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Mg–Fe carpholites from aluminous schists in the Diahot region and implications for preservation of high‐pressure/low‐temperature schists, northern New Caledonia
Author(s) -
BLACK P. M.,
MAURIZOT P.,
GHENT E. D.,
STOUT M. Z.
Publication year - 1993
Publication title -
journal of metamorphic geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.639
H-Index - 114
eISSN - 1525-1314
pISSN - 0263-4929
DOI - 10.1111/j.1525-1314.1993.tb00162.x
Subject(s) - pyrophyllite , schist , geology , chlorite , geochemistry , kaolinite , hydrothermal circulation , quartz , mineralogy , subduction , metamorphic rock , seismology , tectonics , paleontology
Mg–Fe carpholite is widespread in the Diahot region of New Caledonia in highly aluminous schists and as veins in what was originally a clay‐rich hydrothermal alteration envelope about massive suphide deposits. These carpholites have Fe/(Fe + Mg) ratios of 0.03–0.65 and no significant Mn component. Mg‐carpholite + quartz occur in assemblages with chlorite or pyrophyllite, pyrophyllite + kaolinite and pyrophyllite + diaspore. Temperatures of 230–320° C and minimum pressures of 7 kbar are indicated for the Mg–Fe carpholite‐bearing rocks. The regional distribution of aragonite and Mg–Fe carpholite parallel to a major zone of dominantly transcurrent movement and oblique to the trend of the subduction complex indicates the high‐ P /low‐ T schists owe their rapid uplift and preservation to the vertical component of the transcurrent faulting.