Figures

(Figure 0.1) Simplified geological map of the area covered by the guide: the locations of excursions are shown diagrammatically by numbered dots. A key to the numbers is provided in the Contents list and also (more briefly) on the inside back cover. HBF = Highland Boundary Fault, SUBF = Southern Upland Boundary Fault, H = Helensburgh, D = Dumbarton, GL = Glasgow, K = Kilmarnock, A = Ayr, GI = Girvan, S = Stirling.

(Figure 0.2) Diagrammatic section through the north-western part of the Midland Valley, showing the positions of relevant excursions: the numbers in brackets are of excursions which are not on the line of the section.

(Figure 0.3) Map showing by the numbered dots the centres of location of the excursions: a key to the numbers is provided in the Contents list and on the back cover. The National Grid 100 km and 10 km lines are shown.

(Figure 0.4) Map showing the present coverage of the area by British Geological Survey (B.G.S.) maps. The names in bold with the larger numbers indicate the older series of maps, some of which (with numbers in brackets) can no longer be purchased. The italicised names with smaller numbers are for recent maps: there are now separate sheets for the western and eastern parts and their boundaries are shown by broken lines. The Irvine map (22W) is as yet only in Drift edition. More of the new maps will be forthcoming. The National Grid squares are indicated.

(Figure 0.5) The disposition of plates and the tectonic environments associated with them. A, showing the various plate-tectonic domains with particular reference to oceanic crust, and B, the various tectonic elements associated with continental crust.

(Figure 0.6) A, The detailed structural elements of a destructive margin, along with the spatial and vertical scales. In the accretionary prism the sequence (i),(ii) etc records the relative ages of the slices scraped off as the ocean plate descends beneath the continent. In the fore-arc basin (i),(ii) etc refers to the sequence of filling, which contrasts markedly with the accretion in the trench. d, the distance from the volcanic surface to the top of the descending plate, is normally 90 km. B, is a compilation of the distances between the arc and the trench taken from present-day systems.

(Figure 0.7) A map of the Palaeozoic tectono-stratigraphic blocks within Scotland. 1, Ballantrae ophiolite, 2, the Girvan cover sequence, 3, the Southern Uplands, 4, the Midland Valley, 5, Highland Border Complex, 6, the Dalradian Block, 7, the Islay-Colonsay Terrane. HBF=Highland Boundary Fault; SUF=Southern Uplands Fault; IS=lapetus Suture; L= Isle of Lewis; OT=Outer Isles Thrust; MT=Moine Thrust; GGF=Great Glen Fault. Blocks to the north of the great Great Glen Fault are not numbered as they are not covered in this account.

(Figure 0.8) Cross sections through Scotland. A assumes that there are no tectonic elements missing, B assumes that there are tectonic elements missing and that the Caledonides is a collage of largely unrelated terranes. The positions of the Highland Boundary Fault (HBF) and Southern Uplands Fault (SUF) are as they are today, and are only positioned for reference; at the time of the sections, the positions of these faults is unknown.

(Figure 0.9) A general view of the dispositions of the landmasses of the North Atlantic during the Palaeozoic. In Cambrian times the dispersed continental blocks we see today were assembled into the single large continent of Laurentia. The southern margin (i.e. south with respect to the present pole) was a large passive margin seqence (see (Figure 0.5)) which included the Cambrian rocks of the NW Highlands. By Ordovican times this whole southern continental margin of Laurentia became destructive and took on the characteristics which resemble the present-day western Pacific. To the south of it lay the Iapetus Ocean, on the other side of which lay continents such as Baltica (roughly including Norway, Sweden, Finland and Denmark) and Gondwana (which also included southern Britain and central and southern Europe).

(Figure 0.10) Diagram illustrating the origin of the Ballagan beds, and showing how the limestone-shale, sandstone and caliche can all be integrated into one environment of deposition.

(Figure 0.11) Showing the evolution of the main tectonic elements, Highland Border Complex, (NBC); Midland Valley (MV) and the Southern Uplands (SU) through time. In the Ordovician they were distinctive terranes which were being produced somewhere along the southern margin of Laurentia, and then progessively came together. By Devonian times these terranes were probably all overlapping each other, almost, but not quite, in the positions we now see them. During this time when the terranes were accreting, many basins developed along their margins forming the fault basins of the Old Red Sandstone. By Carboniferous times, but already beginning in the Devonian, sheets of sandstone produced from the erosion of the Caledonian mountains of Scandinavia and Greenland spread over the terranes, thus demonstrating them to be in postion at that time.

