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pyroxene
pyroxene hornfels facies
pyroxene hornfels facies A set of metamorphic
mineral assemblages (produced by the
metamorphism of a wide range of starting rock types under the same metamorphic conditions), typically characterized by the development of the mineral assemblage
clinopyroxene–
labradorite–
quartz in rocks of
basic igneous composition. Other rocks of contrasting composition, e.g.
shales or
limestones, would each develop their own specific mineral assemblage, even though they are all being metamorphosed under the same conditions. The variation of mineral assemblage with starting rock composition reflects a particular range of pressure, temperature, and
P(H
2O) conditions. Experimental studies of mineral pressure—temperature stability fields indicates that the
facies represents a range of low pressures (0–2 kb) and moderate temperatures (550–750°C) characteristic of contact metamorphic conditions.
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Data on economic geology detailed by researchers at University of Tasmania.
Newspaper article from: Economics Week; 1/2/2009; 700+ words
; ...rocks consists of disseminated diopsidic pyroxene (Di(64)Hd(36) to Di(88)Hd...35, mostly Me18-26) and/or green pyroxene (Di(14)Hd(80) to Di(20)Hd...that typically have a garnet + minor pyroxene inner zone, a wollastonite and/or...
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Pre-eruptional magmatic zircon, neogene alboran volcanic province, SE Spain
Magazine article from: Journal of the Geological Society; 7/1/2002; ; 700+ words
; Hornblende-biotite- (?)pyroxene dacite from Cerro Morron de Mateo...Mateo hornblende-biotite-(?)pyroxene dacite. Geological Setting, location...rhyolites with variable amounts of pyroxene, hornblende and biotite. For further...
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Research from Y. Shimizu et al broadens understanding of mineralogy and petrology.
Newspaper article from: Mining & Minerals; 10/31/2008; 700+ words
; ...from Tokyo, Japan, We found spinel-pyroxene symplectites in lherzolite xenoliths...geochemical signatures. The spinel-pyroxene symplectites are divided into two types...aggregates of coarser-grained spinel-pyroxene. The petrography and major-element...
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Compositional variation of clinopyroxenes of basaltic, essexitic and tephriphonolitic rocks from the Doupovské hory Volcanic Complex, NW Bohemia
Magazine article from: Journal of the Czech Geological Society; 1/1/2005; ; 700+ words
; ...essexite; tephriphonolite Introduction Pyroxenes are the most abundant rock-forming...Thanks to the long period during which pyroxenes crystallize - from first stage of crystallization...microcrysts crystallization in matrix pyroxenes contain the most complete record of the...
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Scientists at University of Lyon target planetary science.
Newspaper article from: Chemicals & Chemistry; 1/16/2009; 700+ words
; ...the shear melt vein and in pyroxene grains attached to the wall...akimotoite are interwoven with a pyroxene glass with a lower Na and...adjacent akimotoite. This pyroxene glass is probably the product...state transformation of former pyroxenes with subsequent diffusion...
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Studies from Nagoya University further understanding of mineralogy.
Newspaper article from: China Weekly News; 2/24/2009; 700+ words
; ...successive replacement of pyroxenes during metamorphism...Suggests that all three pyroxenes were stable locally...of Fe2+-Mg between pyroxene pairs is consistent...local equilibrium for pyroxene pairs. The observed...Mineralogist (Coexistence of pyroxenes jadeite, omphacite...
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Investigators at University of Parma release new data on geochemistry.
Newspaper article from: Physics Week; 10/20/2009; 700+ words
; ...examined together with LiCrSi2O6 pyroxene. In LiCrSi2O6 the h + k odd...in P2(1)/c and C2/c pyroxenes indicates that the high temperature...LiNiSi2O6 with respect to other pyroxenes is suggested, possibly in...thermal behaviour of LiNiSi2O6 pyroxene. Physics and Chemistry of...
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Late-orogenic Variscan magmatism: the case of quartz monzodiorite dykes from the Blanice Graben, southern Bohemia
Magazine article from: Journal of the Czech Geological Society; 1/1/2006; ; 700+ words
; Pyroxene-biotite quartz monzodiorite of the Stepnovice...and whole-rock geochemical affinity to pyroxene microgranodiorite-quartz monzodiorite...dykes (termed Sevetn dyke swarm here) of pyroxene microgranodiorite to amphibole-pyroxene...
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Studies from V.N. Yakovenchuk et al add new findings in the area of mineralogy.
Newspaper article from: Mining & Minerals; 3/20/2009; 700+ words
; Seven pyroxene varieties were identified...augite is the predominant pyroxene in all types of nepheline...Microprobe analyses of 265 pyroxenes samples allowed us to distinguish...typomorphic features of pyroxenes. Compositional variations...
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New mineralogy findings from China University described.
Newspaper article from: Mining & Minerals; 8/14/2009; 700+ words
; ...investigation. The water incorporated in these pyroxenes is low (cpx, 37-399 ppm; opx, 9...literature data on water contents in mantle pyroxenes, which include peridotites from on...craton) xenoliths. Cratonic mantle pyroxenes are only represented by a few determinations...
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pyroxene
Book article from: A Dictionary of Earth Sciences
pyroxene An important group of inosilicates...comprising the orthorhombic pyroxenes ( orthopyroxenes ) and the monoclinic pyroxenes ( clinopyroxenes ) with the...jadeite , and also the alkali pyroxenes aegirine and aegirine augite...
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pyroxene gneiss
Book article from: A Dictionary of Earth Sciences
pyroxene gneiss See GRANULITE .
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pyroxene hornfels facies
Book article from: A Dictionary of Earth Sciences
pyroxene hornfels facies A set of metamorphic mineral assemblages (produced by the metamorphism of a wide range of starting rock types...
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rock-forming silicate minerals
Book article from: The Oxford Companion to the Earth
...families—the olivines, pyroxenes, amphiboles, micas, clay minerals...Fayalite occurs in acid lavas. Pyroxenes There are some 21 species in the pyroxene group, many of them rare. The pyroxenes are anhydrous single-chain silicates...
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basalt
Book article from: A Dictionary of Earth Sciences
...rock composed of plagioclase feldspar , pyroxene , and magnetite , with or without olivine...olivine, plagio-clase feldspar and pyroxene. Basalts are divided into two main types...alkali basalts have as their groundmass pyroxene titanaugite (an augite rich in titanium...
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