Strachan, R., Alsop, I., Friend, C. and Miller, S. (Eds.) 2010. A Geological Excursion Guide to the Moine Geology of the Northern Highlands of Scotland. Edinburgh Geological Society, Glasgow Geological Society in association with NMS Enterprises. ISBN: 978-1-905267-33-0. Copies of EGS geological excursion guides can be purchased on the EGS website: purchase excursion guides.

Figures

(Figure F.1) Locations of the excursions on a generalized geological map of the Northern Highlands of Scotland.

(Figure S.1) Geological map of the Northern Highlands of Scotland. Abbreviations as follows: MT = Moine Thrust; NT = Naver Thrust; SwT = Swordly Thrust; SkT = Skinsdale Thrust; SoT = Sole Thrust; SH = Strath Halladale Granite; CC = Carn Chuinneag-Inchbae Granite; GU = Glen Urquhart; S = Scardroy; SBT = Sgurr Beag Thrust; BW = Ben Wyvis; SG = Strontian Granite

(Figure S.2) Generalized reconstructions of the positions of the main continents from the late Neoproterozoic to late Silurian times (from Open University, 2003). The configuration of Laurentia, Baltica and Gondwana depicted here in S.2a remained stable throughout the Neoproterozoic from the formation of the supercontinent Rodinia to the rifting at c.600 Ma which led to the formation of the Iapetus Ocean.

(Figure S.3) A fence diagram, viewed from the south, of different stratigraphic columns within the southern Moine (from Soper et al., 1998). Vertical exaggeration x2.5. Dots represent psammitic lithologies of varying proximality, but coarse dots in column 9 signify quartzite. Close fine dots are Loch Eil Group psammites. Lines represent pelite or semi-pelite (undistinguished). Dot-dash ornament represents striped and banded pelitic, semi-pelitic and psammitic units.

(Figure S.4) Tectonic model for Grampian phase of the Caledonian orogeny (from Open University 2003, with acknowledgement to Woodcock & Strachan, 2000). A. A pre-Grampian stage showing the opening of the Iapetus Ocean and sedimentation of the Dalradian Supergroup on the rifted Laurentian crust. B. S-directed subduction formed an island arc on continental crust. C. Initial collision led to narrowing of ocean tracts, the obduction of ophiolites, and widespread deformation of the Moine and Dalradian supergroups on the Laurentian margin. D. Continued collision resulted in folding and underthrusting of the Laurentian margin, and a N-dipping subduction zone.

(Figure S.5) A simplified tectonic model for the Scandian phase of the Caledonian orogeny at c.435-424 Ma in Northern Scotland (from Open University, 2003). A. Development of an active margin in post-Grampian times by westwards subduction of the northern arm of Iapetus beneath Laurentia. B. Underthrusting of Baltica beneath Laurentia and the development of both E- and W-directed thrust systems. In the Northern Scotland sector of the collision zone, this culminated in the Moine Thrust. This was followed by strike-slip displacement along the Great Glen Fault (omitted here for clarity) that brought the Northern Highlands to its present position relative to the Grampian Highlands which was unaffected by Scandian phase deformation and metamorphism.

(Figure 1.1) Simplified geology map of the Ross of Mull, showing the localities described in the text.

(Figure 1.2) NW-SE cross-section across the Moine rocks of the Ross of Mull (modified from Holdsworth et al., 1987).

(Figure 1.3) Cross-bedding and cross-lamination within the Upper Shiaba Psammite at Locality 1.13.

(Figure 1.4) Garnetiferous amphibolite cutting obliquely across bedding within host Moine psammite at Locality 1.22.

(Figure 1.5) F₃ folds within the core of the Assapol Synform at Locality 1.23.

(Figure 2.1) Map of the Loch Eil-Glenfinnan area showing the generalized geology and the localities for the excursion. BATS = Ben an Tuim Synform, D₃; DSS = Druim na Saille Synform, D₄ GDA = Glen Dubh Lighe Antiform, D₄ CS = Callop Synform, D₄; MCA = Meall na Cuartaige Antiform, D₄; GFLA = Glen Fionne Lighe Antiform, D₃; LES = Loch Eil Synform, D₄; MBS = Meall a Bhainne Synform, D₄ CGA = Coire Ghuibhsachain Antiform, D4

(Figure 2.2) Typical exposure of the Ardgour Granite Gneiss at Locality 2.6, showing abundant concordant quartz-feldspathic segregations parallel to gneissic banding.

