- 责任者：Zhao Xiaoyan (School of Geosciences and Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yang Zhusen
- 刊名：Acta Petrologica Sinica
- 出版年：2013
- 卷期：29(11)
- 关键词：辉绿玢岩 ; diabase porphyry ; 斑岩矿床 ; porphyry deposit ; 西藏 ; Tibet
- 页码：p.3767-3778
- 图表：10 illus., 3 tables, 48 refs.
- 分类号：0801
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
Bangpu is found as a large-scale porphyry deposit after Qulong and Jiama in Gangdese porphyry copper metallogenic beh which contains mainly porphyry Mo-Cu with skarn Pb-Zn accompanying. There are different species of rock masses in Bangpu mining area, which possess about half of the total area. The diabase porphyrite locates in the north of the mining area as independent vein. The contents of SiO2 are between 48.39% - 50. 08% , the average content of （K2O ＋ Na2O） is 3.50% , A/CNK is 1.23 and it is belonging to the peraluminous series. MgO =7. 92% -9. 12% , Mg^# =61.72 -64. 79. The REEs vary from 44. 93 x 10-6 to 67. 58 x 10-6 without detense differentiation between LREE and HREE. The average contents of Ni and Cr are 89 x 10-6 and 256 x 10-6 respectively which are lower to native basaltic magma, indicating the diabase porphyrite undergoes mafic minerals such as olivine and clinopyroxene fractional crystallization but not strong, so the diabase porphyrite can be considered as product of equilibrium partial melting. The zircon U-Pb age is 14.46 ±0. 38Ma which is similar to the mineralization age. The average ear（t） value in situ is 4. 7. There is a high degree of consistency between the diabase porphyrite and Dazi basalt in geochemical characteristics which showing the same source region they share. That is the upwelling and partial melting of the asthenospheric because of the break off of Indian plate. The gap between their diagenetic ages is the result of continued northward subduction of Indian plate. The diabase porphyrite has been contaminated by crustal material to a certain extent. It is discovered as a magma-mafic-end member in post collision stage which gives us the opportunity to limit the character of mantle-derived magma and its effect to regional magmatism and mineralization.