Chrome-Spinels from the Massif du Sud, Southern New Caledonia

K. A. Rodgers
Department of Geology, University of Auckland, New Zealand

Summary: Approximately forty, variously shaped, chromitite bodies occur in dunites and harzburgites of the alpine-type peridotite complex of southern New Caledonia. The chromitites consist of pichrochromite (59 to 42% Cr2O3) and serpentinized olivine (Fo96-92) and display a variety of textures (massive, disseminated, and orbicular) consistent with a magmatic cumulate origin. Dunites contain olivine (Fo93−97) and 1 to 3% picrochromite (50 to 39% Cr2O3). Harzburgites have less than 1% spinel, ranging from picrochromite to ceylonite (45 to 28% Cr2O3) and often forming symplectic intergrowths with bronzite. Temperatures of crystallization of the cumulate picrochromites are believed to have been about 1200 δC while the more aluminous symplectic spinels equilibrated under different conditions and may reflect a late stage recrystallization episode.

Mineralogical Magazine; September 1973 v. 39; no. 303; p. 326-339; DOI: 10.1180/minmag.1973.039.303.09
© 1973, The Mineralogical Society
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