Chromite in Komatiites, II. Modification during Greenschist to Mid-Amphibolite Facies Metamorphism

A lithium isotopic study of sub-greenschist to greenschist facies metamorphism in an accretionary prism, New Zealand

Chromite composition as evidence of metamorphism in komatiites, greenstone belt, Mozambique

Archaean komatiites of the greenstone belt in Manica area, western Mozambique contains accessory amount of disseminated chromite grains. The komatiite rocks comprise peridotitic and basaltic komtiite. These komatiites are affected by regional metamorphism as all of the studied area. It is observed that only chromian spinel is preserved as the primary mineral and that all the other primary miner...

Mineral Chemistry and metamorphic evolution of the Late Neoproterozoic metabasites of Do-Chah metamorphic - igneous complex (SE Shahrood)

Metapelites of the Do Chah complex (SE Shahrood) are composed of micaschist, garnet micaschist, chloritoid schist and garnet-bearing gneiss. In the highest degree of metamorphism, metapelites have been affected by partial melting, resulting as granitization. A significant part of these rocks, imposed by compressional tectonic regime and show typical evidence of plastic deformation and intensive...

An albite-anorthite assemblage in low-grade amphibolite facies rocks

Poikiloblastic amphibole schists from an ophiolite series in the vicinity of the Tertiary Bergell granite contain the assemblage albite (An 0)-anorthite (An 95), actinolite-pargasite, together with clinozoisite. TEM illustrates how large andesine crystals with a periodic APB (anti-phase boundaries) structure of e plagioclase change over a few hundred angstroms to pure albite and pure PT anorthi...

Following the Amphibolite to Greenschist Metamorphic Path through the Structural Parameters of Spinels from Amsaga (Mauritania)

We investigated the crystal and structural behavior of several Cr-bearing spinels from the Archean chromitites of Amsaga (Mauritania). The chemical and structural data testified a retrograde metamorphism from amphibolite to greenschist facies, witnessed by relative changes in the amount of all the major oxides (Cr, Al, Mg, Fe2+, Fe3+), the relative proportion of Fe/Fetot as well as the structur...