Record Details

Carbon isotope studies of auriferous quartz carbonate veins from two orogenic gold deposits from the Neoarchean Chitradurga schist belt, Dharwar craton, India: Evidence for mantle/magmatic source of auriferous fluid

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Carbon isotope studies of auriferous quartz carbonate veins from two orogenic gold deposits from the Neoarchean Chitradurga schist belt, Dharwar craton, India: Evidence for mantle/magmatic source of auriferous fluid
 
Creator SARANGI, S
SARKAR, A
SRINIVASAN, R
PATEL, SC
 
Subject Carbon isotopes
Oxygen isotopes
Archaean
Orogenic gold deposits
Dharwar craton
Southern India
MANTLE-DERIVED FLUIDS
SOUTH-INDIA
GREENSTONE-BELT
CONTACT-METAMORPHISM
ORE-DEPOSITS
SHEAR ZONE
MINERALIZATION
GEOCHEMISTRY
KARNATAKA
PROVINCE
 
Description Carbon and oxygen isotopic compositions of carbonates from auriferous quartz carbonate veins (QCVs) of two orogenic gold deposits - Aijanahalli and Guddadarangavvana Halli (G.R. Halli) - from the Neoarchean Chitradurga schist belt of the Dharwar craton, southern India are examined to understand the origin of the mineralizing fluids. The average carbonate carbon (delta C-13(pdb)) and oxygen (delta O-18(smow)) isotope compositions of QCVs of Ajjanahalli are -5.5 +/- 1.3 parts per thousand and 14.1 +/- 2.7 parts per thousand, respectively. The same ratios for the QCVs of G.R. Halli are -6.2 +/- 1.9 parts per thousand and 14.1 +/- 0.5 parts per thousand. The corresponding average fluid delta C-13 and delta O-18 compositions are -5.81 +/- 1.14 parts per thousand, 13.78 +/- 5.1 parts per thousand. for Ajjanahalli and -4.64 +/- 0.7 parts per thousand, -6.50 +/- 0.6 parts per thousand for G.R. Halli. The delta C-13(pdb) of syn-sedimentary carbonates of BIF of Ajjanahalli (-1.8 +/- 0.1 parts per thousand), carbonated metabasalts of Ajjanahalli (-1.4 parts per thousand) and G.R. Halli (-1.3 parts per thousand) fall in the compositional range of marine carbonates (0 +/- 2 parts per thousand). As dissolution/decarbonation reactions during metamorphism of pre-existing carbonate/carbonated rocks produce CO2 with delta C-13 values similar to or more enriched than parent rock, the carbonate or fluid delta C-13 ratios of the QCVs (which fall in the compositional range of mantle/magmatic derived CO2 or carbonates) obtained in this work cannot be the result of metamorphism. It is proposed that gold mineralizing fluids were derived from juvenile magmatic melts and were channeled through crustal scale shear zones to give rise to the gold deposits. (C) 2012 Elsevier Ltd. All rights reserved.
 
Publisher PERGAMON-ELSEVIER SCIENCE LTD
 
Date 2014-10-15T10:27:29Z
2014-10-15T10:27:29Z
2012
 
Type Article
 
Identifier JOURNAL OF ASIAN EARTH SCIENCES, 521-11
http://dx.doi.org/10.1016/j.jseaes.2012.02.004
http://dspace.library.iitb.ac.in/jspui/handle/100/14744
 
Language en