Figures and tables

Figures

(Figure 1.1) Simplified geology of northern Scotland, showing the extent of the area described in this volume. Modified after British Geological Survey original.

(Figure 1.2) Table of geological events in northern Scotland. Abbreviations for periods within the Phanerozoic are: P — Permian; Ca — Carboniferous; D — Devonian; S — Silurian; O — Ordovician; C — Cambrian. Based on Harris (1991), Trewin (2002) and Kinny et al. (2005).

(Figure 1.3) Palaeogeographical reconstruction of Laurentia and Baltica, showing Archaean cratons and Palaeoproterozoic belts. After Buchan et al. (2000).

(Figure 1.4) Map of suggested terranes in the Lewisian Gneiss Complex of the Outer Hebrides and mainland Scotland, with a summary of isotopic dates. Based on Friend and Kinny (2001) and Kinny et al. (2005).

(Figure 1.5) Generalized palaeogeography of Laurentia and Baltica during the period 1300–870 Ma, showing the setting of deposition of the Stoer, Torridon and Moine sequences. Hatched areas show locations of sedimentary deposition. T — Torridon Group; Mo — Moine Supergroup; Kr — Krummedal sequence. After Strachan and Holdsworth (2000).

(Figure 1.6) Palaeogeographical reconstructions from the Neoproterozoic to the Silurian. (a) The supercontinent Rodinia at c. 750 Ma. The Grenvillian orogenic belts that welded the Rodinia continent together are indicated. Rifting has commenced between Laurentia and East Gondwana. (b) Mid-Neoproterozoic, c. 600–580 Ma. Rifting between the continents of Laurentia, Baltica and Amazonia. (c) Neoproterozoic—Cambrian, c. 550–540 Ma. The Iapetus Ocean is at its widest. Clastic and carbonate deposition occurs along the southern margin of Laurentia. (d) Ordovician, c. 470 Ma. The Iapetus Ocean is in the process of closing. Collision of oceanic and microcontinental arcs with Laurentia (e.g. the Midland Valley Terrane), results in the Grampian Event in Scotland and the Taconic Event in North America. (e) Early Silurian, c. 440 Ma. Collision of peri-Gondwanan continental terranes, notably Avalonia, with Laurentia as the Iapetus Ocean closes and the Rheic Ocean widens. The start of the Scandian Event. (t) Silurian, c. 425 Ma. Final closure of Iapetus and Tornquist oceans. Collision of Baltica and Greenland (Laurentia) gives rise to the main Scandian Event (438–425 Ma). MVT — Midland Valley Terrane. Based on Torsvik et al. (1996) and Holdsworth et al. (2000).

(Figure 2.1) Simplified geological map of the Outer Hebrides.

(Figure 2.2) Photograph of a discordant 'Younger Basic' dyke cutting Scourian migmatitic felsic and subsidiary mafic gneisses, by Loch Leòsaid, North Harris [NB 055 083]. The hammer head is 14 cm long. (Photo: British Geological Survey, No. P008271, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.3) Photograph of folded and boudinaged 'Younger Basic' dykes, Howmore Quarry, South Uist [NF 7659 3645]. The hammer is 42 cm long. (Photo: British Geological Survey, No. P008305, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.4) Simplified geological map of South Harris. After Fettes et al. (1992).

(Figure 2.5) Eaval (347 m), North Uist, showing the dip-slope of the Outer Hebrides Fault Zone. View from Grimsay. (Photo: British Geological Survey, No. P001011, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.6) The distribution of rock types and features related to the Outer Hebrides Fault Zone.

(Figure 2.7) Simplified geological map of Roineabhal, South Harris. After Fettes et al. (1992).

(Figure 2.8) Photographs of the Roineabhal GCR site. (a) View of Roineabhal from Roghadal (Rodel). The southwestern boundary of the anorthosite is clearly shown by the pale-grey to dark-grey colour change of the bedrock. (b) Garnetiferous leucogabbro from the Upper Zone of the Roineabhal Intrusion. The hand lens is 6 cm long. (Photos: J.R. Mendum.)

(Figure 2.9) Simplified geological map of Na Buirgh (Borve), South Harris.

(Figure 2.10) Foliated metadiorite and included amphibolitic and felsic gneiss enclaves at Bagh Steinigidh. The hammer is 42 cm long. (Photo: British Geological Survey, No. P008366, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.11) Map showing the regional lithologies and structure of North Uist and the Sound of Harris. The positions of the North Pabbay Figure 2.12 and North Uist Coast Figure 2.15 GCR sites are indicated. After Fettes et al. (1992).

(Figure 2.12) Simplified geological map of North Pabbay. After Graham (1970).

(Figure 2.13) Photograph of 'Younger Basic' dyke cross-cutting Scourian felsic gneisses, east side of Rubha Scarasdail (Scarasdale Point), North Pabbay. (Photo: K.M. Goodenough.)

(Figure 2.14) (a) Sketch diagram of the Sound of Harris Antiform and the nature of Laxfordian strain (after Graham, 1970). (b) Detailed diagram of weakly deformed 'Younger Basic' dyke.

(Figure 2.15) Geological map of the North Uist Coast GCR site showing the detailed lithology and structure. After Graham (1970).

(Figure 2.16) (a) 'Younger Basic' dykes and pods at Rubha Ghriminis (Griminish Point). Note that although the dykes are boudinaged, foliated and now amphibolites, they cross-cut the prominently banded Archaean felsic and mafic gneisses. (b) Small shear-zone in granulite-facies 'Younger Basic' body at Caisteal Odair. Relative dextral movement across the shear zone can be inferred from the foliation traces. The hand lens is 6 cm long. (Photos: J.R. Mendum.)

(Figure 2.17) Simplified geological maps of Gearraidh Siar (Garry-a-siar) and Baile a' Mhanaich (Balivanich), Benbecula. Based on Dearnley and Dunning (1968), Coward (1973a) and BGS mapping. (G4, etc. — locality numbers from Coward (1973a); Dyke A, etc. — locality from Dearnley and Dunning (1968); see text for details.)

(Figure 2.18) Gearraidh Siar. (a) Discordant 'Younger Basic' dyke apophyses unaffected by Laxfordian strain. The compass is 18 cm long. (b) Foliated 'Younger Basic' dyke apophyses in an area of moderately strong Laxfordian strain. The hammer head is 14 cm long. (Photos: J.R. Mendum.)

(Figure 2.19) Simplified geological map of Rhughasinish, South Uist. After Coward (1969).

(Figure 2.20) Simplified geological map of Loch Sgioport (Skipport), South Uist. After Coward (1969).

(Figure 2.21) Loch Sgioport. (a) Schistose and gneissose semipelitic rocks by Loch Teanga. (b) Deformed thin planar 'Younger Basic' dykes cutting Scourian felsic gneisses at [NF 812 389]. The hammer is 37 cm long. (Photos: J.R. Mendum.)

(Figure 2.22) Simplified geological map of Cnoca Breac, South Uist.

(Figure 2.23) 'Older Basic' body at Cnoca Breac [NF 7338 3385], showing attenuated and metamorphosed mafic, ultramafic and felsic igneous layering. The hammer is 42 cm long. (Photo: British Geological Survey, No. P008306, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.24) Deformed and metamorphosed mafic and felsic (anorthositic) banding in the north-east part of the 'Older Basic' body at Cnoca Breac [NF 7347 3390]. The banding reflects the original igneous compositional layering. (Photo: British Geological Survey, No. P008309, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.25) Simplified geological map of Leinis (Leanish), Barra. After Francis (1973).

(Figure 2.26) Mafic concentrates defining a folded fabric in a late-Scourian microdiorite dyke, Leinis peninsula [NF 7032 9876]. The hammer head is 14 cm long. (Photo: British Geological Survey, No. P008327, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.27) Photograph of undeformed 'Younger Basic' dyke cutting a late-Scourian pegmatite, which itself cuts a late-Scourian microdiorite dyke, Leinis peninsula [NF 7026 9836]. The hammer is 28 cm long. (Photo: British Geological Survey, No. P219737, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 2.28) Simplified geological map of Barra showing Cnoc an Fhithich and other features related to the Outer Hebrides Fault Zone. Based on 1:100 000 geological map, Institute of Geological Sciences (1981).

(Figure 2.29) Cnoc an Fhithich. (a) Pseudotachylite veining in Lewisian gneisses on the south side of Aird Grein at [NF 6582 0402]. The hammer is 42 cm long. (Photo: British Geological Survey, No. P008346, reproduced with the permission of the Director, British Geological Survey, © NERC.). (b) Pseudotachylite breccia showing rounded and angular clasts and patchy development of pseudotachylite on Aird Grein. The hammer is 37 cm long. (Photo: J.R. Mendum.)

(Figure 3.1) Simplified map of the Lewisian Gneiss Complex of mainland Scotland. GCR sites: 1— Badcall; 2 — Scourie Mor; 3 — Sìthean Mar; 4 — Scourie Bay; 5 — Tarbet to Rubha Ruadh; 6 — Loch Drumbeg; 7 — An Fharaid Mhòr to Clachtoll; 8 — Gruinard River; 9 — Creag Mhor Thollaidh; 10 — Kerrysdale; 11 — Flowerdale; 12 — An Ard; 13 — Loch Braigh Horrisdale to Sidhean Mòr; 14 — Alligin (Diabaig). After Park and Tarney (1987).

