St. Kilda: an illustrated account of the geology - Revision history

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	The dominant topographical features of St Kilda are the result of Quaternary glaciation and a small glacier probably occupied Village Bay during the Devensian glacial maximum. Today St Kilda is part of a drowned landscape.		The dominant topographical features of St Kilda are the result of Quaternary glaciation and a small glacier probably occupied Village Bay during the Devensian glacial maximum. Today St Kilda is part of a drowned landscape.

	~~== Geological history ==~~

	~~{\| Class="wikitable"~~
	~~\|\|'''''1'''''~~
	~~\|\|'''''Formation of early mafic complex'''''~~
	\|-
	\|A
	\|Initiation of magmatism in the vicinity of St Kilda, located at the intersection of lines of weakness in the Precambrian crust. Crystal accumulation from mafic magma to produce the Western Gabbro E''<sup>W</sup>''
	\|-
	\|B
	~~\|Intrusion of the Cambir Dolerite into solid but still hot E''<sup>W</sup>'' to form basic granulites and spinel-amphibole assemblages.~~
	\|-
	\|C
	\|Intrusion of dolerites and gabbros and disintegration of E''<sup>W</sup>'' with general uplift of these rocks during formation of the igneous breccia EK. Intrusion of basalts and explosion microbreccias at a high level (probably less than 5 km deep) accompanying surface volcanism. Hydrothermal activity during cooling and solidification of the EK breccia.
	\|-
	~~\|'''''2'''''~~
	~~\|'''''Formation of complex comprising a range of mafic rocks and major granitic components'''''~~
	\|-
	\|A
	\|Renewed surface volcanism followed by collapse of block of cold EK breccia into a basaltic magma chamber formed at a high level in the crust. Development of thick chilled zone round this block and formation of the Glen Bay Gabbro.
	\|-
	\|B
	~~\|Crushing of Glen Bay Gabbro followed by intrusion of Glen Bay Granite and then by porphyritic felsite dyke.~~
	\|-
	\|C
	~~\|Development of Mullach Sgar Complex involving at least four major intrusive phases each with felsic and mafic components. Intrusion of Glen Bay Dykes.~~
	\|-
	\|D
	~~\|Intrusion of Conachair Granite at a high level in the crust, with N or NNW fracturing of the Mullach Sgar Complex.~~
	\|-
	~~\|'''''3'''''~~
	~~\|'''''Uplift, loss of volatiles, minor intrusion and cooling'''''~~
	\|-
	\|A
	~~\|Consolidation of Conachair Granite followed by NW faulting and hydrothermal activity at temperatures between 260° and 100°C.~~
	\|-
	\|B
	~~\|Intrusion of dolerites and felsites as cone sheets and dykes; NE faulting.~~
	\|-
	\|C
	~~\|Zeolite-grade hydrothermal alteration accompanying final cooling of the St Kilda complex in reversed polarity geomagnetic field.~~
	\|-
	~~\|'''''4'''''~~
	~~\|'''''Erosion'''''~~
	\|-
	\|A
	~~\|Uplift and erosion during much of Tertiary time, with circumstantial evidence of some deposition.~~
	\|-
	\|B
	~~\|Erosion by glaciers and deposition of glacial and periglacial sediments; rise in sea level.~~
	\|}

	== Specimens referred to in the text ==		== Specimens referred to in the text ==

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	[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]		[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]

			[[Minor intrusions - geochemistry - St. Kilda: an illustrated account of the geology\|Minor intrusions - geochemistry]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]		[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

Scotfot at 20:54, 5 November 2019

2019-11-05T20:54:36Z

← Older revision		Revision as of 21:54, 5 November 2019
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	[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]		[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]

			[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]		[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

Scotfot: /* St. Kilda: an illustrated account of the geology */

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St. Kilda: an illustrated account of the geology

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	[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]		[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]

	[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]		[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex - field description]]

	[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]		[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex - petrology]]

	[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]		[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]

Scotfot: /* St. Kilda: an illustrated account of the geology */

2019-11-05T19:44:03Z

St. Kilda: an illustrated account of the geology

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	[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]		[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]

	[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|~~The~~ Glen Bay Gabbro]]		[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|Glen Bay Gabbro]]

	[[Pegmatites - St. Kilda: an illustrated account of the geology\|Pegmatites]]		[[Pegmatites - St. Kilda: an illustrated account of the geology\|Pegmatites]]
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	[[Metamorphism - St. Kilda\|Metamorphism]]		[[Metamorphism - St. Kilda\|Metamorphism]]

	[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|~~The~~ Glen Bay Granite]]		[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]

	[[Mullach Sgar Complex - St. Kilda: an illustrated account of the geology\|~~The~~ Mullach Sgar Complex]]		[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]

	[[~~Conachair Granite~~ - St. Kilda: an illustrated account of the geology\|~~The Conachair Granite~~]]		[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]

	[[~~Minor intrusions~~ - St. Kilda: an illustrated account of the geology\|~~The minor intrusions~~]]		[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|~~The~~ Quaternary deposits]]		[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]

			[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

	[[Mineralogy of stream sediments of Hirta - St. Kilda: an illustrated account of the geology\|The mineralogy of stream sediments of Hirta]]		[[Mineralogy of stream sediments of Hirta - St. Kilda: an illustrated account of the geology\|The mineralogy of stream sediments of Hirta]]

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St. Kilda: an illustrated account of the geology

