The thermal behaviour of some feldspars from Egypt

El Sokkary A. A.: The thermal behaviour of some feldspars from Egypt. In: Acta mineralogica-petrographica, (32). pp. 49-57. (1991)

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A new and sensitive Hungarian derivatograph is used in studying the thermal behaviour of six feldspars from Egypt and U.S.A., its temperature range is up till 1200 °C. Four endothermic peaks could be noted in the dta curves of the studied feldspars. These are: PI at 225—330 °C, P2 at 425—600 °C, P3 at 695—860 °C and P4 at 940—980 °C. The first peak PI is partly correlated with loss of adsorbed water and partly with loss of constitutional water of certain hydrated silicate minerals like clays present as aiteratic n product of feldspar. This peak can express the extent of alteration of the feldspar. The second peak P2 is shown to be correlated with the miscibility of the two feldspars forming the perthite or antiperthite under study. Moreover, it is shown to be empirically correlated with temperature of formation. The third and fourth peaks P3 and P4 are transition temperatures of plagioclase and microline to the high temperature forms respectively. The last two reaction temperatures are particularly useful as petrogenetic indicators.

Item Type: Article
Journal or Publication Title: Acta mineralogica-petrographica
Date: 1991
Volume: 32
ISSN: 0365-8066
Page Range: pp. 49-57
Language: English
Publisher: University of Szeged, Department of Mineralogy, Geochemistry and Petrology
Place of Publication: Szeged
Related URLs:
Uncontrolled Keywords: Kőzettan, Ásványtan, Földtan
Additional Information: Bibliogr.: p. 56-57. ; ill. ; összefoglalás angol nyelven
Subjects: 01. Natural sciences
01. Natural sciences > 01.05. Earth and related environmental sciences
Date Deposited: 2016. Oct. 17. 09:25
Last Modified: 2022. Jul. 27. 08:06

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