(Figure 3.2) Sketch map of the Badcall area, Scourie, showing the major Scourie dykes and later shear-zones. Based on the Geological Survey 1:10 560 Sheet Sutherland 39 (1912), and Beach (1978).

(Figure 3.3) Map of the coastal area immediately north of Geodh' nan Sgadan, showing the distribution of the different types of gneisses and the position of some of the later cross-cutting leucotonalite (trondhjemitic) sheets and Scourie dykes. After Rollinson and Windley (1980).

(Figure 3.4) Map of the Scourie area, including the areas covered by the Scourie Mor, Scourie Bay and Sìthean Mòr GCR sites. Based on the Geological Survey 1:10 560 sheets Sutherland 30 (1913), 39 (1912), and O'Hara (1961a).

(Figure 3.5) Mafic rocks at Camas nam Buth, showing the typical development of garnet porphyroblasts with plagioclase-rich decompression coronas. The matchstick is 4.4 cm long. (Photo: C.R.L. Friend.)

(Figure 3.6) Poll Eorna and Creag a' Mhail, Scourie Bay. The notch in the distant promontory, the small bay in the middle distance, and the notch in the foreground, are all formed along the line of the type example of a Scourie dyke. (Photo: British Geological Survey, No. P001655, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 3.7) Small satellite Scourie dyke showing cross-cutting relationship with the gneisses, about 150 m NNW of the gate at Scourie graveyard, Scourie Bay. The dyke is amphibolitized and has small, rounded garnet porphyroblasts. It also has a steep contact displaced by several minor faults, which seem to be related to early joints in the gneisses. The pen is 15 cm long. (Photo: C.R.L. Friend.)

(Figure 3.8) Map of the Tarbet to Rubha Ruadh area. Based on Beach (1978), Coward (1990), and Geological Survey 1:10 560 Sheet Sutherland 30 (1913).

(Figure 3.9) Map of an irregular Scourie dyke south of Tarbet. Areas in the dyke with a fabric are stippled, undeformed portions are blank. The discordance with the banding in the gneisses is shown. After Beach (1978).

(Figure 3.10) Thick Scourie dyke cutting discordantly across banded, mainly felsic gneisses by Rubh' an Tiompain. The dyke is internally deformed and shows partial amphibolitization. It contains shear zones that are notably abundant near the dyke margins. Its markedly lenticular form is interpreted as an original intrusive feature. (Photo: J.R. Mendum.)

(Figure 3.11) Map of the Drumbeg mafic–ultramafic intrusion. After Bowes et al. (1964) and Geological Survey 1:10 560 Sheet Sutherland 48 (1888).

(Figure 3.12) Banding in metaperidotite from Drumbeg. The hammer head is 15 cm long. From Bowes et al. (1964).

(Figure 3.13) Map of the Achmelvich area, including the An Fharaid Mhòr. to Clachtoll GCR site and showing the western part of the Canisp Shear Zone. Based on Tarney (1978) and Attfield (1987).

(Figure 3.14) Diagrammatic cross-section of the western end of the Canisp Shear Zone, as seen at the An Fharaid Mhòr to Clachtoll GCR site. After Attfield (1987).

(Figure 3.15) Deformed but discordant amphibolitic Scourie dyke in banded felsic and mafic gneisses near to the north-east margin of the Canisp Shear Zone. Port Alltan na Bradhan. The hammer is 37.5 cm long. (Photo: J.R. Mendum.)

(Figure 3.16) Map of the northern part of the Gruinard River area. Based on Crane (1973) and Corfu et al. (1998).

(Figure 3.17) Tonalitic and granodioritic ('trondhjemitic') gneiss containing abundant mafic enclaves, Creag-mheall Beag. The map case is 33 cm deep. (Photo: R.G. Park.)

(Figure 3.18) Map of the area between Meall Fuaraidh and Creag Mhor Thollaidh. After Park (2002).

(Figure 3.19) Gently plunging rodding lineation, south of Loch Tollie. (Photo: R.G. Park.)

(Figure 3.20) Map of the Loch Maree Group outcrops around Gairloch showing the position of the Kerrysdale, Flowerdale and An Ard GCR sites. After Park et al. (2001).

(Figure 3.21) Map of the Kerrysdale area, Gairloch. Based on Park (1978) and British Geological Survey 1:50 000 Provisional Series Sheet 91, Gairloch (1999).

(Figure 3.22) Quartz-biotite-rich schistose semipelite with strongly developed rodding lineation, Kerrysdale. The hammer is 37 cm long. (Photo: R.G. Park.)

(Figure 3.23) Map of the Flowerdale area, Gairloch. Based on Park (1978) and British Geological Survey 1:50 000 Provisional Series Sheet 91, Gairloch (1999).

(Figure 3.24) Map of the An Ard area, Gairloch. Based on Park (1978) and British Geological Survey 1:50 000 Provisional Series Sheet 91, Gairloch (1999).

(Figure 3.25) Gneissose granodiorite (Ard Gneisses) showing augen structure and well-developed foliation, An Ard peninsula [NG 803 753]. 6-inch ruler for scale. (Photo: R.G. Park.)

(Figure 3.26) Amphibolite (Loch Maree Group) cut by pale-grey granodiorite sheets (Ard Gneisses) that themselves are tightly folded. Note the steeply plunging lineation parallel to the fold axes. The hammer is 37 cm long. An Ard peninsula [NG 803 753]. (Photo: R.G. Park.)

(Figure 3.27) Map of the area between Loch Braigh Horrisdale and Sidhean Mòr After Park (2002).

(Figure 3.28) Undeformed Scourie dyke cutting steeply dipping Inverian foliation on the north-east slopes of Sidhean Mòr (Photo: R.G. Park.)

(Figure 3.29) Map of the Alligin (Diabaig) GCR site. After Cresswell (1972).

(Figure 3.30) Thin, undeformed Scourie dyke cutting Badcallian banded gneiss on the south-west slopes of An Ruadh Mheallan. The hammer is 37.5 cm long. (Photo: R.G. Park.)

(Figure 4.1) Geological map showing the distribution of the main stratigraphical divisions of the Torridonian in north-west Scotland and the location of GCR sites: 1— Stoer; 2 — Loch na Dal; 3 — Kylerhea Glen; 4 — Loch Eishort; 5 — Diabaig; 6 — Upper Loch Torridon; 7 — Rubha Dunan; 8 — Enard Bay; 9 — Achduart; 10 — Aultbea; 11 — Cailleach Head.

(Figure 4.2) Diagrammatic section through the Torridonian, parallel to the dominant easterly palaeocurrent directions. The stratigraphical positions of GCR sites are shown as boxes, numbered as in Figure 4.1.

(Figure 4.3) Stratigraphical section through the Stoer Group perpendicular to the dominant western and eastern palaeocurrent directions. The stratigraphical positions of GCR sites are shown as boxes, numbered as in Figure 4.1.

(Figure 4.4) Stratigraphical section through the Torridon Group perpendicular to the dominant palaeocurrent direction of the Applecross Formation (A = 123°). The Applecross and Aultbea formations are not separable over the southern half of the section. The stratigraphical positions of GCR sites are shown as boxes, numbered as in Figure 4.1.

(Figure 4.5) Spectacular cliffs composed of sandstones belonging to the Torridon Group, Sgurr a' Chaorachain, Kishorn, Ross-shire. (Photo: British Geological Survey, No. P002854, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 4.6) Geological map of the area around Stoer.

(Figure 4.7) Stratigraphical log of the type section of the Stoer Group, along the north side of the Bay of Stoer, west of the old graveyard. Grain-size scale from +4 0 to -4 0 (0.06–16 mm).

(Figure 4.8) (a) Trough-cross-bedded red sandstones of the Bay of Stoer Formation at Clachtoll [NC 0359 2728] in the Stoer GCR site. Contorted bedding is common in the formation; the crest of a water-escape cusp is marked by the ruler (20 cm long). (b) Planar cross-bedded red sandstone of the Meall Dearg Formation at Meall Dearg [NC 0299 2855] in the Stoer GCR site. The two sets in the centre of the photograph are each about 25 cm thick. Contorted bedding is absent from this formation. (Photos: A.D. Stewart.)

(Figure 4.9) Breccia of the Clachtoll Formation resting on Lewisian gneisses at Clachtoll Bay in the Stoer GCR site. The hammer is 50 cm long. (Photo: British Geological Survey, No. P005850, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 4.10) Geological map of the central part of the Sleat peninsula, Skye, showing the areas of the Loch na Dal, Kylerhea Glen and Loch Eishort GCR sites.

(Figure 4.11) Trough-cross-bedded epidotic sandstone, typical of the lower part of the Rubha Guail Formation in Skye. The grain size of the sandstone is coarse to very coarse, with a maximum of 5 mm. The observer looks roughly eastwards, parallel to the palaeocurrent direction. The locality is near high-water mark 60 m north-east of the mouth of Allt an Eireannaich [NG 7296 1535]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.12) Graphic log of part of the Beinn na Seamraig Formation in Kylerhea Glen, about 150 m north-east of the road summit. The grain-size scale at the top of the log spans +4 0 to 0 0 units (0.06–1mm). Sedimentary structures are illustrated schematically, but drawn as seen and to scale.

(Figure 4.13) Geological map of the Diabaig area. After Stewart (2002).

