M. Alene, L. Secco, A. Dal Negro, R. Sacchi; Crystal chemistry of clinopyroxene in Neoproterzoic metavolcanic rocks of Tigrai, northern Ethiopia. Italian Journal of Geosciences ; 119 (3): 581–586. doi:
The crystal chemistry of clinopyroxene in metavolcanic rocks from the Neoproterozoic sequence of Tigrai, Northern Ethiopia, turned out to be transitional between basaltic and trachytic series. By the literature, the metavolcanics in the studied area are products of an orogenic, calc-alkaline island arc magmatism; the clinopyroxene chemistry suggests the subordinate presence of rocks derived from non-cogenetic magma.