Redefinition and Geochemical Characteristics of the Mesozoic Shoshonite Rock Series of the Meifeng Formation in Northern Yichun City, Heilongjiang Province
详细信息
- 责任者：Pan Rong (College of Geosciences ; China University of Petroleum ; Beijing 102249 ; China) ; Zhu Xiaomin
- 刊名：Geological Journal of China Universities
- 出版年：2013
- 卷期：19(2)
- 关键词：火山岩 ; volcanic rocks ; 黑龙江省 ; Heilongjiang Province
- 页码：p.316-326
- 图表：illus., 1 table, 26 refs.
- 分类号：0801
- issnNo：ISSN1006-7493
- isbnNo：CN32-1440/P
摘要
The intermediate-basic volcanic rocks of the Meifeng Formation were studied systematically to characterize its mineralogy,petrology and geochemistry in Wuyiling area,northern Yichun city of Heilongjiang Province.The rocks are characterized by high-K,high-alkali(w(Na 2 O+K 2 O)=3.90%-9.53%),low-Ti(w(Ti 2 O)=0.37%-1.90%),high-Al(w(Al 2 O 3)=14.05%-18.24%) values,and are enriched in large ion lithophile elements(Cs,Rb,Ba,Th) and light rare earth elements.With the mineralogical features of micro-crystal potash feldspar texture and iddingsite olivine phenocrysts in the rock matrix,the volcanic rocks are identified as the shoshonite series,which are mainly composed of potassic trachybasalt,shoshonite,latite and trachyte.The zircon SHRIMP U-Pb dating is(105±5) Ma,which suggests that the volcanic rocks are formed during the late Early Cretaceous.Based on the geochemical features,the dehydration associated with the low-angle,deep subduction of the West Pacific plate caused melting of the mantle-derived source areas.The tectonic regime for the Meifeng Formation belongs to an intraplate extensional environment.