Metasedimentary and metavolcanic rocks to the east of the Walls Boundary Fault on Shetland have lithological similarities to those of the Dalradian Supergroup of the Scottish mainland. In particular, the middle part of the succession, termed the Whiteness Group, includes numerous metalimestones and associated pelites in a shallow-marine succession that recalls the upper parts of the Appin Group and the Argyll Group of mainland Scotland. Metavolcanic rocks within the deeper water turbiditic sequence of the succeeding Clift Hills Group might be broadly coeval with those of the Southern Highland Group of Scotland. Beyond that, correlations with the established Dalradian succession are tenuous and are not possible at formation level. A local succession immediately west of the Walls Boundary Fault is of even more-dubious Dalradian affinity.The dominant structure is the regional-scale, downward- and east-facing East Mainland Mega-monocline. This has a vertical western limb, which youngs to the east, and an eastern top limb that dips to the north-west at 20-30 degrees. Strata on the eastern limb are inverted on Mainland, Whalsay and Out Skerries but are right way up on the west side of Unst, having been folded around the tight Valla Field Anticline. The Shetland Ophiolite-complex has been thrust over the inverted limb of the Valla Field Anticline on the east side of Unst. The regional monocline folds earlier small- to medium-scale, tight to isoclinal folds with associated planar and linear structures, which are all assigned to a single 'Main Deformation'. It also post-dates the regional metamorphism, which ranges from chlorite to garnet grade, with localized development of staurolite-kyanite, gneissose fabrics, and the emplacement of schistose granitic sheets in the Colla Firth Permeation Belt.The GCR sites have been selected mainly to be representative of the East Mainland Succession with its associated structures and metamorphism. Highlights include well-preserved sedimentary structures, high-grade gneisses permeated by granitic material, basaltic pillow lavas and serpentinized ultramafic rocks. Some of the latter contain enigmatic skeletal pseudomorphs after olivine and have been interpreted as former high-magnesium lavas. (c) 2012 Natural Environment Research Council. Published by Elsevier Ltd on behalf of The Geologists' Association. All rights reserved.

In their paper on the last glaciation of Shetland, Golledge et al. (2008) concluded on the basis of a remote sensing study that during that period Shetland had been overrun by ice from Scandinavia. Since the method of study they used does not reveal the sense of the direction in which the ice flowed and since they ignored earlier ground-based work involving striations which do reveal the sense of direction of ice flow their conclusions have no scientific basis.

Synopsis The Dalradian succession in Shetland is shown to have experienced an extensional tectonic and metamorphic episode prior to the Caledonian orogeny. Sedimentary deposition ended with a major basic and ultrabasic volcanic episode following a long period of extensional basin deposition involving both basic volcanics and turbidites. The ending of deposition was marked by the emplacement of a spinifex-textured komatiite indicating instantaneous rifting of the crust and the underlying Laurentian plate, and the formation of a Laurentian passive continental margin, probably during the opening of Iapetus. The entire contents of the Dalradian depositional basin were rotated bodily 90° to face the rift and to form a 12 km wide vertical belt in the middle of Shetland. A continued rotation in the same sense formed a 25 km wide recumbent inverted limb to form a mega-monocline. The formation of this monocline is considered to have occurred during the extensional phase accompanying rifting because the absence of subsidiary buckle folds of any and every size precludes compressional folding. The metamorphism of the rocks shows a gradual increase from bottom to top of the stratigraphic succession, predating the formation of the monocline, and probably owes its existence to crustal thinning and heating from below the deposition basin during extension. Much of the tectonic and metamorphic history shown by the Dalradian of Shetland may have been overprinted and masked in Scotland by the Caledonian orogeny. In the Dalradian of Shetland the Caledonian orogeny is represented only by the emplacement of the Shetland Ophiolite.