(Figure 1.1) Sketch map of central Glasgow showing route of excursion.

(Figure 2.1) Ground plan of Fossil Grove. See text for explanation (After MacGregor and Walton 1972).

(Figure 2.2) Sketch of the features seen from the eastern balcony. Numbers and letters refer to (Figure 2.1).

(Figure 2.3) Carboniferous non-marine fossils.

(Figure 3.1) Simplified geological map of the Milngavie and Mugdock area.

(Figure 3.2) View to the north from Locality 4. P = car park, ORS = Old Red illustrates this view.

(Figure 4.1) Sketch of geology in stream section at the Linn of Baldernock.

(Figure 4.2) Sketch of Blairskaith Quarry.

(Figure 4.3) Some fossils from Blairskaith Quarry.

(Figure 5.1) Geological map of the Campsie Glen district.

(Figure 6.1) Geological map of the area near Corrie Burn.

(Figure 7.1) Geological map of the north-western part of Dumbarton Rock.

(Figure 7.2) Diagrammatic representation of three stages in the development of the Dumbarton Rock vent: 1) active volcano; 2) withdrawal of magma accompanied by fracturing and subsidence; 3) emplacement of plug basalt.

(Figure 8.1) Plants from the Lower Old Red Sandstone of Auchensail Quarry. a. Sawdonia ornata (reconstruction, × 0.1), b. Sawdonia ornata (stems, × 0.05), c. Drepanophycus spinæformis (reconstruction, × 0.15) [Redrawn after Rolfe, 1976]

(Figure 8.2) Map, with illustrative sections and plans, of Ardmore Point.

(Figure 9.1) Showing the relationship between the uplift of a basement and the accumulation of the sediments, sand and gravels, which have been eroded off it. The basement in this example has been thrust over the sediment pile which has accumulated in a basin which is to the right in the diagram. Gravels accumulate near to the source and sands further away. The volume of material removed from the basement is represented by the envelope in dotted lines; the present land surface exposes the metamorphic zones, with the lowest (GS=green-schist) going via E=epidote–amphibolite facies; AA=lower amphibolite facies, to MA=middle amphibolite facies (the highest) The times at which the rocks cooled are given in Ma= millions of years, and the thick lines join all points which cooled at the age given. In the example illustrated the centre of the basement pile was uplifted first (it has the oldest ages of 500Ma) and from this region there was the greatest removal of overlying rock.

(Figure 9.2) Illustrates a similar structural situation in which the basement as in (Figure 9.1) was uplifted at the same time as sediments were accumulating in a basin which is now juxtaposed against it. The sediment in the basin is shale which is not the sediment expected from the erosion of an adjacent mountain compare (Figure 9.1) This situation implies that these two blocks (shale basin and basement) had a history which is not compatible with their having been formed adjacent to each other.

(Figure 9.3) Geological map of part of the Balmaha region with Localities. HBC = Highland Border Complex; ORS = Old Red Sandstone; GF = Gualann Fault; HBF = Highland Boundary Fault. Serpentinous Lst, Conglomerate etc. refers to rocks which include detrital as well as tectonic fragments of serpentinite. The conglomerates are marked 1, 2, 3 in the local order; they bear no relationship to the regional order.

(Figure 9.4) A compound section of the post Dalradian rocks at Balmaha, together with the localities where they are to be seen. In this section the Highland Border Complex is seen to be repeated: there is a southern sequence (mainly overlain by Upper Old Red Sandstone) and a northern sequence which is seen at Arrochymore Point.

(Figure 9.5) Detail of the geology of Arrochymore Point, with localities.

(Figure 9.6) A showing the simple overlap of sediment towards the SW as mapped out in (Figure 9.3), but with the beds brought back to horizontal as at the time of deposition. The sediments rest on an eroded surface of Highland Border Complex, a, b, c, d. B, showing the overlap of the beds now rotated as seen in the map ((Figure 9.3)) where they outcrop on the land surface. The basement to the basin and the basin itself is projected vertically and along the plane of unconformity. The present map is then seen to be a section through a basin which extends upward and downward.

