dc.creator | Velásquez, German | |
dc.creator | Salvi, Stefano | |
dc.creator | Siebenaller, Luc | |
dc.creator | Béziat, Didier | |
dc.creator | Carrizo, Daniel | |
dc.date.accessioned | 2019-05-31T15:21:00Z | |
dc.date.available | 2019-05-31T15:21:00Z | |
dc.date.created | 2019-05-31T15:21:00Z | |
dc.date.issued | 2018 | |
dc.identifier | Minerals, Volumen 8, Issue 10, 2018, Pages 1-21 | |
dc.identifier | 2075163X | |
dc.identifier | 10.3390/min8100430 | |
dc.identifier | https://repositorio.uchile.cl/handle/2250/169473 | |
dc.description.abstract | The El Callao district, with a total endowment of more than 2000 t Au, is considered to be the
most prolific gold resource in Venezuela. Mineralization is hosted by a vein system that is genetically
associated with the El Callao transpressional shear zone. This vein system consists of a network of
interconnected quartz–albite–ankerite veins enveloping a large number of metabasaltic fragments
that host gold-bearing pyrites. Based on detailed mineralogical, microstructural, and fluid inclusion
studies, a pressure-temperature pathway was established for the evolution of the mineralizing
fluid during shear-zone development and exhumation. This path is characterized by repeated
episodes of fluid pressure fluctuation from lithostatic (higher than 1.6 kbar) to near-hydrostatic values
(<0.4 kbar), recorded throughout the transition from the quasi-plastic to frictional deformation
cortical domains. Each successive pressure drop induced boiling of the hydrothermal fluid,
with the resulting fluid phase separation controlling: (i) pyrite and invisible gold crystallization,
which occurred during ductile and ductile-brittle transition strain conditions, and (ii) primary gold
remobilization with consequent native-refined gold precipitation, occurring mainly under brittle
conditions. The metallogenic framework that was proposed for the El Callao shear zone can be
used as a vector to explore and characterize other mineralized shear zones in the Guiana Shield and
analogous orogenic systems worldwide. | |
dc.language | en | |
dc.publisher | MDPI AG | |
dc.rights | http://creativecommons.org/licenses/by-nc-nd/3.0/cl/ | |
dc.rights | Attribution-NonCommercial-NoDerivs 3.0 Chile | |
dc.source | Minerals | |
dc.subject | Boiling | |
dc.subject | Ductile-brittle transition | |
dc.subject | Orogenic gold mineralization | |
dc.subject | Pyrite textures | |
dc.subject | Quartz microstructures | |
dc.subject | Shear-zones | |
dc.title | Control of Shear-Zone-Induced Pressure Fluctuations
on Gold Endowment: The Giant El Callao District,
Guiana Shield, Venezuela | |
dc.type | Artículo de revista | |