scholarly journals Geology, Rock Geochemistry and Ore Fluid Characteristics of the Brambang Copper-Gold Porphyry Prospect, Lombok Island, Indonesia.

2021 ◽  
Vol 6 (1) ◽  
pp. 67-73
Author(s):  
Arifudin Idrus ◽  
Aji Syailendra Ubaidillah ◽  
I Wayan Warmada ◽  
Syafruddin Maula
Keyword(s):  
Meteoric Water ◽  
High Salinity ◽  
Porphyry Copper ◽  
Magmatic Fluid ◽  
Mass Balance Calculation ◽  
Potassic Alteration ◽  
Copper Sulfides ◽  
Sunda Arc ◽  
Copper Gold ◽  
Fluid Characteristics

Brambang is one of the porphyry copper-gold prospects/deposits situated along eastern Sunda arc. This study is aimed to understand geological framework, alteration geochemistry and ore fluid characteristics of the prospect. Fieldworks and various laboratory analyses were performed including petrography, ore microscopy, rock geochemistry, chlorite chemistry and fluid inclusion microthermometry. The prospect is composed of andesitic tuff and diorite which are intruded by tonalite porphyries. Tonalite porphyries are interpreted as ore mineralisation-bearing intrusion. Various hydrothermal alterations are identified including potassic, phyllic, propylitic, advanced argillic and argillic types. Ore mineralisation is characterized by magnetite and copper sulfides such as bornite and chalcopyrite. Potassic alteration is typified by secondary biotite, and associated with ore mineralisation. Mass balance calculation indicates SiO2, Fe2O3, K2O, Cu and Au are added during potassic alteration process. Ore forming fluid is dominated by magmatic fluid at high temperature (450-600ºC) and high salinity (60-70 wt. % NaCl eq.). Hydrothermal fluid was diluted by meteoric water incursion at low-moderate temperature of 150-400ºC and salinity of 0.5-7 wt. % NaCl eq.

scholarly journals Critical Metal Particles in Copper Sulfides from the Supergiant Río Blanco Porphyry Cu–Mo Deposit, Chile

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 519 ◽  
Author(s):  
Jorge Crespo ◽  
Martin Reich ◽  
Fernando Barra ◽  
Juan Verdugo ◽  
Claudio Martínez
Keyword(s):  
Noble Metals ◽  
Porphyry Copper ◽  
Alteration Zone ◽  
Limited Information ◽  
Critical Metals ◽  
Potassic Alteration ◽  
Copper Sulfides ◽  
Porphyry Cu ◽  
Critical Metal ◽  
Te Inclusions

Porphyry copper–molybdenum deposits (PCDs) are the world’s most important source of copper, molybdenum and rhenium. Previous studies have reported that some PCDs can have sub-economic to economic grades of critical metals, i.e., those elements that are both essential for modern societies and subject to the risk of supply restriction (e.g., platinum group elements (PGE), rare earth elements (REE), In, Co, Te, Ge, Ga, among others). Even though some studies have reported measured concentrations of Pd and Pt in PCDs, their occurrence and mineralogical forms remain poorly constrained. Furthermore, these reconnaissance studies have focused predominantly on porphyry Cu–Au deposits, but very limited information is available for porphyry Cu–Mo systems. In this contribution, we report the occurrence of critical metal (Pd, Pt, Au, Ag, and Te) inclusions in copper sulfides from one of the largest PCDs in the world, the supergiant Río Blanco-Los Bronces deposit in central Chile. Field emission scanning electron microscope (FESEM) observations of chalcopyrite and bornite from the potassic alteration zone reveal the presence of micro- to nano-sized particles (<1–10 μm) containing noble metals, most notably Pd, Au, and Ag. The mineralogical data show that these inclusions are mostly tellurides, such as merenskyite ((Pd, Pt) (Bi, Te)2), Pd-rich hessite (Ag2Te), sylvanite ((Ag,Au)Te2) and petzite (Ag3AuTe2). The data point to Pd (and probably Pt) partitioning in copper sulfides during the high-temperature potassic alteration stage, opening new avenues of research aimed at investigating not only the mobility of PGE during mineralization and partitioning into sulfides, but also at exploring the occurrence of critical metals in porphyry Cu–Mo deposits.

