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GEOREF RECORD

The alkali feldspars; VI, Sanidine and orthoclase perthites from the Slieve Gullion area, Northern Ireland

C. H. Emeleus and J. V. Smith
The alkali feldspars; VI, Sanidine and orthoclase perthites from the Slieve Gullion area, Northern Ireland
American Mineralogist (1959) 44 (11-12): 1187-1209

Abstract

The porphyritic felsite and granophyre ring dikes of Slieve Gullion have been studied mineralogically to ascertain the genesis of the alkali feldspars particularly. Most of the alkali feldspar phenocrysts in the granophyre fall between the sanidine and orthoclase series, and consist of intergrowths of monoclinic K-feldspar, anorthoclase, and Na-rich plagioclase. It is postulated that the phenocrysts formed slowly at depth, changed from homogeneous sanidine to the present forms through a sequence of unmixing and ordering reactions that were affected by the amount of available volatiles. The unusual occurrence of microcline in a hypabyssal rock may result from granodiorite fragments trapped in the rising magma.


ISSN: 0003-004X
EISSN: 1945-3027
Coden: AMMIAY
Serial Title: American Mineralogist
Serial Volume: 44
Serial Issue: 11-12
Title: The alkali feldspars; VI, Sanidine and orthoclase perthites from the Slieve Gullion area, Northern Ireland
Pages: 1187-1209
Published: 1959
Text Language: English
Publisher: Mineralogical Society of America, Washington, DC, United States
Accession Number: 1959-001493
Categories: Mineralogy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. (incl. geol. sketch map)
N51°30'00" - N55°19'60", W10°30'00" - W06°30'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Update Code: 1959
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