The aureole of the Rum Tertiary igneous complex, Scotland

Saved in:
Online Access: Get full text
doi: 10.1144/0016-764901-098
Authors:Holness, M. B.; Isherwood, C. E.
Author Affiliations:Primary:
University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, Vol.160(Part 1), p.15-27. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:2003
Note:In English. 40 refs.; illus., incl. 4 tables, geol. sketch map
Summary:The aureole of the Tertiary Rum Igneous Complex formed at shallow levels in amphibolite-facies migmatitic Lewisian gneisses and previously unmetamorphosed Precambrian arkose of the Torridonian Group. Contact metamorphism of arkose resulted in the breakdown of chlorite-rich cement and detrital muscovite, feldspar disordering, and melting. A simplified thermal model shows that magma chamber filling may have occurred over a few hundred years. Contact metamorphism of Lewisian gneiss, exposed only within the Main Ring Fault of the complex, resulted in the breakdown of hornblende to pyroxene, plagioclase, biotite and magnetite. Biotite in high-grade gneisses is replaced by feldspar and orthopyroxene. Extensive melting of the gneiss occurred only locally. Prominent migmatitic structures predate contact metamorphism. Significant mobility of Fe, Mg and Al occurred in the aureole, probably effected via circulation of aqueous fluids confined to the metamorphic peak within the Main Ring Fault but extending to lower temperatures outside. Significant differences between cooling rate of rocks within and outside the Main Ring Fault are inferred from textural observations. These probably relate to a combination of a relatively extended metamorphic event for the innermost rocks and a greater cooling influence of circulating aqueous fluids on the outermost rocks.
Sections:Petrology
Subsections:Metamorphism: thermal, metasomatic
Subjects:Amphibolite facies; Aureoles; Chemical reactions; Contact metamorphism; Deformation; Facies; Fluid dynamics; Gneisses; Intrusions; Lewisian; Melting; Meta-arkose; Metamorphic rocks; Metamorphism; Metasedimentary rocks; Mineral assemblages; Mineral composition; P-T conditions; Precambrian; Proterozoic; Textures; Upper Precambrian; Europe; Great Britain; Hebrides; Highland region Scotland; Inner Hebrides; Inverness-shire Scotland; Rhum; Scotland; United Kingdom; Western Europe; Main Ring Fault
Coordinates:N570000 N570000 W0061200 W0061200
Abstract Numbers:03M/2224
Record ID:2003018477
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom
Tags: Add Tag
No Tags, Be the first to tag this record!
LEADER 04416naaaa2200709zu 4500
001 2003018477
003 ViAlAGI
005 20190221174335.0
008 190110e200301 xxka 0 0 eng d
034 0 |a a  |d W0061200  |e W0061200  |f N570000  |g N570000 
040 |a ViAlAGI  |c ViAlAGI 
072 7 |a 05A  |2 georeft 
100 1 |a Holness, M. B.  |e analytic author  |u University of Cambridge, Department of Earth Sciences, Cambridge 
245 1 4 |a The aureole of the Rum Tertiary igneous complex, Scotland 
300 |a p. 15-27 
500 |a In English. 40 refs. 
500 |a Abstract number: 03M/2224 
500 |a Category Section: Petrology 
500 |a Category Subsection: Metamorphism: thermal, metasomatic 
500 |a Affiliation: University of Cambridge, Department of Earth Sciences; Cambridge; GBR; United Kingdom 
500 |a Key title: Journal of the Geological Society of London 
500 |a Source note: Journal of the Geological Society of London, Vol.160(Part 1), p.15-27. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649 
500 |a Publication type: journal article 
504 |b 40 refs. 
510 3 |a GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom 
520 |a The aureole of the Tertiary Rum Igneous Complex formed at shallow levels in amphibolite-facies migmatitic Lewisian gneisses and previously unmetamorphosed Precambrian arkose of the Torridonian Group. Contact metamorphism of arkose resulted in the breakdown of chlorite-rich cement and detrital muscovite, feldspar disordering, and melting. A simplified thermal model shows that magma chamber filling may have occurred over a few hundred years. Contact metamorphism of Lewisian gneiss, exposed only within the Main Ring Fault of the complex, resulted in the breakdown of hornblende to pyroxene, plagioclase, biotite and magnetite. Biotite in high-grade gneisses is replaced by feldspar and orthopyroxene. Extensive melting of the gneiss occurred only locally. Prominent migmatitic structures predate contact metamorphism. Significant mobility of Fe, Mg and Al occurred in the aureole, probably effected via circulation of aqueous fluids confined to the metamorphic peak within the Main Ring Fault but extending to lower temperatures outside. Significant differences between cooling rate of rocks within and outside the Main Ring Fault are inferred from textural observations. These probably relate to a combination of a relatively extended metamorphic event for the innermost rocks and a greater cooling influence of circulating aqueous fluids on the outermost rocks. 
650 7 |a Amphibolite facies  |2 georeft 
650 7 |a Aureoles  |2 georeft 
650 7 |a Chemical reactions  |2 georeft 
650 7 |a Contact metamorphism  |2 georeft 
650 7 |a Deformation  |2 georeft 
650 7 |a Facies  |2 georeft 
650 7 |a Fluid dynamics  |2 georeft 
650 7 |a Gneisses  |2 georeft 
650 7 |a Intrusions  |2 georeft 
650 7 |a Lewisian  |2 georeft 
650 7 |a Melting  |2 georeft 
650 7 |a Meta-arkose  |2 georeft 
650 7 |a Metamorphic rocks  |2 georeft 
650 7 |a Metamorphism  |2 georeft 
650 7 |a Metasedimentary rocks  |2 georeft 
650 7 |a Mineral assemblages  |2 georeft 
650 7 |a Mineral composition  |2 georeft 
650 7 |a P-T conditions  |2 georeft 
650 7 |a Precambrian  |2 georeft 
650 7 |a Proterozoic  |2 georeft 
650 7 |a Textures  |2 georeft 
650 7 |a Upper Precambrian  |2 georeft 
651 7 |a Europe  |2 georeft 
651 7 |a Great Britain  |2 georeft 
651 7 |a Hebrides  |2 georeft 
651 7 |a Highland region Scotland  |2 georeft 
651 7 |a Inner Hebrides  |2 georeft 
651 7 |a Inverness-shire Scotland  |2 georeft 
651 7 |a Rhum  |2 georeft 
651 7 |a Scotland  |2 georeft 
651 7 |a United Kingdom  |2 georeft 
651 7 |a Western Europe  |2 georeft 
653 |a Main Ring Fault 
700 1 |a Isherwood, C. E.,  |e analytic author 
773 0 |t Journal of the Geological Society of London  |d London : Geological Society of London, Jan. 2003  |x 0016-7649  |y JGSLAS  |n Journal of the Geological Society of London, Vol.160(Part 1), p.15-27. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649 Publication type: journal article  |g Vol. 160, Part 1  |h illus., incl. 4 tables, geol. sketch map 
856 |u urn:doi: 10.1144/0016-764901-098