scholarly journals Geochemical Characteristics of Metamorphic Rock-Hosted Gold Deposit At Onzon-Kanbani Area, Central Myanmar

2017 ◽  
Vol 2 (3) ◽  
pp. 191
Author(s):  
Aung Tay Zar ◽  
I Wayan Warmada ◽  
Lucas Donny Setijadji ◽  
Koichiro Watanabe
Keyword(s):  
Fluid Inclusion ◽  
Base Metal ◽  
Hydrothermal Alteration ◽  
Hydrothermal System ◽  
Research Area ◽  
Fluid Inclusion Study ◽  
Small Scale ◽  
Gold Deposition ◽  
Western Boundary ◽  
Gangue Mineral

Gold and associated base metal mineralization of Onzon-Kabani area located in the western border of generally N-S trending Mogoke Metamorphic Belt where well-known Sagaing fault is served as a western boundary of this area. In this research area, many artisanal and small-scale gold mines were noted in last three decades. Gold mineralization is hosted in marble and gneiss unit of research area but most common in marble unit. Variety of igneous intrusions are also observed in research area. Mineralizations are observed as fissure filling veins as well as lesser amount of disseminated nature in marble unit. Mineralogically, gold are associated with other base metal such as pyrite, galena, sphalerite, chalcopyrite, marcasite and arsenopyrite. Hydrothermal alteration halos are developed in peripheral of hydrothermal conduits or mineralization veins from proximal to distal such as 1) silicic, 2) sericite-illite, and 3) propylitic alteration.  Most of hydrothermal minerals from each altered zones showed that near neutral condition of pH (e.g. adularia, calcite, illite, sericite and chlorite). Alternatively, hydrothermal alteration zones that show with ore minerals such as native gold, electrum, sphalerite, galena, chalcopyrite, arsenopyrite and marcasite which mostly observed in silicic alteration zone. Typical boiling characters of vein textures and fluid inclusion petrography are observed in hydrothermal system of research area. Boiling, cooling and mixing are possiblily responsible for gold deposition in hydrothermal system. In this paper, authors are documented to clarify the type of mineralization based on hydrothermal alterations, ore and gangue mineral assemblages and fluid inclusion study. All of these data can describe and play an important role for both with respect to understanding deposit genesis and in mineral exploration.

scholarly journals ALTERATION, VEIN TEXTURES AND FLUID INCLUSION PETROGRAPHY OF METAMORPHIC ROCK-HOSTED GOLD DEPOSIT AT ONZONKANBANI AREA, CENTRAL MYANMAR: IMPLICATION FOR ITS GENESIS

2018 ◽  
Vol 8 (2) ◽  
pp. 48-63
Author(s):  
Aung Tay Zar ◽  
I Wayan Warmada ◽  
Lucas Donny Setijadji ◽  
Koichiro Watanabe
Keyword(s):  
Fluid Inclusion ◽  
Base Metal ◽  
Fluid Inclusions ◽  
Gold Mineralization ◽  
Homogenization Temperature ◽  
Fluid Inclusion Study ◽  
Small Scale ◽  
Western Boundary ◽  
Metamorphic Belt ◽  
Neutral Ph

