3、MgO-SiO2、MgO-P2O5的图解都显示区内硅质岩具有明显的热水沉积的特征;MnO/TiO2、Al/(Al+Fe)比值,V、Ba、Sr、Rb等微量元素含量,Fe2O3/TiO2～Al2O3/(Al2O3+Fe2O3)双变量图解判别显示硅质来源于大陆边缘-远洋盆地;CaO/(Fe+CaO),MgO/(Al2O3)比值指示出其形成于高盐度环境。The siliceous rocks in Wumishan Formation in western Liaoning Province were characterized by low content of the siliceous minerals with an average content of 75%,and it was enriched in the major elements such as Fe and Mn and the trace elements such as Ba and V,and depleted in the major elements such as Al,Ti and Mg.The ratios of Al/(Al+ Fe+Mn)、Fe2O3/FeO、K2O/Na2O and Ba/Sr(2.4),and Al-Fe-Mn and SiO2-Al2O3,MgO-SiO2,MgO-P2O5diagrams show that the siliceous rocks are the sedimentary rocks of hydrothermal origin.From the MnO/TiO2ratios,Al/(Al+ Fe)ratios,the trace elements such as V,Ba,Sr,Rb,and Fe2O3/TiO2-Al2O3/(Al2O3+Fe2O3)diagrams,the siliceous rocks are inferred to the deposition in the hemipelagic-pelagic environments such as continental slopes and oceanic basins.The ratios of CaO/(Fe+CaO)and MgO/Al2O3)×100show that the seawater during the deposition of the siliceous rocks in Wumishan Formation of western Liaoning Province might be freshened.

关 键 词：硅质岩 热水沉积 地球化学 沉积环境 雾迷山组 辽西 

分 类 号：P588.2[天文地球—岩石学]