(Figure 3.1) Geological map of part of the SW Moine between Glenfinnan and Arisaig, showing locations of Localities 3.1-3.7.

(Figure 3.2) 'Eye'-folds deforming interbanded psammites and migmatitic pelites of the Glenfinnan Group at Locality 3.1A. Lighter is 8cm long.

(Figure 3.3) Geological section across the SW Moine.

(Figure 3.4) Isoclinally refolded isoclines picked out by vertically dipping sedimentary layering in the Lochailort Pelitic Group at Locality 3.4C. Compass-clinometer is 10 cm long.

(Figure 3.5) Foliated microdiorite sheet dipping eastwards and cutting near vertical interbanded psammites and semi-pelites of the Upper Morar Psammite at Locality 3.5A. Note easterly-dipping internal schistosity oblique to sheet margins. Lighter is 8cm long.

(Figure 3.6) Geological setting of Localities 3.8 and 3.9.

(Figure 3.7) Simplified geology of the Rhue peninsula.

(Figure 3.8) Examples of graphic sedimentological logs from the Upper Morar Psammite.

(Figure 3.9) Cross-bedding in psammite layer of an interbedded psammite-pelite sequence of the Upper Morar Psammite at Locality 3.8.

(Figure 4.1) Location map and general geology of Excursion 4.

(Figure 4.2) Geological map of Locality 4.2, also showing location of Locality 4.3.

(Figure 4.3) Geological map of Locality 4.3, the Quoich dam spillway.

(Figure 4.4) Geological map of the central part of the Loch Quoich shore section (Locality 4.5) (from Holdsworth & Roberts, 1984).

(Figure 4.5) D₂ sheath fold viewed looking NW. Note the intense L₂ mineral lineation above coin (15 mm diameter) (Locality 4.5 [NH 0438 0174]).

(Figure 4.6) West-vergent D₃ folds directly below Quoich Bridge (viewed north at Locality 4.6 [NH 0148 0406]).

(Figure 4.7) Geological map of Locality 4.8, Allt Coire Shubh Beag.

(Figure 4.8) Geological map of Locality 4.9, Kinloch Hourn to Skiary (lithostratigraphic symbols as (Figure 4.1)).

(Figure 5.1) Map showing the regional geology, route and approximate locations of the localities.

(Figure 5.2) Steep, ramifying pegmatites of the Glen Garry Vein Complex intruding flat-lying Moine psammites at Locality 5.1. Note the sheet of concordant amphibolite at the base of the exposure.

(Figure 5.3) Detailed sketch map of the Sgurr Beag Thrust zone at Locality 5.6. Refer to text for stops 5.6A and 5.6B. Dip and strike symbols refer to orientation of regional gneissosity.

(Figure 6.1) General geological map of the Glenelg and Loch Hourn region.

(Figure 6.2) Axial traces of the major D₁, D₂ and D₃ folds.

(Figure 6.3) A detailed outcrop map of the exposures in Glenelg Bay at Locality 6.1.

(Figure 6.4) Map of the Moine and Lewisian rocks in the Arnisdale-Corran region. The Lewisian is found in three fold hinges, two of western facies (A and B) and one of eastern facies (C), an arrangement exactly comparable with that seen on the NW side of the Strathconon Fault. The Moine strip between B and C opens southward into a major D₁ syncline on Druim Fada.

(Figure 6.5) Detailed map of the coastal exposures on Rudha Camas na Caillin (Locality 6.6B). The Lewisian gneisses are found in the cores of SE-plunging D₁ anticlines and the Moine rocks in the cores of D₁ synclines. The red stars refer to outcrops of special interest.

(Figure 7.1) Geological map of Glenelg and Loch Duich, showing the locations of ((Figure 7.2)), ((Figure 7.4)) and ((Figure 7.5)).

(Figure 7.2) Geological map north of Glen More covering Localities 7.1A-E (modified from Sutton & Watson, 1959, plate 9).

(Figure 7.3) Thin section of typical eclogite from Locality 7.1E.Grt = garnet; Rut = rutile; Omph = omphacite. Field of view = 3 mm.

(Figure 7.4) Geological map south of Glenmore covering Locality 7.2A-C (modified from Ramsay, 1958, plates 37 & 38).

(Figure 7.5) Geological map north of Loch Duich covering Localities 7.3 to 7.7 (based on May et al., 1993, figure 5).

(Figure 7.6) Thin section of high-pressure mafic granulite from Locality 7.3A. Grt = garnet Plag = plagioclase Zo = zoisite Diop = diopside Amph = amphibole Field of view = 3 mm

(Figure 8.1) General geological map of the Monar region and upper parts of Glen Strathfarrar.

