Ore distribution in the Herminia mine (Julcani, Peru): ore bands and role ore shoots

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6196464

Petersen, U; Murdock, G

Julcani has been one of the major silver and bismuth producing districts of Peru during the past 30 years. The veins are related to a late Miocene volcanic complex and the ore minerals are mainly enargite, tetrahedrite, various silver sulfosalts and galena; gangue minerals are mostly pyrite and barite. Extensive mining, good accessibility and excellent record keeping provide a good opportunity to study ore distribution patterns and zoning in the Herminia mine. Six veins were selected because of their abundant information and coverage of the zoning sequence. The inner copper, intermediate silver and outer lead grade maxima are shown to form parallel ore bands that are generally concordant with the previously reported metal ratio contours, despite the different ages of the ore minerals. These systematic relations are corroborated by logarithmic covariation diagrams. Ore bands join at vein junctions, demonstrating that the vein network constituted a connected hydrothermal system. Oreshoots form at ore band lobes that are related to greater vein widths. Grade and ratio contours indicate that solution flow was generally horizontal to the SW within a favorable volcanic horizon in the 420-580 level range. Several exploration and development applications are illustrated.

• Research Organization: Harvard Univ., Cambridge, MA (USA)
• OSTI ID: 6196464
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
BISMUTH COMPOUNDS
CENOZOIC ERA
DEVELOPING COUNTRIES
EXPLORATION
GEOLOGIC AGES
GEOLOGY
LATIN AMERICA
MINERALIZATION
MINERALOGY
MINERALS
MIOCENE EPOCH
ORES
PERU
PETROLOGY
SILVER ORES
SOUTH AMERICA
SULFIDE MINERALS
TERTIARY PERIOD