St. Ninian's Ayre (sand tambala), on the south-west coast of Shetland, occurs in an environment of deeply plunging hard-rock cliffs which enclose the area containing the tombolo so that the maximum fetch of local wind-driven waves is no more than 2 km. As a result of the presence of the plunging cliffs, there are no adjacent beaches to supply sand to the tombolo by longshore drift. The sea around St. Ninian's Island, at the seaward end of the tambala is so deep that wave refraction in the vicinity is restricted. Thus, the various explanations usually offered for the origin of tombolos are precluded or incomplete. Satellite image and airphotos show that wave patterns in the vicinity of the tombolo result from the prevailing ocean swell from the west being diffracted round the island, on either side. As the sea shallows, the diffracted swell is increasingly modified by refraction, before breaking on either side of the tombolo. The shorelines on either side of the tombolo are nearly parallel to the crests of the diffracted and refracted swell-derived waves that these break along the length of the tambala at the same instant. Local wind driven waves have little effect. The tombolo owes its position and shape directly to the diffraction and refraction of the ocean-swell waves transporting sand from the adjacent sea floor into the area where the waves meet behind the island. Longshore drift acts only within the confines of the tombolo and matches its shape to that the crests of the waves break over it.

A group of small diatomite deposits occur within the outcrop of a serpentinite forming part of the Shetland Ophiolite. They occur on sloping hillsides where no standing water can have existed, often adjacent to springs, and in the beds of abandoned streams. They vary in size from a few metres in diameter and several centimetres thick to more than 100 metres across and nearly a metre thick. No diatomite has accumulated in ponds in the area at depths of less than one metre due to wind disturbance. It is suggested the diatoms lived in springs and in their outflow and that they accumulated as sieve-type deposits where the spring water seeped away into the ground and eventually through the accumulated diatomite. Two l4C dates from peat immediately underlying diatomite indicate deposition following 2380 and 1570 BP. The chemical influence of the serpentinite, then as now, inhibited the growth of plants and peat on the serpentinite, thus making possible the accumulation of diatomite instead of peat.

The island of Yell in the north of Shetland is largely formed of rocks which have been correlated with the Glenfinnan/ Loch Eil Division of the Moine in mainland Scotland. The rocks forming Yell are dominantly granoblastic to schistose quartzo-feldspathic psammitic rocks of greywacke composition. Over about a third of Yell these rocks have been transformed partially or completely to gneisses by a recrystallization, which results in a trebling, or more, of the grain size of the psammites, together with the loss of sedimentary lamination, banding and bedding-like partings. The end result for mica-poor granofels is a granoblastic gneiss of diatexite appearance, recognizable as a paragneiss due to its gradation to unaltered metasedimentary rocks. Mica-rich granofels and mica schists interbedded or interbanded with the granofels also recrystallize and develop quartzo-feldspathic leucosomes of typical migmatitic appearance. This gneissification by recrystallization takes place in a patchy and unpredictable manner throughout the psammite outcrop. The gneissified and the ungneissified metasediments are of similar bulk composition and metamorphic grade throughout the island, the grade being too low for melting to have occurred. In the absence of any published mechanisms of gneissification which could explain all these features, it is suggested that the grain-growth recrystallization was caused by the pasage of a fluid through the rocks.

Screes on high serpentinite sea cliffs in Shetland have been internally cemented by deposits of brucite, hydromagnesite and aragonite since the last glaciation. These minerals have been deposited from solutions originating as rain (often contaminated with salt spray), which fell on the serpentinite screes and dissolved Mg and minor amounts of Ca from the more finely divided and powdery scree components. As the solutions filtered down through the screes they deposited cements in the form of spherulitic layers of brucite and hydromagnesite with minor amounts of aragonite. At sea level the Mg-rich solutions mingled with sea water impregnating the scree and there cementation within the scree took place by the crystallization of plush-type layers of aragonite on the serpentinite fragments.

