dyke swarms emplacement constitutes one of the conspicuous features of the neoproterozoic arabian-nubian shield (ans) (~950-540ma). based on field investigations, petrographic and geochemical characteristics the dyke swarms in nw sinai (egypt) comprise of mafic (dolerite-trachy-basalt-basalt), intermediate (basaltic-andesite trachy-andesite) and felsic (rhyodacite-rhyolite) varieties. geochemic...

Cretaceous mafic dykes in the Moyar Shear Zone (MSZ) area, north Kerala, India, provide signatures to probe into the nature of their source and thereby the evolution of the Mesozoic lithospheric mantle beneath the South Indian Granulite Terrain (SIGT). Bulk of the dykes in northern parts of Kerala is broadly in spatial association with the shear system. Mafic dykes striking NE-SW, NWSE, NNW-SSE...

the igneous dykes are a small mafic rock unit exposed in the south gorgan of eastern alborz, north iran. these mafic dykes are intruded in the middle–upper paleozoic sedimentary and metamorphic rocks units representing a part of the north gondwana province. the studied samples were collected from various locations along the exposed bodies. thin sections of these rocks show medium to coarse grai...

melt fractions that percolated pervasively throughout the massif and On the basis of their structural and compositional characteristics, had a refractory, calc-alkaline character. Locally, these melts were mafic rocks in the Ronda peridotite are classified into four groups: tapped into cracks forming intrusive dykes. group A (garnet-bearing rocks) occurring in the spinel tectonite domain; group...

Archean volcanic rocks in the mafic-dominated, ca. 2.66–2.69 Ga Point Lake and Beaulieu River belts, Slave Province, Northwest Territories, are significant in demonstrating the facies that characterize specific portions of pillow volcanoes or seamounts, irrespective of tectonic setting. Three distinct localities mapped in detail display facies consistent with: (1) proximal, deep-water, (2) medi...

SUMMA R Y. In the Dahomeyan of the western Accra Plains marie gneisses, amphibolites, and orthoamphibolite dykes in granitic gneiss occur. During the latest recrystallization, metamorphic conditions ranged (north to south) from oligoclase--epidote amphibolite subfacies through andesineepidote amphibolite subfacies to at least the medium or upper part of the amphibolite facies. Chemical analyses...

Previous studies have shown that the 2.04 Ga Kangâmiut dyke swarm of SW Greenland was injected into an active tectonic environment associated with the formation of the Nagssugtoqidian orogenic belt. Major and trace element modelling of the swarm shows that its chemical evolution was controlled by simple clinopyroxene–plagioclase fractionation. However, such trends — although typical of continen...