(Figure 8.2) Geological map of the southern limb of the Loch Monar Synform showing localities around the eastern end of Loch Monar, together with details of the internal lithologies found in the Lewisian sheet.

(Figure 8.3) Structures visible at Locality 8.3, all around [NH 1989 3882]: (a) upright D₃ folds deforming migmatitic veins; (b) 'dome and basin' (type 2) patterns produced by the interference of D₂ and D₃ fold sets; (c) D₂ isoclinal fold of a migmatitic vein deformed by upright D₃ folds; (d) D₃ fold set showing cuspate-lobate shapes developed at the interface between psammitic and pelitic lithologies.

(Figure 9.1) Geology of the Moine rocks between the Fannich mountains and Ullapool, showing the localities to be visited.

(Figure 9.2) Sketch map for Locality 9.2. See (Figure 9.1) for key.

(Figure 9.3) Sketch map for Locality 9.9.

(Figure 10.1) Simplified geology of south and central Sutherland together with the localities for the excursion. A = Altnaharra; BB = Bonar Bridge; DF = Dornoch Firth; L = Lairg; T = Tain; ST = Sole Thrust; MT = Moine Thrust; NT = Naver Thrust; ST = Swordly Thrust; SKT = Skinsdale Thrust

(Figure 10.2) Well-developed mullions plunging parallel to the regional L₂ lineation at Oykell Bridge (Locality 10.1).

(Figure 10.3) Geological map of Locality 10.3, the Airde of Shin.

(Figure 10.4) Boudinaged mafic pods within strongly deformed intermediate to felsic gneiss of the Loch Shin basement inlier at Locality 10.3B.

(Figure 10.5) Geological map of Locality 10.4, the Creich Peninsular (from Strachan & Holdsworth, 1988 & Grant and Harris, 2000).

(Figure 10.6) Detailed geological map of the area around Vagastie Bridge (from Holdsworth & Strachan, 1988).

(Figure 10.7) Geological map of Locality 10.6, the Loch Naver area.

(Figure 11.1) Simplified geological map of the northern part of the Moine Thrust Belt, in the vicinity of Loch Eriboll, Foinaven to Whiten Head. The sites of the four transects are indicated by boxed areas (1-4). AT = Arnaboll Thrust; CST = Creag Shomhairle Thrust.

(Figure 11.2) Simplified map of the south Eriboll district, showing the positions of sites visited on transect 1. Located as 1 on Figure 11-1. CST = Creag Shomhairle Thrust.

(Figure 11.3) Annotated photograph view SW from slopes of An Lean Charn (e.g. [NC 406 526]) onto Conamheall – showing some of the outcrop locations from transect 1. (Note that this viewpoint is not part of the excursion, but can be visited readily by hiking up from Strath Beag bothy or from the southern end of the Creag na Faoilinn crags. For photographs the best lighting is generally in the morning).

(Figure 11.4) Annotated photograph (a) and cross-section (b) of the Foinaven-Meall Horn ridge, illustrating the imbricate structure of Cambrian quartzites. (after Butler, 2004b.) LQ = Lower Quartzites; PR = Pipe Rock; MT = Moine Thrust

(Figure 11.5) Annotated photograph of Creag Shomhairle (from Location 11.1E; after Butler, 2004b) showing the culminations in imbricated Cambrian strata that fold higher thrust sheets (Creag Shomhairle and Moine).

(Figure 11.6) Photograph of the antiformal stack duplex at Creag Shomhairle (after Butler, 1987).

(Figure 11.7) Simplified geological map (a) and cross-section (b) of the Arnaboll hill area. Modified after Coward, 1984 (but see recent interpretation by Wibberley & Butler, 2010, of the structural relations between Lewisian and adjacent quartzites). AT = Arnaboll Thrust.

(Figure 11.8) The classic location (2C) of the Arnaboll Thrust and of Lapworth's (1883) mylonites: (a) general aspect of the thrust, carrying Lewisian gneisses onto Pipe Rock; hammer (circled) for scale (b) detail of the Arnaboll Thrust, showing deflected Skolithos (pipes) that indicate the sense of shear (top to WNW); scale from lens cap (circled)

(Figure 11.9) Geological map of the Kempie area (modified after Butler et al., 2006). X-Y is the section line of (Figure 11.10).

(Figure 11.10) Cross-section through the Kempie area (modified after Butler et al., 2006). KT = Kempie Thrust; AT = Arnabol Thrust; MT = Moine Thrust.

