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Lithogeochemical, Re – Os and U – Pb Geochronological, Hf – Lu and S – Pb Isotope Data of the G a'erqiong‐Galale Cu – Au Ore‐Concentrated Area: Evidence for the Late Cretaceous Magmatism and Metallogenic Event in the B angong‐ N ujiang Suture Zone, Northwestern T ibet, C hina
Author(s) -
Zhang Zhi,
Yao XiaoFeng,
Tang JuXing,
Li ZhiJun,
Wang LiQiang,
Yang Yi,
Duan JiLin,
Song JunLong,
Lin Xin
Publication year - 2015
Publication title -
resource geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 43
eISSN - 1751-3928
pISSN - 1344-1698
DOI - 10.1111/rge.12064
Subject(s) - geology , molybdenite , geochemistry , diorite , isochron , skarn , zircon , lile , magmatism , mineralization (soil science) , geochronology , quartz , partial melting , mantle (geology) , fluid inclusions , tectonics , paleontology , soil water , soil science
The G a'erqiong‐ G alale skarn–porphyry copper–gold ore‐concentrated area is located in the western part of the B angong‐ N ujiang suture zone north of the L hasa T errane. This paper conducted a systematic study on the magmatism and metallogenic effect in the ore‐concentrated area using techniques of isotopic geochronology, isotopic geochemistry and lithogeochemistry. According to the results, the crystallization age of quartz diorite (ore‐forming mother rock) in the G a'erqiong deposit is 87.1 ± 0.4 Ma, which is later than the age of granodiorite (ore‐forming mother rock) in the G alale deposit (88.1 ± 1.0 Ma). The crystallization age of granite porphyry ( GE granite porphyry) in the G a'erqiong deposit is 83.2 ± 0.7 Ma, which is later than the age of granite porphyry ( GL granite porphyry) in the Galale deposit (84.7 ± 0.8 Ma).The quartz diorite, granodiorite, GE granite porphyry and GL granite porphyry both main shows positive ε Hf (t) values, suggesting that the magmatic source of the main intrusions in the ore‐concentrated area has the characteristics of mantle source region. The Re – Os isochron age of molybdenite in the G a'erqiong district is 86.9 ± 0.5 Ma, which is later than the mineralization age of the G alale district (88.6 ± 0.6 Ma). The main intrusive rocks in the ore‐concentrated area have similar lithogeochemical characteristics, for they both show the relative enrichment in large‐ion lithophile elements( LILE : Rb , Ba , K , etc.), more mobile highly incompatible lithophile elements( HILE : U , Th ) and relatively depleted in high field strength elements ( HFSE : Nb , Ta , Zr , Hf , etc.), and show the characteristics of magmatic arc. The studies on the metal sulfides' S and Pb isotopes and R e content of molybdenite indicate that the metallogenic materials of the deposits in the ore‐concentrated area mainly come from the mantle source with minor crustal source contamination. Based on the regional tectonic evolution process, this paper points out that the G a'erqiong‐ G alale copper–gold ore‐concentrated area is the typical product of the L ate C retaceous magmatism and metallogenic event in the collision stage of the B angong‐ N ujiang suture zone.