Portal de Periódicos da CAPES

A Modified Placer Origin for Refractory Gold Mineralization Within the Archean Radioactive Quartz-Pebble Conglomerates from the Eastern Part of the Singhbhum Craton, India

2018; Volume: 113; Issue: 3 Linguagem: Inglês

10.5382/econgeo.2018.4563

1554-0774

Rajarshi Chakravarti, Sahendra Singh, A. S. Venkatesh, Kinjal Patel, Prabodha Ranjan Sahoo,

Geochemistry and Geologic Mapping

Research Article| May 01, 2018 A Modified Placer Origin for Refractory Gold Mineralization Within the Archean Radioactive Quartz-Pebble Conglomerates from the Eastern Part of the Singhbhum Craton, India R. Chakravarti; R. Chakravarti Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India Search for other works by this author on: GSW Google Scholar S. Singh; S. Singh Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India †Corresponding author: e-mail, sahendrasingh02@gmail.com Search for other works by this author on: GSW Google Scholar A. S. Venkatesh; A. S. Venkatesh Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India Search for other works by this author on: GSW Google Scholar K. Patel; K. Patel Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India Search for other works by this author on: GSW Google Scholar P. R. Sahoo P. R. Sahoo Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India Search for other works by this author on: GSW Google Scholar Author and Article Information R. Chakravarti Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India S. Singh Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India A. S. Venkatesh Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India K. Patel Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India P. R. Sahoo Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India †Corresponding author: e-mail, sahendrasingh02@gmail.com Publisher: Society of Economic Geologists Accepted: 22 Feb 2018 First Online: 13 Apr 2018 Online Issn: 1554-0774 Print Issn: 0361-0128 © 2018 Economic GeologyEconomic Geology Economic Geology (2018) 113 (3): 579–596. https://doi.org/10.5382/econgeo.2018.4563 Article history Accepted: 22 Feb 2018 First Online: 13 Apr 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. Chakravarti, S. Singh, A. S. Venkatesh, K. Patel, P. R. Sahoo; A Modified Placer Origin for Refractory Gold Mineralization Within the Archean Radioactive Quartz-Pebble Conglomerates from the Eastern Part of the Singhbhum Craton, India. Economic Geology 2018;; 113 (3): 579–596. doi: https://doi.org/10.5382/econgeo.2018.4563 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEconomic Geology Search Advanced Search Abstract Archean quartz-pebble conglomerates are one of the most extensively studied stratigraphic horizons and are globally well known for their gold and uranium prospects of economic grades. Similar quartz-pebble conglomerate horizons have been delineated within the Neoarchean-Paleoproterozoic Gorumahisani-Badampahar schist belt and Dhanjori volcano-sedimentary basin lying along the northeastern fringe of the Singhbhum-Orissa craton in eastern India. Gold and uranium occurrences have been reported previously from the quartz-pebble conglomerates of the Singhbhum craton; however, no detailed report on gold occurrences and genesis is available. This work focuses on the nature and genesis of gold mineralization hosted by radioactive quartz-pebble conglomerates from the eastern Iron Ore Group and the Dhanjori basin within the Singhbhum-Orissa craton. The quartz-pebble conglomerates reported in this work are predominantly matrix supported and oligo-mictic in nature. Petrography, microprobe data, and scanning electron microscopy studies reveal the presence of chromite, zircon, rutile, magnetite, monazite, pyrite, chalcopyrite, pyrrhotite, stibnite, and brannerite. Laser ablation-inductively coupled plasma-mass spectrometry analyses on various generations of arsenian pyrites reveal significant concentrations of Au in solid solution. The gold was initially incorporated in its detrital form onto growing pyrite surfaces, possibly due to microbial mediation. The trace element data coupled with back-scattered electron images and X-ray compositional maps suggest remobilization of detrital Au and associated trace elements from the diagenetic pyrites and their precipitation onto the younger hydrothermal pyrites. The sulfide-hosted gold mineralization, trace element signatures, and zoning patterns studied in this work mimic the mineralization style reported from sediment-hosted gold deposits such as Spanish Mountain and Carlin. However, in broad terms, the origin of Au within these quartz-pebble conglomerates resembles the modified placer model of gold deposition within the Witwatersrand conglomerates. This is the first report of refractory gold mineralization within arsenian pyrites from the radioactive quartz-pebble conglomerates of eastern India and has important implications for gold exploration in this region and analogous areas. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.