(Figure 9.7) Simplified sections through the rocks at Balmaha, A shows the present configuration of the rocks, B, the configuration at the time of deposition of the Lower Old Red Sandstone.

(Figure 10.1) Geological map of the Aberfoyle district with locality numbers.

(Figure 10.2) Geological map of Limecraig Quarry and environs, with locality numbers (From Bluck et al 1984).

(Figure 10.3) (a) Geological cross section (as indicated on (Figure 10.2)); (b), the attitude of the Highland Border Complex at the time of Lower Old Red Sandstone deposition. (from Bluck et al 1984).

(Figure 10.4) Diagrammatic section from south to north along the excursion route to show how the folding can be interpreted from the exposures visited.

(Figure 11.1) Locations (a), metamorphic isograds and cross-section (to east of Loch Lomond–(b) illustrating the main geological features.

(Figure 11.2) Summary of phases of metamorphic mineral growth in relation to major episodes.

(Figure 11.3) Map of Rudha Mor and examples of structural features.

(Figure 11.4) Map of Rudha Dubh and examples of structural features.

(Figure 12.1) Geological map of Sithean Sluaigh (adapted from Smith 1965) Numbers (e.g. 6543) refer to specimens in the Hunterian Museum.

(Figure 13.1) Regional setting of the Localities 1–8 described in this guide. Dalradian rocks are shown by a dotted ornament. m, Loch Lomond Readvance terminal moraine.

(Figure 13.2) Schematic cross-section parallel to the Gare Loch (Figure 13.1) showing the main structural elements in the area. HBF, Highland Boundary Fault.

(Figure 13.3) Vertical section showing in cartoon form the style, orientation and sequence of deformations along the section shown in (Figure 13.2) Numbers 1–8 refer to the Localities described in this guide.

(Figure 13.4) a) True-scale drawing of geological features seen at Locality 1 on the headland in Camsail Bay, viewed from the NE. Younging directions are shown by a short arrow: c, cross-bedding; g, graded bedding. x, locality where bedding-cleavage intersection lineation can be seen. b) Locality and outline stratigraphical map of the area around Rosneath. R1 & 2 are localities from Roberts (1977) c) three-dimensional sketch of an idealised fold. d) Geometry of kink bands at Locality 1. s₁ maximum principal compressive stress. HBF, Highland Boundary Fault.

(Figure 13.5) a) Down-plunge true-scaled d awing of a D₂ fold at Locality 2. L, location of bedding-cleavage intersection lineation; S, possible stretching lineation. b) Close-up view of the D₂ cleavage showing the deformed D₁ cleavage.

(Figure 13.6) Sketch showing the salient features of the disharmonic, curvilinear late folds (?D₄) at Locality 3. Arrows indicate the approximate direction of plunge of the fold hinges.

(Figure 13.7) Composite diagram showing the geometrical relationships between:- a) D₂ folds; b) D₂ penetrative cleavage in phyllite, and c) lineated quartz veins, at Locality 4. k, kink bands; s, bedding trace on D₂ cleavage.

(Figure 13.8) Composite diagram showing the relationships between inverted bedding (b), D₁ cleavage and D₂ microlithons (m) at Locality 5.

(Figure 13.9) Sketch map showing the location at Portincaple of sections AB (Locality 6), CD (Locality 7) on (Figure 13.10) and of dykes Da-d mentioned in the text.

(Figure 13.10) True-scaled N–S sections at Portincaple along lines AB, CD (Localities 6 & 7) on (Figure 13.9) Locations a-f referred to in the text.

(Figure 13.11) Sketch of the fabrics seen on a flat rock face at location f, (Figure 13.10) at Portincaple. See text for explanation. The convergence of the top right and bottom left sides of the drawing is partly the result of perspective.

(Figure 14.1) Geological map of the area from Greenock to Largs.

(Figure 15.1) Simplified geological map of Great Cumbrae.