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	[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]		[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]

	[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro]]		[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro - field description]]

	[[Western Gabbro -petrology - St. Kilda: an illustrated account of the geology\|The Western Gabbro - petrology]]		[[Western Gabbro -petrology - St. Kilda: an illustrated account of the geology\|The Western Gabbro - petrology]]
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	[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]		[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]

	[[Breccia of gabbros and dolerites - field description - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]		[[Breccia of gabbros and dolerites - field description - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - field description]]

	[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]		[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]

	[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]		[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]

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St. Kilda: an illustrated account of the geology

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	[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]		[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]

	[[Breccia of gabbros and dolerites - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]		[[Breccia of gabbros and dolerites - field description - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]

			[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]

	[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]		[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]

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	{{StKilda}}		{{StKilda}}
	[[File:P991884.jpg\|thumbnail\|Front cover.]]		[[File:P991884.jpg\|thumbnail\|Front cover.]]
			[[File:P991885.jpg\|thumbnail\|Rear cover. St. Kilda: an illustrated account of the geology]]

	== St. Kilda: an illustrated account of the geology ==		== St. Kilda: an illustrated account of the geology ==

Scotfot: /* St. Kilda: an illustrated account of the geology */

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St. Kilda: an illustrated account of the geology

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	[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro]]		[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro]]

			[[Western Gabbro -petrology - St. Kilda: an illustrated account of the geology\|The Western Gabbro - petrology]]

	[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]		[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]

Scotfot at 00:03, 5 November 2019

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	== St. Kilda: an illustrated account of the geology ==		== St. Kilda: an illustrated account of the geology ==

	[[~~Summary -~~ St. Kilda: an illustrated account of the geology\|Summary]]		[[St. Kilda: an illustrated account of the geology#Summary\|Summary]]

	[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]		[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]

← Older revision		Revision as of 22:00, 5 November 2019
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	[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]		[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]

			[[Minor intrusions - geochemistry - St. Kilda: an illustrated account of the geology\|Minor intrusions - geochemistry]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]		[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

← Older revision		Revision as of 21:54, 5 November 2019
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	[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]		[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]

			[[Minor intrusions - petrology - St. Kilda: an illustrated account of the geology\|Minor intrusions - petrology]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]		[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

← Older revision		Revision as of 20:45, 5 November 2019
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	[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]		[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]

	[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]		[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex - field description]]

	[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]		[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex - petrology]]

	[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]		[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]

← Older revision		Revision as of 20:44, 5 November 2019
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	[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]		[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]

	[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|~~The~~ Glen Bay Gabbro]]		[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|Glen Bay Gabbro]]

	[[Pegmatites - St. Kilda: an illustrated account of the geology\|Pegmatites]]		[[Pegmatites - St. Kilda: an illustrated account of the geology\|Pegmatites]]
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	[[Metamorphism - St. Kilda\|Metamorphism]]		[[Metamorphism - St. Kilda\|Metamorphism]]

	[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|~~The~~ Glen Bay Granite]]		[[Glen Bay Granite - St. Kilda: an illustrated account of the geology\|Glen Bay Granite]]

	[[Mullach Sgar Complex - St. Kilda: an illustrated account of the geology\|~~The~~ Mullach Sgar Complex]]		[[Mullach Sgar Complex - field description - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]

	[[~~Conachair Granite~~ - St. Kilda: an illustrated account of the geology\|~~The Conachair Granite~~]]		[[Mullach Sgar Complex - petrology - St. Kilda: an illustrated account of the geology\|Mullach Sgar Complex]]

	[[~~Minor intrusions~~ - St. Kilda: an illustrated account of the geology\|~~The minor intrusions~~]]		[[Conachair Granite - St. Kilda: an illustrated account of the geology\|Conachair Granite]]

	[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|~~The~~ Quaternary deposits]]		[[Minor intrusions - St. Kilda: an illustrated account of the geology\|Minor intrusions]]

			[[Quaternary deposits - St. Kilda: an illustrated account of the geology\|Quaternary deposits]]

	[[Mineralogy of stream sediments of Hirta - St. Kilda: an illustrated account of the geology\|The mineralogy of stream sediments of Hirta]]		[[Mineralogy of stream sediments of Hirta - St. Kilda: an illustrated account of the geology\|The mineralogy of stream sediments of Hirta]]

← Older revision		Revision as of 20:10, 5 November 2019
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	[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]		[[Introduction - St. Kilda: an illustrated account of the geology\|Introduction]]

	[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro]]		[[Western Gabbro - St. Kilda: an illustrated account of the geology\|The Western Gabbro - field description]]

	[[Western Gabbro -petrology - St. Kilda: an illustrated account of the geology\|The Western Gabbro - petrology]]		[[Western Gabbro -petrology - St. Kilda: an illustrated account of the geology\|The Western Gabbro - petrology]]
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	[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]		[[Cambir Dolerite - St. Kilda: an illustrated account of the geology\|The Cambir Dolerite]]

	[[Breccia of gabbros and dolerites - field description - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]		[[Breccia of gabbros and dolerites - field description - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - field description]]

	[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites]]		[[Breccia of gabbros and dolerites - petrology - St. Kilda: an illustrated account of the geology\|Breccia of gabbros and dolerites - petrology]]

	[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]		[[Glen Bay Gabbro - St. Kilda: an illustrated account of the geology\|The Glen Bay Gabbro]]