| FIG. | | PAGE |
| 1. | Vesicular structure, Lava from Ascension Island, slightly less than
natural size | [15] |
| 2. | Elongation and branching of steam-vesicles in a lava, Kilninian, Isle
of Mull, a little less than natural size | [17] |
| 3. | Microlites of the Pitchstone of Arran (magnified 70 diameters) | [19] |
| 4. | Perlitic structure in Felsitic Glass, Isle of Mull (magnified) | [19] |
| 5. | Spherulitic structure (magnified) | [19] |
| 6. | Micropegmatitic or Granophyric structure in Granophyre, Mull (magnified) | [20] |
| 7. | Ophitic structure in Dolerite, Gortacloghan, Co. Derry (magnified) | [20] |
| 8. | Variolitic or orbicular structure, Napoleonite, Corsica (nat. size) | [22] |
| 9. | Flow-structure in Rhyolite, Antrim, slightly reduced | [23] |
| 10. | Lumpy, irregular trachytic lava-streams (Carboniferous), East Linton,
Haddingtonshire | [24] |
| 11. | View at the entrance of the Svinofjord, Faroe Islands, illustrating the
terraced forms assumed by basic lavas | [25] |
| 12. | Sack-like or pillow-form structure of basic lavas (Lower Silurian),
Bennan Head, Ballantrae, Ayrshire | [26] |
| 13. | Alternations of coarser and finer Tuff | [34] |
| 14. | Alternations of Tuff with non-volcanic sediment | [35] |
| 15. | Ejected block of basalt which has fallen among Carboniferous shales
and limestones, shore, Pettycur, Fife | [37] |
| 16. | Effects of denudation on a Vesuvian cone | [40] |
| 17. | Section to illustrate the structure of the Plateau type | [43] |
| 18. | Diagram illustrating the structure and denudation of Puys | [45] |
| 19. | Section illustrating submarine eruptions; alternations of lavas and
tuffs with limestones and shales full of marine organisms | [48] |
| 20. | Diagram illustrating volcanic eruptions on a river-plain | [49] |
| 21. | Diagram illustrating volcanic eruptions on a land-surface | [50] |
| 22. | Ground-plans of some volcanic vents from the Carboniferous districts
of Scotland | [55] |
| 23. | View of an old volcanic "Neck" (The Knock, Largs, Ayrshire, a vent
of Lower Carboniferous age) | [56] |
| 24. | Section of neck of agglomerate, rising through sandstones and shales | [58] |
| 25. | Neck filled with stratified tuff | [64] |
| 26. | Section of neck of agglomerate with plug of lava | [65] |
| 27. | Section of agglomerate neck with dykes and veins | [66] |
| 28. | Section of neck filled with massive rock | [68] |
| 29. | Successive shiftings of vents giving rise to double or triple cones | [70] |
| 30. | Section to show the connection of a neck with a cone and surrounding
bedded tuffs | [71] |
| 31. | Diagram illustrating the gradual emergence of buried volcanic cones
through the influence of prolonged denudation
| [75] |
| 32. | Dyke, Vein, and Sill | [80] |
| 33. | Section of Sill or Intrusive Sheet | [83] |
| 34. | Ideal section of three Laccolites. (After Mr. Gilbert) | [86] |
| 35. | Diagram illustrating the stratigraphical relations of the pre-Cambrian
and Cambrian rocks of the North-west Highlands of Scotland | [112] |
| 36. | Map of a portion of the Lewisian gneiss of Ross-shire | [118] |
| 37. | Section showing the position of sills in the mica-schist series
between Loch Tay and Amulree | [124] |
| 38. | Sketch of crushed basic igneous rock among the schists, E. side of
Porth-tywyn-mawr, E. side of Holyhead Straits | [128] |
| 39. | Section across the Uriconian series of Caer Caradoc | [132] |
| 40. | Map of the volcanic district of St. David's | [146] |
| 41. | Section showing the interstratification of tuff and conglomerate
above Lower Mill, St. David's | [154] |
| 42. | Basic dyke traversing quartz-porphyry and converted into a kind of
slate by cleavage. West side of Llyn Padarn | [162] |
| 43. | Section of well-cleaved tuff, grit and breccia passing up into
rudely-cleaved conglomerate and well-bedded cleaved fine
conglomerate and grit. East side of Llyn Padarn | [163] |
| 44. | Section of Clegyr on the north-east side of Llyn Padarn, near the
lower end | [164] |
| 45. | Section across the Cambrian formations of the Malvern Hills, showing
the position of the intercalated igneous rocks. After Phillips | [170] |
| 46. | Section across Rhobell Fawr | [178] |
| 47. | Section at the Slate Quarry, Penrhyn Gwyn, north slopes of Cader Idris | [180] |