(Figure 16.1) Explanation of the structural and stratigraphical context of the Upper Old Red Sandstone basin. A, Cross section, B, Interpretation of the upward fining megacycles in terms of contemporary faulting, C, Explanation of the regional control on the basin formation. A sinistral movement on a fault (the Highland Boundary Fault or some fault which may be associated with it) which has a bend in the region of Arran, caused extension in the areas a-b in Ci. There is extension here because it is difficult to move material on the south side of the fault around the bend at (a) Because of this extension there is a sequence of normal faults developed which form the basins at (d, e, f, g) (Cii) where (d) is the basin at Rosneath, (e) at Wemyss Bay and (f) at Portencross. (g) is a remaining source block on Arran. HBFZ, Highland Boundary Fault Zone; SUF, Southern Uplands Fault

(Figure 16.2) The effects of changing slope, distance from source, grain-size and the water depth on the structure of alluvium. These changes are seen not only in the structure of the bars but also in the structure of the overbank (floodplain) areas. A, alluvial fans (a), lakes or alluvium (b) and internal structure (c) B, gravel bars with coarse heads (a) and fine tails (b) and with coarse floodplain sediments (c) C, deeper channels than B, with well defined bars (a) and splays of sand (b) into the floodplain areas (c) D, deep channels (b) with sandy bars (a) and crevasse splays (c); deltas (d), dunes (e) and temporary lakes (f).

(Figure 16.3) Explanation of upward coarsening units with head (coarse) differentiated from the tail (fine) and with the head migrating over the tail to form the upward coarsening structure.

(Figure 16.4) Map of localities along the Firth of Clyde, which are also positioned on a composite stratigraphical sequence.

(Figure 16.5) Explanation of the development of caliche. A traces the stages in its development through time in section. Stage 1, at the initial stage only nodules form but as time proceeds the nodules coalesce into pillars if the muds are mudcracked or into larger nodules if not. Stage 3 occurs when the pillars and nodules grow into a massive bed; and stage 4 occurs when the massive bed no longer lets water through and pools appear on the surface in which pisoliths form. B, provides an explanation for the growth of caliche; d refers to the depth to which percolation of the rainwater normally goes. C, the development of thick beds of stage 1 or 2 etc occurs when there is a continous addition of sediment to the surface, so that the depth of water percolation dl, and the zone of nodule formation Z1 rises as the sediment is added. The surface does not mature because the process is not operating in the same zone (Z1) for a sufficient length of time.

(Figure 16.6) Map of the region: Inverkip–Wemyss Bay.

(Figure 16.7) A, Section through sediment bar, Locality 4. b1 etc. refers to lithofacies described in the text B, interpretation in terms of an alluvial bar where the head refers to the upstream (coarse) segment and the tail, the downstream fine. The farthest downstream facies is the bar lee where the finest sediment accretes. T=thickness of cross strata; CS=cross strata! dip orientation, both given for the lithofacies (b2 etc) The wall is to the right of the section.

(Figure 16.8) Interpretation of the development of the bar complex at Locality 4; b2 etc. refer to the lithofacies discussed in the text and in (Figure 16.7).

(Figure 16.9) Map of Farland Head with localities and a simplified cross-section A-B.

(Figure 16.10) Map of gravel bar (a) at Locality 8 together with cross strata) dip orientations (b).

(Figure 16.11) Explanation of the development of the gravel bar at Locality 8; a, b etc refer to the location of lithofacies discussed in text and shown in (Figure 16.10).

(Figure 16.12) Map of Bastion Craig (A) together with section (B) Letters in bold capitals refer to lithofacies; letters in lower case to localities. C3 refers to tabular cross strata at the base of the section; C4, to trough cross stratified sands which are the main part of the outcrop; C5 to the thick, coarse-grained tabular cross strata which can be seen only at low tide. At (a) there is a transition between the tabular cross stratified sands of C3 and the trough cross strata of C4; at (b) the C5 the tabular cross stratified pebbly sandstones of C5 grade into the trough cross strata of C4. P = the point from where it is best to see the transitions.

(Figure 16.13) Map of the floodbasins sediments. The lithologies are mapped as set out in the legend, but in addition an interpretation of these lithologies is given by the following codes: Cs=crevasse splays; De=deltas; ch=channels. In this notation deltas (which are the result of crevasse sands building onto the floodplains) are a combination of two gradational or interfingering lithologies- medium grain-size sandstone and pebbly sandstone. Rose diagrams refer to the cross stratification dip directions n=number of readings, L=vector magnitude (which is inversely related to the standard deviation of spread of the data) The diagram total cross strata (overbank) refers to dip directions of the cross strata in the sandstone sheets which have originated as sandstone crevasse splays i.e. De and Cs.