Geological JournalVolume 29, Issue 1 p. 81-84 Article Essay review: Coastal geomorphology and the coastal landform without a name Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, UKSearch for more papers by this author Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, UKSearch for more papers by this author First published: January/March 1994 https://doi.org/10.1002/gj.3350290108Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume29, Issue1January/March 1994Pages 81-84 RelatedInformation

Geological JournalVolume 29, Issue 3 p. 281-284 Article Essay review: Kinematic analysis–-pure nonsense or simple nonsense? Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, UKSearch for more papers by this author Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, UKSearch for more papers by this author First published: July/September 1994 https://doi.org/10.1002/gj.3350290308Citations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume29, Issue3July/September 1994Pages 281-284 RelatedInformation

Geological JournalVolume 27, Issue 1 p. 87-90 Article Essay review: Let us not praise famous men: A critique of Lyell's Principles Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, U.K.Search for more papers by this author Derek Flinn, Derek Flinn Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, U.K.Search for more papers by this author First published: January/March 1992 https://doi.org/10.1002/gj.3350270108Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat References Bailey, E. 1962. Charles Lyell. Nelson, London. Buckland, W. 1836. Geology and Mineralogy Considered in Relation to Natural Theology, 2v. Pickering, London. Conybeare, W. D. and Phillips, E. 1822. Outline of the Geology of England and Wales. Phillips, London. Cumming, D. A. 1985. John MacCulloch. blackguard, thief and high priest reassessed. In: A. Wheeler and J. H. Price, (Eds). Linnaeus to Darwin: Commentaries on the History of Biology and Geology. Society for the History of Natural History, 77–88. Dean, D. R. 1989. James Hutton's role in the history of geomorphology. In: K. J. Tinkler (Ed.), History of Geomorphology. Unwin Hyman. de la Beche, H. 1831. A Geological Manual. Treuttel et al., London. Flinn, D. 1980. James Hutton and Robert Jameson. Scott. J. Geol., 16, 251–258. Geikie, A. 1875. Life of Sir Roderick Impey Murchison, 2v. Murray, London. Flinn, D. 1905. The Founders of Geology. Macmillan. Lawrence, P. 1978. Charles Lyell versus the Theory of Central Heat: A Reappraisal of Lyell's Place in the History of Geology. J. Hist. Biology, 11, 101–128. Lyell, C. 1830-33. Principles of Geology, 3v. Murray, London. Lawrence, P. 1990-91. Principles of Geology. 3v. Reprint. University of Chicago Press, Chicago. MacCulloch, J. 1831. System of Geology. Longman et al., London. Murchison, R. I. 1833. Address to the Geological Society. Proc. Geol. Soc. Lond., 1, 362–386. Oldroyd, D. R. 1990. The Highlands Controversy. University of Chicago Press. Chicago. Penn, G. 1828. Conversations on Geology. Maunder, London. Phillips, W. 1826. Outlines of Mineralogy and Geology, 2nd edn. Phillips, London. Porter, R. 1977. The Making of Geology. Cambridge University Press, London. Citing Literature Volume27, Issue1January/March 1992Pages 87-90 ReferencesRelatedInformation

Cannat (1989) uses misplaced and absent boundaries on her geological sketch-map of Unst and Fetlar to support her proposal of a numerous set of northeast-trending sinistral faults and the presence of only one ophiolite nappe in the area. Her proposal of northeastward directed thrusting arises from her assertion, based on her interpretation of several deformed pebbles, that the rocks in the imbricate thrust zone below the nappe were deformed by simple shear as a result of northeastward thrusting. Previous published work has shown that both fabrics and structures in these rocks indicate a major episode of orthorhombic deformation resulting in a shortening of the intermediate deformation axis (pure shear) with no signs of any monoclinic structures indicative of such thrusting.

