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Mesoproterozoic rift-related alkaline magmatism at Elchuru, Prakasam Alkaline Province, SE India
Lithos, 2006Abstract The Elchuru alkaline complex in the Prakasam igneous province represents one occurrence of several alkaline bodies within the craton–Eastern Ghats Belt contact zone in Peninsular India. Nepheline syenites and associated mafic rocks intruded the cratonic crust at ≈1321 Ma and were deformed–metamorphosed to amphibolite facies condition during ...
Upadhyay, D. +3 more
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Mesozoic mafic alkaline magmatism of southern Scandinavia
Contributions to Mineralogy and Petrology, 2004More than 100 volcanic necks in central Scania (southern Sweden) are the product of Jurassic continental rift-related mafic alkaline magmatism at the southwest margin of the Baltic Shield. They are mainly basanites, with rarer melanephelinites. Both rock groups display overlapping primitive Mg-numbers, Cr and Ni contents, steep chondrite-normalized ...
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Ultra-alkaline magmatism with or without rifting
Tectonophysics, 1987Abstract Examination of the relationship between rifting and types of alkaline magmatism reveals features at present overlooked by current theories of plate tectonics. For example, in East Africa the majority of ultra-alkaline igneous rocks (carbonatites, melilitites, nephelinites, rijolites) lie west of the site of the Gregory Rift Valley and pre ...
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Introduction to Special Section on Alkaline Arc Magmatism
Journal of Geophysical Research: Solid Earth, 1989Alkaline magmas are an uncommon but intriguing member of many of the Earth's volcanic arc systems. This peculiar magmatism is generally associated with perturbations to the “normal” tectonic setting of arc magmatism. In December 1986, we convened a symposium at the AGU Fall Meeting to explore connections between the tectonic environments of alkaline ...
Stephen E. Box, Martin F. J. Flower
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Tertiary alkaline magmatism in Trans-Pecos Texas
Geological Society, London, Special Publications, 1987Summary Alkaline magmatism in far W Texas extended from 48 to 16 Ma ago, peaking in volume during the interval 37-26 Ma when all the felsic rocks were emplaced. Primitive magmas are rare, if not entirely lacking, but ne- and {ol+hy}-normative hawaiite and mugearite liquids (Ni <120 ppm; 100Mg/(Mg+Fe)<
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Alkaline magmatism and uplift of continental crust
Proceedings of the Geologists' Association, 1980Doming associated with alkaline magmatism can be developed in East Africa and elsewhere on three quite different scales; lithospheric, crustal and sub-volcanic. Each is considered to be the result of separate mantle and crustal processes, and require distinction. Lithospheric domes, e.g. the East African Dome, are seen as extensive areas of continental
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Post-collisional alkaline lamprophyre magmatism in northern Iran
2022The Shanderman lamprophyre dykes crop out in the western part of the Alborz Mountains (Talesh). These rocks are classified as camptonites, composed of primary olivine, Ti-rich diopside, kaersutite, biotite, plagioclase, K-feldspar, and minor Ti-rich spinels, magnetite, pentlandite-pyrrhotite/chalcopyrite, and powellite-scheelite.
Omrani, Hadi +3 more
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Alkaline Magmatism in the Deccan Volcanic Province
Journal Geological Society of India, 1980Abstract Alkaline magmatism in the Deccan volcanic province is characterised by i) relative spatial restriction, being manifested in the western and northwestern parts of the province, ii) development of alkaline rock assemblages in plug like bodies and hypabyssal minor intrusions, iii) alignment of magmatic activities along three (or ...
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Kimberlites and Associated Alkaline Magmatism
1982The substantial contribution of the alkaline igneous rocks to the South African economy is well known and far exceeds their abundance in the geologic record. Most notable are the diamondiferous kimberlites and the rocks of the Palabora Intrusive Suite containing copper, iron, phosphate, uranium, and vermiculite. Kimberlites are also significant because
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Contributions to Mineralogy and Petrology, 1990
The polyphasal magmatic evolution of the Caledonian Karmoy Ophiolite Complex includes: (1) formation of an axis sequence from island-arc tholeiitic (IAT) and more MORB-like magmas (493+7/-4 Ma); (2) intrusion of magmas of boninitic affinity (485±2 Ma); (3) intrusion of MORB- and IAT-like magmas; (4) intrusion and extrusion of calc-alkaline magmas (470 ...
Pedersen, R. B., Hertogen, J.
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The polyphasal magmatic evolution of the Caledonian Karmoy Ophiolite Complex includes: (1) formation of an axis sequence from island-arc tholeiitic (IAT) and more MORB-like magmas (493+7/-4 Ma); (2) intrusion of magmas of boninitic affinity (485±2 Ma); (3) intrusion of MORB- and IAT-like magmas; (4) intrusion and extrusion of calc-alkaline magmas (470 ...
Pedersen, R. B., Hertogen, J.
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