Icons / Logo / Facebook Created with Sketch. Icons / Logo / Google Created with Sketch. Icons / Logo / ORCID Created with Sketch. Branding/Logomark minus Citation Combined Shape Icon/Bookmark-empty Icon/Copy Icon/Collection Icon/Close Copy 7 no author result Created with Sketch. Icon/Back Created with Sketch. Match!

Alteration mineralogy, fluid inclusions and stable isotope studies from Chigargunta and Bisanatham gold deposits, South Kolar Greenstone Belt, Dharwar Craton, India: Implications on genesis of gold mineralization

Published on May 1, 2019in Ore Geology Reviews 3.39
· DOI :10.1016/j.oregeorev.2019.102946
Debasis Pal (NITR: National Institute of Technology, Rourkela), Sakthi Saravanan Chinnasamy (NITR: National Institute of Technology, Rourkela)+ 2 AuthorsSubhasish Ghosh5
Estimated H-index: 5
(Geological Survey of India)
Cite
Abstract
Abstract There are many Neoarchaean orogenic gold hosting greenstone belts in the Dharwar Craton (DC), India; among them the southern extension of the Kolar greenstone belt (SKGB) contain promising gold deposits such as Chigargunta and Bisanatham. Auriferous laminated quartz-calcite veins are hosted mainly within the sheared and altered Champion gneiss and amphibolite in Chigargunta and Bisanatham respectively. The hydrothermal alteration mineral assemblages show three main alteration zones at Chigargunta. However, only two alteration zones were identified at Bisanatham. The hydrothermal mineral assemblage at Chigargunta and Bisanatham indicate a similar mineralogy that consists of tourmaline, muscovite, biotite, chlorite, epidote, sericite, calcite and quartz along with sulfide and gold. Sulfides associated with ore are predominantly pyrrhotite, pyrite, arsenopyrite, chalcopyrite, ±molybdenite in both the places. Native gold is mainly associated with pyrrhotite in the inner and proximal zone of both the deposits. Fluid inclusion petrography and microthermometry from quartz-calcite veins within the mineralized zone at Chigargunta reveal a low to medium salinity (0.5 to 13.3 wt% NaCl equiv.) H 2 O-NaCl-CO 2 -CH 4  ± N 2 bearing fluid. However, at Bisanatham only H 2 O-NaCl fluid with low salinity (1.56 to 6.44 wt% NaCl equiv.) was observed. P-T conditions of the gold mineralization at the Chigargunta and Bisanatham deposits range between 1.7 and 3.5 kbar pressure/285 °C to 378 °C temperature and 0.8 to 1.2 kbar pressure/365 °C to 405 °C temperature respectively. Alteration mineralogy, ore mineral assemblages, fluid compositions and P-T conditions from the SKGB confirm that the near neutral to slightly alkaline mineralizing fluid transported gold as Au(HS) 2 − complexes with low ƒ O 2 conditions. The observed drastic pressure and temperature fluctuation suggests that fault-valve mechanism/pressure cycling occurred at the time of gold precipitation. Carbon (δ 13 C CO2 ) isotopic composition of ore fluid deduced from calcite varies from −2.4 to +3.3‰ (average: −0.3‰) and −2.1 to +1.4‰ (average: −0. 8‰) for Chigargunta and Bisanatham respectively. Oxygen isotopic (δ 18 O H2O ) values for both the deposits vary from +7.2 to +14.6‰ (average: +9.3) and +7.3 to +8.9‰ (average: +8.3‰) respectively. Ore-forming fluid could have possibly been derived from the decarbonation of marine carbonates during the metamorphic devolatilization of greenstones. The slight intra-deposit variation of the carbon isotopic value implies the Rayleigh fractionation with progressive consumption of the CO 2 as a result of interaction between hydrothermal fluid and wall rock as well as immiscibility of CH 4 and CO 2 fluid. Ore fluid sulfur (δ 34 S H2S ) isotopic composition, derived from δ 34 S values of sulfides, varies from −0.42 to +2.43‰ and +0.25 to +2.34‰ for Chigargunta and Bisanatham respectively. Both the sulfur and carbon isotopic values, from these deposits are comparable with other orogenic gold deposits in the DC and elsewhere in the world. Although carbon isotopic values possibly indicate the metamorphic fluid source, the sulfur isotopes signify average crustal sulfur composition that is from crustally derived/modified fluid. Based on the field-geological, mineralogical, fluid, and isotopic compositions, the possible fluid source could be from the metamorphic devolatilization process of the thick greenstone sequence in the SKGB. However, a magmatic source could be further tested with geochronological studies on intrusives in the area.