Geological JournalVolume 25, Issue 2 p. 205-206 Book ReviewFree Access Theory of earth science, by W. von Englehardt and J. Zimmermann (trans. L. Fischer). Cambridge University Press, Cambridge, 1989. No. of pages: 361. Price: $75.00 (£45.00) (hardback) D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: April/June 1990 https://doi.org/10.1002/gj.3350250212AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume25, Issue2April/June 1990Pages 205-206 RelatedInformation

Geological JournalVolume 23, Issue 4 p. 346-347 Book ReviewFree Access Statistical analysis of spherical data by N. Fisher, T. L. Lewis and B. J. Embleton, Cambridge University Press, 1987. no. of pages: 329. price: £35.00 (hardback) D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: October/December 1988 https://doi.org/10.1002/gj.3350230414AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume23, Issue4October/December 1988Pages 346-347 RelatedInformation

Geological JournalVolume 21, Issue 2 p. 207-209 Short Communication A reply to R. W. Nesbitt and L. A. Hartmann D. Flinn, D. Flinn Department of Geology, University of Liverpool, Liverpool L69 3BX, U.K.Search for more papers by this authorD. T. Moffat, D. T. Moffat Department of Geology, University College of Swansea, U. K.Search for more papers by this author D. Flinn, D. Flinn Department of Geology, University of Liverpool, Liverpool L69 3BX, U.K.Search for more papers by this authorD. T. Moffat, D. T. Moffat Department of Geology, University College of Swansea, U. K.Search for more papers by this author First published: April/June 1986 https://doi.org/10.1002/gj.3350210209Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume21, Issue2April/June 1986Pages 207-209 RelatedInformation

Geological JournalVolume 20, Issue 3 p. 293-293 Book ReviewFree Access Ophiolites and oceanic lithosphere by I. G. Gass, S. J. Lippard, and A. W. Shelton (Eds), Geological Society Special Publication No. 13, Blackwell Scientific Publications 1984. No. of pages: 426. Price: £37.50 (hardback). D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: July 1985 https://doi.org/10.1002/gj.3350200310AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume20, Issue3July 1985Pages 293-293 RelatedInformation

AbstractKomatiite lavas occur in the Dunrossness Spilitic Group in southeast Shetland in the Cunningsburgh area. This metavolcanic group is the easternmost member of the East Mainland Succession of Shetland and probably the youngest. It overlies a thick succession of deep‐water metasediments and metavolcanic rocks probably forming part of an extensional basin and has been correlated with a part of the upper Dalradian of Scotland. Komatiites are not common in rock sequences as young as this. Their eruption is thought to require tectonic and thermal conditions which have been unusual since Archean times. Such conditions could arise when the crust beneath an extensional basin splits to form a constructive margin.

Geological JournalVolume 19, Issue 2 p. 201-202 Book ReviewFree Access Great geological controversies by A. Hallam, Oxford University Press, 1983. No. of pages: 182. Price: £15.00 (hardback), £7.95 (paperback) D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: April 1984 https://doi.org/10.1002/gj.3350190209AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue2April 1984Pages 201-202 RelatedInformation

Geological JournalVolume 19, Issue 2 p. 201-201 Book ReviewFree Access Scotland's environment during the last 30,000 YEARS by R. J. Price. Scottish Academic Press, Edinburgh, 1983. No. of pages: 224. Price: £27.50 (hardback), £15.00 (paperback). D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: April 1984 https://doi.org/10.1002/gj.3350190208AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue2April 1984Pages 201-201 RelatedInformation

Geological JournalVolume 18, Issue 3 p. 277-278 Book ReviewFree Access Rock Forming Minerals: Volume 1A (Second edition): ORTHOSILICATES by W. A. Deer. R. A. Howie. and J. Zussman, Longman, 1982. No. of pages: 936. Price: £50.00 (hardback) D. Flinn, D. FlinnSearch for more papers by this author D. Flinn, D. FlinnSearch for more papers by this author First published: July/September 1983 https://doi.org/10.1002/gj.3350180308Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume18, Issue3July/September 1983Pages 277-278 RelatedInformation

Geological JournalVolume 18, Issue 2 p. 187-188 Book ReviewFree Access Hugh Miller: Outrage and Order by G. Rosie. Mainstream Publishing, 1981. No. of pages: 236. Price £10.95 D. Flinn, Search for more papers by this author D. Flinn, Search for more papers by this author First published: April/June 1983 https://doi.org/10.1002/gj.3350180212AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue2April/June 1983Pages 187-188 RelatedInformation