地质学报2011，Vol.85Issue(9)：1435-1451,17.DOI:11-1951/P.20110907.1101.007
新疆北天山黄山东含铜镍矿镁铁-超镁铁岩体的岩石因:主量元素、微量元素和Sr-Nd同位素证据
Petrogenesis of the Huangshandong Ni-Cu Sulfide-Bearing Mafic-Ultramafic Intrusion, Northern Tianshan, Xinjiang: Evidence from Major and Trace Elements and Sr-Nd Isotope
摘要
Abstract
The major and trace elements and Sr-Nd isotopes of the Huangshandong mafic-ultramafic intrusion in the Huangshan-Jing'erquan magmatic Cu-Ni mineralization belt are discussed to constrain its formation and regional tectonic evolution. Three magmatic pulses of the Huangshandong intrusion have been identified. The first pulse formed olivine gabbro, hornblende gabbro and diorite, which constitute the main body of the complex, with olivine gabbro in the central section, hornblende gabbro in upper and lower parts, and olivine gabbro along the margin of the complex. The second pulse formed gabbronorite dykes occurring as dykes in the western and northwestern parts of the intrusion. Iherzolite, the product of the third magmatic pulse is distributed at the bottom of the complex and is the main host rock for the Cu-Ni ores. Except TiO2 contents in olivine gabbro and hornblende gabbro, all other major elements of the samples from the Huangshandong intrusive rocks are plotted within compositons of olivine, orthopyroxene, clnopyroxene and plagioclase, indicating that the complex consists predominantly of rock-forming minerals. Compared with the Permian mantle plume-derived mafic-ultramafic intrusions in Tarim, the Huangshandong intrusion is characterized by deplete high field-strength elments ( HFSE) (Nb, Ta and Ti) and incompatible elements (La, Ba, Th, U) , but higher ∈Nd(t) (7. 32‰~8. 29‰), low Th/V ratio (1. 13~2. 98) and Nb/U ratio (2. 53~7. 02), and high La/Nb ratio (1. 15~4. 19) and Ba/Nb (37. 7~79. 82). These features are similar to those of subduction-related extrusive and intrusive rocks, indicating that the primitive magma for the Huangshandong intrusion was the result of partial melting of a metasomatic mantle modified by the subducted slab-derived melt/fluid and upwelling of asthensphere mantle may provide heat source for the partial metling.关键词
黄山-镜儿泉铜镍成矿带/黄山东镁铁-超镁铁岩体/岩浆铜镍矿床/俯冲交代地幔/地幔柱Key words
Huangshan-Jing'erquan Cu-Ni mineralization belt/Huangshandong mafic-ultramafic intrusion/magmatic Cu-Ni sulfide deposit) metasomatized mantle/mantle plume引用本文复制引用
邓宇峰,宋谢炎,颉炜,程松林,李军..新疆北天山黄山东含铜镍矿镁铁-超镁铁岩体的岩石因:主量元素、微量元素和Sr-Nd同位素证据[J].地质学报,2011,85(9):1435-1451,17.基金项目
本文为国家“973”计划(编号2007CB411408),国家自然科学基金(编号40730420,40973038),中科院方向性项目群(KZCX2-YW-Q04)以及矿床地球化学国家重点实验室创新课题(KCZX20090105)资助的成果. （编号2007CB411408）
