Matches in SemOpenAlex for { <https://semopenalex.org/work/W2194720729> ?p ?o ?g. }
- W2194720729 endingPage "82" @default.
- W2194720729 startingPage "59" @default.
- W2194720729 abstract "This paper is the first documentation of boninites from the Kudrekonda Formation of Shimoga greenstone belt (SGB) in western Dharwar Craton (WDC), India and the occurrence of native gold in the associated quartz veins. We also investigate the gold mineralization hosted in the banded iron formations (BIFs) of Ganajur, Karajgi and Palavanahalli areas of the SBG. The Kudrekonda metavolcanic rocks are composed of clinopyroxene, orthopyroxene and plagioclase with secondary amphibole. The geochemical attributes of these rocks, based on MgO, TiO2 Ni, Cr and Co contents, Al2O3/TiO2, (Gd/Yb)N and (La/Sm)N ratios, classify them as boninites and their relative LILE-HFSE abundance suggests magma generation in an intraoceanic arc setting. The Gd/Yb and Dy/Yb ratios suggest parent magma origin through partial melting of a spinel lherzolite mantle source. Geochemical signatures of the boninites suggest high temperature, shallow level melting of refractory mantle wedge metasomatized by fluids derived through dehydration of oceanic slab during subduction initiation. Quartz veins present in the Kudrekonda boninites contain gold grains showing affinity towards quartz-carbonate vein type greenstone hosted occurrences. EPMA data record 88.5–90.3 wt.% Au content with 7.7–8.4 wt.% Fe, 0.05–2.1 wt.% S and negligible Ag. The Au is hosted in Fe-oxides. Bulk chemical analyses show 4.1–684.4 ppb Au and 139.4–2186.4 ppb Ag in the studied samples. The gold mineralization of Kudrekonda boninites is syngenetic, mesothermal, convergent margin orogenic type. Decarbonation, desulphidization and metamorphism of subducted oceanic lithosphere and devolatilization of metasomatized enriched mantle wedge in intraoceanic arc setting are the viable processes that contributed to gold genesis in the Kudrekonda boninites. Devolatilization during prograde metamorphism, hydrothermal fluid generation, syntectonic gold remobilization and migration of gold enriched fluids through shear zones account for Au transportation and precipitation in quartz veins emplaced within the boninites. The BIFs of Ganajur, Karajgi and Palavanahalli areas of Shimoga greenstone belt dominantly comprise alternating Si-rich layers of quartz and Fe-rich hematite and magnetite layers. Geochemical characteristics of the BIF samples including their depleted ƩREE, positive Eu anomalies, negative to negligible Ce anomalies, and superchondritic Y/Ho ratios suggest that the BIFs were (i) derived by chemical sedimentation from paleo-ocean enriched in dissolved iron and silica with marked contributions from hydrothermal fluids of volcanic origin, and (ii) deposited in an off-shelf marine environment proximal to a mid-oceanic spreading centre where hydrothermal activity induced release of Eu and Y enriched hydrothermal solutions under low oxygen fugacity conditions. Native gold occurs in banded strata-bound disseminated sulphide lenses compositionally characterized as pyrite, arsenopyrite, chalcopyrite and galena. Mineral chemical analyses reveal 73–100% Au content with variable concentrations of Ag (0.02–15.2 wt.%). Geochemical compositions of BIFs are characterized by pronounced enrichment in Au (706–15,831 ppb) and Ag (630–2435 ppb). Gold mineralization in Shimoga BIFs is epigenetic, epithermal type akin to Homestake type iron-formation hosted vein and disseminated lode gold deposit. Gold genesis in these BIFs is attributed to migration of oxygen depleted, reducing, sulphidic–auriferous fluids of hydrothermal origin to the site of BIF deposition that served as chemical traps for the auriferous fluids. The Kudrekonda boninites represent accretion and preservation of a slice of older oceanic crust onto a relatively younger, active continental margin through arc–continent collision during Neoarchean time." @default.
- W2194720729 created "2016-06-24" @default.
- W2194720729 creator A5002436821 @default.
- W2194720729 creator A5025094061 @default.
- W2194720729 creator A5060053337 @default.
- W2194720729 creator A5064070525 @default.
- W2194720729 creator A5066140542 @default.
- W2194720729 creator A5077125917 @default.
- W2194720729 creator A5078633685 @default.
- W2194720729 creator A5080578079 @default.