| 48. | Sketch-section across Cader Idris | [182] |
| 49. | Section across the Moelwyn Range | [185] |
| 50. | Section across the anticline of Corndon | [190] |
| 51. | Structure in finely-amygdaloidal diabase lava, south of mouth of
Stinchar River, Ayrshire | [193] |
| 52. | View of Knockdolian Hill from the east | [194] |
| 53. | Section across the Lower Silurian volcanic series in the south of
Ayrshire (B. N. Peach) | [197] |
| 54. | Section of part of the Arenig volcanic group, stream south of Bennane
Head, Ayrshire | [198] |
| 55. | Flow-structure in the lowest felsite on the track from Llanberis to
the top of Snowdon | [211] |
| 56. | Section of Snowdon | [212] |
| 57. | Section across the Berwyn Hills. (Reduced from Horizontal Section,
Geol. Surv. Sheet 35) | [219] |
| 58. | Section of the strata on the shore at Porth Wen, west of Amlwch | [223] |
| 59. | Section of intercalated black shale in the volcanic series at Porth
yr hwch, south of Carmel Point, Anglesey | [224] |
| 60. | Green slates overlain with volcanic breccia, Carmel Point | [224] |
| 61. | Blue shale or slate passing into volcanic breccia east of Porth
Padrig, near Carmel Point | [225] |
| 62. | Section of felsites in the Coniston Limestone group, west of Stockdale | [232] |
| 63. | Fine tuff with coarser bands near Quayfoot Quarries, Borrowdale | [234] |
| 64. | Diagram of the general relations of the different groups of rock in
the Lower Silurian volcanic district along the western shore of
Lough Mask | [253] |
| 65. | Veins and nests of sandstone due to the washing of sand into fissures
and cavities of an Old Red Sandstone lava. Turnberry Point, Ayrshire | [283] |
| 66. | Ground-plan of reticulated cracks in the upper surface of an Old Red
Sandstone lava filled in with sandstone. Red Head, Forfarshire | [284] |
| 67. | Section across the volcanic series of Forfarshire
| [286] |
| 68. | Section across two necks above Tillicoultry, Ochil Hills | [288] |
| 69. | Section of the granite core between Merrick and Corscrine | [290] |
| 70. | Section across the three Dirrington Laws, Berwickshire | [291] |
| 71. | Section of Papa Stour, Shetlands, showing sill of spherulitic felsite
traversing Old Red Sandstone and bedded porphyrites (Messrs. Peach
and Horne) | [292] |
| 72. | Section across Northmavine, from Okrea Head to Skea Ness, Shetland,
showing dykes and connected sill of granite and felsite (Messrs.
Peach and Horne) | [292] |
| 73. | Section at the edge of one of the bays of Lower Old Red Sandstone along
the northern margin of Lake Caledonia, near Ochtertyre | [295] |
| 74. | Craig Beinn-nan-Eun (2067 feet), east of Uam Var, Braes of Doune. Old Red
Conglomerate, with the truncated ends of the strata looking across into
the Highlands; moraines of Corry Beach in the foreground | [296] |
| 75. | Section showing the top of the volcanic series at the foot of the
precipice of the Red Head, Forfarshire | [300] |
| 76. | Andesite with sandstone veinings and overlying conglomerate. Todhead,
south of Caterline, coast of Kincardineshire | [303] |
| 77. | Section across the Boundary-fault of the Highlands at Glen Turrit,
Perthshire | [305] |
| 78. | Section across the chain of the Sidlaw Hills near Kilspindie | [306] |
| 79. | Section across the Eastern Ochil Hills from near Newburgh to near
Auchtermuchty | [307] |
| 80. | Generalized section across the heart of the Ochil Hills from Dunning on
the north to the Fife coal-field near Saline on the south | [308] |
| 81. | Diagram of the volcanic series of the Western Ochil Hills | [309] |
| 82. | View of Cnoc Garbh, Southend, Campbeltown. A volcanic neck of Lower Old
Red Sandstone age, about 400 yards wide in its longer diameter | [312] |
| 83. | Section of volcanic series on beach, Southend, Campbeltown | [313] |
| 84. | Section of the base of the volcanic series, Reclain, five miles south of
Pomeroy | [316] |
| 85. | Section of shales and breccias at Crossna Chapel, north-east of Boyle | [316] |
| 86. | Section across the north end of the Pentland Hills, from Warklaw Hill to
Pentland Mains. Length about five miles | [318] |
| 87. | View of the lava-escarpments of Warklaw Hill, Pentland chain, from the
north-west | [319] |
| 88. | Section across the Pentland Hills through North Black Hill and Scald Law.
