Further Studies of Ore-Forming Fluid Sources of Bangpu Molybdenum-Copper Polymetallic Deposit, Tibet

2013 ◽  
Vol 746 ◽  
pp. 473-477
Author(s):  
Xiong Zhou ◽  
Yu Zhou ◽  
Yi Zhang
Keyword(s):  
Large Scale ◽  
Porphyry Copper ◽  
Atmospheric Precipitation ◽  
Copper Deposit ◽  
Statistical Research ◽  
Polymetallic Deposit ◽  
Magmatic Degassing ◽  
Copper Gold ◽  
Isotope Study ◽  
Fluid Sources

Bangpu molybdenum-copper polymetallic deposit is located in the eastern section of the Gangdese Porphyry Copper Belt of Tibet. It is a typical large porphyry molybdenum copper polymetallic deposit. The isotope study of fluid inclusions H and O in the quartz (calcite) of various mineralization stages shows that, the ore-forming fluid comes mainly from meteoric hydrothermal caused by atmospheric precipitation, which has consistency with ore-forming fluid sources of Gangdese Porphyry Copper Belt. The Mo-Cu phase with low δD value (-140.5 ~ -104.0 ) suggests a large-scale magmatic degassing. The alteration and mineralization have been caused precisely by the degassing, and the obvious O isotope drift occurred being accompanied by alteration-mineralization, so that the fluid has a low δ18O (vary from 5.50 to 9.0 ). The statistical research indicates that, the massive magmatic degassing occurred in Gangdese Porphyry Copper Belt, and was gradually increased from east to west, suggesting the direct impact of the magmatic degassing on the formation of the porphyry copper-gold deposit and molybdenum copper deposit: the stronger the magmatic degassing, the more easily to form the molybdenum-based porphyry deposit, otherwise it will be formed the deposits dominated by Cu and Au.

Multimillion year thermal history of a porphyry copper deposit: application of U–Pb, 40Ar/39Ar and (U–Th)/He chronometers, Bajo de la Alumbrera copper–gold deposit, Argentina

2007 ◽  
Vol 43 (3) ◽  
pp. 295-314 ◽  
Author(s):  
Anthony C. Harris ◽  
W. James Dunlap ◽  
Peter W. Reiners ◽  
Charlotte M. Allen ◽  
David R. Cooke ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Thermal History ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Copper Gold ◽  
History Of

scholarly journals Re-Os dating, and Pb-H-O isotope characteristics, of the Abra Cu-Ag-Pb-Au polymetallic deposit in Western Australia

2021 ◽  
Author(s):  
Chaozhuang Xi ◽  
Minghong Zheng ◽  
Ling He ◽  
Haodong Xia
Keyword(s):  
Low Temperature ◽  
Western Australia ◽  
Atmospheric Precipitation ◽  
Low Salinity ◽  
Polymetallic Deposit ◽  
Metallogenic Belt ◽  
Copper Gold ◽  
Value Range ◽  
Chemical Conditions ◽  
Physical And Chemical

AbstractThe Abra deposit, a large lead-silver-copper–gold polymetallic deposit in Western Australia, is located at the eastern of the metallogenic belt of the Jillawarra basin in the Bangemall basin. The 4th to the 6th rock section of the Irrigully Group of Edmund Series are the principal ore-host strata, composed mainly of sandstone and fine sandstone. The orebody in Abra can be classified into two types as upper layer-like lead-silver and lower veins or netvein copper–gold. The metal minerals are mainly galena, chalcopyrite, and pyrite, while the gangue minerals are mainly quartz, dolomite, and barite. Both Re-Os isotopic age of the pyrite (1329.5 ± 98 Ma) with the initial (187Os/188Os) = 5.0 ± 3.8 and Pb isotopic compositions (206Pb/204Pb = 15.914–15.967, 207Pb/204Pb = 15.425–15.454, 208Pb/204Pb = 35.584–35.667) suggests that the metal minerals were sourced from the wall-rocks. δDV-SMOW values of quartz range from -35‰ to -17‰ whereas δ18OV-SMOW value range from 12‰ to 16‰ which indicates that the ore-forming fluids of Abra were medium–low temperature and medium–low salinity, and were mainly metamorphic water and secondary atmospheric precipitation. When the medium–low temperature ore-forming fluids are mixed with oxidizing reducing fluids carrying a large number of metal substances, a large number of ore-forming substances will be precipitated when the physical and chemical conditions change, thus it can be considered that the Abra deposit is a medium–low temperature hydrothermal polymetallic deposit.

