Library Open Repository

Volatile phase separation in silicic magmas at Bajo de la Alumbrera porphyry Cu-Au deposit, NW Argentina

Downloads

Downloads per month over past year

Harris, AC and Kamenetsky, VS and White, NC and Steele, DA (2004) Volatile phase separation in silicic magmas at Bajo de la Alumbrera porphyry Cu-Au deposit, NW Argentina. Resource Geology, 54 (3). pp. 341-356.

[img] PDF
ResourceGeology.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Preprint with higher res images)
Harrisetal_ResourceGeologyv54_iss3.pdf | Download (1MB)
Available under University of Tasmania Standard License.

Abstract

At the Bajo de la Alumbrera porphyry Cu-Au deposit, NW Argentina, several key textural elements preserve evidence for volatile separation. Interconnected miarolitic cavities, while being studied extensively in granites, have now been recognized in intrusions related to porphyry Cu mineralization. Pods of saccharoidal quartz are connected by narrow, anastomosing zones of graphic quartz-alkali feldspar intergrowths and ragged biotite (with lesser apatite and magnetite). Their connectivity can be as much as 15 cm; however, more commonly, the interconnected miarolitic cavities are approximately 1 to 2 rum across and 5 cm or less, long. Features such comb-quartz layered textures and magmatic-hydrothermal veins (P veins), combined with aqueous fluid phase equilibria from fluid inclusions, better constrain physical models of exsolution. We interpret these textures in the context of vapour phase formation, coalescence and accumulation in an evolving silicic magma. Recognition of textures, such as the interconnected miarolitic cavities reported here, may provide a simple exploration tool for porphyry Cu deposits, helping explorers to recognize evidence for a potentially fertile intrusions.

Item Type: Article
Keywords: porphyry, copper, volatiles, magma, magmatic-hydrothermal, miarolitic cavities, comb-quartz
Journal or Publication Title: Resource Geology
Page Range: pp. 341-356
Additional Information: The definitive version is available at www.blackwell-synergy.com
Date Deposited: 10 Aug 2006
Last Modified: 18 Nov 2014 03:11
URI: http://eprints.utas.edu.au/id/eprint/347
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page