Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rice, C. M. Articles by Pringle, M. S. Search for Related Content GeoRef GeoRef Citation

DURATION OF MAGMATIC, HYDROTHERMAL, AND SUPERGENE ACTIVITY AT CERRO RICO DE POTOSI, BOLIVIA

C. M. Rice and G. B. Steele^*

Department of Geology and Petroleum Geology, University of Aberdeen AB24 3UE, Scotland

D. N. Barfod, A. J. Boyce and M. S. Pringle

Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, Scotland

Corresponding author: e-mail, c.rice{at}abdn.ac.uk

New high precision ⁴⁰Ar/³⁹Ar dating of sanidine and biotite from two rhyolitic domes and an ignimbrite, combined with existing fission-track data and a hydrothermal sericite age, suggests that the world-class Ag deposit at Cerro Rico was emplaced during a protracted period of magma-related hydrothermal activity beginning at 13.77 ± 0.03 Ma and continuing for at least 0.2 m.y. This may have been sustained by a large single injection or repeated injections of fractionated Ag-enriched magma into a high-level magma chamber. K-Ar dating of alunite indicates that supergene oxidation had begun by about 13.5 Ma, soon after dome emplacement, and progressed semicontinuously for at least 7.5 m.y. This oxidation, while not leading to significant enrichment, has significantly enhanced the economic viability of the disseminated part of the orebody.