P-T path of UHP meta-granites from the Dabie Shan (China) displaying dehydration melting during exhumation (Modified after Xia et al. 2010). The phengite dehydration melting curve (stippled) is shown for a pelitic bulk rock composition (after Vielzeuf and Holloway 1988). The wet granite solidus is after Huang and Wyllie (1981) and Holtz et al. (2001) and the second critical point is extrapolated by Hermann et al. (2006) from the critical curve of Bureau and Keppler (1999). The compositional character of the fluid phase above the second critical point follows the definition of Hermann et al. (2006) (for details see text and caption of Fig. )
Partial melting may occur during decompression in felsic rocks
exhumed from these depths (see Fig. 10.7).
2010; Fig. 10.7) and in the Greenland Caledonides (Lang and
All of these fluid phases are supercritical over a large range of
P-T conditions (Figs. 10.7, 10.8).
2008; Figs. 10.4, 10.7, 10.8).
However, experimental data at 30 ± 5 Kbar and 700 ± 50°C,
concerning the second critical point for meta-pelitic or
meta-granitic rocks, suggest that (supercritical) transitional
fluids can be expected in continental crust, which has suffered UHP
conditions in relatively cold subduction zones (Figs. 10.4,
10.7; also see Hermann et al.
Thus polyphase solid inclusions are construed to be remnants of
transitional fluids or hydrous silicate melts derived by
dehydration melting of the subducting host rock under UHP
conditions in both cold and hot subduction zones (Fig. 10.7).
2009) and may lie very close or even in the field where
transitional fluids are to be expected (Fig. 10.7).
Viewing this image requires a subscription. If you are a subscriber, please log in.
This image is from the chapter titled "Metasomatism During High-Pressure Metamorphism: Eclogites and Blueschist-Facies Rocks"
(from Metasomatism and the Chemical Transformation of Rock), which is copyrighted by Springer Berlin Heidelberg. For more information on the
copyright for this image, please refer to the full image caption and to the
The image is being made available for non-commercial purposes for subscribers to SpringerImages. For more information on what you are allowed to do with this image, please see our copyright policy.
To request permissions to use any copyrighted material, please visit the source document.
Report a copyright concern regarding this image.
Log in or register to save your favorite images and download them as high-quality PowerPoint or PDF files.
Log in or register to save your search criteria.
© Springer, part of Springer Science+Business Media.
Remote Address: 22.214.171.124 Server: 21