The role of exhumation in metamorphic dehydration and fluid production

Vry, J. K.; Powell, Roger; Golden, Kenneth M.; Petersen, Kellen K.

doi:10.1038/ngeo699

Cited by 64 publications

(52 citation statements)

References 24 publications

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“…In both these collision zones, upper crustal material is progressively buried, and then exhumed through erosion. It has been suggested that most of the fluids are generated beneath the Southern Alps as crustal material is being exhumed (Vry et al 2010). Figure 13.27 shows that MT is a powerful tool for imaging the pattern of fluid generation beneath an active orogen in real time.…”

Section: Fluids Generated In Collision Zonesmentioning

confidence: 98%

Mapping the Distribution of Fluids in the Crust and Lithospheric Mantle Utilizing Geophysical Methods

Unsworth

Rondenay

2012

Lecture Notes in Earth System Sciences

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Geophysical imaging provides a unique perspective on metasomatism, because it allows the present day fluid distribution in the Earth's crust and upper mantle to be mapped. This is in contrast to geological studies that investigate midcrustal rocks have been exhumed and fluids associated with metasomatism are absent. The primary geophysical methods that can be used are (a) electromagnetic methods that image electrical resistivity and (b) seismic methods that can measure the seismic velocity and related quantities such as Poisson's ratio and seismic anisotropy. For studies of depths in excess of a few kilometres, the most effective electromagnetic method is magnetotellurics (MT) which uses natural electromagnetic signals as an energy source. The electrical resistivity of crustal rocks is sensitive to the quantity, salinity and degree of interconnection of aqueous fluids. Partial melt and hydrogen diffusion can also cause low electrical resistivity. The effects of fluid and/or water on seismic observables are assessed by rock and mineral physics studies. These studies show that the presence of water generally reduces the seismic velocities of rocks and minerals. The water can be present as a fluid, in hydrous minerals, or as hydrogen point defects in nominally anhydrous minerals. Water can further modify seismic properties such as the Poisson's ratio, the quality factor, and anisotropy. A variety of seismic analysis methods are employed to measure these effects in situ in the crust and lithospheric mantle and include seismic tomography, seismic reflection, passive-source converted and scattered wave imaging, and shear-wave splitting analysis. A combination of magnetotelluric and seismic data has proven an effective tool to study the fluid

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Section: Fluids Generated In Collision Zonesmentioning

confidence: 98%

Mapping the Distribution of Fluids in the Crust and Lithospheric Mantle Utilizing Geophysical Methods

Unsworth

Rondenay

2012

Lecture Notes in Earth System Sciences

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“…Alternatively, other mechanisms that can account for the release of overpressured and hot fluids from below are: (a) fluids resulting from dehydration reactions (e.g. Vry et al 2010;Weisheit et al 2014 and references therein), (b) fluids released from crystallizing intrusions (e.g. Smith 1996), and (c) fluids released by heating or by decompression, the latter being associated with exhumation or an extensional stress field (e.g.…”

Section: Potential Mechanisms Of Overpressured Fluid Flowmentioning

confidence: 99%