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Fibrous nepheline, pectolite and plagioclase from Baffin Island

Donald D. Hogarth, Mihaly Posfai, Peter R. Buseck and Joseph V. Smith
Fibrous nepheline, pectolite and plagioclase from Baffin Island
European Journal of Mineralogy (February 2001) 13 (1): 51-56


At Napoleon Bay, SE Baffin Island, fibrous aggregates define the contacts of Mesoproterozoic lamproite dykes with feldspathic wall-rock. The aggregates consist of nepheline, pectolite and andesine which are, respectively, fibrous along c, b and an indeterminate axis. Optically continuous, polymineralic fibre bundles are 0.1-0.2 mm long at the contact, 0.1-0.5 mm long in the wall-rock but are not found beyond 8 mm from the dykes. The fibrous aggregates were produced by the reaction of strongly alkaline, hydrothermal solutions, emanating from the dykes, with labradorite in the wall rock. Nepheline and pectolite were possibly derived from an unidentified, high-T phase that decomposed during cooling; andesine may have been generated independently. Growth was directed across a set of tension fractures and proceeded with the aid of a thermal gradient as heat was removed continuously through the wall-rock.

ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 13
Serial Issue: 1
Title: Fibrous nepheline, pectolite and plagioclase from Baffin Island
Affiliation: University of Ottawa, Department of Earth Sciences, Ottawa, ON, Canada
Pages: 51-56
Published: 200102
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 6
Accession Number: 2001-022808
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
N62°00'00" - N73°30'00", W90°00'00" - W61°30'00"
Secondary Affiliation: Arizona State University, USA, United StatesUniversity of Chicago, USA, United States
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 200108
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