  • References (96)
  • Citations (0)
Cite
References96
Newest
Published on Apr 1, 2018in Ore Geology Reviews 3.39
S.K. Swain1
Estimated H-index: 1
(IITs: Indian Institutes of Technology),
S. Sarangi5
Estimated H-index: 5
(IITs: Indian Institutes of Technology)
+ 4 AuthorsM. Satyanarayanan1
Estimated H-index: 1
(NGRI: National Geophysical Research Institute)
Abstract Carbon (δ 13 C PDB ) and oxygen (δ 18 O SMOW ) isotopic compositions of carbonates of auriferous quartz-carbonate veins (QCVs), S-isotope (δ 34 S CDT ) composition of gold bearing sulphide minerals and REE geochemical characteristics of the auriferous QCVs of Ajjanahalli and Gadag Gold Fields in the Neoarchaean Chitradurga-Gadag greenstone belt, Dharwar Craton, southern India have been studied in detail to constrain the source of auriferous vein fluids. The carbonate δ 13 C values of th...
Published on Oct 1, 2017in Geoscience frontiers 4.16
Biswajit Mishra16
Estimated H-index: 16
(IIT-KGP: Indian Institute of Technology Kharagpur),
Kamal Lochan Pruseth9
Estimated H-index: 9
(IIT-KGP: Indian Institute of Technology Kharagpur)
+ 1 AuthorsSakthi Saravanan Chinnasamy1
Estimated H-index: 1
(NITR: National Institute of Technology, Rourkela)
Abstract Neoarchean orogenic gold deposits, associated with the greenstone-granite milieus in the Dharwar Craton include (1) the famous Kolar mine and the world class Hutti deposit; (2) small mines at Hira-Buddini, Uti, Ajjanahalli, and Guddadarangavanahalli; (3) prospects at Jonnagiri; and (4) old mining camps in the Gadag and Ramagiri-Penakacherla belts. The existing diametric views on the source of ore fluid for formation of these deposits include fluids exsolved from granitic melts and extra...
Published on May 19, 2017in Geology 5.01
Vikraman Selvaraja6
Estimated H-index: 6
(UWA: University of Western Australia),
Stefano Caruso6
Estimated H-index: 6
(UWA: University of Western Australia)
+ 2 AuthorsThi-Hao Bui1
Estimated H-index: 1
(McGill University)
The origin of sulfur and gold in Archean orogenic gold systems should provide significant insights into the dynamics of fluid movement in the crust of the early Earth, but is poorly constrained and highly debated. Our natural laboratory to address this knowledge gap is the metal-endowed Yilgarn Craton (Western Australia), where we measured the multiple sulfur isotope signatures of representative sulfide-bearing auriferous samples from 24 Archean orogenic gold deposits varying in size and geologi...
Published on May 1, 2017in Mineralogical Magazine 2.21
Pranjit Hazarika6
Estimated H-index: 6
(GU: Gauhati University),
Biswajit Mishra16
Estimated H-index: 16
(IIT-KGP: Indian Institute of Technology Kharagpur),
Kamal Lochan Pruseth9
Estimated H-index: 9
(IIT-KGP: Indian Institute of Technology Kharagpur)
The distribution of Au and associated trace elements in pyrite and arsenopyrite from late Archean Hutti and Hira-Buddini orogenic gold deposits, eastern Dharwar Craton, southern India was investigated by laser ablation-inductively coupled plasma-mass spectrometry. X-ray element maps acquired by electron probe microanalyser reveal oscillatory zoning of Co and As indicating the crystallization of pyrite and arsenopyrite in an episodic fluid flow regime in which fluid salinity fluctuated due to fau...