(Figure 11.11) Geology of transect 4 through the mylonite belt along the Creagan Road.

(Figure 11.12) Quartz mylonites and associated quartz veins deformed by F₃ folds at Locality 11.4D.

(Figure 12.1) Simplified geological map of the Durness-Faraid head area (modified from British Geological Survey, 2002). MT = Moine Thrust.

(Figure 12.2) Geological map of the coastal area around Durness showing Locality 12.1. LRT = Lochan Riabhach Thrust.

(Figure 12.3) View from above Locality 12.1A, looking NW across the Durness outlier and towards the Faraid Head peninsula in the distance. Locations of Lewisianoid rocks of the Moine Nappe, Oystershell Rock (OSR), Lochan Riabhach Thrust (LRT) and the Faraid Head Fault (FHF) are also shown.

(Figure 12.4) View of cliff at Locality 12.1E at NW end of Sango Bay, showing Moine Thrust Zone rocks Oystershell Rock (OSR), Cambrian quartzite (Cq), Lewisian (Lm) and Lochan Riabhach Thrust (LRT) directly overlying totally unmylonitized, autochthonous Durness Limestone (DL) in the uppermost part of the Caledonian foreland sequence.

(Figure 12.5) Geological map of Faraid Head showing Locality 12.2 (modified from Holdsworth et al., 2007). LRT = Lochan Riabhach Thrust.

(Figure 13.1) Simplified geological map of north Sutherland together with the localities for the excursion. LL = Loch Loyal; LH = Loch Hope; MT = Moine Thrust; NT = Naver Thrust; ST = Swordly Thrust; TT = Torrisdale Thrust.

(Figure 13.4) Locality 13.2. A. The Ben Hope Thrust and basement-cover relations in the Ben Hope to Kinloch area of the Moine Nappe; B. detailed map of the Kinloch area; C.Interpretative sketch of D₃ structures in the Kinloch area (from Moorhouse et al., 1988).

(Figure 13.2) Geological map of Locality 13.1 (modified from British Geological Survey, 1997).

(Figure 13.3) (left) 'Eye' structure developed within Moine psammites at Locality 13.1B. This structure is interpreted as a cross section through the nose of a D₂ sheath fold.

(Figure 13.4) Locality 13.2. (a) the Ben Hope Thrust and basementcover relations in the Ben Hope to Kinloch area of the Moine Nappe; (b) detailed map of the Kinloch area; (c) interpretative sketch of D₃ structures in the Kinloch area (from Moorhouse et al., 1988).

(Figure 13.5) Localities 13.4 and 13.5: basement-cover relationships in the Coldbackie Bay and Sletell area of the Moine Nappe (from Moorhouse et al., 1988).

(Figure 13.6) Geological map of Localities 13.6 and 13.7 (modified from British Geological Survey, 1997).

(Figure 13.7) D₃ folds deforming interbanded psammite and garnetiferous semi-pelite at Locality 13.6A.

(Figure 13.8) Geological map of Locality 13.8 (from Burns, 1994). Many granite sheets have been omitted for clarity. NT = Naver Thrust; TT = Torrisdale Thrust.

(Figure 13.9) Geological map of Localities 13.9, 13.10 and 13.11 (from Burns, 1994).

(Figure 13.10) Geological map of Localities 13.12, 13.13 and 13.14 (from Moorhouse et al., 1988 and Burns, 1994).

(Figure 13.11) Migmatitic gneisses at Locality 13.14, showing extensive partial melting.

(Figure 13.12) Simplified coastal geology of the Strathy Complex (from Moorhouse et al., 1988 and Burns, 1994) showing Localities 13.15, 13.16A and 13.17.

(Figure 14.1) Map of the Great Glen showing localities referred to in the text. The arrows indicate site localities adjacent to the fault.

(Figure 14.2) Map of Locality 14.1, on the banks of the River Lochy to the north of Torcastle. The exposures comprise Moine protolith subsequently sheared by late Caledonian displacements on the Great Glen fault. The inset shows trend and plunge of mineral lineations within the shear zones.

(Figure 14.3) Map of sheared Moine protolith exposed at Locality 14.2, to the south of Torcastle. The inset is a schematic diagram to show the interpreted geometric relationship between the main vertical sinistral shear zones and subordinate dextral antithetic shears. The latter are thought to have formed by 'bookshelf' faulting where low strain domains between the main shear zones have experienced horizontal anticlockwise rotations.