(Figure 16.14) A model of floodbasin deposition for the Bell Stane region. Cs etc refers to text and (Figure 16.13).

(Figure 16.15) Map (A) and cross section (B) of the sandstone body at Seamill, Locality 11. Letters in capitals refer to lithofacies, letters in lower case to localities. C2, refers to the soft, friable large-scaled cross strata; C3, to the tabular cross stratified sand sheets; C4, the trough cross stratified deposits and C5 the tabular, pebbly sandstones. At a, C2 interfingers with C3; at bi and bii C4 interfingers and grades into C3; and at c, C5 grades with C4.

(Figure 16.16) Explanation of the Seamill sandstone body, Locality 11. C2 etc as for (Figure 16.15) and text.

(Figure 17.1) Geological map of the coast near Saltcoats.

(Figure 18.1) Plan of Loanhead Quarry.

(Figure 19.1) Plan view and section of Boyleston Quarry showing the approximate positions of Localities 1–5.

(Figure 19.2) Sketch section, from photographs, of the erosional channel in the upper surface of Lava 2.

(Figure 20.1) Location map for Trearne Quarry.

(Figure 20.2) The Carboniferous stratigraphy of North Ayrshire.

(Figure 20.3) Trearne quarry and localities within it.

(Figure 20.4) Stratigraphical column for Trearne Quarry.

(Figure 20.5) Fossils from Trearne Quarry.

(Figure 20.6) More fossils from Trearne Quarry.

(Figure 21.1) Sketch maps of geological section seen in the Ree Burn–Glenbuck Loch traverse (le ft) and of position of Shiel Burn Fish Bed locality (right).

(Figure 21.2) Some of the fish (a-g), eurypterids (h, i) and plant (j) fossils that occur in the Fish Bed: all natural size unless otherwise indicated. a, b, thelodont Lanarkia spinosa (after Traquair), a, as it appears flattened in the rock (Logania taiti also occurs here–compare with (Figure 22.1) b); b, detail of trunk denticles (× 6); c, unarmoured anaspid Lasanius problematicus (after Parrington and Miles); d, armoured anaspid Birkenia elegans (after Stetson, Heintz and Ritchie) denticles are sub-circular, crenulated and interlocking, whereas posteriorly they become more elongate and spined ((Figure 22.1) c-e) The thelodonts Lanarkia horrida, L. spinosa and L. spinulosa are similar to Logania in body form, but their denticles are distinctive in being relatively long, hollow, conical spines ((Figure 21.2) a, b).

(Figure 22.1) Some of the fossils at the Jamoytius horizon: two-thirds natural size unless otherwise indicated. a-e, jawless fish: a, anaspid Jamoytius kerwoodi (after Miles and Ritchie); b-e, Logania [Thelodus] scotica, b, dorsal aspect as it appears flattened in the rock, (after Traquair); c-e, details of skin denticles; c, head denticle, × 24; d, e, trunk denticles; showing d, how they occur on the body, × 8, e, × 24 (c, e, after Gross; d, after Traquair) f, g, crustaceans; f, water-flea Beyrichia cf. kloedeni. × 6 (modified from Henningsmoen); g, pod-shrimp Ceratiocaris papilio, (after Rolfe); h, ?sea-squirt Ainiktozoon loganense (after Ritchie; i, fragment of the possible crustacean Dictyocaris × 114 (after Størmer), stipple indicates network ornament.

(Figure 22.2) Some of the fossil chelicerates from the Jamoytius horizon. a, ?aquatic scorpion Allopalaeophonus caledonicus × 2112 (after Petrunkevitch); b-d, eurypterids (water-scorpions, after Størmer); b, Slimonia acuminata × 116; c, Hughmilleria lanceolata × 112; d, Erettopterus [Pterygotus] bilobus, × 1/6; e, early king crab Cyamocephalus loganensis × 2/3 (after Stormer) The eurypterids are rare at this horizon, but occur more abundantly at Shank Castle, Dunside.

(Figure 23.1) Geological map of the Lugar Water.

(Figure 24.1) Geological map of Heads of Ayr district.

(Figure 24.2) Detailed geological map of the Heads of Ayr vent.

(Figure 25.1) Simplified geological map of the Girvan district showing the relationships between the major rock units.

(Figure 25.2) The Lower Palaeozoic successions in the Girvan district and their chronostratigraphical ages.

