Results 151 to 160 of about 542 (177)

Alkali Feldspars from Gneisses and Granites of the Västervik Area, SE. Sweden

Geologiska Föreningen i Stockholm Förhandlingar, 1968
Abstract Metamorphosed Precambrian sedimentary rocks and associated late-kinematic granites of the Vastervik area in southeastern Sweden contain abundant potassium feldspar. The alkali feldspar from the metasediments shows zero to low obliquity and contains from 8 to 10 % albite in solid solution.
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Ordering and exsolution processes in Or-rich alkali feldspar megacrysts from the Eldzhurtinskiy granite (Caucasus)

Contributions to Mineralogy and Petrology, 1996
The extremely young (2.5 Ma) I-type Eldzhurtinskiy granite complex (Central Caucasus) is uniform with respect to modal composition, major and trace element chemistries of bulk rocks and mineral phases. In contrast, it reveals two types of alkali feldspar megacrysts differing in tetrahedral Al-content (2t1) and exsolution microtextures:
G. Witt-Eickschen, C. Evangelakakis, H. A. Seck, H. Kroll, A. G. Gurbanov   +4 more
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Geology and mineralization of the Jabalat alkali-feldspar granite, northern Asir region, Kingdom of Saudi Arabia

Journal of African Earth Sciences (1983), 1986
Abstract The Jabalat post-tectonic granite pluton is composed of albite- and oligoclase-bearing, low-calcium, F-, Sn- and Rb-rich subsolvus granites. These granites display evidence of late-magmatic, granitophile- and metallic-element specialization, resulting ultimately in the development of post-magmatic, metalliferous hydrothermal systems ...
Jaffar Al Tayyar, Norman J. Jackson, Saeed Al-Yazidi   +2 more
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Intraplate, rift-related magmatism: mainly the A-type, alkali feldspar granites

1997
Contrary to general opinion, a distinctly bimodal magmatism involving rather ordinary biotite granites and coeval basalts has been a feature of the earth’s cratons since the Early Proterozoic. Although I shall concern myself here mainly with the alkalic granites of this same environment, it is important to emphasize that they are really of small volume
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207Pb–208Pb decoupling of alkali feldspar from a late Mesozoic A-type granite in eastern China

Mineralogy and Petrology, 2008
A zircon U–Pb age of 120.2 ± 1.7 Ma has been dated by ion microprobe in situ for the Laoshan A-type granite in eastern China. Fossil 231Pa excess has been inferred to explain the observed 207Pb–208Pb decoupling for alkali feldspar. In order to reconcile the apparent paradox of fossil 231Pa excess for alkali feldspar rather than for zircon, two ...
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Alkali feldspar microtextures from Pogari formation granite pebbles (Middle Bosnia)

2010
Several reactions on minerals of the exotic reddish I-type granite pebbles of Cretaceous Pogari formation (Middle Bosnia) were observed using polarizing microscope: sericitization of plagioclase and chloritization of biotite (with epidote as a possible by-product), myrmekite, „plagioclase overgrowth“, „intergranular plagioclase“, exsolution and „patch“
Brlek, Mihovil, Balen, Dražen, Bermanec, Vladimir   +2 more
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Nb/Ta, Zr/Hf and REE fractionation in exotic pegmatite from the Keivy province, NW Russia, with implications for rare-metal mineralization in alkali feldspar granite systems

Ore Geology Reviews, 2022
Dmitry Zozulya, Ray Macdonald, Bogusław Bagiński   +2 more
exaly  

Mechanism of Nb and REE enrichment in the Tiemuli alkali-feldspar granite, Chongyi County, Jiangxi Province

Acta Petrologica Sinica, 2022
GUO NaXin, LIU ShanBao, CHEN ZhenYu, JIANG ShengXiong, LI HongWei   +4 more
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Green and sustainable recovery of feldspar and quartz from granite tailings

Minerals Engineering, 2023
Li Wang
exaly  

Intraplate magmatism: mainly the A-type, alkali feldspar granites

1993
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