(Figure 14.4) View southwest across Loch Lochy to Coire Lochain and the Clunes Tonalite.

(Figure 14.5) (a) Plan view of shear fabrics within hornblende gneisses at Locality 14.7A [NH 773 627]. Syn-metamorphic and later brittle shear fabrics demonstrate sinistral offsets. (b) Plan view of amphibolite-grade shear fabrics. A sinistral sense of shear is indicated by geometry of the sigmoidal vein in the lower middle section of photograph. (c) Foliated microgranite at Locality 14.7B [NH 772 626] showing well-developed feldspar augen indicating sinistral shearing. (d) Shear banding within granite sheet at Locality 14.7B. Geometry of shear fabrics is highlighted in right-hand image and is suggestive of sinistral shear. (e) White foliated leucogranite at Locality 14.7C [NH 769 621] with sheared muscovite rich core and development of quartz & feldspar augen where muscovite envelopes porphyroclasts. (f) Detail of leucogranite vein at Locality 14.7C. Geometry of synthetic shears within sheared core indicate dextral shearing. [Inset: Evidence of pressure solution (impacting of muscovite) in top left and bottom right quadrants implies dextral shear.]

(Table 1) Summary of the Caledonian and pre-Caledonian history of the Moine rocks of the Northern Highlands of Scotland. Timing based on isotopic dates quoted in the text.

References

Locations of the excursions on a generalized geological map of the Northern Highlands of Scotland.

Geological map of the Northern Highlands of Scotland. Abbreviations as follows: MT = Moine Thrust; NT = Naver Thrust; SwT = Swordly Thrust; SkT = Skinsdale Thrust; SoT = Sole Thrust; SH = Strath Halladale Granite; CC = Carn Chuinneag-Inchbae Granite; GU = Glen Urquhart; S = Scardroy; SBT = Sgurr Beag Thrust; BW = Ben Wyvis; SG = Strontian Granite

Generalized reconstructions of the positions of the main continents from the late Neoproterozoic to late Silurian times (from Open University, 2003). The configuration of Laurentia, Baltica and Gondwana depicted here in S.2a remained stable throughout the Neoproterozoic from the formation of the supercontinent Rodinia to the rifting at c.600 Ma which led to the formation of the Iapetus Ocean.

A fence diagram, viewed from the south, of different stratigraphic columns within the southern Moine (from Soper et al., 1998). Vertical exaggeration x2.5. Dots represent psammitic lithologies of varying proximality, but coarse dots in column 9 signify quartzite. Close fine dots are Loch Eil Group psammites. Lines represent pelite or semi-pelite (undistinguished). Dot-dash ornament represents striped and banded pelitic, semi-pelitic and psammitic units.

Tectonic model for Grampian phase of the Caledonian orogeny (from Open University 2003, with acknowledgement to Woodcock & Strachan, 2000). A. A pre-Grampian stage showing the opening of the Iapetus Ocean and sedimentation of the Dalradian Supergroup on the rifted Laurentian crust. B. S-directed subduction formed an island arc on continental crust. C. Initial collision led to narrowing of ocean tracts, the obduction of ophiolites, and widespread deformation of the Moine and Dalradian supergroups on the Laurentian margin. D. Continued collision resulted in folding and underthrusting of the Laurentian margin, and a N-dipping subduction zone.

A simplified tectonic model for the Scandian phase of the Caledonian orogeny at c.435-424 Ma in Northern Scotland (from Open University, 2003). A. Development of an active margin in post-Grampian times by westwards subduction of the northern arm of Iapetus beneath Laurentia. B. Underthrusting of Baltica beneath Laurentia and the development of both E- and W-directed thrust systems. In the Northern Scotland sector of the collision zone, this culminated in the Moine Thrust. This was followed by strike-slip displacement along the Great Glen Fault (omitted here for clarity) that brought the Northern Highlands to its present position relative to the Grampian Highlands which was unaffected by Scandian phase deformation and metamorphism.

Simplified geology map of the Ross of Mull, showing the localities described in the text.

NW-SE cross-section across the Moine rocks of the Ross of Mull (modified from Holdsworth et al., 1987).

Cross-bedding and cross-lamination within the Upper Shiaba Psammite at Locality 1.13.

Garnetiferous amphibolite cutting obliquely across bedding within host Moine psammite at Locality 1.22.

F₃ folds within the core of the Assapol Synform at Locality 1.23.

