We recognize eight types of ferroan granitoid that can be distinguished on the basis of major element chemistry.These include alkalic granitoids that may be metaluminous or peralkaline, alkali-calcic granitoids that may be metaluminous, peraluminous or peralkaline, calc-alkalic granitoids that may be metaluminous or peraluminous, and rare calcic ferroan granitoids. These granitoids may form by ...

This review paper aims to integrate geological, tectonic and metallogenetic data, including new propose a regional model for the gold (and base metal) mineralization in south Amazonian Craton support mineral exploration concerning magmatic–hydrothermal deposits. The Proterozoic evolution of comprises accretion terrains Archean Carajás Mineral Province. In Tapajós Juruena provinces, located at p...

clinopyroxene phenocrysts and microphenocrysts in potassic and sodic eosen alkaline volcanic rocks from the northern lahrud (nw iran) record various stages in the crystallization and evolution history of the alkaline melt as well as its origin. the rock series hosting the clinopyroxene phenocrysts is phonolitic tephrite and tephritic phonolite composition. theses rocks generally show porphyriti...

sakhtehesar mountain is located in urumieh-dokhtar magmatic belt and is composed of volcanic and subvolcanic rocks (pliocene andesite to dacite) which intruded the volcanics and pyroclastics of paleocene age. three alteration zones including potassic, phyllic and propylitic are recognized in the area. in this paper, the mineral chemistry of magmatic and primary biotite and the mineral chemistry...

Magmatic augites reacted with high temperature aqueous solutions to form secondary calcic pyroxenes during the subsolidus cooling of the Skaergaard intrusion. Secondary, hydrothermal clinopyroxenes replace wall rock igneous augites at the margins of veins filled with calcic amphibole. These veins are up to several millimeters wide and tens of meters in length. Hydrothermal clinopyroxenes are a ...

The Chocó-Panamá block is the land bridge that connects Central and South America forms trailing edge of Caribbean Large Igneous Province (CLIP). New field observations are combined with new geochemical, isotopic 40Ar/39Ar analyses mafic basement Chocó within Colombia. These integrated U/Pb ages detrital zircons extracted from siliciclastic carbonate rocks unconformably overlie basement. data u...

Recent studies of soil–landscape relationships in northeastern Patagonia identified fibrous-clay minerals in calcic and petrocalcic horizons developed on old fluvio-glacial plains called “Rodados Patagónicos” (RP). The objectives of this study were: i) to evaluate the occurrence of fibrous-clay minerals in the arid soil environment, and ii) to establish the relationship between the soil propert...

Ultra-calcic ankaramitic magmas or melt inclusions are ubiquitous in arc, ocean-island and mid-ocean ridge settings. They are primitive in character (XMg 4 0 65) and have high CaO contents (414 wt %) and CaO/Al2O3 (41 1). Experiments on an ankaramite from Epi, Vanuatu arc, demonstrate that its liquidus surface has only clinopyroxene at pressures of 15 and 20 kbar, with XCO2 in the volatile comp...