- W2194720729 creator A5083303415 @default.
- W2194720729 date "2016-03-01" @default.
- W2194720729 modified "2023-10-15" @default.
- W2194720729 title "Geochemical characteristics of gold bearing boninites and banded iron formations from Shimoga greenstone belt, India: Implications for gold genesis and hydrothermal processes in diverse tectonic settings" @default.
- W2194720729 cites W1811875395 @default.
- W2194720729 cites W1827757642 @default.
- W2194720729 cites W1964178171 @default.
- W2194720729 cites W1965596457 @default.
- W2194720729 cites W1969372192 @default.
- W2194720729 cites W1973636328 @default.
- W2194720729 cites W1973787211 @default.
- W2194720729 cites W1977018074 @default.
- W2194720729 cites W1980011138 @default.
- W2194720729 cites W1980636746 @default.
- W2194720729 cites W1980644983 @default.
- W2194720729 cites W1980728841 @default.
- W2194720729 cites W1980951510 @default.
- W2194720729 cites W1981259355 @default.
- W2194720729 cites W1986013659 @default.
- W2194720729 cites W1987799335 @default.
- W2194720729 cites W1989301821 @default.
- W2194720729 cites W1991632011 @default.
- W2194720729 cites W1993044811 @default.
- W2194720729 cites W1993523237 @default.
- W2194720729 cites W1997745935 @default.
- W2194720729 cites W1997958287 @default.
- W2194720729 cites W1999448338 @default.
- W2194720729 cites W2000177754 @default.
- W2194720729 cites W2001363398 @default.
- W2194720729 cites W2004394451 @default.
- W2194720729 cites W2005594856 @default.
- W2194720729 cites W2005925547 @default.
- W2194720729 cites W2006593586 @default.
- W2194720729 cites W2006815492 @default.
- W2194720729 cites W2007139925 @default.
- W2194720729 cites W2007213007 @default.
- W2194720729 cites W2008858004 @default.
- W2194720729 cites W2008999892 @default.
- W2194720729 cites W2009643804 @default.
- W2194720729 cites W2010129653 @default.
- W2194720729 cites W2010614316 @default.
- W2194720729 cites W2011801766 @default.
- W2194720729 cites W2016009420 @default.
- W2194720729 cites W2017444203 @default.
- W2194720729 cites W2018123934 @default.
- W2194720729 cites W2020151603 @default.
- W2194720729 cites W2021531271 @default.
- W2194720729 cites W2022530129 @default.
- W2194720729 cites W2023094921 @default.
- W2194720729 cites W2023885290 @default.
- W2194720729 cites W2024284731 @default.
- W2194720729 cites W2024725545 @default.
- W2194720729 cites W2027228820 @default.
- W2194720729 cites W2027559703 @default.
- W2194720729 cites W2028590108 @default.
- W2194720729 cites W2028917031 @default.
- W2194720729 cites W2029180739 @default.
- W2194720729 cites W2030996811 @default.
- W2194720729 cites W2032466071 @default.
- W2194720729 cites W2033646499 @default.
- W2194720729 cites W2034914622 @default.
- W2194720729 cites W2035595872 @default.
- W2194720729 cites W2036001304 @default.
- W2194720729 cites W2036016724 @default.
- W2194720729 cites W2036313074 @default.
- W2194720729 cites W2039882617 @default.
- W2194720729 cites W2040272282 @default.
- W2194720729 cites W2040326828 @default.
- W2194720729 cites W2043226536 @default.
- W2194720729 cites W2043604832 @default.
- W2194720729 cites W2044095990 @default.
- W2194720729 cites W2044646211 @default.
- W2194720729 cites W2045697928 @default.
- W2194720729 cites W2049639781 @default.
- W2194720729 cites W2050279885 @default.
- W2194720729 cites W2051241532 @default.
- W2194720729 cites W2051937829 @default.
- W2194720729 cites W2052839279 @default.
- W2194720729 cites W2053717892 @default.
- W2194720729 cites W2053767451 @default.
- W2194720729 cites W2055394521 @default.
- W2194720729 cites W2058128109 @default.
- W2194720729 cites W2058195627 @default.
- W2194720729 cites W2060212278 @default.
- W2194720729 cites W2063011715 @default.
- W2194720729 cites W2064972995 @default.
- W2194720729 cites W2068897711 @default.
- W2194720729 cites W2070381462 @default.