摘要
石棚峪超单元位于营口-宽甸台拱西端,与下辽河断陷相毗邻,侵位于燕山旋回早期,与分水金矿田及金山岭铅矿等有着密切的成因联系,其岩石地球化学特征与碱性花岗岩十分相似.通过花岗岩类自然矿物岩石化学换算法证明其应归于碱长花岗岩类,其主要岩石类型为黑云碱长花岗岩.其成岩物质主要是由上地幔衍生的岩浆部分熔融下地壳物质而成.岩石属非造山区的A型花岗岩类.
Shipengyu super unit,distributed in the north of Dashiqiao,Liaoning Province,is tectonically located in the west part of the Yingkou kuandian anteclise,adjecent to the Xialiaohe fault depression.The rock is the result of the tectonomagmatic activities of Yanshanian period,with a whole rock Rb Sr isochron age of 186±13Ma.It has a close genetic relationship with the Fenshui gold ore field and the Jinshanling lead deposit.The chemical component of the super unit rock is characterized by high Si and alkali and low Ca and Mg,to reflect alkaline rock.The content of trace elements also shows the characteristics of alkaline granite,that is rich in Ga,Nb,Ce,Y,Zr,Mo and W and poor in Co,Ni,Cr,V,Sc and Sr.The ΣREE is lower than the average value of the acid rock defined by A.L.Venogradov(1962) and the granite by A.G.Hermann(1970),suggesting typical LREE enrichment type.By chemistry conversion of natural minerals of the granite,the rock of Shipengyu super unit is proved to be alkali feldspar granite.The main type of the super unit rock is biotite alkali feldspar granite.The Sr and O isotopic features show that the diagenetic substance of Shipengyu super unit is formed by the magma,which has been derived from upper mantle and partly melts the substance of lower crust.The rock is formed in the intraplate extensional environment in Early Jurassic or Yanshanian period,genetically belonging to the A type nonorogenic granite.
出处
《地质与资源》
CAS
2002年第3期161-167,共7页
Geology and Resources
关键词
石棚峪超单元
岩石地球化学特征
墨云碱长花岗岩
A型花岗岩
辽宁
Shipengyu super unit
geochemical feature
biotite alkali feldspar granite
A type granite
Liaoning Province