(Figure 25.3) A. Section through typical oceanic crust. B. Diagram showing how oceanic crust is created in an instance of a rapidly growing plate. The peridotite of A belongs to the lithospheric mantle of B.

(Figure 25.4) Compound section through the Ballantrae Complex showing some of the absolute age determinations (the various methods used are shown by the conventional symbols K-Ar etc) and fossil ages (p) On the left of the section the various elements of the complex are interpreted in terms of a conventional ophiolite.

(Figure 25.5) Diagram showing the various ways in which ophiolites form, together with some of the main characteristics which typifies each one. A. Formation at a spreading ridge; B. At an ocean seamount, C. At a marginal basin-arc. SL = sea level. The symbols are as for (Figure 25.3) and 25.4.

(Figure 25.6) Origin and development of a marginal basin. A. Section through a developed marginal basin. B. Stages in the growth of a marginal basin. Stage 1, the splittting of an arc, Stage 2, the development of new ocean crust in the rifted arc, Stage 3, the development of a wide ocean basin. RA, remnant arc. CS = coarse sediment; FS = fine sediment.

(Figure 25.7) Simplified map of the northern part of the Ballantrae Complex, with positions of localities mentioned in Excursions 25 and 26.

(Figure 25.8) Map of the Pinbain Block showng lateral extent of some of the lavas.

(Figure 25.9) Sketch map to illustrate the geology at Locality 2, Pinbain Block. LW and HW refer to low and high water marks.

(Figure 25.10) Map of the southern end of Slockenray. The north margin of map begins at the headland which divides this map from (Figure 25.12), and the two lava types–porphyritic and dark aphyric (not subdivided in the map) They both belong to the Slockenray spilite of the caption.

(Figure 25.11) Explanation of the Slockenray sequence. A. Two lava flows, one porphyritic, the other dark aphyric, are both simultaneously extruded and flow together towards the coastline where they both build out delta cones adjacent to each other, each cone being sourced by their individual lava types. When one lava type becomes dominant the boundary between them i_L) changes position to extend the area of the dominant flow. At the same time the delta produced by the dominant lava expands at the expense of the delta produced by the less dominant lava and the boundary between them (i_D) is affected. B, shows the location of the Slockenray section and the interfingering of the hyalotuff delta deposits which may have been caused by the growth of one delta at the expense of the other.

(Figure 25.12) Map of the north of Slockenray headland, showing the sequence above the lavas. The south margin of the map is north of the car park and a key point in locating the exposures with reference to the map is the small wall on the edge of the road as marked on the map. Lava type 1 refers to the porphyritic spilite; type 2 to the aphyric.

(Figure 25.13) Explanation of the development of various lava structures and tuffs in lavas which enter the sea from the land. A, the lava front is moving slowly and as it enters the sea where it is rapidly chilled, all of it is converted to tuff at the shoreline. Waves and currents move the tuff offshore. If the tuffs are generated in sufficient abundance then the lavas will flow over them to build up a hyalotuff delta, as seen at Slockenray. B, Lava is moving sufficiently rapidly to enter into the sea, but much of its outer skin is chilled by contact with the sea water. The chilled skin is inflated by magma which is under pressure and many pillows are produced. C, the lava advance is rapid, so that the outer skin chills and forms pillows, either by contact with water at its top surface or by tuff at the base. However the rapidly moving interior is insulated by this pillow growth and cools to form a massive lava which cannot be chilled by contact with the sea water. The porphyritic lava at Slockenray is of this type: it is pillowed at the top and sometimes at the base, but has a thick, massive interior.

(Figure 25.14) Explanation of the sediment-lava cycles in the Pinbain Block and elsewhere. When the rate of lava extrusion is rapid or the rate of sea-level change is slow, the lavas advance into the sea. Because of seawater-lava interactions, where the lavas break down by explosive or erosional activity, lavas are always associated with tongues of lava entirely enclosed in breccia. However further towards the source of the lavas there are fewer breccia deposits. Shales and cherts on the other hand accumulate in deeper water and associated with them are tuffs which were deposited there either by air-fall (from explosive activity), storm deposition or turbidites. When volcanic activity has ceased or is waning the sea transgresses over the lavas to yield well rounded conglomerates, sometimes with reddened clasts if the lavas have been subject to subaerial exposure. This association of lava and breccia is common in nearly all the major lava sequences at Ballantrae, and in this Pinbain section massive lavas characterize Pinbain Hill; interfingers of breccias and lavas are seen on the coastal section (Localities 1–10) Transgressive conglomerates are seen at Localities 2 and 7).

