Next Article in Journal
Micropore Structural Heterogeneity of Siliceous Shale Reservoir of the Longmaxi Formation in the Southern Sichuan Basin, China
Previous Article in Journal
Evidence for a Carbonatite-Influenced Source Assemblage for Intraplate Basalts from the Buckland Volcanic Province, Queensland, Australia
Open AccessArticle

Fluid Inclusions and S–Pb Isotopes of the Reshui Porphyry Mo Deposit in East Kunlun, Qinghai Province, China

by 1,2,3, 1,4,*, 2,*, 2 and 2
1
Geological Survey Institute, China University of Geosciences (Wuhan), Wuhan 430074, China
2
Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, MNR, Xi’an Center of China Geological Survey, Northwest China Center for Geoscience Innovation, Xi’an 710054, China
3
Centre for Ore Deposit and Earth Sciences, University of Tasmania, Private Bag 79, Hobart, TAS 7001, Australia
4
Faculty of Earth Resources, China University of Geosciences (Wuhan), Wuhan 430074, China
*
Authors to whom correspondence should be addressed.
Minerals 2019, 9(9), 547; https://doi.org/10.3390/min9090547
Received: 14 July 2019 / Revised: 4 September 2019 / Accepted: 5 September 2019 / Published: 11 September 2019
(This article belongs to the Section Mineral Deposits)
The Reshui porphyry Mo deposit is located in the East Kunlun orogenic belt (EKOB). Molybdenum mineralization is distributed in monzogranite and porphyritic monzogranite rocks, mainly presenting as various types of hydrothermal veinlets in altered wall rocks, and the orebodies are controlled by three groups of fractures. In this paper, we present the results of fluid-inclusion and isotopic (S and Pb) investigations of the Reshui Mo deposit. The ore-forming process of the deposit can be divided into three stages: an early disseminated molybdenite stage (stage 1), a middle quartz–molybdenite stage (stage 2) and a late quartz–polymetallic sulfide stage (stage 3). The alteration was mainly potassic and silicic in stage 1, silicic in stage 2, and sericitic and silicic in stage 3. Five types of fluid inclusions (FIs) can be distinguished in quartz phenocrysts and quartz veins, namely W, PL (pure liquid inclusions), PV (pure gas inclusions), C (CO2 three-phase inclusions), and S (daughter mineral-bearing inclusions). The homogenization temperatures of fluid inclusions belonging to stages 1 to 3 are 282.3–378 °C, 238.7–312.6 °C and 198.3–228 °C, respectively. The fluid salinities at stages 1 to 3 are 4.65–8.14% NaCl eq., 4.34–42.64% NaCl eq., and 3.55–4.65% NaCl eq., respectively. The fluids of this deposit were generally moderate–high temperature and moderate–low salinity and belong to the H2O–NaCl–CO2 ± CH4 system. The temperature and pressure changed considerably between stage 2 (high–medium-temperature) and stage 3 (low-temperature). The evidence for ore-forming fluids containing different types of coexisting inclusions in stage 2 and a decrease in the fluid temperature from stage 2 to stage 3 indicate that fluid boiling and fluid mixing were the main mechanisms of ore precipitation. The sulfide 34SV-CDT values range from 4.90‰ to 5.80‰, which is characteristic of magmatic sulfur. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the ore minerals are 18.210–18.786, 15.589–15.723, and 38.298–39.126, respectively. These lead isotopic compositions suggest that the ores were mainly sourced from crustally derived magmas, with minor input from the mantle. The fluid inclusions and S–Pb isotopes provide important information on the genesis of the Reshui porphyry Mo deposit and indicate that the Triassic has high metallogenic porphyry potential in the EKOB. View Full-Text
Keywords: fluid inclusion; S–Pb isotopes; Reshui porphyry Mo deposit; East Kunlun fluid inclusion; S–Pb isotopes; Reshui porphyry Mo deposit; East Kunlun
Show Figures

Graphical abstract

MDPI and ACS Style

Guo, X.; Lü, X.; Jia, Q.; Li, J.; Kong, H. Fluid Inclusions and S–Pb Isotopes of the Reshui Porphyry Mo Deposit in East Kunlun, Qinghai Province, China. Minerals 2019, 9, 547.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

1
Back to TopTop