(Figure 4.14) Graphic log of the grey 'shale' facies (Diabaig Formation) and Allt na Beiste Member (Applecross Formation), exposed along the coast west of Diabaig jetty

(Figure 4.15) Desiccation cracks in the grey 'shale' fades of the Diabaig Formation at Diabaig. The exposure is on the shore about 400 m north-west of Diabaig jetty [NG 7964 6017]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.16) Grey sandstone beds in the upper part of the grey 'shale' fades at Diabaig. The two prominent beds touching the hammer are at 96–97 m on the section in Figure 4.14. The location is just above high-water mark at the mouth of Allt na Beiste [NG 7927 6027]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.17) Contorted bedding in the Applecross Formation at Diabaig. Note the truncation plane at the level of the hammer head. Water-escape structures like this affect over half the Applecross Formation and the whole of the Aultbea Formation. The exposure is about 170 m west of Diabaig township [NG 7867 6037]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.18) Geological map of the Upper Loch Torridon area. After Stewart (2002).

(Figure 4.19) True-scale cross-section along the south side of Upper Loch Torridon, showing undulating topography developed in the basement gneisses, buried by Torridon Group sedimentary rocks. The section follows grid-line northing 542. Kilometre castings are shown.

(Figure 4.20) Tabular ripple-marked sandstones of the Diabaig Formation filling the centre of the palaeovalley at Balgy Bay, Upper Loch Torridon GCR site. The sandstones here are unusual in being mainly grey rather than red. The locality is at high-water mark, 700 m east of the mouth of the Balgy River [NG 8528 5472]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.21) Geological map of the Rubha Dunan headland, near Achiltibuie.

(Figure 4.22) The unconformity between the Stoer Group (dipping to the left) and the Torridon Group (dipping right) just above high-water mark on the south side of Rubha Dunan. The cliff section is 15 m high. (Photo: A.D. Stewart.)

(Figure 4.23) Red sandstone block in the Diabaig Formation (basal Torridon Group), derived from the Stoer Group, which forms the hill-slope behind. High-water mark on the south side of Rubha Dunan [NC 0244 0678]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.24) Geological map and true-scale cross-section of the Enard Bay area.

(Figure 4.25) Massive breccio-conglomerate at the base of the Stoer Group at Enard Bay. The breccia passes upwards, to the right, into brown tabular-bedded coarse sandstone. The hammer, which is 53 cm long, marks the base of a small outlier of Applecross Formation unconformably overlying the breccia. The locality is to the south-east of Rubh' a' Choin at [NC 0359 1470]. (Photo: A.D. Stewart.)

(Figure 4.26) Gneiss blocks in the bedded breccia facies of the Stoer Group at Enard Bay, interpreted by Davison and Hambrey (1996) as glacial dropstones. The dark-brown sandstones between the boulders range in grain size from fine to very coarse. Lewisian basement is seen in the background above the block with the hammer. The locality is at high-water mark about 250 m north-west of the ruined bothy [NC 0278 1463]. The hammer shaft is 50 cm long. (Photo: A.D. Stewart.)

(Figure 4.28) Graphic log of the contact between the Rubha Dubh Ard Member and the Achduart Member in the type section about 500 m west of Achduart [NC 0449 0355]. The grain-size scale at the top of the log spans +3 0 to —10 units (0.12–2mm). Fissile red siltstone is black on the log, and red sandstone is white. Sedimentary structures are illustrated schematically, but drawn as seen in the section. Pebbles over 1 cm across are shown. Rose diagrams, each based on 13 measurements of foresets, show palaeocurrent directions in the two members.

(Figure 4.27) Geological map of the Achduart area. After 1:50 000 Sheet 101W, Summer Isles (British Geological Survey, 1998).

(Figure 4.29) Geological map of the Rubha Mor peninsula. After 1:50 000 Sheet 91, Gairloch (British Geological Survey, 1999).

(Figure 4.30) (a) Geological map of the Cailleach Head peninsula (compiled by A.D. Stewart, 1994). (b) Projected true-scale cross-section of the Cailleach Head Formation. After Stewart (2002).

(Figure 4.31) Graphic logs of cyclothems II, III and part of IV in the Cailleach Head Formation at Cailleach Head. The grain-size scale near the top of the log spans +50 to +1 0 units (0.03–0.5 mm).

(Figure 4.32) The Cailleach Head Formation at Cailleach Head. The cave is in the micaceous, varicoloured facies 2b, which forms the top half of cyclothem II. The grassy, boulder-strewn slope in the middle of the photograph covers the siltstone at the base of cyclothem IV The cliff is about 40 m high at this point, 100 m south-west of the lighthouse [NG 985 984]. (Photo: British Geological Survey, No. 216879, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 4.33) Cyclothem II in the Cailleach Head Formation at Cailleach Head. The sandstones below the man in the photograph belong to facies 1, those above belong to facies 2. The location is the left hand extremity of the cliff shown in Figure 4.32, which corresponds to the 32–44 m interval on the stratigraphical log, Figure 4.31. (Photo: British Geological Survey, No. P216884, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 5.1) Map of the Moine Thrust Belt with locations of GCR sites indicated. Lines of sections of Figure 5.2 are also indicated. The Moine Thrust Belt lies between the Moine Supergroup and the foreland rocks, and its eastern boundary is the Moine Thrust itself.

(Figure 5.2) Selected simplified cross-sections across the Moine Thrust Belt, showing variations along strike. MT — Moine Thrust; AT — Arnaboll Thrust; CST: — Creag Shomhairle Thrust; GT — Glencoul Thrust; KT — Kinlochewe Thrust. (a) Arnabol—Durness; (b) Foinaven; (c) north Assynt; (d) An Teallach—Carn na Canaich. Sections (a)—(d) by R.W.H. Butler. Selected simplified cross-sections across the Moine Thrust Belt, showing variations along strike: (e) Torridon; (f) Lochalsh. Section (e) by SJ. Matthews (in Butler et al., 2007), section (f) by AJ. Barber.

(Figure 5.3) Stratigraphical column of Cambro–Ordovician sequence in north-west Scotland. Based on Swett (1969), Prigmore and Rushton (1999)and British Geological Survey (2002).

(Figure 5.4) Idealized thrust geometries. (a) Idealized duplex (Boyer and Elliott, 1982): three imbricate thrust slices between a roof and a floor thrust. (b) Suppe's model for the development of fault-bend fold in the hangingwall, formed as a thrust sheet climbs up a footwall ramp (after Suppe, 1983). (c) Diagram showing imbricate thrusts, duplex, duplex floor and roof and other thrust geometries.

(Figure 5.5) Example of a single-bed duplex structure developed within the Pipe Rock. This is the Beyond Hope duplex of Bowler (1987), exposed in coastal outcrops south of Whiten Head. (Photo: R.W.H. Butler.)

(Figure 5.6) Small-scale fold-thrust complex in quartzite, Heilam, Eriboll GCR site. (Photo: R.W.H. Butler.)

(Figure 5.7) Simplified structure of the Moine Thrust Belt at Loch Eriboll. (a) Map of the area around Loch Eriboll. (b) Map of the area around Ben Arnaboll. (c) Map of the area between Bealach Mhari and Church Crag. AT — Arnaboll Thrust. After Butler et al. (2006).

(Figure 5.8) Sketch sections through the Moine Thrust Belt at Loch Eriboll, see Figure 5.7 for locations. (a) Ben Heilam (x—x'), after Coward (1984a); (b) Kempie—Bealach Mhari (y—y'), after Butler et al. (2006).

(Figure 5.9) The Arnaboll Thrust at its type locality at Ben Arnaboll: Lewisian gneisses are thrust over Pipe Rock quartzite. The hammer is about 30 cm long. (Photo: R.W.H. Butler.)

(Figure 5.10) Map of the area around Cleit an t-Seabhaig. See Figure 5.12 (Faraid Head GCR site report) for location.

(Figure 5.11) Southward view of the cliff section near Alltan Rhiabhach (stream with waterfalls to right) in the western part of the Creit an t-Seabhaig GCR site. Lewisian mylonites ('Oystershell Rock') have been thrust westward over Basal Quartzite (BQ), which overlies Lewisian gneisses, which are less pervasively sheared than the Dystershell Rock'. LRT — Lochan Riabhach Thrust, mapped as the Moine Thrust by the original surveyors. In the eastern part of the cliff, sheared Lewisian below the LRT is thrust over a unit of Basal Quartzite that in turn unconformably overlies almost undeformed Lewisian gneisses at the base of the cliff. The westward continuation of the quartzite and associated thrust is uncertain to the right of the subvertical Fault A, but the thrust may follow the indicated boundary between sheared and less-deformed Lewisian gneisses. Note that the lower quartzite is offset by several steep late normal faults. (Photo: R.E. Holdsworth.)

(Figure 5.12) Map showing the relationship between the Moine Thrust Sheet and the Durness Klippe. Arrow drawn parallel to regional thrust transport direction (290°) shows minimum displacement of 15 km required along Moine Thrust due to preservation of Faraid Head klippe. Areas of Figures 5.10 and 5.13 are indicated.

(Figure 5.13) Map of the area around Faraid Head. After Holdsworth et al. (2007). See Figure 5.12 for location.

(Figure 5.14) Map and cross-section (x—x') of Sango Bay, Durness.

(Figure 5.15) Thrust contact at Sango Bay, emplacing 'Oystershell Rock' over quartz mylonite and Durness carbonate. This thrust was interpreted by Peach et al. (1907) as the Moine Thrust. (Photo: R.W.H. Butler.)

(Figure 5.16) (a) Map of the Foinaven Arkle area. (b) Cross-section through Foinaven; position of section (x—x') is indicated on (a). After Butler (2004a).