scholarly journals Stream Sediment Datasets and Geophysical Anomalies: A Recipe for Porphyry Copper Systems Identification—The Eastern Papuan Peninsula Experience

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 299
Author(s):  
Nathan Mosusu ◽  
Angela Bokuik ◽  
Michael Petterson ◽  
Robert Holm
Keyword(s):  
Large Scale ◽  
Porphyry Copper ◽  
Stream Sediment ◽  
Magnetic Data ◽  
Tectonic History ◽  
Ore Bodies ◽  
Copper Gold ◽  
Systems Identification ◽  
Sediment Data ◽  
Host Rocks

Airborne magnetic and radiometric datasets have, over the past few years, become powerful tools in the identification of porphyry systems which may host economic porphyry copper–gold–molybdenum ore bodies. Magnetisation contrasts with the unaltered host rocks, coupled with the elevated radiometric signature, compared to the host rock, makes identification of large-scale porphyry copper systems possible. Integrating these two different datasets with stream sediment data and other geochemical exploration methods results in a higher degree of confidence. Stream sediment data were analysed to see the distribution of copper and gold elements throughout the study area, located within the Eastern Papuan Peninsula of Papua New Guinea. Airborne geophysics data over the same area were also processed for magnetic and radiometric responses. The processing of the magnetic data revealed several magnetic anomalies related to concealed intrusive rock units, with associated radiometric signatures. The distribution of gold and copper anomalism was correlated with the geology and geophysical signatures. Results indicate varying degrees of correlation, with some areas showing a strong correlation between gold/copper occurrence and geophysical signatures, compared to other areas. Some factors that we believe impact the level of correlation may include tectonic history, volcanic cover, and weathering patterns. We recommend caution when applying multi-data exploration for porphyry copper systems.

scholarly journals Mineralogical Setting of Precious Metals at the Assarel Porphyry Copper-Gold Deposit, Bulgaria, as Supporting Information for the Development of New Drill Core 3D XCT-XRF Scanning Technology

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 946
Author(s):  
Mihaela-Elena Cioacă ◽  
Marian Munteanu ◽  
Edward P. Lynch ◽  
Nikolaos Arvanitidis ◽  
Mikael Bergqvist ◽  
...  
Keyword(s):  
Porphyry Copper ◽  
Precious Metals ◽  
Copper Deposit ◽  
Drill Core ◽  
X Ray ◽  
Physicochemical Changes ◽  
Multi Stage ◽  
Xrf Scanning ◽  
Copper Gold ◽  
Metallogenic Zone

A petrographic investigation of ore samples from the Assarel porphyry copper deposit in the Srednogorie metallogenic zone (Bulgaria) constrains the setting and character of precious metals (Au, Ag, PGE) and related minerals within the deposit. This work supports renewed interest in understanding the deportment of precious metals and provides mineralogical knowledge during the testing and validation of novel drill core 3D X-ray computed tomography–X-ray fluorescence (XCT-XRF) scanning technology being developed as part of the X-MINE project. Scanning electron microscopy–energy dispersive spectrometry (SEM-EDS) results indicate precious metals occur in their native state (Au, Ag), as sulfides (Ag), sulfosalts (Au), tellurides (Ag, Pd), and selenides (Ag), and typically form micron-sized inclusions in pyrite and chalcopyrite or are disseminated in the groundmass of the rock. Preservation of early Fe oxide–chalcopyrite ± bornite assemblage as relics in the more dominant pyrite-chalcopyrite mineralization assemblage supports mineral disequilibrium relationships and multi-stage mineralization events. Several rare minerals (e.g., merenskyite, acanthite, sorosite, tetra-auricupride, auricupride, greenokite, bismuthinite, nagyagite, native Ni) are reported for the first time at Assarel and highlight the mineralogical diversity of the ore. The occurrence of precious metals and related minerals at Assarel attest to a complex hydrothermal system that underwent progressive physicochemical changes during the evolution of the mineralizing system (e.g., redox conditions, fluid chemistry).

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