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Boletín de la Sociedad Geológica Mexicana Volumen 72, núm. 3, A260719, 2020 |
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Porphyry-related high-sulfidation mineralization early in Central American Arc development: Cerro Quema deposit, Azuero Peninsula, Panama
Mineralización de alta sulfuración en relación con pórfidos en el desarrollo del Arco Centroamericano: El depósito de Cerro Quema, Península de Azuero, Panamá
José Perelló1,*, Alfredo García2, Robert A. Creaser3
1 Antofagasta Minerals S.A., Apoquindo 4001, piso 18, Las Condes, Santiago, Chile.
2 Avenida Kennedy 4820, departamento 42, Vitacura, Santiago, Chile.
3 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T2G 2E3, Alberta, Canada.
* Corresponding author: (J. Perelló) This email address is being protected from spambots. You need JavaScript enabled to view it.
How to cite this article:
Perelló, J., García, A., Creaser, R.A. ,2020, Porphyry-related high-sulfidation mineralization early in Central American Arc Development: Cerro Quema deposit, Azuero Peninsula, Panama: Boletín de la Sociedad Geológica Mexicana, 72(3), A260719. http://dx.doi.org/10.18268/BSGM2020v72n3a260719
Abstract
The 70.74 to 70.66 Ma age range for three molybdenite samples accompanying pyrite- and enargite-bearing assemblages effectively constrains an earliest Maastrichtian age for the high-sulfidation Au-Cu mineralization at Cerro Quema, Panama. The epithermal system was contemporaneous with emplacement of a composite dacite dome complex in a geotectonic setting transitional from mafic, primitive intraoceanic (Azuero Protoarc) to more evolved island arc magmatism (Azuero Arc), during initial construction of the Central American land bridge at the trailing edge of the Caribbean Large Igneous Province (CLIP). The molybdenite ages confirm the rapid evolution of the earliest stages of the Central American Arc, from subduction initiation at 75–73 Ma to arc maturation at 71 Ma. A porphyry connection is apparent at Cerro Quema and characterized by highly contorted, banded, and planar quartz-veinlet stockworks and sheeted zones in pyrophyllite- and sericite-bearing patchy-textured rock. These are cut by ledges of quartz, alunite, and dickite, which implies overprinting of the advanced argillic lithocap onto the underlying porphyry environment. Hydrothermal telescoping resulted from synmineralization uplift congruent with an actively emerging volcanic arc, which the Re-Os molybdenite dates accurately constrain at 71 Ma, presumably as a far-field effect of collision between the leading edge of the CLIP with parts of North and South America.
Keywords: Azuero, Caribean Large Igneous Province, Central American Arc, High-sulfidation, Molybdenite.