(Figure 5.17) Thrust structures in the Foinaven duplex, in the N-facing cliff overlooking Srath Dionard. The Moine Thrust on the left overlies a thick stack of imbricates formed of Pipe Rock that dip towards the hinterland. (Photo: R.W.H. Butler.)

(Figure 5.18) View onto the western flank of Creag Shomhairle. The Moine Thrust (MT) is folded by underlying duplexes of An t-Sron Formation and Pipe Rock. CST — Creag Shomhairle Thrust. (Photo: R.W.H. Butler.)

(Figure 5.19) Imbricated Pipe Rock forming an antiformal stack on the western flank of Creag Shomhairle. (Photo: R.W.H. Butler.)

(Figure 5.20) The Glencoul Thrust on Beinn Aird da Loch, from the south-west side of Loch Glencoul. Lewisian gneiss has been thrust over cliffs of Cambrian quartzite. Compare with cross-section shown in Figure 5.2 lb. (Photo: R.W.H. Butler.)

(Figure 5.21) Geological relationships at the Glencoul GCR site. (a) Map of the area around Loch Glencoul (modified after Peach et al., 1907; Coward et al., 1980; British Geological Survey, 2007). (b) Schematic cross-section through the Moine Thrust Belt on Beinn Aird da Loch (vertical and horizontal scales equal and as (a)).

(Figure 5.22) (a) Map of the ground to the west of the Stack of Glencoul see Figure 5.21 a based on remap-ping by the author. (b) Schematic cross-section (x-x') through the map area of (a) showing the relationships between layer extensional (dotted) and contractional (solid) faults. These are grouped and numbered in the inferred order of displacement (I-1V in time). The relative timing of the Moine Thrust is uncertain but it probably moved broadly simultaneously with these other shearing deformations.

(Figure 5.23) (a) Map of the imbricate thrust slices north of Skiag Bridge. After Coward (1984b). (b) Cross-section through the Skiag Bridge GCR site. Location x-x' on (a). Note that the line of secton is oblique to the direction of thrusting.

(Figure 5.24) Map of the area south-east of Inchnadamph showing the relationship between the Stronchrubie Cliff and Traligill Burn GCR sites. Structure in Durness Group rocks modified from British Geological Survey (2007).

(Figure 5.25) Stronchrubie Cliff, viewed towards the NNE, showing imbricate thrust slices of Durness Group carbonate rocks above the Sole Thrust. (Photo: R.W.H. Butler.)

(Figure 5.26) Cross-section (x—x' on Figure 5.24) drawn near-orthogonal to the inferred thrust transport direction, illustrating the thrust geometries at the Stronchrubie Cliff and Traligill Burn GCR sites.

(Figure 5.27) Thrust at Traligill Burn, carrying dark dolomites of the Ghrudaidh Formation onto pale carbonate rocks of the Eilean Dubh Formation. Viewed looking along strike towards the ESE. (Photo: R.W.H. Butler.)

(Figure 5.28) Map of the Ben More Thrust Sheet in the Assynt District of the Moine Thrust Belt. A = Allt an Dubh Loch Mhoir. The locations of Figures 5.29a and 5.31a are indicated. After British Geological Survey (2007).

(Figure 5.29) (a) Map of the Ben More Thrust Sheet at Conival. Location shown on Figure 5.28. Topographical contours in metres. After Butler (1997). (b) Cross-section through the Ben More Thrust Sheet at Conival (location: x-x' on (a). After Butler (1997).

(Figure 5.30) Fold and thrust structures in the hangingwall of the Ben More Thrust at Na Tuadhan, viewed from Conival. (Photo: R.W.H. Butler.)

(Figure 5.31) (a) Map of the Ben More Thrust Sheet at Bealach Choinnich, Sgonnan Mòr—Dubh Loch Beag—Upper Glen Oykel GCR site (see Figure 5.28 for location). Topographical contours in metres. Two inliers of Torridonian strata are shown; the one south of the bealach was remapped by the author, whereas the map of the inlier near Coirean Dubh is modified after Milne (1978). (b) Sketch cross-section through the southern inlier (x—x' on (a)). The geometry of the sub-Cambrian unconformity (upper inferred boundary) is placed using adjacent outcrops farther to the south-east and at Bealach Choinnich. After Butler (1997).

(Figure 5.32) The structural setting of the Cam Loch Klippe and other klippen in southern Assynt. LT — Ledbeg Thrust. Based on Geological Survey of Great Britain (1923), Elliott and Johnson (1980), Coward (1985) and British Geological Survey (2007).

(Figure 5.33) (a) Field relationships in the northern part of the Cam Loch Klippe (based on mapping by the author, location shown on Figure 5.32. (b) Simplified cross-section through the Cam Loch Klippe, x—x' on (a).

(Figure 5.34) View eastwards towards the Knockan Crag from the slopes of Cul Mor. To the right (south), the Moine Thrust rests directly on the foreland succession; to the left (north) is the southern termination of the Assynt Culmination, with imbricated slices of Durness Group carbonate rocks separating the Moine Thrust from the foreland. (Photo: R.W.H. Butler.)

(Figure 5.35) (a) Map and cross-sections through the Knockan Crag GCR site. (b) Section x—x' is constructed parallel to the inferred direction of thrusting. The nature of the Moine Thrust (MT) shown here, truncating imbricated thrust slices of Durness Group and An t-Sron Formation in its footwall, is based on the stream section shown on the map. (c) Section y—y' is perpendicular to the inferred direction of thrusting. It shows the Uamh Mhòr Thrust truncating thrusts in its hangingwall but being folded by imbricate thrust slices in its foot-wall. All structures are cut by the Moine Thrust which here dips gently towards the south.

(Figure 5.36) The Moine Thrust at Knockan Crag. The dark-grey rocks above are mylonitic Moine rocks; the cream-weathered rocks below are Durness Group carbonate rocks. (Photo: R.W.H. Butler.)

(Figure 5.37) Map and cross-section through the antiformal-stack duplex structure of the Dundonnell GCR site. Based on Matthews (1984) and modified after Elliott and Johnson (1980). Note that the section line is highly oblique to the direction of movement.

(Figure 5.38) Map and cross-section of the area of Càrn na Canaich. Section x—x' is constructed at right angles to the thrusting direction.

(Figure 5.39) View looking east onto the Càrn na Cainich GCR site from the upper part of the Sail Liath ridge of An Teallach. Moine rocks have been thrust towards the viewer over a duplex formed in the An t-Sron Formation. (Photo: R.W.H. Butler.)

(Figure 5.40) Map of the Slioch–Meall a' Ghuibhais–Beinn Eighe area, showing the regional geological setting of the Slioch–Heights of Kinlochewe GCR site (north-east of Loch Maree) and the Meall a' Ghiubhais GCR site. KT = Kinlochewe Thrust; UKT = Upper Kinlochewe Thrust. Locations of Figures 5.42a and 5.43 are indicated. Based on Geological Survey of Scotland (1913a) and Matthews (1984).

(Figure 5.41) View north-east from the Beinn Eighe Nature Reserve to Beinn a' Mhilinidh showing the Kinlochewe Thrust Sheet. Lewisian gneisses are thrust WNW over the Cambrian rocks along the Kinlochewe Thrust (KT). Moine rocks form the hills to the north-east, including in the Fannich Mountains on the far skyline. The Moine Thrust is hidden from view. (Photo: R.W.H. Butler.)

(Figure 5.42) Map (a) and cross-section (b) of the Slioch–Heights of Kinlochewe GCR site. The part to the southeast of the Fhasaigh Fault is based on the work of Matthews (1984). Note that the section line is segmented and offset to the south-west at several points.

(Figure 5.43) Map of the Meall a' Ghiubhais GCR site. KT — Kinlochewe Thrust. Based on Geological Survey of Scotland (1913a) and Matthews (1984).

(Figure 5.44) Looking north to the Meall a' Ghiubhais Klippe from Beinn Eighe. The darker, upper part of the hill is made up of Torridon Group rocks in the Kinlochewe Thrust Sheet. The Kinlochewe Thrust occurs just above the pale Cambrian quartzites, which lie in a separate thrust sheet. In the foreground are imbricated thrust slices of Torridonian sandstones and Cambrian quartzites. (Photo: R.W.H. Butler.)

(Figure 5.45) Cross-section from the Meall a' Ghiubhais Klippe to the Moine Thrust Belt (location indicated on Figure 5.40). After Butler et al. (2007).

(Figure 5.46) Map (a) and cross-section (b) of Beinn Liath Mhor. Inset box on section shows location of Figure 5.47. Based on Matthews (1984), Morgan (1985) and Butler et al. (2007).

(Figure 5.47) The south side of the Beinn Liath Mhor ridge from Sgorr Ruadh. Steep thrusts separate imbricate thrust slices containing Torridon Group sandstones and Cambrian quartzites. A hangingwall anticline occurs left of centre. Compare with cross-section shown in Figure 5.46b. (Photo: R.W.H. Butler.)

(Figure 5.48) (a) Map of the area around the Cnoc nam Broc–Kishorn Valley area, mainly based upon Institute of Geological Sciences (1975a) and Geological Survey of Scotland (1913b). (b) Detail of the northern slopes of Sgurr a' Gharaidh, illustrating the relationships between folds and thrusts in the footwall to the Kishorn Thrust. After Butler et al. (2007).

(Figure 5.49) View to the ENE of the trace of the Kishorn Thrust. The Lewisian gneisses that form the steep slopes and north face of Sgurr a' Gharaidh to the right have been thrust over pale-grey Pipe Rock and white Durness Group carbonates. The Kishorn Thrust is located on top of the bench. (Photo: R.W.H. Butler.)

