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

Conference · Tue Jan 01 00:00:00 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-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

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