alkali feldspar


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Related to alkali feldspar: Plagioclase feldspar, quartz, hornblende, K feldspar

alkali feldspar

[′al·kə‚lī ′feld‚spar]
(mineralogy)
A feldspar composed of potassium feldspar and sodium feldspar, such as orthoclase, microcline, albite, and anorthoclase; all are considered alkali-rich.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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References in periodicals archive ?
Cao et al., "Selective dissolution of alkali feldspars and its effect on Lower Triassic sandy conglomerate reservoirs in the Junggar Basin, northwestern China," Geological Journal, vol.
Feldspar Dissolution and Its Influence on Reservoirs: A Case Study of the Lower Triassic Baikouquan Formation in the Northwest Margin of the Junggar Basin, China
###11La(W)###Coarse###Angular-###Moderately###Grain###Ferruginous###Plagioclase, alkali Feldspar,
Mineralogical Investigation of the Bara Formation from Lakhra Anticline, Sindh province, Pakistan
Quartz is low to moderate in abundance and feldspar is in significant proportion with plagioclase: alkali feldspar ratio high.
MODAL ANALYSIS OF SANDSTONE AND SILTSTONE LITHOFACIES FROM NORTHLAND ALLOCHTHON ROCKS, NEW ZEALAND
Alkali feldspars are represented by orthoclase and microcline.
The study of selected magmatic rocks thermic reworking for the purpose of thermic sinking
They contain clinopyroxene ([Wo.sub.43-50][Fs.sub.6-14]), olivine ([Fo.sub.43-82]), Ti-biotite, Ti-magnetite [+ or -] ilmenite, plagioclase ([An.sub.31-78]), alkali feldspar ([Or.sub.60-84]), interstitial nepheline-analcime ([Ne.sub.37-82][Ks.sub.15-23]), and alkali feldspar ([Or.sub.80-97]).
Magmatism in the Asuncion-Sapucai-Villarrica Graben (Eastern Paraguay) revisited: petrological, geophysical, geochemical, and geodynamic inferences
The alkali feldspar, including microcline, is mostly perthitic and occurs as megacrysts that occasionally display simple twinning (Figures 3(a) and 3(b)).
Petrography and physicomechanical properties of rocks from the ambela granitic complex, NW Pakistan
In these zones, few of the primary igneous features are preserved, but the rocks appear to have been coarse grained, with abundant quartz and alkali feldspar (Fig.
The Cape Porcupine Complex, northern mainland Nova Scotia--no longer a geological orphan
The degree of porosity depends on the composition of the parent feldspar grain, with plagioclase producing a dense clay matrix and alkali feldspar a highly porous clay matrix.
Relationships between fabric, water retention, and strength of hard subsoils in the south of Western Australia
It has a typical rapakivi texture with alkali feldspar megacrysts (ovoids) mantled by plagioclase.
Surface weathering of rapakivi granite outcrops--implications for natural stone exploration and quality evaluation/Rabakivi graniidi paljandite pindmise murenemise tahendus loodusliku kivi uuringutel ja kvaliteedi hindamisel
Acid igneous rock fragments: composed of quartz, alkali feldspar, plagioclase feldspar, and occasional muscovite/and or biotite mica, amphibole, and microcline.
Goddesses, snake tubes, and plaques: analysis of ceramic ritual objects from the LM IIIC shrine at Kavousi
Different aliquots were dated, and for the control quartz was used parallel to alkali feldspars. As a rule, the alkali feldspar measurements give somewhat higher ages than OSL from quartz, which can be explained by slower bleaching of the feldspar in the sunlight exposure.
Application of OSL and [sup.10]Be techniques to the establishment of deglaciation chronology in Estonia/Optiliselt stimuleeritud luminestsentsmeetodi (OSL) ja berulliumimeetodi ([sup.10]Be) kasutamine mandrijaa taandumise kronoloogia tapsustamiseks Eestis
and Stewart, D.B., 1968, X-ray and optical study of alkali feldspar: I.
Corregidum

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