(Figure 25.15) Plane-table map of the region near Pinbain Burn. Letters a, b etc refer to localities discussed in the text; inset is the approximate position of (Figure 25.16).

(Figure 25.16) Plane table map of the ground south of Pinbain Burn (see (Figure 25.15) for position).

(Figure 25.17) Plane-table map of Bonney's Dyke.

(Figure 26.1) Map of the metamorphic sole at Knocklaugh, Excursion 26.

(Figure 26.2) Detailed map showing the relationship between the dykes and the metamorphic sole at Knocklaugh (see Locality 7).

(Figure 26.3) Possible explanation of the metamorphic sole to the ophiolite. A an arc, because of changes in the location and sense of subduction, is driven towards the source of the plate which created it. In colliding with the under-riding plate it underplates onto it the high pressure rocks belonging to this oceanic plate (B) But only fragments of this plate are accreted to the sole of the arc (C).

(Figure 26.4) General map of the Carleton Hill–Knockormal area, Locality 8.

(Figure 26.5) Detailed map showing the locations of the outcrops discussed (Locality 8).

(Figure 27.1) Simplified map of Bennane Head. In the breccia symbol, C refers to coarse, F refers to fine grain size. (Note that the A77 road has been rerouted to the east of Bennane Hill and reaches the coast at the south of this map.)

(Figure 27.2) Graptolites recovered from the Bennane Head sequence by Stone and Rushton (1983) a, b. Tetragraptus approximatus, c. Tetragraptus reclinatus reclinatus. d. Sigmagraptus praecursor, e. Tetragraptus fruticosus, f. Isograptus caduceus, g, h. Pseudoisograptus dumosus

(Figure 27.3) Detailed plane-table map of the contact beween the serpentinite and the dolerite-tuff and chert; the cherts and conglomerates and associated rocks, N of Bennane Lea.

(Figure 27.4) Diagram showing in A the structures typical of the cherts south of Bennane Head. The folds, with associated injection features, were probably formed at position 1; the extensional structures probably formed in position 2. B shows the structures which may occur when a large scale slump takes place.

(Figure 27.5) Maps showing the location of the pillows north of Downan Point, Locality 6. A, detailed map, LW, low water and HW high water marks; B, general map of the region.

(Figure 27.6) A, sketch showing the details of some of the pillows. The outer surface (a) is chilled, and can rarely be seen as a glass; mostly it is glass which has been almost totally replaced by chlorite, thus giving many of the pillows a green external colour. The interior of the pillow often has vesicles (b) which may be in radiating trails or in concentric lines which are preferentially developed towards the top of the pillows. The spaces beween the pillows are often filled with a fibrous calcite (c) and the centre of the pores may be filled with chert (d) B, illustrates two tubes T1 and T2 in section, with the lavas flowing from the right. T1 has provided the relief over which T2 has flowed; P are the two pillow-buds (incipient pillows) developed on the top of T2, and one pillow probably flopped over after it was inflated. The dark area is unfilled space. C is a plan sketch of the base of a sequence of pillow lavas. T1, T2 and T3 are the bases of three tubes. T1, 2 in particular have grown many pillow-buds b1 and b2, and some pillows (P) The dark areas are pore-space fillings which occur between the tubes and pillows. D, a section through a pillow which, when inflated did not fill with lava. It was subsequently partly filled with chert.

(Figure 28.1) a,b A panoramic geological map from Kennedy's Pass to Girvan showing the disposition of the main groups and formations and their re lationships.

(Figure 28.2) A detailed geological map of the southern end of Byne Hill (see also (Figure 28.1).

(Figure 29.1) Generalised succession in the Brockloch area.

(Figure 29.2) A geological map of the upper Stinchar Valley.

(Figure 29.3) A detailed locality map of the Doularg Formation and its members in the Plantation Burn, east of Doularg Farm.

(Figure 29.4) The succession in the Plantation Burn, east of Doularg Farm.

(Figure 29.5) Local correlation within the Barr and Albany groups in the upper Stinchar Valley, showing depositional environments.