Length about three miles | [322] |
| 89. | Section from the valley of the Gutterford Burn through Green Law and Braid
Law to Eight-Mile Burn | [322] |
| 90. | Section across the north end of the Pentland Hills, and the southern edge
of the Braid Hill vent. Length about two miles | [324] |
| 91. | Section across the northern end of the Biggar volcanic group, from Fadden
Hill to beyond Mendick Hill | [326] |
| 92. | Section across the southern part of the Biggar volcanic group from
Covington to Culter | [328] |
| 93. | Section from Thankerton Moor across Tinto to Lamington | [328] |
| 94. | Section across the Duneaton volcanic district from the head of the
Duneaton Water to Kirklea Hill | [330] |
| 95. | Cavernous spaces in andesite, filled in with sandstone, John o' Groats
Port, Turnberry, Ayrshire | [333] |
| 96. | Section of andesites, Turnberry Castle, Ayrshire | [334] |
| 97. | Lenticular form of a brecciated andesite (shown in [Fig. 96]), Turnberry,
Ayrshire | [334] |
| 98. | Section across the volcanic area of St. Abb's Head (after Prof. J. Geikie) | [339] |
| 99. | View of terraced andesite hills resting on massive conglomerate, south of
Oban | [341] |
| 100. | Section of lava-escarpment at Beinn Lora, north side of mouth of Loch
Etive, Argyllshire | [342] |
| 101. | Section across Strathbogie, below Rhyme, showing the position of the
volcanic band
| [344] |
| 102. | View of Knockfeerina, Limerick, from the north-east—a volcanic neck of
Upper Old Red Sandstone age | [349] |
| 103. | Section of the volcanic zone in the Upper Old Red Sandstone, Cam of Hoy,
Orkney | [351] |
| 104. | Section of the volcanic zone in the Upper Old Red Sandstone at Black
Ness, Rackwick, Hoy | [351] |
| 105. | Section across the volcanic band and its associated necks, Hoy, Orkney | [352] |
| 106. | Ground-plan of volcanic neck piercing the Caithness Flagstone series on
the beach near John o' Groat's House | [353] |
| 107. | View of the escarpment of the Clyde Plateau in the Little Cumbrae, from
the south-west | [368] |
| 108. | View of the edge of the Volcanic Plateau south of Campbeltown,
Argyllshire | [370] |
| 109. | View of North Berwick Law from the east, a phonolite neck marking one of
the chief vents of the Garleton Plateau. (From a photograph) | [371] |
| 110. | The Bass Rock, a trachytic neck belonging to the Garleton plateau, from
the shore at Canty Bay | [372] |
| 111. | Corston Hill—a fragment of the Midlothian Plateau, seen from the north | [373] |
| 112. | View of Arthur Seat from Calton Hill to the north | [374] |
| 113. | View of Arkleton Fell, part of the Solway Plateau, from the south-west | [376] |
| 114. | Vertical sections of the escarpment of the Clyde plateau from north-east
to south-west | [384] |
| 115. | Section of Craiglockhart Hill, Edinburgh | [387] |
| 116. | Section of the bottom of the Midlothian Plateau, Linnhouse Water above
Mid-Calder Oilworks | [387] |
| 117. | Section of the top of the Midlothian Plateau in the Murieston Water | [388] |
| 118. | Section of Calton Hill, Edinburgh | [389] |
| 119. | Cliff of tuff and agglomerate, east side of Oxroad Bay, a little east
from Tantallon Castle, East Lothian | [391] |
| 120. | Section across part of the Clyde Plateau to the west of Bowling (reduced
from Sheet 6 of the Horizontal Sections of the Geological Survey of
Scotland) | [392] |
| 121. | Diagram illustrating the thinning away southwards of the lavas of the
Clyde Plateau between Largs and Ardrossan. Length about 10 miles | [393] |
| 122. | Diagram illustrating the thinning away eastwards of the lavas of the
Clyde Plateau in the Fintry Hills. Length about 12 miles | [394] |
| 123. | View of the two necks Dumgoyn and Dumfoyn, Stirlingshire, taken from
the south | [395] |
| 124. | Ground-plan of Plateau-vents near Strathblane, Stirlingshire, on the
scale of 6 inches to a mile | [395] |
| 125. | Ground-plans of double and triple necks in the Plateau series, on the
scale of 6 inches to a mile | [396] |
| 126. | Ground-plan of tuff-neck, shore east of Dunbar | [398] |
| 127. | Section across the vents Dumgoyn and Dumfoyn, and the edge of the Clyde
plateau above Strathblane, Stirlingshire | [400] |
| 128. | Section through the large vent of the Campsie Hills | [400] |
| 129. | Diagrammatic section across the central vent of the Clyde plateau in
Renfrewshire | [400] |
| 130. | Section across Southern Berwickshire, to show the relation of the
volcanic plateau to the vents lying south from it | [401] |
| 131. | Section of south end of Dumbuck Hill. East of Dumbarton | [403] |