Gold and base metal mineralization of Onzon-Kabani area is located at the western part of Mogok Metamorphic Belt in central Myanmar, where the well-known Sagaing Fault serves as its western boundary. Artisanal and small-scale gold operations started here three decades ago on gold mineralization hosted in marble and gneiss. Mineralization occurs as fracture-filling veins of several types: gold-bearing quartz vein, base metal quartz-carbonate vein, and carbonate base metal sulfides vein. Three types of hydrothermal alteration zones develop from the proximal to distal zone of hydrothermal conduit: silicic, sericite-illite and propylitic alteration. Alteration mineral assemblages consist of quartz, calcite, sericite, adularia, epidote, chlorite, illite and smectite which are typical of neutral pH hydrothermal fluid. The presence of adularia and calcite within veins indicate boiling event of near-neutral pH condition. Common vein textures of quartz and calcite are banded, crustiform, bladed calcite, lattice, mosaic or jigsaw, cockade, comb and zonal. Boiling-related mineral textures (e.g. banded, bladed and lattice) and fluid inclusion characteristics of coexisting liquid-rich and vapor-rich fluid inclusions have been identified in mineralized samples. Common ore minerals are pyrite, sphalerite, galena, chalcopyrite and minor marcasite, electrum and native gold. Gold is mostly associated with quartz gangue, pyrite, sphalerite and galena. Fluid-inclusion study suggests the presence of liquid-rich and vapor-rich fluid inclusions which were trapped in boiling fluid at homogenization temperature of 159 to 315°C and moderate salinity of 0.88 to 12.51 wt.% NaCl equivalent. It is concluded that despite mesothermal gold system is more typical style of gold mineralization in the Mogok Metamorphic Belt, it is not the type of mineralization in the Onzon-Kanbani area. Instead, a low-sulfidation epithermal system is more characteristic to be present here. The knowledge generated from this study can serve as a guide in understanding new deposit type as well as mineral exploration in the region.

Fluid immiscibility and gold deposition in the Xincheng deposit, Jiaodong Peninsula, China: A fluid inclusion study

2015 ◽  
Vol 65 ◽  
pp. 701-717 ◽  
Author(s):  
Zhong-Liang Wang ◽  
Li-Qiang Yang ◽  
Lin-Nan Guo ◽  
Erin Marsh ◽  
Jian-Ping Wang ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusion Study ◽  
Gold Deposition ◽  
Fluid Immiscibility ◽  
Jiaodong Peninsula ◽  
Inclusion Study

Hydrothermal alteration and fluid inclusion study of the Lower Cretaceous porphyry Cu–Au deposit of Tiámaro, Michoacán, Mexico

2006 ◽  
Vol 89 (1-3) ◽  
pp. 124-128 ◽  
Author(s):  
Carlos Garza-González ◽  
Antoni Camprubí ◽  
Eduardo González-Partida ◽  
Germán Arriaga-García ◽  
Fernando Rosique-Naranjo
Keyword(s):  
Fluid Inclusion ◽  
Hydrothermal Alteration ◽  
Lower Cretaceous ◽  
Fluid Inclusion Study ◽  
Porphyry Cu ◽  
Inclusion Study

scholarly journals Mineralogy, Fluid Inclusion, and C-O-Sr Isotope Geochemistry to Unravel the Evolution of the Magmatic-Hydrothermal System at the Igoudrane Silver-Rich Deposit (Imiter District, Eastern Anti-Atlas, Morocco)

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 997
Author(s):  
Mamadoudjan Diallo ◽  
Mohammed Bouabdellah ◽  
Gilles Levresse ◽  
Johan Yans ◽  
Francesca Castorina ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Base Metal ◽  
Hydrothermal System ◽  
Isotope Geochemistry ◽  
Black Shales ◽  
Fluid Mixing ◽  
Total Production ◽  
Sr Isotope ◽  
Silver Deposition ◽  
Rock Interaction