(Figure 5.50) Map of the area around the Slumbay Island GCR site (based on mapping by M.R.W. Johnson).

(Figure 5.51) Close-up view of laminated mylonite below the Moine Thrust, with abundant late kink-folds, some of which form conjugate sets (e.g. left of centre). Western shore of Slumbay Island. (Photo: A.J. Barber.)

(Figure 5.52) Map of the Lochalsh peninsula, showing the overall geology. Positions of Figures 5.53, 5.54, 5.56 and 5.57 are indicated. Based on Barber and May (1976) and Institute of Geological Sciences (1976a). Trace of Lochalsh Syncline after Coward and Potts (1985).

(Figure 5.53) Map of the area around the Carn  a' Bhealaich Mhoir GCR site. After Kanungo (1956).

(Figure 5.54) Diagrammatic east–west cross-section across the northern part of the Lochalsh peninsula through Carn a' Bhealaich Mhòr, showing the geological setting of the overturned unconformity. See Figure 5.52 for location.

(Figure 5.55) Sheared and disrupted quartzofeldspathic clasts in schistose chloritic matrix, basal conglomerate of the Torridonian sequence, Carn a' Bhealaich Mheir, Lochalsh. (Photo: A.J. Barber.)

(Figure 5.56) Map of the area around the Hangman's Bridge GCR site. The location of this figure is shown on Figure 5.52.

(Figure 5.57) Map of the area around the Ard Hill GCR site. The location of this figure is shown on Figure 5.52.

(Figure 5.58) Laminated mylonite with alternating quartzofeldspathic and chloritic (dark) laminae, derived from layered Lewisian gneiss, Moine Thrust Zone, southern point of Ard Hill, Lochalsh. (Photo: A.J. Barber.)

(Figure 5.59) Geological map of the Ord Window, after the work of Clough (see Institute of Geological Sciences, 1976b; and Potts, 1983). Note that different authors refer to many of the lithological contacts by different names. On the map, disputed contacts are numbered as follows: (1) — Sgiath-bheinn an Uird Thrust, eastern limb (Clough in Peach et al., 1907); Kishorn Thrust (Bailey, 1939); Western Fault, normal fault (Potts, 1983). (2) a+b — Sgiath-bheinn an Uird Thrust, eastern limb (Clough in Peach et al., 1907); lower branch of Kishorn Thrust (Bailey, 1939); (2a) Allt a' Chinn Mhoir Fault, normal fault; (2b) normal stratigraphical contact (Potts, 1983). (3) — Sgiath-bheinn Tokavaig Thrust, eastern limb (Clough in Peach et al., 1907); upper branch of Kishorn Thrust (Bailey, 1939); normal stratigraphical contact (Potts, 1983). (4) Eastern Fault (Potts, 1983).

(Figure 5.60) Cross-sections through the Ord Window. (a) After Clough (in Peach et al., 1907). (b) After Bailey (1939). (c) After Potts (1983). Sections (a) and (b) follow the same line, but section (c) lies farther south-west. Several contacts, interpreted as thrusts by both Clough and Bailey, have been re-interpreted as normal stratigraphical contacts or as extensional faults by Potts. The Ord Syncline has been interpreted as an antiform by Bailey, but a synform by Potts. For explanation of numbered contacts, see Figure 5.59.

(Figure 5.61) Geological map of the Tarskavaig nappes in south-east Skye. After Cheeney and Mathews (1965).

(Figure 5.62) The Tarskavaig Thrust at the south side of Tarskavaig Bay. Tarskavaig Moine rocks lie above the thrust with folded Torridonian Sleat Group rocks below. (Photo: K.M. Goodenough.)

(Figure 5.63) Map of area around the Ard Thurinish GCR site.

(Figure 6.1) Simplified geological map of the Moine (North) area. GCR sites: 1— Ben Hutig; Port Vasgo—Strathan Bay; 3 — Melness; 4 — Allt na Caillich; 5 — Allt an Dherue; 6 — Coldbackie Bay; 7 — Strathan Skerray to Skerray Bay; 8 — Aird Torrisdale; 9 — Ard Mor; 10 — Farr Bay; 11 — Glaisgeo—Farr Point; 12 — Sgeir Ruadh; 13 — Dirlot Castle; 14 — Ben Klibreck; 15 — Oykel Bridge; 16 — The Airde of Shin; 17 — Allt Doir' a' Chatha; 18 — Creag na Croiche; 19 — Aberscross Burn—Kinnauld; 20 — Brora Gorge; 21 — Carn Gorm; 22 — Comrie; 23 — Cromarty and Rosemarkie Inners.

(Figure 6.2) Stratigraphy of the Moine Supergroup in Sutherland and Easter Ross.

(Figure 6.3) Schematic cross-section across the Moine rocks of north Sutherland.

(Figure 6.4) Tectonostratigraphy of the Moine (North) area.

(Figure 6.5) Geological map of the Ben Hutig area.

(Figure 6.6) Rodded, flattened and locally folded pebbles in conglomeratic psammites of the R. Mhoine Psammite Formation, Ben Hutig, 40 m south-east of summit. The hammer is 37 cm long. (Photo: J.R. Mendum, BGS No. P552316, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.7) Rodded, folded and segregated, originally discordant quartz veins in pebbly and gritty psammites of the A' Mhoine Psammite Formation. Ben Hutig, 100 m south-west of the summit. The hammer is 37 cm long. (Photo: J.R. Mendum, BGS No. P552315, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.8) Geological map of the Port Vasgo–Strathan Bay area.

(Figure 6.9) Tight minor folding in psammites of the Altnaharra Psammite Formation (Moine Supergroup). Cliff face, c. 300 m east of Port Vasgo. Note variable fold profiles along axial surfaces and possible cut-offs by overlying bedding planes. Possible slump folds or F1 folds, tightened during the D2 deformation event. The hammer is 37 cm long. (Photo: J.R. Mendum, BGS No. P552297, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.10) Geological map of the Melness area.

(Figure 6.11) Inverted slump-folds in the Altnaharra Psammite Formation, south end of Ard Skinid. The pencil is 16 cm long. (Photo: J.R. Mendum, BGS No. P552293, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.12) Map of the Allt na Caillich GCR site.

(Figure 6.13) View north from Dun Dornaigil to Alltnacaillich farm and Ben Hope. The Ben Hope Sill and Lewisianoid gneisses form the mid- and upper parts of the prominent cliffs of Leitir Mhuiseil to the right. They lie in the hangingwall of the Ben Hope Thrust with gently E-dipping psammites of the Mhoine Psammite Formation in the footwall below and in the bluff to the left. (Photo: British Geological Survey, No. P002763, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.14) NNE–SSW longitudinal cross-section showing thickness changes and lateral branching of the Ben Hope Thrust that occurs between the north-west face of Ben Hope and Allt na Caillich, including the cliffs of Leitir Mhuiseil. After Holdsworth (1989a, fig. 4).

(Figure 6.15) Map of the Alit an Dherue GCR site.

(Figure 6.16) Srath an Dherue, looking NNE to Loch an Dherue. The foreground crags are composed of Lewisianoid gneisses and the small knoll is formed of the Loch a' Mhoid Metadolerite Suite. (Photo: J.R. Mendum, BGS No. P552312, reproduced with permission of the Director, British Geological Survey, © NERC.)

(Figure 6.17) Attenuated Lewisianoid felsic and mafic gneisses with small ultramafic (hornblendite) pods and lenses, 300 m west of Loch an Dherue. The compass is 18 cm long. (Photo: J.R. Mendum, BGS No. P552305, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.18) Geological map of the Coldbackie Bay area.

(Figure 6.19) Cnoc an Fhreiceadain (Watch Hill), 307 m, from the sand dunes above Bagh Challbacaidh. The road cut on the A836 is composed of Moine psammites and semipelites, but the massive cliffs of Watch Hill are formed of probable Lower Devonian conglomerate and minor sandstone, which occur in a faulted outlier around Coldbackie. (Photo: J.R. Mendum, BGS No. P552318, reproduced with the permission of the Director, British Geological Survey © NERC.)

(Figure 6.20) Mullioned and folded psammites and subsidiary semipelites of the Altnaharra Psammite Formation. Road (A836) cutting at the western end of Coldbackie village. The chain fence is 2 m high. (Photo: J.R. Mendum, BGS No. P552317, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.21) Map of the Strathan Skerray to Skerray Bay GCR site.

(Figure 6.22) Map of the Aird Torrisdale–Bettyhill-Farr area, showing the general geology encompassing the Aird Torrisdale, Ard Mor, Farr Bay and Glaisgeo–Farr Point GCR sites. Adapted from British Geological Survey 1:50 000 sheets 114E, Tongue (1997b), 115W, Strathy Point (1996), and Cheng (1942, 1943).

(Figure 6.23) Map of the Aird Torrisdale–Torrisdale Bay area. Compiled from data collected by G.I. Alsop, J.R. Mendum, C.G. Dyke and V.E. Moorhouse.

