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Ore genesis of the Tieshajie Cu deposit: Implications for Cu mineralization in the Qin-Hang Metallogenic Belt, South China.
- Source :
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Ore Geology Reviews . Jan2024, Vol. 164, pN.PAG-N.PAG. 1p. - Publication Year :
- 2024
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Abstract
- [Display omitted] • Hydrothermal titanite yields a weighted mean 206Pb/238U age of 160.1 ± 4.4 Ma. • Sulfur isotope compositions of ore sulfides indicate minor contributions from the host rocks via fluid-rock interaction. • The variations of in-situ Cu isotope compositions (δ65Cu: −1.13 to +0.12 ‰) are inconsistent with the ancient VMS deposits. • Our results suggest that the Tieshajie deposit has a Late Jurassic magmatic-hydrothermal origin instead of a Meso-Neoproterozoic VMS origin. The Tieshajie Cu deposit, located in the northeastern part of the Qin-Hang Metallogenic Belt (QHMB), South China, has long been regarded as a representative Meso-Neoproterozoic volcanogenic massive sulfide (VMS) deposit. Here we present a hydrothermal titanite U-Pb age, Re-Os and in-situ S-Cu isotope data for chalcopyrite to constrain the timing and ore genesis of the Tieshajie deposit. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb dating of titanite from the disseminated Cu ore yielded a weighted mean 206Pb/238U age of 160.1 ± 4.4 Ma. Chalcopyrite from different ore types has low 187Os/188Os (0.85–3.60) and 187Re/188Os (46.1–614.0) ratios, combined with initial 187Os/188Os (0.74–2.00), excluding a mantle source. A Re-Os isochron age (188 ± 30 Ma) for five chalcopyrite samples is consistent with the titanite U-Pb age within errors. Moreover, the variations in Cu isotope compositions (δ65Cu: −1.13 to +0.12 ‰) and δ34S values (+3.8 to +7.7 ‰) of chalcopyrite are inconsistent with those reported from the ancient VMS deposits in previous studies. Therefore, our results are indicative of a Late Jurassic magmatic-hydrothermal origin instead of a VMS origin for the Tieshajie deposit. In combination with previous studies, we propose that the Tieshajie Cu deposit belongs to the distal part of the Mid-Late Jurassic (170–150 Ma) porphyry-skarn Cu mineralization event in the QHMB, likely triggered by the subduction of the Paleo-Pacific plate during the Late Mesozoic. This study also has new insights into the genesis of Cu mineralization in the QHMB and further provides implications for future exploration. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01691368
- Volume :
- 164
- Database :
- Academic Search Index
- Journal :
- Ore Geology Reviews
- Publication Type :
- Academic Journal
- Accession number :
- 174794237
- Full Text :
- https://doi.org/10.1016/j.oregeorev.2023.105846