Published on Jan 1, 2016in Ore Geology Reviews 3.39
Pranjit Hazarika6
Estimated H-index: 6
(IIT-KGP: Indian Institute of Technology Kharagpur),
Biswajit Mishra16
Estimated H-index: 16
(IIT-KGP: Indian Institute of Technology Kharagpur),
Kamal Lochan Pruseth9
Estimated H-index: 9
(IIT-KGP: Indian Institute of Technology Kharagpur)
Abstract Gold mineralization at Hutti, southern India has occurred in two stages. Stage-1 mineral assemblage comprises biotite, chlorite, plagioclase, calcite, epidote, actinolite, tourmaline, arsenopyrite, pyrite, pyrrhotite and gold, whereas the stage-2 mineral assemblage is represented by sericite, chlorite, calcite, scheelite, tourmaline, apatite, titanite, pyrrhotite, arsenopyrite and gold. We report here the occurrence of scheelite from the stage-1 assemblage and compare major and trace el...
Published on Oct 1, 2015in Ore Geology Reviews 3.39
S.K. Swain1
Estimated H-index: 1
(IIT: Indian School of Mines),
S. Sarangi5
Estimated H-index: 5
(IIT: Indian School of Mines)
+ 5 AuthorsR.H. Sawkar1
Estimated H-index: 1
Abstract Carbon (δ 13 C PDB ) and oxygen (δ 18 O SMOW ) isotopic compositions of auriferous quartz-carbonate veins (QCVs) of gold deposits from Sangli, Kabuliyatkatti, Nagavi, Nabapur and Mysore mining areas developed on the Central Lode system of the Gadag Gold Field (GGF) in the Neoarchaean Gadag schist belt of the Dharwar Craton, southern India have been examined for the first time to understand the origin of the mineralising fluids. In majority of the samples (46 out of 49), δ 13 C pdb of ca...
Published on Sep 1, 2015in Lithos 3.91
Richard J. Goldfarb39
Estimated H-index: 39
,
David I. Groves60
Estimated H-index: 60
Abstract Orogenic gold deposits of all ages, from Paleoarchean to Tertiary, show consistency in chemical composition. They are the products of aqueous-carbonic fluids, with typically 5–20 mol% CO 2 , although unmixing during extreme pressure fluctuation can lead to entrapment of much more CO 2 -rich fluid inclusions in some cases. Ore fluids are typically characterized by significant concentrations of CH 4 and/or N 2 , common estimates of 0.01–0.36 mol% H 2 S, a near-neutral pH of 5.5, and salin...
Published on Mar 1, 2015in Economic Geology 3.29
Pranjit Hazarika6
Estimated H-index: 6
(IIT-KGP: Indian Institute of Technology Kharagpur),
Biswajit Mishra16
Estimated H-index: 16
(IIT-KGP: Indian Institute of Technology Kharagpur),
Kamal Lochan Pruseth9
Estimated H-index: 9
(IIT-KGP: Indian Institute of Technology Kharagpur)
The Late Archean Hutti-Maski greenstone belt hosts the largest operational gold mine in India at Hutti, as well as two satellite mines at Hira-Buddini and Uti. Tourmaline is a common accessory mineral in the auriferous altered wall rocks, proximal to the gold-bearing veins of these orogenic gold deposits. We report here major, rare earth element (REE), and selected trace element compositions of tourmalines from these alteration zones at Hutti and Hira-Buddini, and from spatially associated volca...
Published on Oct 1, 2014in Ore Geology Reviews 3.39
Qing-Feng Ding4
Estimated H-index: 4
(JLU: Jilin University),
Chang-Zhi Wu10
Estimated H-index: 10
(CAS: Chinese Academy of Sciences)
+ 4 AuthorsLianxing Gu11
Estimated H-index: 11
(NU: Nanjing University)
Abstract The Awanda gold deposit is located within the southern Tianshan Accretionary Complex, a late Paleozoic orogenic belt in the northern margin of Tarim block in NW China. The gold mineralization here occurs in primarily within shear zones and secondary s faults with quartz mica schist as the principal host rock. The sulfide mineral assemblage is dominated by arsenopyrite, and pyrrhotite, with minor pyrite and gudmundite. Alteration includes silicification, sericitization and rare carbonati...
Published on Dec 1, 2013in Geology 5.01
Andrew G. Tomkins24
Estimated H-index: 24
(Monash University)
Gold has historically been a key strategic commodity, and the study of gold deposit formation has long been investigated. Debate on the genesis of so-called “orogenic gold deposits” (>75% of gold recovered through history; [Phillips, 2013][1]), continues largely because it is difficult to
Cited By0
Newest