Influence of Preexisting Low Metamorphic Grade Sedimentary Successions on the Distribution of Iron Oxide Copper-Gold Mineralization in the Olympic Cu-Au Province, Gawler Craton

2015 ◽  
Vol 110 (8) ◽  
pp. 2147-2157 ◽  
Author(s):  
Anthony J. Reid ◽  
Adrian Fabris
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Metamorphic Grade ◽  
Copper Gold

The Hypogene Iron Oxide Copper-Gold Mineralization in the Mantoverde District, Northern Chile

2010 ◽  
Vol 105 (7) ◽  
pp. 1271-1299 ◽  
Author(s):  
A. A. Rieger ◽  
R. Marschik ◽  
M. Diaz ◽  
S. Holzl ◽  
M. Chiaradia ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Northern Chile ◽  
Copper Gold

Fluid inclusion and stable isotope constraints on the origin of Wernecke Breccia and associated iron oxide – copper – gold mineralization, Yukon

2011 ◽  
Vol 48 (10) ◽  
pp. 1425-1445 ◽  
Author(s):  
Julie A. Hunt ◽  
Tim Baker ◽  
James Cleverley ◽  
Garry J. Davidson ◽  
Anthony E. Fallick ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Fluid Inclusion ◽  
Gold Mineralization ◽  
Fluid Pressure ◽  
Yukon Territory ◽  
Metasedimentary Rocks ◽  
Isotopic Compositions ◽  
Copper Gold ◽  
Oxygen Isotopic ◽  
Hydrothermal Sulfides

Iron oxide – Cu ± Au ± U ± Co (IOCG) mineralization is associated with numerous Proterozoic breccia bodies, collectively known as Wernecke Breccia, in Yukon Territory, Canada. Multiphase breccia zones occur in areas underlain by Paleoproterozoic Wernecke Supergroup metasedimentary rocks and are associated with widespread sodic, potassic, and carbonate alteration assemblages. Fluid inclusion data indicate syn-breccia fluids were hot (185–350 °C) saline (24–42 wt.% NaCl equivalent) NaCl–CaCl2–H2O brines. Estimates of fluid pressure vary from 0.4 to 2.4 kbar (1 kbar = 100 MPa). Carbon and oxygen isotopic compositions of breccia-related carbonates range from ~–11‰ to +1.5‰ (Pee Dee belemnite (PDB)) and –2‰ to 20‰ (Vienna standard mean ocean water (V-SMOW); δ18Owater ~–8‰ to +15‰), respectively. δ13C and δ18O values for host Wernecke Supergroup limestone/dolostone vary from ~–2‰ to 1.6‰ and 12‰ to 25‰, respectively. Sulfur isotopic compositions of hydrothermal sulfides and sulfate vary from ~–12‰ to +13‰ and +8‰ to +17‰ (Cañon Diablo Troilite (CDT)), respectively. Syn-breccia biotite, muscovite, and actinolite have δD and δ18O values of ~–141‰ to –18‰ and +7‰ to +12‰ (V-SMOW; δ18Owater ~7‰ to 11‰), respectively. The Wernecke Breccias and the associated IOCG mineralization appear to have formed from largely nonmagmatic fluids — based on isotopic, fluid inclusion, and geological data. The emerging hypothesis is that periodic overpressuring of dominantly formational/metamorphic water led to repeated brecciation and mineral precipitation. The weight of overlying sedimentary rocks led to elevated fluid temperatures and pressures; fluid flow may have been driven by tectonics and (or) gravity with metals scavenged from host strata.

Magnetic modeling of iron oxide copper-gold mineralization constrained by 3D multiscale integration of petrophysical and geochemical data: Cloncurry District, Australia

2013 ◽  
Vol 1 (1) ◽  
pp. T63-T84 ◽  
Author(s):  
James R. Austin ◽  
Phillip W. Schmidt ◽  
Clive A. Foss
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Signal Amplitude ◽  
Gold Deposits ◽  
Geochemical Data ◽  
Geophysical Investigation ◽  
Structural Controls ◽  
Breccia Pipe ◽  
Copper Gold

Magnetite-rich iron oxide copper-gold deposits (IOCGs) are geologically and geochemically complex and present major challenges to geophysical investigation. They often sit beneath significant cover, exhibit magnetic remanence, and suffer from self-demagnetization effects. Because remanence in magnetite-bearing drill core samples is commonly overprinted by drilling, in situ natural remanent magnetization is difficult to measure accurately, and thus IOCGs cannot be modeled definitively using geophysics alone. We examined structural controls on a magnetite-rich IOCG in northwest Queensland and the relationships between structure, alteration, Fe oxides, and mineralization at core to deposit scale. Magnetite within the deposit has a multidomain structure, and thus it would commonly have an in situ magnetization parallel to the earth’s field. In contrast, pyrrhotite has a pseudosingle-domain structure and so it is the predominant carrier of stable remanence within the ore system. Geophysical lineament analyses are used to determine structural controls on mineralization, geophysical filters (e.g., analytic signal amplitude) are used to help define structural extent of the deposit, and basement geochemistry is used to map mineral footprints beneath cover. These techniques identified coincident anomalies at the intersection of north and northwest lineaments. Leapfrog™ interpolations of downhole magnetic susceptibility and Cu, Au, and Fe assay data were used to map the distribution of magnetite, copper, gold, and sulfur in 3D. The analysis revealed that Cu and Au mineralization were coupled with the magnetite net-vein architecture, but that Cu was locally enriched in the east–northeast-trending demagnetized zone. The results from this suite of geophysical, petrophysical, and geochemical techniques were integrated to constrain modeling of the Brumby IOCG. Brumby can be described as a breccia pipe sitting at the intersection of north-striking, east-dipping, and northwest-striking, southeast-dipping structures that plunges moderately to the south–southeast. The breccia pipe was overprinted by a relatively late net-vein magnetite breccia and crosscut by a later, magnetite-destructive, east–northeast-striking fault.

Iron Oxide-Copper-Gold Mineralization at Thanewasna, Western Bastar Craton

2017 ◽  
Vol 112 (05) ◽  
pp. 1045 ◽  
Author(s):  
M. L. Dora ◽  
K. R. Randive ◽  
H. M. Ramachandra ◽  
G. Suresh
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Bastar Craton ◽  
Copper Gold

Iron oxide-copper-gold mineralization of the Devonian Laoshankou deposit (Xinjiang, NW China) in the Central Asian Orogenic Belt

2019 ◽  
Vol 104 ◽  
pp. 628-655 ◽  
Author(s):  
Pei Liang ◽  
Huayong Chen ◽  
Jinsheng Han ◽  
Chao Wu ◽  
Weifeng Zhang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Nw China ◽  
Central Asian ◽  
Copper Gold

Evidence of iron oxide-copper–gold mineralization in the Torud-Chahshirin Magmatic Belt, northern Iran: Insight from the Robaie area

2020 ◽  
pp. 103937
Author(s):  
Mehdi Mahdavi Akerdi ◽  
Azadeh Malekzadeh Shafaroudi ◽  
Mohammad Hassan Karimpour ◽  
Behnam Rahimi ◽  
Jose Francisco Santos
Keyword(s):  
Iron Oxide ◽  
Gold Mineralization ◽  
Northern Iran ◽  
Copper Gold
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