ISSN:
1432-0967
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract High temperature (〉900 °C) metamorphism affected the New Russia gneiss complex in the aureole of the Marcy anorthosite, Adirondack Highlands, New York. Dehydration melting of pargasitic hornblende and plagioclase in metagabbro during contact metamorphism produced garnet among other phases, an indicator that pressure exceeded 700 MPa during anatexis. Partial melting also occurred in mangerite and charnockite. Minerals that equilibrated during melting yield barometric estimates of 970 ± 100 MPa (garnet–orthopyroxene–plagioclase–quartz in metagabbro and mangerite) and 735 ± 100 and 985 ± 100 MPa (garnet–hornblende–plagioclase–quartz, metagabbro and mangerite, respectively). From these results we infer that the Marcy anorthosite was emplaced at a depth of at least 23 km and probably near 32 km.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004100000165
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