The Precambrian rocks in western Ethiopia consist of highand low-grade terranes intruded by granitoids with a wide compositional spectrum. The formation ages of these granitoid rocks are, so far, poorly understood. Single-grain zircon Pb/Pb evaporation and conventional U/Pb dating conducted on four granitoids places time constraints on their emplacement and tectonothermal events. Three granitoi...

Time-resolved geochemical data from the orthogneisses of basal units Allochthonous complexes NW Iberian Massif allow us to track changes in composition magmas generated a subduction-related setting that affects continental margin, which evolves building volcanic arc its dismantlement during rifting episode. The are interpreted as peripheral section North African margin Gondwana and record Neopr...

Pichagchi pluton is situated in the northeastern part of the Soursat complex in Sanandaj-Sirjan metamorphic belt of Iran. The pluton with the age of 74.20 Ma is composed mainly granodiorite, diorite, and tonalite in which mafic minerals are biotite and amphibole. In this study, composition of minerals used to describe the nature of the granitic magma and estimate the pressure and temperature at...

The temporal-spatial coincidence of saline deposits with rifting and alkaline magmatism has now become a commonly accepted fact. The congruency of these three phenomena implies logically, their trilateral genetic interrelation. The conventional concept for the formation of saline deposits, i.e an "evaporation process" can not be properly applied to giant saline deposits. The proposed "Volc...

Two fundamentally different types of silicic volcanic rocks formed during the Cenozoic of the western Cordillera of the United States. Large volumes of dacite and rhyolite, mostly ignimbrites, erupted in the Oligocene in what is now the Great Basin and contrast with rhyolites erupted along the Snake River Plain during the Late Cenozoic. The Great Basin dacites and rhyolites are generally calc-a...