Geological Characteristics and Exploration Potential of the NO.III Deposit in the Xiongcun District, Tibet, China

2013 ◽  
Vol 868 ◽  
pp. 217-223 ◽  
Author(s):  
Xing Hai Lang ◽  
Ju Xing Tang ◽  
Fu Wei Xie
Keyword(s):  
Gold Deposit ◽  
Porphyry Copper ◽  
Early Jurassic ◽  
Quartz Diorite ◽  
Geochemical Anomaly ◽  
The South ◽  
Potassic Alteration ◽  
Geological Characteristics ◽  
Copper Gold ◽  
Diorite Porphyry

The Xiongcun district is located along the south margin of the Gangdese porphyry copper belt, approximately 53 km west of the Xigaze. No.III deposit is a newly discovered porphyry copper-gold deposit in the Xiongcun district. This paper first reports geological characteristics and exploration potential of No.III deposit. No.III deposit is hosted by Early Jurassic hornblende quartz diorite porphyry. Pervasive alteration is dominated by a well-mineralized potassic alteration. Major ore-bearing vein types include quartz-sulfide and chlorite-sulfide veins. Drilling holes and geochemical anomaly indicated the No.III deposit has excellent potential for exploration.

scholarly journals Fluid Inclusion Characteristics of the Kışladağ Porphyry Au Deposit, Western Turkey

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 64 ◽  
Author(s):  
Nurullah Hanilçi ◽  
Gülcan Bozkaya ◽  
David A. Banks ◽  
Ömer Bozkaya ◽  
Vsevolod Prokofiev ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Meteoric Water ◽  
High Salinity ◽  
Gold Mineralization ◽  
Magmatic Fluid ◽  
Salinity Range ◽  
Western Turkey ◽  
Magmatic Complex ◽  
Low Salinity

The deposit occurs in a mid-Miocene monzonite magmatic complex represented by three different intrusions, namely Intrusion 1 (INT#1), Intrusion 2 (INT#2, INT #2A), and Intrusion 3 (INT#3). Gold mineralization is hosted in all intrusions, but INT#1 is the best mineralized body followed by INT#2. SEM-CL imaging has identified two different veins (V1 and V2) and four distinct generations of quartz formation in the different intrusions. These are: (i) CL-light gray, mosaic-equigranular quartz (Q1), (ii) CL-gray or CL-bright quartz (Q2) that dissolved and was overgrown on Q1, (iii) CL-dark and CL-gray growth zoned quartz (Q3), and (iv) CL-dark or CL-gray micro-fracture quartz fillings (Q4). Fluid inclusion studies show that the gold-hosted early phase Q1 quartz of V1 and V2 veins in INT#1 and INT#2 was precipitated at high temperatures (between 424 and 594 °C). The coexisting and similar ranges of Th values of vapor-rich (low salinity, from 1% to 7% NaCl equiv.) and halite-bearing (high salinity: >30% NaCl) fluid inclusions in Q1 indicates that the magmatic fluid had separated into vapor and high salinity liquid along the appropriate isotherm. Fluid inclusions in Q2 quartz in INT#1 and INT#2 were trapped at lower temperatures between 303 and 380 °C and had lower salinities between 3% and 20% NaCl equiv. The zoned Q3 quartz accompanied by pyrite in V2 veins of both INT#2 and INT#3 precipitated at temperatures between 310 and 373 °C with a salinity range from 5.4% to 10% NaCl eq. The latest generation of fracture filling Q4 quartz, cuts the earlier generations with fluid inclusion Th temperature range from 257 to 333 °C and salinity range from 3% to 12.5% NaCl equiv. The low salinity and low formation temperature of Q4 may be due to the mixing of meteoric water with the hydrothermal system, or late-stage epithermal overprinting. The separation of the magmatic fluid into vapor and aqueous saline pairs in the Q1 quartz of the V1 vein of the INT#1 and INT#2 and CO2-poor fluids indicates the shallow formation of the Kışladağ porphyry gold deposit.

scholarly journals Critical metal particles in copper sulfides from the supergiant Río Blanco porphyry Cu-Mo deposit, Chile

2018 ◽  
Author(s):  
Jorge Crespo ◽  
Martin Reich ◽  
Fernando Barra ◽  
Juan José Verdugo ◽  
Claudio Martínez
Keyword(s):  
Noble Metals ◽  
Porphyry Copper ◽  
Alteration Zone ◽  
Limited Information ◽  
Critical Metals ◽  
Potassic Alteration ◽  
High Resolution Data ◽  
Copper Sulfides ◽  
Porphyry Cu ◽  
Critical Metal

Porphyry copper-molybdenum deposits (PCDs) are the world’s most important source of copper, molybdenum and rhenium. Previous studies have reported that some PCDs can have sub-economic to economic grades of critical metals, i.e., those elements that are both essential for modern societies and subject to the risk of supply restriction (e.g., platinum group elements (PGE), rare earth elements (REE), In, Co, Te, Ge, Ga, among others). Even though some studies have reported measured concentrations of Pd and Pt in PCDs, their occurrence and mineralogical form remain poorly constrained. Furthermore, these reconnaissance studies have focused predominantly on porphyry Cu-Au deposits, but very limited information is available for porphyry Cu-Mo systems. In this contribution, we report the occurrence of critical metal (Pd, Pt, Au, Ag, and Te) inclusions in copper sulfides from the world’s largest PCD, the supergiant Río Blanco-Los Bronces deposit in central Chile. Field emission scanning electron microscope (FESEM) observations of chalcopyrite and bornite from the potassic alteration zone reveal the presence of micro- to nano-sized particles (&lt;1-10 μm) of noble metals, most notably Pd, Au, and Ag. The high-resolution data show that these inclusions are mostly tellurides, such as merenskyite [PdTe2], Pd-rich hessite [Ag2Te], sylvanite [(Ag, Au)Te2] and petzite [Ag3AuTe2]. The data point to Pd (and probably Pt) partitioning in copper sulfides during the high-temperature potassic alteration stage, opening new avenues of research aimed at investigating not only the mobility of PGE during mineralization and partitioning into sulfides, but also at evaluating the potential of porphyry Cu-Mo deposits as a source for noble metals.

