ISSN:
1440-1738
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
The petrogenetic grid between the eclogite and other high-pressure/temperature (P/T) metamorphic facies in a basaltic system is constructed by considering barroisite as one of the important phases in high-P/T metamorphism and by using previous petrological data combined with Schreinemakers' analysis and slope calculation. In the constructed petrogenetic grid, the eclogite facies is bounded by the blueschist and epidote–amphibolite facies with negative-slope reactions at lower temperatures (450–550 °C) and by the epidote–amphibolite, amphibolite and granulite facies with positive-slope reactions at higher temperatures (〉 550–600 °C). The eclogite facies does not contact the greenschist facies, and the lowest P condition for the eclogite facies exists at the boundary between the eclogite and epidote–amphibolite facies. The temperature range of the epidote–amphibolite facies increases with increasing pressure until 8–11 kbar and then decreases up to 13–15 kbar. Compared to boundaries of other facies, boundaries of the eclogite facies may have wider P–T ranges. The boundary between the blueschist and eclogite facies occurs over a large temperature range from 450 to 620 ± 30 °C, and the transitions between the eclogite and amphibolite or high-pressure granulite facies occur over a pressure range in excess of 6–10 kbar.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1440-1738.1998.00180.x
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