(Figure 6.24) Sheared amphibolitic mafic rocks inter-banded with micaceous psammite and semipelite, showing tight F2 folds, cut by a quartz-feldspar pegmatite vein that is in turn deformed and folded by F3 folds. The hammer (37 cm long) is aligned with its handle parallel to the trace of the dominant planar fabric (S2). The exposure lies in the Naver Thrust Zone and Torrisdale Steep Belt. Druim Chuibhe, Torrisdale Bay [NC 6901 6167]. (Photo: J.R. Mendum, BGS No. P581267, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.25) Map of the Ard Mor GCR site. Compiled from data from British Geological Survey 1:50 000 Sheet 115W, Strathy Point (1996), Cheng (1943) and from mapping by G.I. Alsop.

(Figure 6.26) Hook-shaped fold formed by superimposition of an upright F3 fold on an earlier tight recumbent F2 minor fold. A later non-foliated pegmatitic granite vein cross-cuts the refolded structure. On hillside above Creag Ruadh at [NC 6982 6300]. (Photo: V.E. Moorhouse, BGS No. P580517, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.27) Map of the Farr Bay GCR site. Based on Cheng (1943) and British Geological Survey 1:50 000 Sheet 115W, Strathy Point (1996).

(Figure 6.28) Tight F2 folds refolded by more-open F3 folds giving a type-3 interference structure. Top of sandy scree slope, Farr Bay, at [NC 7159 6272]. The compass is 18 cm long. (Photo: V.E. Moorhouse, BGS No. P580518, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.29) Map of the Glaisgeo–Farr Point GCR site. Based on Cheng (1943) and British Geological Survey 1:50 000 Sheet 115W, Strathy Point (1996).

(Figure 6.30) Foliated augened diorite with deformed amphibolitic mafic stringers and lamellae. Foreshore at Glaisgeo [NC 7142 6362]. The compass is 18 cm long. (Photo: J.R. Mendum, BGS No. P577534, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.31) Simplified geological map of the Sgeir Ruadh site.

(Figure 6.32) Oblique aerial photo of Rubha Bhrà and Portskerra. Mid-Devonian rocks, lying unconformably on the Moine succession, form the upper parts of the cliffs and underlie the higher parts of the peninsula. (Photo: BGS No. 21/6 (Fletcher and Key, 1991); reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.33) Geological map of Dirlot Castle with sketch section through gorge. Based on Donovan (1973) and Trewin and Hurst (1994). common. The rocks are intruded by numerous, unfoliated, medium- to coarse-grained granite and aplitic microgranite veins. The granite is highly reddened, the colouration increasing with weathering towards the contact with the overlying sedimentary rocks. In thin section, the feldspars are largely altered to fine-grained white mica (sericite), and the biotite is highly chloritized.

(Figure 6.34) Geological map of the Ben Klibreck area.

(Figure 6.35) Banded felsic and mafic Lewisianoid orthogneiss of the Naver Inlier at [NC 584 325]. The map case is 32 cm high. (Photo: R.A. Strachan, BGS No. P580516, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.36) Simplified geological map of the Oykel Bridge area. After Wilson (1953).

(Figure 6.37) A (a) Down-plunge view of mullions composed of psammites of the Altnaharra Psammite Formation in the gorge of the River Oykel, immediately downstream from the new road bridge [NC 386 009]. The mullions show internal cuspate structures interpreted as deformed cross-bedding. (Photo: N.J. Soper.). (b) Psammite mullion with traces of cross-bedding showing oversteepened foreset angles. Polished face on specimen collected by N.J. Soper. (Photo: British Geological Survey, No. P580524, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.38) (a) Location map of the Loch Shin area showing the strip of Lewisianoid rocks that extends from Loch Shin to the River Cassley. (b) The Airde of Shin Lewisianoid Inlier. Based on Winchester and Lambert (1970) and Strachan and Holdsworth (1988).

(Figure 6.39) Boudins of white-weathering calcite marble in calc-silicate schist in Lewisianoid gneisses in the hinge zone of a D2 anticline. Western shore of The Airde of Shin at [NC 521 139]. (Photo: Susan Hall.)

(Figure 6.40) Sketch map of the Ant Doir' a' Chatha Lewisianoid Inlier; amphibolitic mafic gneiss outcrops shown in darker grey.

(Figure 6.41) View downstream from the upper Moine contact in the Alit Doir' a' Chatha. (Photo: N.J. Soper.)

(Figure 6.42) Geological map of the eastern part of the Rogart Complex.

(Figure 6.43) Geological map of the Creag na Croiche area.

(Figure 6.44) Geological map of the Aberscross Burn to Kinnauld area.

(Figure 6.45) Marian's Rock, cliffs formed of gneisses of the migmatite complex above Morvich at [NC 750 010]. (Photo: N.J. Soper.)

(Figure 6.46) Geological map of the Brora Gorge area.

(Figure 6.47) Geological map of the Garve area showing the location of Carn Gorm. Compiled from BGS 1:50 000 sheets 83W Strathconon (British Geological Survey, 2001) and 93W, Ben Wyvis (British Geological Survey, 2004a).

(Figure 6.48) Specimen of pegmatitic leucogranite from Carn Gorm. The crude foliation, defined by quartz and muscovite, encloses lenticular aggregates of white feldspar and subsidiary pale-grey quartz. Dark-red garnets up to 5 mm across are prominent. (Photo: E.K. Hyslop.)

(Figure 6.49) Geology of the area around Comrie Farm, Strathconon.

(Figure 6.50) Glaciated rock knolls formed of amphibolitic mafic sheets and lenticular pods. Looking northwest to Comrie Farm. (Photo: J.R. Mendum, BGS No. P552291, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 6.51) Geology of the Rosemarkie and Cromarty area. Compiled from British Geological Survey one-inch Sheet 94, Cromarty (Institute of Geological Sciences, 1973), 1:50 000 Sheet 84'W, Fortrose (British Geological Survey, 1997c), and Rathbone and Harris (1980).

(Figure 6.52) Salmon-pink lineated and foliated leucocratic microgranite vein cutting subvertical, thinly banded amphibolitic felsic Lewisianoid gneisses. The hammer is 37 cm long. Learnie shore [NH 7620 6124]. (Photo: J.R. Mendum, BGS No. P581260, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.1) Geological map of the Moine (Central) area, with the location of the GCR sites: 1 — Fannich; 2 — Meall an t-Sithe and Creag Rainich; 3 — Loch Monar; 4 — Abhainn Gleann nam Fiadh; 14 — Ard Ghunel. GCR sites 5–13 are located within or marginal to the Glenelg–Attadale Inlier and are shown on Figure 7.2.

(Figure 7.2) Geological sketch map of the Glenelg–Attadale Inlier and surrounding area (after Barber  and May, 1976), showing the location of the GCR sites within or marginal to the Glenelg–Attadale Inlier.  5 — Attadale; 6 — Dornie—Inverinate Road Section; 7 — Avernish; 8 — Totaig; 9 — Allt Cracaig Coast;  10 — Druim Iosal; 11 — Beinn a' Chapuill; 12 — Eilean Chlamail—Camas nan Ceann; 13 — Rubha Camas na Cailinn.

(Figure 7.3) Tectonostratigraphy of the Moine succession within the Moine (Central) area.

(Figure 7.4) Geological map of the Fannich Mountains. Based on Geological Survey of Scotland (1913a) (Sheet 92), and Kelley and Powell (1985).

(Figure 7.5) (a) View south-west of the east face of Sgùrr nan Clach Geala [NH 184 715]. The uppermost dark-grey part of the mountain consists of foliated gneissose semipelite of the Meall an t-Sithe Pelite Formation (Glenfinnan Group), which is separated by the Sgurr Beag Thrust from the underlying Meall a' Chrasgaidh Psammite (Morar Group). The psammites form the paler-grey, flaggy crags that dominate the lower and middle steep parts of the Eace. (Photo: British Geological Survey, No. P002105, reproduced with the permission of the Director, British Geological Survey, © NERC.) (b) Foliated gneissose muscovite-biotite semipelite of the Meall an t-Sithe Pelite Formation (Glenfinnan Group). The hammer head is 16 cm long. Sgùrr nan Clach Geala [NH 184 715]. (Photo: British Geological Survey, No. P215729, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.6) Geological map of the Meall an t-Sithe and Creag Rainich area. Based on Geological Survey of Scotland (1913a) (Sheet 92) and Kelley and Powell (1985).

(Figure 7.7) Map of the Loch Monar GCR site and immediate surrounding area.

(Figure 7.8) Synoptic block diagram of the superposed folds at Loch Monar. After Ramsay and Huber (1987).

(Figure 7.9) (a) Interference fold patterns (F2 + F3) in thinly bedded Morar Group psammites, semipelites and pelites. Pegmatite veins are also present. Type-3 structures dominate here. The hammer is 37 cm long. Low-water exposure at Loch Monar, 300 m north-west of the cut-off dam. (Photo: J.R. Mendum, BGS No. P552321, reproduced with the permission of the Director, British Geological Survey, © NERC.) (b) Interference fold patterns (F2 + F3) in thinly bedded Morar Group psammites and subsidiary semipelites. Type-1, Type-2 and Type-3 interference patterns are all represented here. The hand lens is 6 cm long. Low-water exposure at Loch Monar, 270 m north-west of the cut-off dam. (Photo: J.R. Mendum, BGS No. P552324, reproduced with the permission of the Director, British Geological Survey, © NERC.)(c) Interference fold patterns (F2 + F3) in thinly bedded Morar Group psammites and semipelites with early pegmatite veins. Type-2 and Type-3 interference patterns are represented here. The hammer is 37 cm long. Low-water exposure at Loch Monar, 220 m north-west of the cut-off dam. (Photo: J.R. Mendum, No. P552325, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.10) (a) Map of the Abhainn Gleann nam Fiadh site area and surrounding geology.(b) Detailed map of the Abhainn Gleann nam Fiadh site area and surrounding geology.

