Ore deposits introductory courseSlides to Chapter N
Ore deposits in maetamorphic rocks and orogenic gold deposits
Nevado Huaguruncho (5723 m) in the Cordillera Oriental of Peru.
Photo taken from the gold district of Huachón during the 2005 field trip
of the SEG student chapters of the University of Geneva and the ETH Zürich
http://www.unige.ch/sciences/terre/mineral/studchap/Activities/fieldtrips/peru2005.html
Photograph ©: R. Moritz (1.10.2005)
Click on the picture for an enlarged version of this photograph
Photomicrographs of gold and base metal sulfide textural relationships in the Pataz orogenic ores, Peru. Abbreviations: as = arsenopyrite, Au = native gold, el = electrum, gn = galena, py = pyrite, qz = quartz, sl = sphalerite. A. Sphalerite veinlet with chalcopyrite, galena, and electrum crosscutting arsenopyrite and pyrite of stage I (Mercedes vein). B. Galena and gold filling cracks in strongly fractured pyrite I (La Lima 2 vein). C. Galena crystal with coeval inclusions of gold grains and small crystals of second-stage arsenopyrite (Mercedes vein). D. Gold in the cracks of an isolated idiomorphic arsenopyrite I in a sulfide-poor lode (Pencas piso vein). -- Click on the picture for an enlarged version of this photograph.
More on the Pataz orogenic gold belt:
Haeberlin, Y., Moritz, R., Fontboté, L. & Cosca, M. Carboniferous orogenic gold deposits at Pataz, eastern Andean Cordillera, Peru: Geological and structural framework, paragenesis, alteration, and 40 Ar/ 39 Ar geochronology. Economic Geology. In press. v. 99, p. 73-112 (pdf abstract)
More on gold in the Cordillera Oriental, Peru:
Yves Haeberlin, Robert Moritz, Lluı́s Fontboté,
"Paleozoic orogenic gold deposits in the eastern Central Andes and its foreland, South America" ,
Ore Geology Reviews Volume 22, Issues 1–2, January 2003, Pages 41–59
More on the geology and geochronology of the Cordillera Oriental, Peru:
Miskovic A., Schaltegger U., Spikings R., Kosler J. & Chew D.M. (2009) Tectono-magmatic evolution of Western Amazonia: geochemical characterization and zircon U-Pb geochronologic constraints from the Peruvian Eastern Cordillera granitoids. Geol. Soc. Am. Bull. 121, 1298-1324.