scholarly journals Fluid Evolution of the Magmatic Hydrothermal Porphyry Copper Deposit Based on Fluid Inclusion and Stable Isotope Studies at Darrehzar, Iran

ISRN Geology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
B. Alizadeh Sevari ◽  
A. Hezarkhani
Keyword(s):  
Hydrothermal Alteration ◽  
Meteoric Water ◽  
High Salinity ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Quartz Crystals ◽  
Copper Mineralization ◽  
Kerman City ◽  
Southwestern Iran ◽  
Lower Temperature

The Darrehzar porphyry Cu-Mo deposit is located in southwestern Iran (~70 km southwest of Kerman City). The porphyries occur as Tertiary quartz-monzonite stocks and dikes, ranging in composition from microdiorite to diorite and granodiorite. Hydrothermal alteration and mineralization at Darrehzar are centered on the stock and were broadly synchronous with its emplacement. Early hydrothermal alteration was dominantly potassic and propylitic and was followed by later phyllic and argillic alteration. The hydrothermal system involved both magmatic and meteoric water which were boiled extensively. Copper mineralization was accompanied by both potassic and phyllic alterations. Based on number, nature, and phases number which are available in room temperature, three types of fluid inclusions are typically observed in these veins: (1) vapor rich, (2) liquid rich and (3) multi phase. The primary multiphase inclusions within the quartz crystals were chosen for microthermometric analyses. Early hydrothermal alteration was caused by high-temperature, high-salinity orthomagmatic fluid and produced a potassic assemblage. Phyllic alteration was caused by high-salinity and lower-temperature orthomagmatic fluid. Magmatic and meteoric water mixtures were developed in the peripheral part of the stock and caused propylitic alteration which is attributed to a liquid-rich, lower temperature.

scholarly journals Mineralogy of hydrothermal breccia cement of Humpa Leu East porphyry copper-gold prospect, Sumbawa Island, Indonesia

2021 ◽  
Vol 325 ◽  
pp. 04008
Author(s):  
Okki Verdiansyah ◽  
Arifudin Idrus ◽  
Lucas Donny Setijadji ◽  
Bronto Sutopo ◽  
I Gde Sukadana
Keyword(s):  
Porphyry Copper ◽  
High Temperature Phase ◽  
Gold Deposits ◽  
Temperature Phase ◽  
Medium Temperature ◽  
Sunda Arc ◽  
Copper Gold ◽  
Porphyry System ◽  
The Stability ◽  
Three Phases

Indonesia is a country that has several world-class copper-gold deposits, particularly in eastern Sunda arc. The Hu’u complex has several prospects in the surface as lithocap of extensive epithermal style alteration, but some were detected associated with porphyry beneath the surface. The study focuses on hydrothermal breccia cement as a factor influencing the porphyry system in the Hu’u district. The methods used is mineralogical analysis with petrography and μ-XRF elemental mapping on hydrothermal breccia samples. The Hu’u district is interpreted as a paleo-volcano; a member of the Old Volcanics Rocks Formation. The Humpa Leu East lithology consists of pre-volcanics unit (lava and pyroclastics), diorite, andesite-μ-diorite, and tonalitic intrusion at the depth. Hydrothermal alteration evolved from tonalite body to outward, consist of potassic, inner propyllitic and overprinted by phyllic and advanced argillic. Several phases of hydrothermal activities occur in this system, including the hydrothermal breccia phase associated with complex fluids. The hydrothermal cement of Humpa Leu East porphyry at least have three phases of mineralogical assemblages and possibly influencing the mineralization. The mineralogical assemblage of hydrothermal cement in HLE consists of quartz-feldspar-plagioclase-biotite as a high-temperature phase; then followed by epidote-sericite-chlorites-anhydrite-carbonates in medium temperature; there are aluminum-rich clay minerals interpreted as gibbsite. Mineralization occurs in three phases including chalcopyrite-magnetite, bornite-chalcopyrite and chalcopyrite-sphalerite phases. The occurrences of chalcopyrite at all phases indicate the stability of intermediate sulfidation proses in Humpa Leu and as a possible factor to answer the abundant copper in the Hu’u hydrothermal fluid system

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