(Figure 7.11) Cross-bedding and slump structures in psammite with micaceous laminae. Succession youngs to the east (top of photo). The hammer is 37 cm long. Abhainn Gleann nan Fiadh [NH 1945 2591]. (Photo: British Geological Survey, No. P219449, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.12) Geological map (a) and cross-section (x—x') (b) of the Attadale GCR site and surroundings Based on field mapping by F. May, and Barber and May (1976).

(Figure 7.13) Flattened quartzofeldspathic clasts in schistose matrix, basal Moine conglomerate, above avalanche shelter, Attadale. The hammer is 37 cm long. (Photo: A.J. Barber.)

(Figure 7.14) Map of the Dornie–Inverinate Road Section GCR site. Based on field mapping by A.J. Barber.

(Figure 7.15) Layered gneiss produced by strong attenuation of quartzofeldspathic gneiss and amphibolite, Eastern Unit, Creag nan Spor. The hammer shaft is 33 cm long. (Photo: A.J. Barber.)

(Figure 7.16) Diopside nodule enclosed in layered forsterite marble, Eastern Unit, Creag Reidh Raineach. The hammer is 37.5 cm long. (Photo: A.J. Barber.)

(Figure 7.17) Map of the Avernish GCR site. After mapping by A.J. Barber.

(Figure 7.18) Amphibolite dyke cutting quartzofeldspathic gneiss at high angles to gneissic layering, attesting to the relative low-strain state of the eastern part of the Avernish GCR site, Nostie Bay. The hammer is 37.5 cm long. (Photo: A.J. Barber.)

(Figure 7.19) Map of Totaig GCR site. Based on Sutton and Watson (1958) and Geological Survey of Scotland (1909).

(Figure 7.20) Layered forsterite marble with calc-silicate-rich and calc-silicate-poor layers and diopside nodule, Beinn Fhada. The field notebook is 16 cm high. (Photo: A.J. Barber.)

(Figure 7.21) Tight fold in layered eclogite, shore of Loch Dutch, Letterfearn. The hammer is 37.5 cm long. (Photo: A.J. Barber.)

(Figure 7.22) Map of the Allt Cracaig Coast GCR site. After Ramsay (195713).

(Figure 7.23) Schistose conglomerate at inverted base of Moine rocks, with clasts of vein quartz, 800 m WSW of Mam nan Uranan [NG 790 167]. The hammer head (top left) is c. 3 cm across.. (Photo: British Geological Survey, No. P214739, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.24) Map of the Druim Iosal GCR site. After Ramsay (1957b).

(Figure 7.25) View of Druim Iosal from Dun Grugaig, Gleann Beag. The crags in the centre are composed of garnetiferous kyanite-biotite gneiss. (Photo: A.J. Barber.)

(Figure 7.26) Map of the Beinn a' Chapuill GCR site, after Ramsay (1957b). The outcrop pattern of the Moine is the result of large-scale fold interference between the two main fold phases.

(Figure 7.27) Fold interference structure in layered Moine psammite, near the hinge of the Beinn a' Chapuill Fold at Sron an Fheadain. The lens cap (lower right) is 5.2 cm across. (Photo: A.J. Barber.)

(Figure 7.28) Map of the Eilean Chlamail—Camas nan Ceann GCR site. Modified from field maps of J.G. Ramsay.

(Figure 7.29) Amphibolitic 'Scourie dyke' cross-cutting gneissic layering at low angle; both gently folded, Western Unit of the Glenelg—Attadale Inlier [NG 7880 1168]. The notebook is 20 cm long. (Photo: British Geological Survey, No. P571654, reproduced with the permission of the Director, British Geological Survey, © NERC).

(Figure 7.30) Detailed map of the Rubha Camas na Cailinn GCR site, from a field map by J.G. Ramsay. F1 folds can be demonstrated at points A, B and C.

(Figure 7.31) Plan view of tight fold closure of Lewisianoid gneiss, cored by Moine psammites. Parasitic folds of probable F1 age are visible left of the notebook. The notebook is 20 cm long. Rubha Camas na Cailinn [NG 8502 0798]. (Photo: M. Krabbendam, BGS No. P571662, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 7.32) Diagrammatic representation of the mineralogical zones developed in the Ard Ghunel ultramafic body. After Matthews (1967).

(Figure 8.1) Simplified geological map of the Moine (South) area, showing the location of the GCR sites.

(Figure 8.2) View westwards to Loch Eilt from The Muidhe [NM 857 815]. In the foreground glaciated slabs show complex folded Glenfinnan Group pelitic and psammitic rocks cross-cut by thick pegmatitic veins that are themselves folded. The craggy and mainly grassy hills are typical of the 'Steep Belt'. (Photo: J.R. Mendum, British Geological Survey, reproduced with the permission of the director, British Geological Survey, © NERC.)

(Figure 8.3) Tectonostratigraphy of the Moine succession within the Moine (South) area, showing the main formations.

(Figure 8.4) Map of Knoydart, Morar and Ardnamurchan showing the distribution of formations of the Morar Group.

(Figure 8.5) Map showing the Caledonian major and minor intrusions. Granitic vein-complexes: Ba — Banavie; GG — Glen Garry; GM — Glen Moriston; LA — Loch Arkaig; LE — Loch Eil; MA — Maine.

(Figure 8.6) Map of the metamorphic zones of the Moine (South) and Moine (Central) areas. After Fettes et al. (1985).

(Figure 8.7) Map of the Glen Doe GCR site. (1) Inset Locality A — detail of tight to isoclinally folded amphibolitic mafic dykes. (2) Inset Locality B — detailed map, showing field relationships between different generations of metagabbro, metadolerite and granite gneiss.

(Figure 8.8) Tight to isoclinally folded amphibolitic mafic dykes in the Glen Doe Granite Gneiss, River Doe section [NH 2169 1265]. The hammer (arrowed) is 32 cm long. (Photo: I.L. Millar, British Geological Survey, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.9) Map of Kinloch Hourn GCR site and surroundings. After Roberts and Barr (1988).

(Figure 8.10) Photograph of layered hornblende gneisses with small boudins of amphibolite from Lewisianoid rocks in the Sgurr Beag Slide at Kinloch Hourn. The hammer is 37 cm long. (Photo: British Geological Survey, No. P218788, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.11) (a) Map of the Quoich Spillway GCR site and surrounding area (after Roberts and Barr, 1988). (b) The local geological setting of the Quoich Spillway section (after Roberts and Barr, 1988).

(Figure 8.12) Typical aspect of the Quoich Granite Gneiss at the site, showing the gneissose foliation and migmatitic segregations deformed by a sinistral ductile shear-zone. The coin is 2.4 cm in diameter. (Photo: A.M. Roberts.)

(Figure 8.13) Plan of the Knoydart Mica prospect prior to quarrying operations. Modified from original plan (Kennedy et al., 1943).

(Figure 8.14) Photomicrograph showing garnet within pelitic host rock to Knoydart pegmatites. Garnet core contains fine-grained inclusions aligned to give a planar fabric perpendicular to the main fabric, surrounded by a broad inclusion-free rim. The garnet is c. 1 mm across. (Photo: E.K. Hyslop, thin section N4940.)

(Figure 8.15) Geology of the North Morar GCR site and surrounding area. Compiled from 1:63 360-scale Sheet 61(Arisaig) (Institute of Geological Sciences, 1971), and Powell (1974).

(Figure 8.16) Attenuated and folded Lewisianoid felsic and mafic gneisses at Rubh' Àird na Murrach [NM 8661 9374], Loch Nevis. The prominent open to close folds are F3 and in parts refold earlier very tight F2 folds: an example can be seen to the top right. The hammer is 28 cm long. (Photo: G.S. Johnstone, BGS No. P254880, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.17) Map of Druimindarroch GCR site and surrounding area (from BGS field maps).

(Figure 8.18) F2 fold in psammites and semipelites of the Lower Morar Psammite Formation. The psammites are locally cross-bedded. Microcline porphyroblasts are abundant in the semipelite. North side of pier [NM 6884 8420]. The compass is 18 cm long. (Photo: J.R. Mendum, British Geological Survey, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.19) Geology of the Fassfern to Lochailort region.

(Figure 8.20) Tightly folded and boudinaged Knoydartian/Morarian pegmatites within subvertical, highly strained Morar Group psammites at Loch Eilt. (Photo: R.A. Strachan.)

(Figure 8.21) Map of Lochailort-Loch Eilt area showing the regional structure. Note that the Lochailort, Arieniskill and Sgurr Beag thrusts are one and the same dislocation. After Baird (1982).

(Figure 8.22) (a) General view of the Sgurr Beag Slide at Tom na Faing looking towards the north-east. The low flaggy rocks on the left are the layered psammites of the Morar Group to the west, whilst the higher more-massive ground on the right are the pelitic gneisses of the Glenfinnan Group to the east. (b) Closer view of the Sgurr Beag Slide, again with fiaggy banded psammites of the Morar Group to the west, and pelitic gneisses of the Glenfinnan Group to the east. The figure is standing immediately to the right of the contact. (Photos: E.K. Hyslop.)

(Figure 8.23) Map of Eas Chia-Aig Waterfalls GCR site.

