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).

scholarly journals Tracking Cobalt, REE and Gold from a Porphyry-Type Deposit by LA-ICP-MS: A Geological Approach towards Metal-Selective Mining in Tailings

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 109 ◽  
Author(s):  
Germán Velásquez ◽  
Daniel Carrizo ◽  
Stefano Salvi ◽  
Iván Vela ◽  
Marcial Pablo ◽  
...  
Keyword(s):  
High Resolution ◽  
Porphyry Copper ◽  
Precious Metals ◽  
Copper Deposit ◽  
Mineral Deposit ◽  
Critical Metals ◽  
Mining Operations ◽  
Gold Silver ◽  
Selective Mining ◽  
Mineral Characterization

High-resolution mineral characterization performed on mine material from a giant porphyry copper deposit shows that critical and precious metals, such as cobalt, lanthanum, gold, silver, and tellurium, are concentrated in pyrite in the form of visible micro-inclusions, invisible mineral nano-inclusions, and trace metals in the mineral lattice. Visible and invisible inclusions consist of Ag-Au-Te sulfosalt and monazite-(La) particles. Trace metal concentrations grade up to 24,000 g/t for cobalt, up to 4000 g/t for lanthanum, and up to 4 g/t for gold. Pyrite, considered a waste material, is removed from the valuable copper ore material and sent to the tailings. Thus, tailings with high contents of pyrite can represent a prime target to explore for critical metals in the porphyry copper mining operations, transforming it into a new source of supply for critical metals. We propose that high-resolution mineral characterization is the key to evolve from a quasi-single-metal (copper) operation to a multi-metals business by developing metal-selective mining. To address this challenge, we coined the Metal-Zone concept to identify zones enriched in a specific metal within a mineral deposit, instead of zones enriched in an ore mineral.

scholarly journals A Comparative Study of Porphyry-Type Copper Deposit Mineralogies by Portable X-ray Fluorescence and Optical Petrography

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 431 ◽  
Author(s):  
Connor Gray ◽  
Adrian Van Rythoven
Keyword(s):  
Mineral Exploration ◽  
Porphyry Copper ◽  
Fluorescence Analysis ◽  
Copper Deposit ◽  
Porphyry Copper Deposits ◽  
Rock Composition ◽  
X Ray ◽  
Core Logging ◽  
Ore Minerals ◽  
Optical Mineralogy

Porphyry-type deposits are crucial reserves of Cu and Mo. They are associated with large haloes of hydrothermal alteration that host particular mineral assemblages. Portable X-ray fluorescence analysis (pXRF) is an increasingly common tool used by mineral prospectors to make judgments in the field during mapping or core logging. A total of 31 samples from 13 porphyry copper deposits of the Western Cordillera were examined. Whole-rock composition was estimated over three points of analysis by pXRF. This approach attempts to capture the rapid and sometimes haphazard application of pXRF in mineral exploration. Modes determined by optical petrography were converted into bulk rock compositions and compared with those determined by pXRF. The elements S, Si, Ca, and K all were underestimated by optical mineralogy, and the elements Cu, Mo, Al, Fe, Mg, and Ti were overestimated by optical mineralogy when compared with pXRF results. Most of these porphyry samples occur in veined porphyritic quartz monzonite that is characteristic of these deposits. Sulfide and silicate vein stockworks are pervasive in most of the samples as well as dissemination of sulfides outwards from veinlets. Ore minerals present include chalcopyrite and molybdenite with lesser bornite. Chalcocite, digenite, and covellite are secondary. Potential sources of analytical bias are discussed.

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

Precious metals assemblages at the Mikheevskoe porphyry copper deposit (South Urals, Russia) as proxies of epithermal overprinting

2018 ◽  
Vol 94 ◽  
pp. 239-260 ◽  
Author(s):  
Olga Y. Plotinskaya ◽  
Oksana B. Azovskova ◽  
Sergei S. Abramov ◽  
Elena O. Groznova ◽  
Konstantin A. Novoselov ◽  
...  
Keyword(s):  
Porphyry Copper ◽  
Precious Metals ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
South Urals

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.

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