Map of the Loch Eil-Glenfinnan area showing the generalized geology and the localities for the excursion. BATS = Ben an Tuim Synform, D₃; DSS = Druim na Saille Synform, D₄ GDA = Glen Dubh Lighe Antiform, D₄ CS = Callop Synform, D₄; MCA = Meall na Cuartaige Antiform, D₄; GFLA = Glen Fionne Lighe Antiform, D₃; LES = Loch Eil Synform, D₄; MBS = Meall a Bhainne Synform, D₄ CGA = Coire Ghuibhsachain Antiform, D4

Typical exposure of the Ardgour Granite Gneiss at Locality 2.6, showing abundant concordant quartz-feldspathic segregations parallel to gneissic banding.

Geological map of part of the SW Moine between Glenfinnan and Arisaig, showing locations of Localities 3.1-3.7.

'Eye'-folds deforming interbanded psammites and migmatitic pelites of the Glenfinnan Group at Locality 3.1A. Lighter is 8cm long.

Geological section across the SW Moine.

Isoclinally refolded isoclines picked out by vertically dipping sedimentary layering in the Lochailort Pelitic Group at Locality 3.4C. Compass-clinometer is 10 cm long.

Foliated microdiorite sheet dipping eastwards and cutting near vertical interbanded psammites and semi-pelites of the Upper Morar Psammite at Locality 3.5A. Note easterly-dipping internal schistosity oblique to sheet margins. Lighter is 8cm long.

Geological setting of Localities 3.8 and 3.9.

Simplified geology of the Rhue peninsula.

Examples of graphic sedimentological logs from the Upper Morar Psammite.

Cross-bedding in psammite layer of an interbedded psammite-pelite sequence of the Upper Morar Psammite at Locality 3.8.

Location map and general geology of Excursion 4.

Geological map of Locality 4.2, also showing location of Locality 4.3.

Geological map of Locality 4.3, the Quoich dam spillway.

Geological map of the central part of the Loch Quoich shore section (Locality 4.5) (from Holdsworth & Roberts, 1984).

D₂ sheath fold viewed looking NW. Note the intense L₂ mineral lineation above coin (15 mm diameter) (Locality 4.5 [NH 0438 0174]).

West-vergent D₃ folds directly below Quoich Bridge (viewed north at Locality 4.6 [NH 0148 0406]).

Geological map of Locality 4.8, Allt Coire Shubh Beag.

Geological map of Locality 4.9, Kinloch Hourn to Skiary (lithostratigraphic symbols as (Figure 4.1)).

Map showing the regional geology, route and approximate locations of the localities.

Steep, ramifying pegmatites of the Glen Garry Vein Complex intruding flat-lying Moine psammites at Locality 5.1. Note the sheet of concordant amphibolite at the base of the exposure.

Detailed sketch map of the Sgurr Beag Thrust zone at Locality 5.6. Refer to text for stops 5.6A and 5.6B. Dip and strike symbols refer to orientation of regional gneissosity.

General geological map of the Glenelg and Loch Hourn region.

Axial traces of the major D₁, D₂ and D₃ folds.

A detailed outcrop map of the exposures in Glenelg Bay at Locality 6.1.

Map of the Moine and Lewisian rocks in the Arnisdale-Corran region. The Lewisian is found in three fold hinges, two of western facies (A and B) and one of eastern facies (C), an arrangement exactly comparable with that seen on the NW side of the Strathconon Fault. The Moine strip between B and C opens southward into a major D₁ syncline on Druim Fada.

Detailed map of the coastal exposures on Rudha Camas na Caillin (Locality 6.6B). The Lewisian gneisses are found in the cores of SE-plunging D₁ anticlines and the Moine rocks in the cores of D₁ synclines. The red stars refer to outcrops of special interest.

Geological map of Glenelg and Loch Duich, showing the locations of ((Figure 7.2)), ((Figure 7.4)) and ((Figure 7.5)).

Geological map north of Glen More covering Localities 7.1A-E (modified from Sutton & Watson, 1959, plate 9).

Thin section of typical eclogite from Locality 7.1E.Grt = garnet; Rut = rutile; Omph = omphacite. Field of view = 3 mm.

Geological map south of Glenmore covering Locality 7.2A-C (modified from Ramsay, 1958, plates 37 & 38).

Geological map north of Loch Duich covering Localities 7.3 to 7.7 (based on May et al., 1993, figure 5).

Thin section of high-pressure mafic granulite from Locality 7.3A. Grt = garnet Plag = plagioclase Zo = zoisite Diop = diopside Amph = amphibole Field of view = 3 mm

General geological map of the Monar region and upper parts of Glen Strathfarrar.