(Figure 8.24) Thinly banded, locally gneissose and migmatitic psammite, semipelite and pelite with calc-silicate rock lenses (Achnacarry Striped Formation), cross-cut by concordant and discordant quartz-feldspar pegmatite veins. Abhainn Chia-Aig above the Eas Chia-Aig waterfalls [NN 176 890]. The compass (upper right) is 10 cm long. (Photo: R.A. Strachan.)

(Figure 8.25) Map of Loch Moidart Road Cuttings, showing regional setting (a) and detailed geology (b).

(Figure 8.26) (a) View ESE along the northern shore of Loch Moidart showing the road cuts (A861) that expose the Upper Morar Psammite Formation, folded by F2 and F3 folds [NM 681 736]. (Photo: J.R. Mendum, British Geological Survey, reproduced with the permission of the Director, British Geological Survey, © NERC.) (b) Close to tight, moderately plunging F2 + F3 folds in striped psammites and semipelites of the Upper Morar Psammite Formation. The quartz and quartz-feldspar veins lie close to the penetrative S3 axial-planar cleavage. Rock face adjacent to the A861 at An Dùn on the northern side of Loch Moidart [NM 6815 7354]. The hammer head is 14 cm long. (Photo: J.R. Mendum, British Geological Survey, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.27) Map of Eilean Mòr GCR site (based on British Geological Survey maps).

(Figure 8.28) Cross-bedding in feldspathic psammites of the Upper Morar Psammite Formation. The hammer is 37 cm long. West side of Rubha Camp an Righ [NM 5797 6153]. (Photo: J.R. Mendum, British Geological Survey, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 8.29) Map of the Ardalanish Bay GCR site on the eastern margin of the Ross of Mull Pluton. Adapted from 1:50 000 Sheet 43S, Ross of Mull (British Geological Survey, 1997a) and unpublished work, University of Liverpool.

(Figure 8.30) Highly strained and hornfelsed rocks of the Ardalanish Striped and Banded Formation at the eastern contact of the Ross of Mull Pluton, cut by veins of the contaminated marginal granite variant. A' Bhualaidh looking NNE. (Photo: A.J. Highton.)

(Figure 9.1) Simplified geological map of Shetland, showing the major rock units and structures. US — Uyea Shear Zone; VS — Virdibreck Shear Zone; WKS — Wester Keolka Shear Zone; MF — Melby Fault; WBF — Walls Boundary Fault; NF — Nesting Fault; BSF — Bluemull Sound Fault. GCR sites: 1 — Uyea to North Roe Coast; 2 — Gutcher; 3 — North Sandwick; 4 — Cullivoe; 5 — Hascosay; 6 — Voxter Voe and Valayre Quarry.

(Figure 9.2) Map of the north-east coast of Yell showing the main rock units and the locations of the Gutcher, North Sandwick, Hascosay and Cullivoe GCR sites. After 1:50 000 Sheet 130, Yell (British Geological Survey, 1994).

(Figure 9.3) Map of the Uyea to North Roe Coast GCR site, North Maven, Mainland, Shetland.

(Figure 9.4) The entrance to Sand Voe, North Roe, showing the position of the Wester Keolka Shear Zone (WKS). View northwards from [HU 3560 9191]. (Photo: D. Flinn.)

(Figure 9.5) Rocks of the Wester Keolka Shear Zone at [HU 3560 9191] on the south side of the entrance to Sand Voe, North Roe. The coin lies over the shear plane and is 2.5 cm in diameter. (Photo: D. Flinn.)

(Figure 9.6) Map of the north-east coast of Yell, around the Gutcher GCR site.

(Figure 9.7) Microcline-plagioclase leucosome gneiss from [HU 5506 9840], 1 km south of Wick of Gutcher. Coin is 2.5 cm in diameter. (Photo: D. Flinn.)

(Figure 9.8) Map of the north-east coast of Yell, around the North Sandwick GCR site.

(Figure 9.9) Interbanded mica-rich and mica-poor psammites in the Cullivoe 'Lens' on the south side of Sand Wick [HU 5487 9655]. Coin is 2.5 cm in diameter. (Photo: D. Flinn.)

(Figure 9.10) Map of the south-east part of the island of Hascosay.

(Figure 9.11) View of the south-east part of Hascosay with the east coast of Yell behind. The cliff section through the Hascosay Slide Zone is indicated (see Figure 9.10). (Photo: D. Flinn.)

(Figure 9.12) Map of the Ness of Cullivoe and the area around Culli Voe, on the north-east coast of Yell.

(Figure 9.13) Typical blastomylonites of the Hascosay Slide Zone on the Ness of Cullivoe. (a) 'Banded blastomylonite' with hornblende and biotite [HP 551 022]. The lens cap is 7 cm in diameter. (Photo: D. Flinn, BGS No. P541972, reproduced with the permission of the Director, British Geological Survey, © NERC.) 1 (b) Folded blastomylonites [HP 548 028]. The hammer is 40 cm long. (Photo: D. Flinn, BGS No. P541974, reproduced with the permission of the Director, British Geological Survey, © NERC.)

(Figure 9.14) Map of the Voxter Voe area on the east side of Sullom Voe, Mainland Shetland.

(Figure 9.15) Microcline-megacryst augen gneiss of the Valayre Gneiss in the Burn of Valayre, Voxter [HU 3676 6945]. 20 p coin for scale. (Photo: D. Flinn.)

(Figure G1) The classification of coarse-grained crystalline felsic and mafic igneous rocks based on their felsic mineral content. The distinction between gabbroic and dioritic rocks is based on the composition of the plagioclase feldspar present. Medium-grained rocks are named by attaching the prefix 'micro', for example microgranodiorite. However, in this volume and commonly elsewhere dolerite is used as a synonym for microgabbro.

(Figure G2) The more detailed classification of coarse-grained mafic crystalline igneous rocks falling in the gabbroic rocks field in Figure G1. (a) Based on the plagioclase, total pyroxene and olivine content; (b) based on the plagioclase, orthopyroxene and clinopyroxene content; (c) shows how the triangular sections (a) and (b) combine in three dimensions to form a tetrahedron (see also G3).

(Figure G3) The classification of coarse-grained crystalline ultramafic rocks, based on their olivine, orthopyroxene and clinopyroxene content.

(Figure G4) The chemical classification of fine-grained crystalline igneous rocks, used where it is not possible to classify the rocks according to their mineralogy due to their very fine grain-size (Le Maitre, 2002). Note that alteration can lead to loss or addition of more mobile elements such as sodium (Na) and potassium (K) with consequent changes in silica (SiO₂) and hence inaccuracies in classification.

(Figure G5) Pressure-Temperature diagram showing the fields of metamorphic facies (Yardley, 1989). Abbreviations used: hfls — hornfels; a—e — albite—epidote; hbl — hornblende; px — pyroxene; preh = prehnite; pump = pumpellyite.

(Figure G6) Fold terminology (a) Single inclined fold pair illustrating the basic fold nomenclature. (b) Fold strain showing the change from upright to recumbent fold and the concept of an enveloping surface (from McClay, 1987). (c) Terms to describe the tightness of folds (McClay, 1987). (d) Asymmetrical minor folds showing Z, S and M symmetry and their typical relationship to larger-scale antiformal and synformal structures (from McClay, 1987). (e) Fold profile showing direction of vergence of an asymmetrical fold (from Bell, 1981). (f) Geometry of coaxially refolded folds showing F1 and F2 major folds and related minor fold structures. Note that minor F1 folds maintain a consistent vergence across the F2 fold axial traces but change their facing direction from upwards to downwards. However, they do change vergence across F1 fold axial traces. Minor F2 folds change their vergence across the F2 axes (after Bell, 1981). (g) Geometry of orthogonally refolded folds. Note that both F1 and F2 folds change vergence across F2 fold axes but not facing direction (arrows indicate facing direction of F1 folds) (after Bell, 1981).

(Figure G7) Thrust terminology. (a) Basic thrust features generated when a thrust propagates structurally up-sequence in a layered succession, creating a ramp—flat geometry and repetition of the strata (b) Thrust duplex (Imbricate zone'), developed when the propagating thrust cuts repeatedly up-section, generating individual horses ('imbricates') that are then transported on the active lower thrust. Note the relative age of generation of the horses and the 'piggy-back' nature of the thrusting. The leading edge of the duplex defines a branch line than can be traced across country. Similarly the trailing edge generates a trailing branch line. (c) Block diagram illustrating a thrust imbricate generated by a subsidiary thrust (splay), and related branch lines and branching points (from McClay, 1992). (d) Block diagram show the formation of a culmination above thrust ramps and the orientation of culmination walls (e.g. frontal, lateral) relative to a thrust transport direction (large arrow) (from Butler, 1982a).

Tables

(Table 1.1) GCR site selection criteria — Lewisian, Moine and Torridonian

(Table 2.1) Chronology of the Lewisian Gneiss Complex in the Outer Hebrides.

(Table 7.2) Deformation sequences in the Moine (Central) area. Note that structural events do not correlate simply across different areas.

(Table 2.2) Rock types and kinematic history of the Outer Hebrides Fault Zone (OHFZ). Based on information from Fettes et al. (1992), Maclnnes et al. (2000) and Imber et al. (2001).

(Table 3.1) Summary of isotopic ages from the Lewisian Gneiss Complex of the Northern and Central regions of mainland Scotland.

(Table 6.1) Sequence of tectonometamorphic events recognized in the Naver Nappe.

(Table 7.1) Continued Caledonian and later minor intrusions — Moine (Central) and Moine (South) areas.

(Table 8.1) Moine Stratigraphy in North Morar.

(Front cover)

References