The primary mineral constituents are present in a number of morphological varieties, which show evidence of high-temperature deformation and moderate recrystallization. The porphyroclasts are heterogeneous, with more Ca, A1, Cr, and Ni in the cores than in the rims. Small, undulatory, orthopyroxenes are chemically comparable to the rims of the porphyroclasts. The orthopyroxene in mosaic arrangement is lower in Ca, Ti, Ni, and Cr than the porphyroclasts. We explain this by a combined process of porphyroclast disintegration and exsolution of clinopyroxene.
Porphyroclastic grains display similar core-rim variations as orthopyroxenes.
Undeformed interstitial clinopyroxene, believed to have formed from exsolved clinopyroxene in orthopyroxene, is chemically indistinguishable from other textural varieties. Evidence for magmatic impregnation is absent. The bulk chemical composition of the serpentinized peridotites was modified by alteration. Cr are the only elements that do not indicate mobility during alteration. All other determined elements, including light rare-earth elements, were more or less mobile.