Geological map of the southern limb of the Loch Monar Synform showing localities around the eastern end of Loch Monar, together with details of the internal lithologies found in the Lewisian sheet.

Structures visible at Locality 8.3, all around [NH 1989 3882]: (a) upright D₃ folds deforming migmatitic veins; (b) 'dome and basin' (type 2) patterns produced by the interference of D₂ and D₃ fold sets; (c) D₂ isoclinal fold of a migmatitic vein deformed by upright D₃ folds; (d) D₃ fold set showing cuspate-lobate shapes developed at the interface between psammitic and pelitic lithologies.

Geology of the Moine rocks between the Fannich mountains and Ullapool, showing the localities to be visited.

Sketch map for Locality 9.2. See (Figure 9.1) for key.

Sketch map for Locality 9.9.

Simplified geology of south and central Sutherland together with the localities for the excursion. A = Altnaharra; BB = Bonar Bridge; DF = Dornoch Firth; L = Lairg; T = Tain; ST = Sole Thrust; MT = Moine Thrust; NT = Naver Thrust; ST = Swordly Thrust; SKT = Skinsdale Thrust

Well-developed mullions plunging parallel to the regional L₂ lineation at Oykell Bridge (Locality 10.1).

Geological map of Locality 10.3, the Airde of Shin.

Boudinaged mafic pods within strongly deformed intermediate to felsic gneiss of the Loch Shin basement inlier at Locality 10.3B.

Geological map of Locality 10.4, the Creich Peninsular (from Strachan & Holdsworth, 1988 & Grant and Harris, 2000).

Detailed geological map of the area around Vagastie Bridge (from Holdsworth & Strachan, 1988).

Geological map of Locality 10.6, the Loch Naver area.

Simplified geological map of the northern part of the Moine Thrust Belt, in the vicinity of Loch Eriboll, Foinaven to Whiten Head. The sites of the four transects are indicated by boxed areas (1-4). AT = Arnaboll Thrust; CST = Creag Shomhairle Thrust.

Simplified map of the south Eriboll district, showing the positions of sites visited on transect 1. Located as 1 on Figure 11-1. CST = Creag Shomhairle Thrust.

Annotated photograph view SW from slopes of An Lean Charn (e.g. [NC 406 526]) onto Conamheall – showing some of the outcrop locations from transect 1. (Note that this viewpoint is not part of the excursion, but can be visited readily by hiking up from Strath Beag bothy or from the southern end of the Creag na Faoilinn crags. For photographs the best lighting is generally in the morning).

Annotated photograph (a) and cross-section (b) of the Foinaven-Meall Horn ridge, illustrating the imbricate structure of Cambrian quartzites. (after Butler, 2004b.) LQ = Lower Quartzites; PR = Pipe Rock; MT = Moine Thrust

Annotated photograph of Creag Shomhairle (from Location 11.1E; after Butler, 2004b) showing the culminations in imbricated Cambrian strata that fold higher thrust sheets (Creag Shomhairle and Moine).

Photograph of the antiformal stack duplex at Creag Shomhairle (after Butler, 1987).

Simplified geological map (a) and cross-section (b) of the Arnaboll hill area. Modified after Coward, 1984 (but see recent interpretation by Wibberley & Butler, 2010, of the structural relations between Lewisian and adjacent quartzites). AT = Arnaboll Thrust.

The classic location (2C) of the Arnaboll Thrust and of Lapworth's (1883) mylonites: (a) general aspect of the thrust, carrying Lewisian gneisses onto Pipe Rock; hammer (circled) for scale (b) detail of the Arnaboll Thrust, showing deflected Skolithos (pipes) that indicate the sense of shear (top to WNW); scale from lens cap (circled)

Geological map of the Kempie area (modified after Butler et al., 2006). X-Y is the section line of (Figure 11.10).

Geology of transect 4 through the mylonite belt along the Creagan Road.

Quartz mylonites and associated quartz veins deformed by F₃ folds at Locality 11.4D.

Simplified geological map of the Durness-Faraid head area (modified from British Geological Survey, 2002). MT = Moine Thrust.

Geological map of the coastal area around Durness showing Locality 12.1. LRT = Lochan Riabhach Thrust.

View from above Locality 12.1A, looking NW across the Durness outlier and towards the Faraid Head peninsula in the distance. Locations of Lewisianoid rocks of the Moine Nappe, Oystershell Rock (OSR), Lochan Riabhach Thrust (LRT) and the Faraid Head Fault (FHF) are also shown.

