Discovery and Metallogenic Significance of the Late Cretacous Adakites from Zetang, Tibet
详细信息
- 责任者：Zhao Zhen (Institute of Geomechanics ; Chinese Academy of Geological Sciences ; Beijing 100081 ; China) ; Hu Daogong
- 刊名：Journal of Geomechanics
- 出版年：2013
- 卷期：19(1)
- 关键词：铜矿 ; copper ores ; 埃达克岩 ; adakite ; 西藏 ; Tibet
- 页码：p.45-52,112
- 图表：illus., 1 table, 32 refs.
- 分类号：0801
- issnNo：ISSN1006-6616
- isbnNo：CN11-3672/P
摘要
Adakites have an indicative significance to deep-seated structures of orogenic belt and thermal regime,and a closely relationship with the minralization of Cu and Au.The metallogenic mother rock of Sangbujiala skarn copper deposit,in Zetang,southern margin of the East Gangdise metallogenic belt is Late Cretaceous granodiorite.The major elements are characterized by higher SiO2(>56%),Al2O3(>15%),Na2O(≥3.5%) and K2O(>2%),lower MgO(<3%).Na2O/K2O is 1.03~1.43,with an average of 1.22.The analyzing results of race earth and trace elements show higher Sr(>400×10-6),lower Yb(<1.9×10-6) and Y(<15×10-6),higher Sr/Y(86.88~132.22,>20) and La/Yb(>10),enriched in LREE and depleted in HREE,and no negative anomalies of Eu,similar to those of adakite.By geochemical and geological characteristics,it was may be formed in partial melting of subduction oceanic plate of the O-type adakites,which interacted with mantle peridotite,showing that the southern margin of Gangdise has O-type adakites mineralization.