(Figure 29.6) Chronostratigraphical correlation of the upper Stinchar Valley successions.

(Figure 30.1) Detailed geological map of the area around Kennedy's Pass.

(Figure 30.2) Detailed geological map of the central part of the Whitehouse Shore.

(Figure 30.3) Detailed geological map of the foreshore at Port Cardloch.

(Figure 30.4) Simplified geological map of Woodland Point.

(Figure 30.5) Stratigraphical sketch section, illustrating the nature of the sub-Silurian unconformity in the Girvan district, which is believed to reflect submarine channelling across pre-Silurian fault blocks: basement faulting has not only controlled Ordovician sedimentation but the effects continue into the Silurian.

(Figure 30.6) Detailed geological map of part of the foreshore at Myoch Bay (Shalloch Mill)

(Figure 30.7) A selection of trilobites and brachiopods from various horizons in the Ordovician strata of the Girvan district.

(Figure 30.8) Detailed map of the geology around Craigskelly: the strata are almost vertical so that outcrop widths reflect thicknesses.

(Figure 31.1) Geological map of the area around Craighead Quarry.

(Figure 31.2) Geological map of the central sector of the Craighead Inlier

(Figure 31.3) Detailed geological map of the area adjacent to Lady Burn (Threave Glen) (after Harper 1982).

(Figure 31.4) Geological map of part of the north· eastern sector of the Craighead Anticline.

(Figure 31.5) Detailed geological map around High Mains Farm (after Harper 1981).

(Figure 31.6) A selection of trilobites and other fossils from various horizons in the Silurian strata of the Girvan district.

(Figure 32.1) Locality map and geological succession of Dob's Linn (after Williams 1980, fig . 1).

(Figure 32.2) Ranges of some characteristic genera of the Moffat Shale: dotted line indicates rare occurrence or range recorded from elsewhere (after Williams 1980, fig. 2) All drawings approximately × 1 unless otherwise stated.

(Figure 32.3) Schematic figures illustrating some of the characteristic Upper Ordovician graptolites found at Dob's Linn.

(Figure 32.4) Schematic figures illustrating some of the characteristic Upper Ordovician and Lower Silurian graptolites found at Dob's Linn.

(Figure 32.5) Sketch showing geology and structure of the northern side of the Linn Branch gorge (reproduced from Williams 1988, fig. 3, by permission of the Trustees of the British Museum, Natural History).

(Figure 32.6) Sketch of Linn Branch trench (reproduced from Williams 1988, fig. 4, by permission of the Trustees of the British Museum, Natural History).

(Figure 32.7) Geological sketch map showing localities and approximate positions of Lower Silurian graptolite zones in the sides and stream bed of the Linn Branch burn.

(Figure 32.8) Illustrations of some characterisitic Lower Silurian graptolites found at Dob's Linn (adapted from Webb et al. in press).

(Figure 32.9) Illustrations of some characterisitic Lower Silurian graptolites found at Dob's Linn (adapted from Webb et al. in press).

(Figure 33.1) Location map for Excursion 33. The localities denoted by numbers are those included in the excursion. Other localities mentioned in the text are denoted by capital letters.

(Figure 33.2) Map of the area to the NW of Glasgow, showing locations mentioned in the text of marine deposits of the Windermere Interstadial and on the Loch Lomond Stadial; adapted from Jardine 1986, figure 3.

(Figure 33.3) Composite W-E section formerly exposed at Junction 27 on the M8 motorway near Paisley, showing a roche moutonnee (of dolerite) overlain by till which, in turn, is overlain by laminated clay and fossiliferous marine sediments (Clyde Beds) deposited during the Windermere Interstadial. The overlying layer of fine sandy silt alternating with sand probably represents land conditions. The conditions under which the uppermost bed, of sandy clay, accumulated are uncertain. Adapted from Aspen & Jardine 1968, Figure 1.

Tables

(Table 0.1) Stratigraphical succession for the Glasgow Girvan areas.

(Table 13.1) Stratigraphy of the Dalradian rocks of the Rosneath–Loch Long area Southern Highland Group south of the Aberfoyle Anticline north of the Aberfoyle Anticline Bulirock Greywacke Dunoon Phyllite Beinn Bheula Schists Dunoon Phyllite

(Table 33.1) Summary of the sequence of events in the Glasgow district during the Quaternary Period.