View of cliff at Locality 12.1E at NW end of Sango Bay, showing Moine Thrust Zone rocks Oystershell Rock (OSR), Cambrian quartzite (Cq), Lewisian (Lm) and Lochan Riabhach Thrust (LRT) directly overlying totally unmylonitized, autochthonous Durness Limestone (DL) in the uppermost part of the Caledonian foreland sequence.

Geological map of Faraid Head showing Locality 12.2 (modified from Holdsworth et al., 2007). LRT = Lochan Riabhach Thrust.

Simplified geological map of north Sutherland together with the localities for the excursion. LL = Loch Loyal; LH = Loch Hope; MT = Moine Thrust; NT = Naver Thrust; ST = Swordly Thrust; TT = Torrisdale Thrust.

Locality 13.2. A. The Ben Hope Thrust and basement-cover relations in the Ben Hope to Kinloch area of the Moine Nappe; B. detailed map of the Kinloch area; C.Interpretative sketch of D₃ structures in the Kinloch area (from Moorhouse et al., 1988).

Locality 13.2. (a) the Ben Hope Thrust and basementcover relations in the Ben Hope to Kinloch area of the Moine Nappe; (b) detailed map of the Kinloch area; (c) interpretative sketch of D₃ structures in the Kinloch area (from Moorhouse et al., 1988).

Geological map of Locality 13.1 (modified from British Geological Survey, 1997).

(left) 'Eye' structure developed within Moine psammites at Locality 13.1B. This structure is interpreted as a cross section through the nose of a D₂ sheath fold.

Localities 13.4 and 13.5: basement-cover relationships in the Coldbackie Bay and Sletell area of the Moine Nappe (from Moorhouse et al., 1988).

Geological map of Localities 13.6 and 13.7 (modified from British Geological Survey, 1997).

D₃ folds deforming interbanded psammite and garnetiferous semi-pelite at Locality 13.6A.

Geological map of Locality 13.8 (from Burns, 1994). Many granite sheets have been omitted for clarity. NT = Naver Thrust; TT = Torrisdale Thrust.

Geological map of Localities 13.9, 13.10 and 13.11 (from Burns, 1994).

Geological map of Localities 13.12, 13.13 and 13.14 (from Moorhouse et al., 1988 and Burns, 1994).

Migmatitic gneisses at Locality 13.14, showing extensive partial melting.

Simplified coastal geology of the Strathy Complex (from Moorhouse et al., 1988 and Burns, 1994) showing Localities 13.15, 13.16A and 13.17.

Map of the Great Glen showing localities referred to in the text. The arrows indicate site localities adjacent to the fault.

Map of Locality 14.1, on the banks of the River Lochy to the north of Torcastle. The exposures comprise Moine protolith subsequently sheared by late Caledonian displacements on the Great Glen fault. The inset shows trend and plunge of mineral lineations within the shear zones.

Map of sheared Moine protolith exposed at Locality 14.2, to the south of Torcastle. The inset is a schematic diagram to show the interpreted geometric relationship between the main vertical sinistral shear zones and subordinate dextral antithetic shears. The latter are thought to have formed by 'bookshelf' faulting where low strain domains between the main shear zones have experienced horizontal anticlockwise rotations.

View southwest across Loch Lochy to Coire Lochain and the Clunes Tonalite.

(a) Plan view of shear fabrics within hornblende gneisses at Locality 14.7A [NH 773 627]. Syn-metamorphic and later brittle shear fabrics demonstrate sinistral offsets. (b) Plan view of amphibolite-grade shear fabrics. A sinistral sense of shear is indicated by geometry of the sigmoidal vein in the lower middle section of photograph. (c) Foliated microgranite at Locality 14.7B [NH 772 626] showing well-developed feldspar augen indicating sinistral shearing. (d) Shear banding within granite sheet at Locality 14.7B. Geometry of shear fabrics is highlighted in right-hand image and is suggestive of sinistral shear. (e) White foliated leucogranite at Locality 14.7C [NH 769 621] with sheared muscovite rich core and development of quartz & feldspar augen where muscovite envelopes porphyroclasts. (f) Detail of leucogranite vein at Locality 14.7C. Geometry of synthetic shears within sheared core indicate dextral shearing. [Inset: Evidence of pressure solution (impacting of muscovite) in top left and bottom right quadrants implies dextral shear.]

Summary of the Caledonian and pre-Caledonian history of the Moine rocks of the Northern Highlands of Scotland. Timing based on isotopic dates quoted in the text.