The Igoudrane mine with a total production of 700,000 t of ore grading 485 g/t Ag is currently one of the most productive mines in the Imiter district of the eastern Anti-Atlas in Morocco. The silver-rich ± base metal deposit occurs dominantly as vein- and hydrothermal breccia-hosted orebodies at the interface between the lower Ediacaran turbidites of the Saghro Group and the unconformably overlying, dominantly felsic volcanic, and volcaniclastic rocks of the late Ediacaran Ouarzazate Group. Higher-grade ores are lithologically hosted by the uppermost organic-rich black shale unit and structurally controlled by the intersection of subvertical NW- and NE-trending fault systems. Ore-related hydrothermal alteration includes, in order of decreasing abundance, carbonatization, silicification, sericitization, and chloritization. Three primary paragenetic stages of veining and associated silver ± base metal mineralization have been recognized: (1) early pyrite + quartz + Ag-bearing sulfides and sulfosalts; (2) main Ag-bearing sulfides and sulfosalts + calcite ± fluorite ± dolomite; and (3) late quartz + calcite + base-metal sulfides (galena, sphalerite, pyrite, chalcopyrite). Irrespective of the ore stage, the dominant Ag-bearing ore minerals are Ag-Hg amalgam, argentite, freibergite, acanthite, polybasite, pyrargyrite, and proustite. Fluid inclusion data show a trend of decreasing temperatures with time, from the main silver stage (Th = 180 ± 12 °C) to late base-metal stage (Th = 146 ± 7 °C), consistent with fluid mixing, cooling, and/or dilution. The coexistence of aqueous-rich and vapor-rich fluid inclusions together with variations in bulk salinity (NaCl + CaCl2) of the mineralizing fluids during the main silver stage, at similar temperatures, indicate that boiling and subsequent degassing occurred during the main ore-forming event due to a pressure decrease. Calculated δ18Ofluid values along with REE+Y and Sr isotope constraints suggest that the ore-forming fluids originated from a predominantly magmatic source, although incursion of meteoric waters during collapse of the hydrothermal system could have contributed to deposition. The post-ore, base-metal quartz-carbonate-dominated mineralization was deposited from dilute Ca-Na-Cl-bearing fluids at temperature below 150 °C. Overall, fluid–rock interaction with the black shales along major faults and thin permeable horizons, boiling-degassing—with subsequent fluid mixing, cooling, and/or dilution—were the main mechanisms of silver deposition.

scholarly journals Fluid Inclusion Study of Epithermal Gold-Base Metal Mineralization System in the Shwebontha Prospect, Monywa Mining District, Central Myanmar Monywa

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Toe Naing Oo ◽  
Agung Harijoko ◽  
Lucas Donny Setijadji ◽  
Kotaro YONEZU
Keyword(s):  
Fluid Inclusion ◽  
Base Metal ◽  
Homogenization Temperature ◽  
Hydrothermal Fluids ◽  
Fluid Inclusion Study ◽  
Mining District ◽  
Quartz Veins ◽  
Ore Mineralization ◽  
Inclusion Study ◽  
Gold Bearing

The Shwebontha Prospect area is one of prominent epithermal Au-Ag prospects in Monywa mining district, central Myanmar, characterized by the appearance of gold-bearing and base metal quartz veins with gold grade is around 3g/t -10.4g/t. The geology of the area consists of the volcanic and volcaniclastic rocks of Upper Oligocene-Middle Miocene Magyigon Formation that served as the host rock of the ore mineralization. This research focused on fluid inclusion study is aimed to know the characteristics of hydrothermal fluids during ore mineralization as well as the possible paleo- depth and temperature of formation of gold-bearing and base metal quartz veins. The mineralization styles are gold-bearing brecciated quartz veins and chalcedonic quartz veins where sulfides are clustered as well as disseminated both in quartz gangue and volcanic host rocks. Those quartz veins include pyrite, sphalerite, galena, chalcopyrite and gold (electrum). Fluid inclusion microthermometry indicates that the ore mineralization is characterized by the values of homogenization temperature range from 158°C to 310°C and salinities range from 0.35 to 2.41wt.% NaCl equiv. This temperature is consistent with the formation temperature of 250°C to 270 °C and also their estimate paleo-depth of formation is between 440m and 640m respectively. Microthermometric data indicates that fluid mixing and dilution were significant processes during ore mineralization and evolution of hydrothermal fluids. Based on the petrography of fluid inclusion, microthermometric measurements and ore minerals assemblage as well as estimation of paleo-depth from the Shwebontha Prospect imply that forming in under shallow level epithermal environment

Fluid inclusion study in the Huanuni mine, Bolivia.

1989 ◽  
Vol 105 (14) ◽  
pp. 1073-1078 ◽  
Author(s):  
Osvaldo ARCE ◽  
Masateru NAMBU
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusion Study ◽  
Inclusion Study
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