Results 131 to 140 of about 188 (175)

Note on a Picrite from the Liskeard District

Mineralogical Magazine and Journal of the Mineralogical Society, 1888
Specimens of this rock were presented a short time since to the British Museum by the Earl of St. Germans, and Mr. T. Davies, knowing my interest in pierites and peridotites, kindly requested me to examine them and communicate the results to the Mineralogical Society. The rock occurs, as I am informed, in boulders between Menheniot and St. Germans. The
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Metamorphism and melting of picritic crust in the early Earth

Lithos, 2014
Abstract Partial melting experiments with models of Archean oceanic crust (MAOC; with 11, 13 and 15 wt.% MgO) are used to investigate the role of metamorphism and melting of primary picritic compositions in the formation of TTG-like melts and continental crust on the early Earth.
Karen Ziaja, Stephen F. Foley, Richard W. White, Stephan Buhre   +3 more
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Partitioning of nickel between immiscible picritic liquids

Earth and Planetary Science Letters, 1977
Proterozoic lavas from the Ventersdorp Supergroup in South Africa display liquid immiscibility textures with ocelli up to 15 cm in diameter. The magmas are of an unusual high-magnesia, but quartz-normative, composition. The high silica and high magnesia content may cause the liquid immiscibility, producing a “pyroxene-type” and “tridymite-type ...
R. Grant Cawthorn, T.S. McCarthy
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Picritic magmas and the Rum ultramafic complex, Scotland

Geological Magazine, 2002
Three small picritic dykes, intruded at a late stage in the evolution of the Rum basic–ultra-basic complex, Inner Hebrides, shed new light on the nature of the magmas responsible for the main complex. The magmas are of transitional (mildly alkalic) type, generated by relatively small-fraction (6–7%) melting of a depleted mantle source.
Upton, B.G.J., Skovgaard, Anna Cecilie, McClurg, J., Kirstein, L., Cheadle, M., Emeleus, C.H., Wadsworth, W.J., Fallick, A.E.   +7 more
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Hornblende, gabbros and picrites at Rhiw, Caernarvonshire

Geological Journal, 1970
AbstractThree hornblende‐bearing intrusive masses consisting mainly of cumulate rocks derived from a water‐rich, alkali‐basalt magma are described. They probably all belong to one Lower Palaeozoic 'sill‐like' intrusion with an original sloping floor.
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Picrite basalts of talnakh ore field

Chemical Engineering
The processes of melting and crystallization of Si-Al-Ti-Fe-Mg-Ca-Na-K-O system which is picrobasalt - ultrabasic volcanic rock of the subparty of normal alkaline rocks (35% ≤ SiO2 ≤ 45%, 0% ≤ (Na2O+K2O) ≤ 2%) have been studied by methods of physical-chemical computer modeling. The total content of Na2O and K2O in the rock does not exceed 2%.
S.V. Fomichyov, V.A. Krenyov, E.N. Pechyonkina, E.I. Berbekova   +3 more
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The eruption of komatiites and picrites in preference to primitive basalts

Earth and Planetary Science Letters, 1991
Abstract Many Archaean greenstone and post-Archaean flood-basalt provinces exhibit flows of komatiites or picrites in close spatial and temporal association with fractionated basalts. It follows that picrites and komatiites can erupt through the same crustal sections in which basaltic magmas apparently pond and fractionate.
John R. Lister, Ian H. Campbell, Ross C. Kerr   +2 more
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VI.—The Picrite of Foel lwyd, Carnarvonshire

Geological Magazine, 1913
During a short holiday to North Wales in Whit-week, 1910, I was investigating the igneous rocks to the south of Llanfairfechan, more particularly the intrusive greenstones of the Geological Survey map. Since the publication of this map, over fifty years ago, several districts within it have been investigated in greater detail, especially as to the ...
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Picrites as parental magma of MORB-type tholeiites

Nature, 1982
Recent experimental work on peridotites and basalts1–3 and a reappraisal of ophiolite complexes4 supports the concept that basalts are derived from picritic parents5–7. The occurrence of a density minimum in the liquid line of descent8–10 explains why mid-ocean ridge tholeiites fall in a restricted compositional range, and parental picrites can only be
D. J. Beets, G. Th. Klaver, F. F. Beunk, C. Kieft, P. Maaskant   +4 more
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III.—Picrite from the Ampwihi River, Mozambique

Geological Magazine, 1917
Almost due west of Mozambique Island, at a distance of about forty-two miles from the sea, the military road from Mosuril to Nampula crosses the Ampwihi River, an important tributary of the Monapo. During the dry season the stream is reduced to a string of stagnant pools, separated by long reaches of sand and gravel that here and there are interrupted ...
Arthur Holmes, H. F. Harwood
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