However, further east protoliths
of oceanic affinity for metabasites of the Arquia Complex and volcanic rocks of the Quebradagrande Complex (Ruiz et al.
Underplating of the lithosphere with mantle-derived mafic magma is required to produce the high temperatures required to melt the relatively anhydrous protoliths
of 'A-type' granites.
With increasing metamorphic conditions, the protoliths
of the staurolite-bearing metapelites were tectonically transported and buried to its maximum depth at the [P.
It is formed by the metamorphosis of magnesium-rich protoliths
, for example serpentine.
One might suppose that the middle crust in the SG-3 area can be represented by rocks similar in age and composition of the protoliths
to the SG-3 Archaean complex but metamorphosed under conditions of high-temperature amphibolite and granulite facies.
Much controversy has existed over rock ages, the natures of contacts, and depositional environments of protoliths
were probably generated within back-arc spreading center and metamorphosed in a nascent subduction zone at depth around 50 km.
Dolostone or magnesite-bearing rocks are the most favourable protoliths
because they provide in situ sources of magnesia.
Rodingite is a massive, coarse-grained to medium-grained rock characterized by calcium-rich clinopyroxene and grossular which forms from the metasomatic alteration of mafic to ultramafic protoliths
The assemblage of belt-form tectonic blocks and sheets of the granulite and amphibolite facies consists mainly of igneous--mafic, intermediate, and felsic volcanic and intrusive protoliths
(Puura 1980; Puura et al.
9 Ga age for the protoliths
of the Los Mangos Granulites.
These mylonitized granitoids may have Jurassic plutonic protoliths