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Fluid and ore sources of the tungsten mineralisation in the Yangbishan iron–tungsten deposit, Heilongjiang Province, North‐eastern China: Constraints from fluid inclusions, sulphide S–Pb isotopes and scheelite C–H–O–Sm–Nd isotopes
Author(s) -
Hao Yujie,
Ren Yunsheng,
Yang Qun,
Sun Zhenming,
Ma Yupeng,
Lai Ke
Publication year - 2020
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3638
Subject(s) - scheelite , fluid inclusions , wolframite , tungsten , geology , skarn , quartz , geochemistry , ore genesis , petrography , mineralogy , metallurgy , materials science , paleontology
The Yangbishan iron–tungsten deposit, located in the central part of the Jiamusi Massif, Heilongjiang Province, NE China, is the oldest tungsten deposit in NE China to date. Both ore‐forming conditions and mineralisation characteristics indicate that tungsten mineralisation belongs to the skarn type. Petrography, microthermometric measurements and laser Raman spectroscopy of fluid inclusions in quartz grains associated with scheelite indicate that the ore‐forming fluid of the tungsten mineralisation in Yangbishan deposit belonged to the moderate‐temperature NaCl–H 2 O–CH 4 ±N 2 system. Fluid inclusion analyses indicate that ore‐forming fluid experienced decreasing temperatures and fluid degassing, inducing scheelite precipitation. Analysis of C, H and O isotopes of fluid inclusions within scheelite grains show δ 13 C values varying from −20.7 to −24.9‰, δD from −109.9 to −119.9‰, δ 18 O from 6.8 to 10.0‰ and δ 18 O H2O from 8.7 to 11.9‰. These data, together with C, H and O isotope compositions of the quartz associated with scheelite in tungsten ores, imply that ore‐forming fluid was derived dominantly from magma but influenced by organic material (reducing carbon) derived from wall rocks. Sm/Nd ratios of scheelite vary from 0.15 to 0.21, ε Nd ( t = 520 Ma) values from −5.64 to −17.95 (average of −10.21) and T DM2 values from 702 and 2693 Ma (average of 2070 Ma), indicating the ores were sourced from ancient crustal rocks. The compositions of C–H–O–S–Pb and Nd isotopes support the fact that interaction between crust‐derived magma and strata rich in organics played an important role in the tungsten mineralisation of the Yangbishan deposit.