| 132. | Section across the East Lothian plateau, to show the relative position
of one of the necks | [403] |
| 133. | View of Traprain Law from the south, a phonolite neck of the Garleton
Plateau | [405] |
| 134. | Veins and dykes traversing the agglomerate and tuff of the great
Renfrewshire vent | [408] |
| 135. | "The Yellow Man," a dyke in volcanic tuff and conglomerate on the shore
a little east of North Berwick | [409] |
| 136. | Trachytic sills, Knockvadie, Kilpatrick Hills
| [410] |
| 137. | Section across the edge of the Clyde plateau, south-east of Beith | [411] |
| 138. | Section across the upper part of the Clyde plateau at Kilbirnie, Ayrshire | [411] |
| 139. | Section across the upper surface of the Clyde volcanic plateau, Burnhead,
north-west of Kilsyth | [412] |
| 140. | Section across the upper surface of the Clyde volcanic plateau at Campsie | [412] |
| 141. | Section across western edge of the Garlton plateau | [412] |
| 142. | Section across the Solway plateau | [413] |
| 143. | Section of volcanic vent at East Grange, Perthshire coal-field,
constructed by Mr. B. N. Peach from the rocks exposed in a
railway-cutting, and from plans of ironstone- and coal-pits | [426] |
| 144. | View of the Binn of Burntisland—a volcanic neck of agglomerate | [428] |
| 145. | View of part of the cliffs of vertical agglomerate, Binn of Burntisland | [431] |
| 146. | Diagram of buried volcanic cone near Dalry, Ayrshire. Constructed from
information obtained in mining operations | [434] |
| 147. | Diagram to illustrate how Volcanic Necks may be concealed and exposed | [434] |
| 148. | Section across the Saline Hills, Fife | [435] |
| 149. | Section across the Binn of Burntisland, in an east and west direction | [436] |
| 150. | Section in old quarry, west of Wester Ochiltree, Linlithgowshire.
Calciferous Sandstone series | [437] |
| 151. | Ejected volcanic block in Carboniferous strata, Burntisland | [438] |
| 152. | View of volcanic agglomerate becoming finer above east end of Kingswood
Craig, two miles east from Burntisland | [439] |
| 153. | Alternations of basalt and tuff, with shale, etc., of Kingswood Craig,
Burntisland | [441] |
| 154. | Section of the upper surface of a diabase ("leckstone") sheet, Skolie
Burn, south-east of Bathgate | [443] |
| 155. | Section across the volcanic ridge of the Linlithgow and Bathgate Hills,
showing the intercalation of limestones that mark important
stratigraphical horizons | [444] |
| 156. | Section in Wardlaw Quarry, Linlithgowshire | [445] |
| 157. | Section from Linlithgow Loch to the Firth of Forth | [446] |
| 158. | Section across the Campsie Fells illustrating the contrast between the
sills below and above the plateau-lavas | [447] |
| 159. | Section showing the position of the basic sills in relation to the
volcanic series at Burntisland, Fife | [448] |
| 160. | Sills between shales and sandstones, Hound Point, Linlithgowshire | [449] |
| 161. | Section of Sill, Cramond Railway, Barnton, near Edinburgh | [450] |
| 162. | Intrusive dolerite sheet enclosing and sending threads into portions
of shale, Salisbury Crags, Edinburgh | [452] |
| 163. | Intrusive sheet invading limestone and shale, Dodhead Quarry, near
Burntisland | [452] |
| 164. | Spheroidal weathering of dolerite sill, quarry east of North Queensferry,
Fife. | [455] |
| 165. | Two thin sills of "white trap" injected into black carbonaceous shale
overlying the Hurlet Limestone, Hillhouse Quarry, Linlithgow | [456] |
| 166. | Dyke cutting the agglomerate of a neck. Binn of Burntisland | [457] |
| 167. | Boss of diabase cutting the Burdiehouse Limestone and sending sills and
veins into the overlying shales. Railway cutting, West Quarry, East
Calder, Midlothian | [458] |
| 168. | Side of columnar basalt-dyke in the same agglomerate as in [Fig. 166] | [459] |
| 169. | Dyke rising through the Hurlet Limestone and its overlying shales.
Silvermine Quarry, Linlithgowshire | [460] |
| 170. | Junction of amygdaloidal basalt with shales and limestone, shore, half
a mile east from Kinghorn, Fife | [464] |
| 171. | Columnar basalt, Pettycur, Kinghorn, Fife
| [469] |
| 172. | Section across the Fife band of Sills | [473] |
| 173. | Section across the upper volcanic band of north Ayrshire. Length about
four miles | [474] |
| 174. | Section showing the connection of the two volcanic bands in Liddesdale | [476] |
| 175. | Diagram to show the position of a mass of Upper Old Red Sandstone which
has fallen into the great vent near Tudhope Hill, east of Mosspaul | [476] |