HR: 1340h
AN: V23A-1226    [Abstracts]
TI: Mass Transfer as a Function of Metamorphic Fluid Flux
AU: * Pitcairn, I K
EM: Iain.Pitcairn@geo.su.se
AF: Stockholm University, Institute of Geology and Geochemistry, Stockholm University, Stockholm, 10691, Sweden
AB: Fluid-rock interaction is an integral part of metamorphism in the crust, and causes significant mass transfer most clearly demonstrated by mineral veins, ore deposits, and alteration fronts that are ubiquitous throughout metamorphic belts. Quantification of major and trace element fluxes during metamorphism and fluid-rock interaction is critical for complete understanding of global element cycles. The SW Highlands of Scotland are an ideal natural laboratory for investigation of major and trace element fluxes during metamorphism. Syn- metamorphic time integrated fluid fluxes within the 6km wide Ardrishaig anticline have been quantified and vary from <10m²/m³ on the limbs of the anticline to >300 m²/m³ in the axial zone (Skelton et al., 1995, J Petrol 36, 563). This study investigates the major and trace element fluxes that occur as a function of the variation in fluid flux within the Ardrishaig anticline. Both depletion and enrichment in chemical elements occurs and the scale of mass transfer increases with increasing fluid flux. Mobile elements include Si, C, K, Na, Sr, As, and Sb, and element mobility varies strongly with lithology. This well-constrained, localized study correlates well with larger regional scale studies (Pitcairn et al., 2006, Econ Geol 101, 1525) where many elements were shown to be locally mobile but very few were shown to have undergone large scale transport.
DE: 3610 Geochemical modeling (1009, 8410)
DE: 3612 Reactions and phase equilibria (1012, 8412)
DE: 3616 Hydrothermal systems (0450, 1034, 3017, 4832, 8135, 8424)
DE: 3630 Experimental mineralogy and petrology
DE: 3653 Fluid flow
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting