Recurring to the evidence by which it was shown that some at least of the parallel ridges, which together compose the Cordillera, were successively and slowly upthrown at widely different periods; and that the whole range certainly once, and almost certainly twice, subsided some thousand feet, and being then brought up by a slow movement in mass, again, during the old tertiary formations, subsided several hundred feet, and again was brought up to its present level by a slow and often interrupted movement; we see how opposed is this complicated history of changes slowly effected, to the views of those geologists who believe that this great mountain-chain was formed in late times by a single blow. I have endeavoured elsewhere to show,[[21]] that the excessively disturbed condition of the strata in the Cordillera, so far from indicating single periods of extreme violence, presents insuperable difficulties, except on the admission that the masses of once liquified rocks of the axes were repeatedly injected with intervals sufficiently long for their successive cooling and consolidation. Finally, if we look to the analogies drawn from the changes now in progress in the earth’s crust, whether to the manner in which volcanic matter is erupted, or to the manner in which the land is historically known to have risen and sunk: or again, if we look to the vast amount of denudation which every part of the Cordillera has obviously suffered, the changes through which it has been brought into its present condition, will appear neither to have been too slowly effected, nor to have been too complicated.
[21] “Geolog. Transact.,” vol. v, p. 626.
NOTE.—As, both in France and England, translations of a passage in Professor Ehrenberg’s Memoir, often referred to in the Fourth Chapter of this volume, have appeared, implying that Professor Ehrenberg believes, from the character of the infusoria, that the Pampean formation was deposited by a sea-debacle rushing over the land, I may state, on the authority of a letter to me, that these translations are incorrect. The following is the passage in question:—“Durch Beachtung der mikroscopischen Formen hat sich nun feststellen lassen, das die Mastodonten-Lager am La Plata und die Knochen-Lager am Monte Hermoso, who wie die der Riesen-Gürtelthiere in den Dünenhügeln bei Bahia Blanca, beides in Patagonien, unveränderte brakische Süsswasserbildungen sind, die einst wohl sämmtlich zum obersten Fluthgebiethe des Meeres im tieferen Festlande gehörten.”—Monatsberichten der königl. Akad., etc., zu Berlin vom April 1845.
[INDEX
TO CORAL-REEFS.]
The names in italics are all names of places, and refer exclusively to the Appendix: in well-defined archipelagoes, or groups of islands, the name of each separate island is not given.
Abrolhos, Brazil, coated by corals [ 50]
Abrolhos (Australia) [130]
Absence of coral-reefs from certain coasts [ 51]
Acaba, gulf of [147]
Admiralty group [124]
Africa, east coast, fringing-reef of [48]
—— Madreporitic rock of [101]
Africa, east coast [141]
Age of individual corals [57], [64]
Aiou [128]
Aitutaki [114]
Aldabra [139]
Alert reef [123]
Alexander, Grand Duke, island [ 115]
Allan, Dr., on Holuthuriæ feeding on corals [21]
—— on quick growth of corals at Madagascar [62]
—— on reefs affected by currents [ 9]
Alloufatou [119]
Alphonse [139]
Amargoura (Amargura) [119]
Amboina [128]
America, west coast [111]
Amirantes [138]
Anachorites [125]
Anambas [133]
Anamouka, description of [99]
Anamouka [119]
Anadaman islands [132]
Antilles [153]
Appoo reef [134]
Arabia Felix [143]
Areas, great extent of, interspersed with low islands
—— of subsidence and of elevation [ 106]
—— of subsidence appear to be elongated [106]
—— of subsidence alternating with areas of elevation [108]
Arru group [128]
Arzobispo [127]
Ascidia, depth at which found [67]
Assomption [139]
Astova [139]
Atlantic islands [121]
Atolls, breaches in their reefs [31], [81]
—— dimensions of [25]
—— dimensions of groups of [ 71]
—— not based on craters or on banks of sediment, or of ck [69], [71], [72], [73], [ 108]
—— of irregular forms [25], [84]
—— steepness of their flanks [ 26]
—— width of their reef and islets [ 25]
—— their lowness [70]
—— lagoons [29]
—— general range [94]
—— with part of their reef submerged, and theory of [29], [81]
Augustine, St. [120]
Aurora island, an upraised atoll [64], [71], [104]
Aurora [112]
Austral islands, recently elevated [99]
Austral islands [114]
Australia, N.W. coast [130]
Australian barrier-reef [42], [93]
Australian barrier [123]
Babuyan group [134]
Bahama banks [149], [150]
Balahac [133]
Bally [131]
Baring [121]
Barrier-reef of Australia [42], [93]
—— of New Caledonia [44]
Barrier-reefs, breaches through [77]
—— not based on worn down margin of rock [43]
—— on banks of sediment [43]
—— on submarine craters [44]
—— steepness of their flanks [ 39]
—— their probable vertical thickness [43], [76]
—— theory of their formation [76], [78]
Bampton shoal [123]
Banks islands [122]
Banks in the West Indies [147]
Bashee islands [134]
Bass island [115]
Batoa [119]
Beaupré reef [123]
Beechey, Captain, obligations of the author to [ 26]
—— on submerged reefs [27]
—— account of Matilda island [ 60]
Belcher, Captain, on boring through coral-reef [ 59]
Belize reef, off [151]
Bellinghausen [113]
Bermuda islands [153]
Beveridge reef [118]
Bligh [122]
Bolabola, view of [12]
Bombay shoal [136]
Bonin Bay [131]
Bonin group [127]
Borings through coral-reefs [59]
Borneo, W. coast, recently elevated [101]
Borneo, E. coast [131]
—— S.W. and W. coast [ 133]
—— N. coast [133]
—— western bank [136]
Boscawen [119]
Boston [121]
Bouka [124]
Bourbon [138]
Bourou [128]
Bouton [132]
Brazil, fringing-reefs on coast of [48]
Breaches through barrier-reefs [71]
Brook [115]
Bunker [115]
Bunoa [133]
Byron [121]
Cagayanes [133]
Candelaria [124]
Cargados Carajos [138]
Caroline archipelago [125]
Caroline island [115]
Carteret shoal [128]
Caryophyllia, depth at which it lives [66]
Cavilli [133]
Cayman island [152]
Celebes [129]
Ceram [128]
Ceylon, recently elevated [101]
Ceylon [137]
Chagos Great Bank, description and theory of [ 37], [85]
Chagos group [86]
Chagos group [137]
Chama-shells embedded in coral-rock [68]
Chamisso, on corals preferring the surf [ 52]
Changes in the state of Keeling atoll [21]
—— of atolls [74]
Channels leading into the lagoons of atolls [ 30], [82]
—— —— into the Maldiva atolls [33], [35]
—— through barrier-reefs [77]
Chase [120]
China sea [135]
Christmas atoll [60], [ 97]
Christmas atoll [116]
Christmas island (Indian Ocean) [ 137]
Clarence [116]
Clipperton rock [111]
Cocos, or Keeling atoll [15]
Cocos (or Keeling) [137]
Cocos island (Pacific) [111]
Cochin China, encroachments of the sea on the coast [95]
Cochin China [183]
Coetivi [139]
Comoro group [139]
Composition of coral-formations [88]
Conglomerate coral-rock on Keeling atoll [ 20]
—— on other atolls [28]
—— coral-rock [88]
Cook islands, recently elevated [98], [103]
Cook islands [114]
Coral-blocks bored by vermiform animals [21], [88]
Coral-reefs, their distribution and absence from certain areas [50]
—— destroyed by loose sediment [ 53]
Coral-rock at Keeling atoll [20]
—— Mauritius [47]
—— organic remains of [88]
Corals dead but upright in Keeling lagoon [ 22]
—— depths at which they live [ 64]
—— off Keeling atoll [17]
—— killed by a short exposure [ 16]
—— living in the lagoon of Keeling atoll [20]
—— quick growth of, in Keeling lagoon [21]
—— merely coating the bottom of the sea [50]
—— standing exposed in the Low archipelago [96]
Corallian sea [94]
Corallian sea [123]
Cornwallis [121]
Cosmoledo [139]
Couthouy, Mr., alleged proofs of recent elevation of the Low archipelago [96]
—— on coral-rock at Mangaia and Aurora islands [64]
—— on external ledges round coral-islands [80]
—— remarks confirmatory of the author’s theory [96]
Crescent-formed reefs [84]
Cuba [150]
Cuming, Mr., on the recent elevation of the Philippines [101]
Dangerous, or Low archipelago [ 111]
Danger islands [116]
Depths at which reef-building corals live [ 63]
—— at Mauritius, the Red Sea, and in the Maldiva archipelago [66]
—— at which other corals and corallines can live [67]
Dhalac group [144]
Diego Garcia, slow growth of reef [56]
Dimensions of the larger groups of atolls [ 71]
Disseverment of the Maldiva atolls, and theory of [37], [82]
Distribution of coral-reefs [50]
Domingo, St. [152]
Dory, Port, recently elevated [100]
Dory, Port [127]
Duff islands [122]
Durour [125]
Eap [126]
arthquakes at Keeling atoll [23]
—— in groups of atolls [75]
—— in Navigator archipelago [ 100]
ast Indian archipelago, recently elevated [ 100]
Easter [111]
Echequier [125]
hrenberg, on the banks of the Red Sea [49], [143]
—— on depths at which corals live in the Red Sea [66]
—— on corals preferring the surf [ 53]
—— on the antiquity of certain corals [57]
Eimeo [112]
levated reef of Mauritius [47]
levations, recent proofs of [98]
—— immense areas of [106]
Elivi [126]
lizabeth island [59]
—— recently elevated [98], [104]
Elizabeth island [112]
Ellice group [120]
ncircled islands, their height [41]
—— geological composition [42], [44]
ua, description of [99]
Eoua [118]
upted matter probably not associated with thick masses of coral-rock [89]
Fais, recently elevated [100], [104]
Fais [126]
Fanning [116]
Farallon de Medinilla [127]
Farson group [144]
Fataka [122]
Fiji archipelago [119]
Fish, feeding on corals [21]
—— killed in Keeling lagoon by heavy rain [24]
Fissures across coral-islands [75]
Fitzroy, Captain, on a submerged shed at Keeling atoll [23]
—— on an inundation in the Low archipelago [74]
Flint [115]
Flores [130]
Florida [149]
Folger [127]
Formosa [135]
Forster, theory of coral-formations [73]
Frederick reef [123]
Freewill [128]
Friendly group recently elevated [99], [105]
Friendly archipelago [118]
Fringing-reefs, absent where coast precipitous [ 5]
—— breached in front of streams [ 54]
—— described by MM. Quoy and Gaimard [98]
—— not closely attached to shelving coasts [46]
—— of east coast of Africa
—— of Cuba [48]
—— of Mauritius [45]
—— on worn down banks of rock [ 9]
—— on banks of sediment [49]
—— their appearance when elevated [ 7]
—— their growth influenced by currents [49]
—— by shallowness of sea [49]
Galapagos archipelago [111]
Galega [139]
Gambier islands, section of [43]
Gambier islands [112]
Gardner [116]
Gaspar rico [121]
Geological composition of coral-formations
Gilbert archipelago [120]
Gilolo [129]
Glorioso [139]
Gloucester island [74]
Glover reef [152]
Gomez [111]
Gouap [126]
Goulou [126]
Grampus [127]
Gran Cocal [120]
Great Chagos Bank, description and theory of [ 37], [85]
Grey, Captain, on sandbars [46]
Grouping of the different classes of reefs [ 93]
Guedes [128]
Hall, Captain B., on Loo Choo [101]
Harvey islands, recently elevated [104]
Height of encircled islands [41]
Hermites [125]
Hervey or Cook islands [114]
Hogoleu [125]
Holothuriæ (Holuthuriæ) feeding on coral [21]
Houden island, height of [71]
Honduras, reef off [151]
Horn [119]
Houtman Abrolhos [130]
Huaheine; alleged proofs of its recent elevation [103]
Huaheine [113]
Humphrey [115]
Hunter [119]
Hurricanes, effects of, on coral-islands [ 74]
Immaum [143]
Independence [120]
India, west coast, recently elevated [ 101]
India [143]
Irregular reefs in shallow seas [49]
Islets of coral-rock, their formation [19]
—— their destruction in the Maldiva atolls [36]
Jamaica [152]
Jarvis [115]
Java, recently elevated [100]
Java [131]
Johnston island [116]
Juan de Nova [139]
Juan de Nova (Madagascar) [140]
Kalatoa [131]
Kamtschatka, proofs of its recent elevation [ 105]
Karkalang [129]
Keeling atoll, section of reef [15]
Keeling, south atoll [137]
—— north atoll [137]
Keffing [128]
Kemin [115], [ 116]
Kennedy [123]
Keppel [119]
Kumi [135]
Laccadive group [137]
Ladrones, or Marianas, recently elevated [ 100]
Ladrones archipelago [127]
Lagoon of Keeling atoll [20]
Lagoons bordered by inclined ledges and walls, and theory of their formation [32], [79]
—— of small atolls filled up with sediment [32]
Lagoon-channels within barrier-reefs [40]
Lagoon-reefs, all submerged in some atolls, and rising to the surface in others [55]
Lancaster reef [115]
Latte [119]
Lauglan islands [123]
Ledges round certain lagoons [32], [79]
Lette [129]
Lighthouse reef [152]
Lloyd, Mr., on corals refixing themselves [ 62]
Loo Choo, recently elevated [101]
Loo Choo [135]
Louisiade [123]
Low archipelago, alleged proofs of its recent elevation [96]
Low archipelago [111]
Lowness of coral-islands [70]
Loyalty group [123]
Lucepara [133]
Lutké, Admiral, on fissures across coral-islands [75]
Luzon, recently elevated [101]
Luzon [134]
Lyell, Mr., on channels into the lagoons of atolls [31]
—— on the lowness of their leeward sides [82]
—— on the antiquity of certain corals [58]
—— on the apparent continuity of distinct coral-islands [89]
—— on the recently elevated beds of the Red Sea [102]
—— on the outline of the areas of subsidence [106]
Macassar strait [131]
Macclesfield bank [136]
Madagascar, quick growth of corals at [62]
—— madreporitic rock of [101]
Madagascar [140]
Madjiko-sima [135]
Madura (Java) [131]
Madura (India) [137]
Mahlos Mahdoo, theory of formation [88]
Malacca, recently elevated [100]
Malacca [133]
Malcolmson, Dr., on recent elevation of W. coast of India [100]
—— on recent elevation of Camaran island [102]
Malden [115]
Maldiva atolls, and theory of their formation [ 33], [80], [82]
—— steepness of their flanks [ 26]
—— growth of coral at [62]
Maldiva archipelago [137]
Mangaia island [64]
—— recently elevated [99], [104]
Mangaia [114]
Mangs [127]
Marianas, recently elevated [100]
Mariana archipelago [127]
Mariere [126]
Marquesas archipelago [113]
Marshall archipelago [121]
Marshall island [127]
Martinique [153]
Martires [126]
Mary’s St. in Madagascar, harbour made in reefs [ 54]
Mary island [116]
Matia, or Aurora [112]
Matilda atoll [60]
Mauritius, fringing-reefs of [45]
—— depths at which corals live there [64]
—— recently elevated [101]
Mauritius [138]
Maurua, section of [43]
Maurua [113]
Menchikoff atoll [25],
Mendana archipelago [113]
Mendana isles [122]
Mexico, gulf of [149]
Millepora complanata at Keeling atoll [16]
Mindoro [134]
Mohilla (Mohila) [139]
Molucca islands, recently elevated [100]
Mopeha [113]
Moresby, Captain, on boring through coral-reefs [ 59]
Morty [129]
Mosquito coast [152]
Musquillo atoll [84]
Mysol [129]
Namourrek group [84]
Natunas [133]
Navigator archipelago, elevation of [99]
Navigator archipelago [117]
Nederlandisch [120]
Nelson, Lieutenant, on the consolidation of coral-rocks under water [59]
—— theory of coral-formations [ 73]
—— on the Bermuda islands [ 154]
New Britain [124]
New Caledonia, steepness of its reefs [39]
—— —— barrier-reef of , [79], [83], [93]
New Caledonia [123]
New Guinea (E. end) [124]
New Guinea (W. end) [127]
New Hanover [124]
New Hebrides, recently elevated [100]
New Hebrides [121]
New Ireland, recently elevated [100]
New Ireland [124]
New Nantucket [116]
Nicobar islands [132]
Niouha [119]
Nulliporæ at Keeling atoll [18]
—— on the reefs of atolls [28]
—— on barrier-reefs [39]
—— their wide distribution and abundance [68]
Objections to the theory of subsidence [7]
Ocean islands [117], [121]
Ono [120]
Onouafu (Onouafou) [119]
Ormuz [143]
Oscar group [120]
Oscillations of level [103], [108]
Ouallan, or Ualan (Oualan) [125]
Ouluthy atoll [60]
Outong Java [124]
Palawan, S.W. coast [133]
—— N.W. coast [134]
—— western bank [136]
Palmerston [114]
Palmyra [116]
Paracells [136]
Paraquas [136]
Patchow [135]
Pelew islands [126]
Pemba island, singular form of [102]
Pemba [142]
Penrhyn [115]
Peregrino [115]
Pernambuco, bar of sandstone at [47]
Persian gulf, recently elevated [102]
Persian gulf [143]
Pescado [115]
Pescadores [135]
Peyster group [120]
Philip [126]
Philippine archipelago, recently elevated [ 101]
Philippine archipelago [134]
Phœnix [116]
Piguiram [126]
Pitcairn [112]
Pitt’s bank [86]
Pitt island [120]
Platte [139]
Pleasant [121]
Porites, chief coral on margin of Keeling atoll [ 16]
Postillions [131]
Pouynipète [95]
—— its probable subsidence [ 95]
Pouynipète [125]
Pratas shoal [135]
Proby [119]
Providence [139]
Puerto Rico [152]
Pulo Anna [126]
Pumice floated to coral-islands [88]
Pylstaart [118]
Pyrard de Laval, astonishment at the atolls in the Indian Ocean [11]
Quoy and Gaimard, depths at which corals live [ 66]
—— description of reefs applicable only to fringing-reefs [98]
Range of atolls [94]
Rapa [115]
Rearson [115]
Red Sea, banks of rock coated by reefs [ 49]
—— proofs of its recent elevation [ 102]
—— supposed subsidence of [ 103]
Red Sea [143]
Reefs, irregular in shallow seas [49]
—— rising to the surface in some lagoons and all submerged in others [55]
—— their distribution [50]
—— their absence from some coasts [ 51]
Revilla-gigedo [111]
Ring-formed reefs of the Maldiva atolls, and theory of , [80]
Rodriguez [138]
Rosario [127]
Rose island [118]
Rotches [120]
Rotoumah [120]
Roug [125]
Rowley shoals [130]
Rüppell, Dr., on the recent deposits of Red Sea [102]
Sable, ile de [138]
Sahia de Malha [137]
St. Pierre [139]
Sala [111]
Salomon (Solomon) archipelago [ 123]
Samoa, or Navigator archipelago, elevation of [ 99]
Samoa archipelago [117]
Sand-bars parallel to coasts [46]
Sandal-wood [129]
Sandwich archipelago, recently elevated [ 98]
Sandwich archipelago [117]
Sanserot [126]
Santa-Cruz group [122]
Savage island, recently elevated [59], [99], [104]
Savage [118]
Savu [129]
Saya, or Sahia de Malha [137]
Scarborough shoal [136]
Scarus feeding on corals [21]
Schouten [124]
Scilly [113]
Scoriæ floated to coral-islands [89]
Scott’s reef [130]
Sections of islands encircled by barrier-reefs [ 43], [176]
—— of Bolabola [76]
Sediment in Keeling lagoon [21]
—— in other atolls [29], [35]
—— injurious to corals [53]
—— transported from coral-islands far seaward [89]
Seniavine [125]
Serangani [129]
Seychelles [138]
Ship-bottom quickly coated with coral [62]
Smyth island [116]
Society archipelago, stationary condition of [ 96]
—— alleged proofs of recent elevation [103]
Society archipelago [112]
Socotra [143]
Solor [130]
Sooloo islands, recently elevated [101]
Sooloo islands [133]
Souvaroff [115]
Spanish [126]
Sponge, depths at which found [67]
Starbuck (Slarbuck) [115]
Stones transported in roots of trees [89]
Storms, effects of, on coral-islands [74]
Stutchbury, Mr., on the growth of an Agaricia [ 63]
—— on upraised corals in Society archipelago [103]
Subsidence of Keeling atoll [28]
—— extreme slowness of [87], [108]
—— areas of, apparently elongated [ 106]
—— areas of immense [106]
—— great amount of [108]
Suez, gulf of [147]
Sulphur islands [127]
Sumatra, recently elevated [100]
Sumatra [132]
Sumbawa [130]
Surf favourable to the growth of massive corals [ 52]
Swallow shoal [136]
Sydney island [116]
Tahiti, alleged proofs of its recent elevation [ 103]
Tahiti [112]
Temperature of the sea at the Galapagos archipelago [51]
Tenasserim [133]
Tenimber island [128]
Teturoa [113]
Theories on coral-formations [69], [73]
Theory of subsidence, and objections to [72], [86]
Thickness, vertical, of barrier-reefs [43], [76]
Thomas, St. [153]
Tikopia [122]
Timor, recently elevated [100]
Timor [129]
Timor-laut [128]
Tokan-Bessees [131]
Tongatabou [118]
Tonquin [137]
Toubai [113]
Toufoa (Toofoa) [119]
Toupoua [122]
Traditions of change in coral-islands [73]
Tridacnæ embedded in coral-rock [63]
—— left exposed in the Low archipelago [96]
Tubularia, quick growth of [63]
Tumbelan [133]
Turneffe reef [152]
Turtle [119]
Ualan [125]
Vanikoro, section of [43]
—— its state and changes in its reefs [95]
Vanikoro [122]
Vine reef [125]
Virgin Gorda [153]
Viti archipelago [119]
Volcanic islands, with living corals on their shores [51]
—— matter, probably not associated with thick masses of coral-rock [88]
Volcanoes, authorities for their position on the map [90]
—— their presence determined by the movements in progress [104]
—— absent or extinct in the areas of subsidence [105]
Waigiou [128]
Wallis island [119]
Washington [116]
Wells’ reef [123]
Wellstead, Lieutenant, account of a ship coated with corals [62]
West Indies, banks of sediment fringed by reefs [ 49]
—— recently elevated [102]
West Indies [147]
Whitsunday island, view of [12]
—— changes in its state [74]
Williams, Rev. J., on traditions of the natives regarding coral-islands [74]
—— on antiquity of certain corals [ 64]
Wolchonsky [111]
Wostock [115]
Xulla islands [128]
York island [116]
Yucutan, coast of [151]
Zones of different kinds of corals outside the same reefs [55], [60]
[INDEX TO VOLCANIC ISLANDS.]
Abel, M., on calcareous casts at the Cape of Good Hope [261]
Abingdon island [234]
Abrolhos islands, incrustation on [188]
Aeriform explosions at Ascension [191]
Albatross, driven from St. Helena [ 225]
Albemarle island [234]
Albite, at the Galapagos archipelago [ 234]
Amygdaloidal cells, half filled [184]
Amygdaloids, calcareous origin of [176]
Ascension, arborescent incrustation on rocks of [188]
—— absence of dikes, freedom from volcanic action, and state of lava-streams [226]
Ascidia, extinction of [258]
Atlantic Ocean, new volcanic focus in [ 226]
Augite, fused [239]
Australia [251]
Azores [182], [ 248]
Bahia in Brazil, dikes at [247]
Bailly, M., on the mountains of Mauritius [ 185]
Bald Head [260]
Banks’ Cove [234], [ 236]
Barn, The, St. Helena [216]
Basalt, specific gravity of [245]
Basaltic coast-mountains at Mauritiu [ 185]
—— at St. Helena [218]
—— at St. Jago [178]
Beaumont, M. Elie de, on circular subsidences in lava [233]
—— on dikes indicating elevation [ 228]
—— on inclination of lava-streams [ 227]
—— on laminated dikes [212]
Bermuda, calcareous rocks of [260], [262]
Beudant, M., on bombs [191]
—— on jasper [197]
—— on laminated trachyte [ 211]
—— on obsidian of Hungary [ 207]
—— on silex in trachyte [270], [197]
Bole [257]
Bombs, volcanic [189]
Bory St. Vincent, on bombs [190]
Boulders, absence in Australia and Cape of Good Hope [265]
Brattle island [238]
Brewster, Sir D., on a calcareo-animal substance [201]
—— on decomposed glass [252]
Brown, Mr. R., on extinct plants from Van Diemen’s land [257]
—— on sphærulitic bodies in silicified wood [207]
Buch, Von, on cavernous lava [233]
—— on central volcanoes [249]
—— on crystals sinking in obsidian [ 243]
—— on laminated lava [209]
—— on obsidian streams [208]
—— on olivine in basalt [234]
—— on superficial calcareous beds in the Canary islands [224]
Calcareous deposit at St. Jago affected by heat [169], [171]
—— fibrous matter, entangled in streaks in scoriæ [174]
—— freestone at Ascension [ 198]
—— incrustations at Ascension [ 199]
—— sandstone at St. Helena [ 222]
—— superficial beds at King George’s sound [260]
Cape of Good Hope [263]
Carbonic acid, expulsion of, by heat [171], [176]
Carmichael, Capt., on glassy coatings to dikes [216]
Casts, calcareous, of branches [261]
Chalcedonic nodules [257]
Chalcedony in basalt and in silicified wood [ 196]
Chatham island [231], [ 235], [241], [248], [259]
Chlorophæite [257]
Clarke, Rev. W., on the Cape of Good Hope [ 258], [263]
Clay-slate, its decomposition and junction with granite at the Cape of Good Hope [264]
Cleavage of clay-slate in Australia [ 252]
Cleavage, cross, in sandstone [253]
Coast denudation at St. Helena [226]
Columnar basalt [173]
“Comptes Rendus,” account of volcanic phenomena in the Atlantic [226]
Concepcion, earthquake of [228], [249]
Concretions in aqueous and igneous rocks compared [206]
—— in tuff [197]
—— of obsidian [206], [208]
Conglomerate, recent, at St. Jago [181]
Coquimbo, curious rock of [261]
Corals, fossil, from Van Diemen’s Land [ 256]
Crater, segment of, at the Galapagos [ 238]
—— great central one at St. Helena [ 219]
—— internal ledges round, and parapet on [220]
Craters, basaltic, at Ascension [189]
—— form of, affected by the trade wind [189]
—— of elevation [227]
—— of tuff at Terceira [182]
—— of tuff at the Galapagos archipelago [230], [231], [235], [237]
—— their breached state [240]
—— small basaltic at St. Jago [ 177]
—— —— at the Galapagos archipelago [232]
Crystallisation favoured by space [211]
Dartigues, M., on sphærulites [ 207]
Daubeny, Dr., on a basin-formed island [ 237]
—— on fragments in trachyte [ 193]
D’Aubuisson on hills of phonolite [222]
—— on the composition of obsidian [ 206]
—— on the lamination of clay-slate [ 210]
De la Beche, Sir H., on magnesia in erupted lime [174]
—— on specific gravity of limestones [198]
Denudation of coast at St. Helena [226]
Diana’s Peak, St. Helena [220]
Dieffenbach, Dr., on the Chatham Islands [ 259]
Dikes, truncated, on central crateriform ridge of St. Helena [219]
—— at St. Helena; number of; coated by a glossy layer; uniform thickness of [216]
—— great parallel ones at St. Helena [222]
—— not observed at Ascension [ 226]
—— of tuff [231]
—— of trap in the plutonic series [ 247]
—— remnants of, extending far into the sea round St. Helena [226]
Dislocations at Ascension [192]
—— at St. Helena [217], [221]
Distribution of volcanic islands [248]
Dolomieu, on decomposed trachyte [182]
—— on laminated lava [210], [211]
—— on obsidian [208]
Drée, M., on crystals sinking in lava [ 243]
Dufrenoy, M., on the composition of the surface of certain lava-streams [209], [ 243]
—— on the inclination of tuff-strata [236]
Eggs of birds embedded at St. Helena [ 224]
—— of turtle at Ascension [ 198]
Ejected fragments at Ascension [192]
—— at the Galapagos archipelago [ 239]
Elevation of St. Helena [225]
—— the Galapagos archipelago [ 241]
—— Van Diemen’s Land, Cape of Good Hope, New Zealand, Australia, and Chatham island [258]
—— of volcanic islands [250]
Ellis, Rev. W., on ledges within the great crater at Hawaii [220]
—— on marine remains at Otaheite [ 184]
Eruption, fissures of [224], [249], [250]
Extinction of land-shells at St. Helena [ 224]
Faraday, Mr., on the expulsion of carbonic acid gas [171]
Feldspar, fusibility of [246]
—— in radiating crystals [ 263]
—— Labrador, ejected [193]
Feldspathic lavas [179]
—— at St. Helena [219]
—— rock, alternating with obsidian [ 202]
—— lamination, and origin of [ 209]
Fernando Noronha [181], [ 210]
Ferruginous superficial beds [259]
Fibrous calcareous matter at St. Jago [ 174]
Fissures of eruption [242], [249], [250]
Fitton, Dr., on calcareous breccia [262]
Flagstaff Hill, St. Helena [216]
Fleurian de Bellevue on sphærulites [ 207]
Fluidity of lavas [234], [235]
Forbes, Professor, on the structure of glaciers [212]
Fragments ejected at Ascension [192]
—— at the Galapagos archipelago [ 239]
Freshwater Bay [238], [ 243]
Fuerteventura (Feurteventura), calcareous beds of [224]
Galapagos archipelago [229]
—— parapets round craters [ 220]
Gay Lussac, on the expulsion of carbonic acid gas [171]
Glaciers, their structure [212]
Glossiness of texture, origin of [206]
Gneiss, derived from clay-slate [264]
—— with a great embedded fragment [ 252]
Gneiss-granite, form of hills of [259]
Good Hope, Cape of [263]
Gorges, narrow, at St. Helena [225]
Granite, junction with clay-slate, at the Cape of Good Hope [263]
Granitic ejected fragments [192], [239]
Gravity, specific, of lavas [243-8]
Gypsum, at Ascension [201]
—— in volcanic strata at St. Helena [215]
—— on surface of the ground at ditto [223]
Hall, Sir J., on the expulsion of carbonic acid gas [171]
Heat, action of, on calcareous matter [ 170]
Hennah, Mr., on ashes at Ascension [189]
Henslow, Prof., on chalcedony [197]
Hoffmann, on decomposed trachyte [182]
Holland, Dr., on Iceland [228]
Horner, Mr., on a calcareo-animal substance [ 201]
—— on fusibility of feldspar [ 246]
Hubbard, Dr., on dikes [247]
Humboldt on ejected fragments [193]
—— on obsidian formations [207], [209]
—— on parapets round craters [ 220]
—— on sphærulites [210]
Hutton on amygdaloids [176]
Hyalite in decomposed trachyte [182]
Iceland, stratification of the circumferential hills [228]
Islands, volcanic, distribution of [248]
—— their elevation [250]
Incrustation, on St. Paul’s rocks [187]
Incrustations, calcareous, at Ascension [ 199]
Jago, St. [167]
James island [234], [ 237], [242]
Jasper, origin of [196]
Jonnès, M. Moreau de, on craters affected by wind [189]
Juan Fernandez [250]
Keilhau, M., on granite [264]
Kicker Rock [232]
King George’s sound [259]
Labrador feldspar, ejected [193]
Lakes at bases of volcanoes [229]
Lamination of volcanic rocks [209]
Land-shells, extinct, at St. Helena [ 224]
Lanzarote, calcareous beds of [223]
Lava, adhesion to sides of a gorge [177]
—— feldspathic [179]
—— with cells semi-amygdaloidal [ 184]
Lavas, specific gravity of [243], [247]
Lava-streams blending together at St. Jago [ 177]
—— composition of surface of [ 208]
—— differences in the state of their surfaces [244]
—— extreme thinness of [238]
—— heaved up into hillocks at the Galapagos archipelago [233]
—— their fluidity [234], [235]
—— with irregular hummocks at Ascension [189]
Lead, separation from silver [244]
Lesson, M., on craters at Ascension [ 189]
Leucite [234]
Lime, sulphate of, at Ascension [200]
Lonsdale, Mr., on fossil-corals from Van Diemen’s land [256]
Lot, St. Helena [221]
Lyell, Mr., on craters of elevation [ 227]
—— on embedded turtles’ eggs [ 198]
—— on glossy coating to dikes [ 216]
Macaulay, Dr., on calcareous casts at Madeira [ 262]
MacCulloch, Dr., on an amygdaloid [184]
—— on chlorophæite [ 287]
—— on laminated pitchstone [ 209]
Mackenzie, Sir G., on cavernous lava-streams [ 233]
—— on glossy coatings to dikes [ 216]
—— on obsidian streams [208]
—— on stratification in Iceland [ 228]
Madeira, calcareous casts at [262]
Magazine, Nautical,—account of volcanic phenomena in the Atlantic [226]
Marekanite [206]
Mauritius, crater of elevation of [184], [227]
Mica, in rounded nodules [168]
—— origin in metamorphic slate [ 264]
—— radiating form of [263]
Miller, Prof., on ejected Labrador feldspar [ 193]
—— on quartz crystals in obsidian beds [202]
Mitchell, Sir T., on bombs [191]
—— on the Australian valleys [ 254]
Mud streams at the Galapagos archipelago [ 236]
Narborough island [234]
Nelson, Lieut., on the Bermuda islands [ 260], [262]
New Caledonia [248]
New Red sandstone, cross cleavage of [ 253]
New South Wales [251]
New Zealand [259]
Nulliporæ (fossil), resembling concretions [169]
Obsidian, absent at the Galapagos archipelago [ 241]
—— bombs of [191]
—— composition and origin of [ 207], [208]
—— crystals of feldspar sink in [ 243]
—— its irruption from lofty craters [246]
—— passage of beds into [202]
—— specific gravity of [243], [246]
—— streams of [208]
Olivine decomposed at St. Jago [178]
—— at Van Diemen’s land [257]
—— in the lavas at the Galapagos archipelago [234]
Oolitic structure of recent calcareous beds at St. Helena [223]
Otaheite [183]
Oysters, extinction of [258]
Panza islands, laminated trachyte of [ 209]
Pattinson, Mr., on the separation of lead and silver [244]
Paul’s, St., rocks of [187]
Pearlstone [206]
Peperino [232]
Péron, M., on calcareous rocks of Australia [262], [263]
Phonolite, hills of [179], [181], [221]
—— laminated [210]
—— with more fusible hornblende [ 246]
Pitchstone [204]
—— dikes of [209]
Plants, extinct [257]
Plutonic rocks, separation of constituent parts of, by gravity [246]
Porto Praya [167]
Prevost, M. C., on rarity of great dislocations in volcanic islands [217]
Prosperous hill, St. Helena [218]
Pumice, absent at the Galapagos archipelago [ 241]
—— laminated [209], [210], [211]
Puy de Dome, trachyte of [193]
Quail island, St. Jago [168], [170], [173]
Quartz, crystals of, in beds alternating with obsidian [202]
—— crystallised in sandstone [ 252]
—— fusibility of [246]
—— rock, mottled from metamorphic action with earthy matter [170]
Red hill [173]
Resin-like altered scoriæ [171]
Rio de Janeiro, gneiss of [252]
Robert, M., on strata of Iceland [228]
Rogers, Professor, on curved lines of elevation [249]
Salses, compared with tuff craters [240]
Salt deposited by the sea [200]
—— in volcanic strata [201], [215]
—— lakes of, in craters [240]
Sandstone of Brazil [265]
—— of the Cape of Good Hope [ 265]
—— platforms of, in New South Wales [252], [265]
Schorl, radiating [263]
Scrope, Mr. P., on laminated trachyte [209], [210], [212]
—— on obsidian [208]
—— on separation of trachyte and basalt [244]
—— on silex in trachyte [176]
—— on sphærulites [210]
Seale, Mr., geognosy of St. Helena [215]
—— on dikes [226]
—— on embedded birds’ bones [ 225]
Seale, on extinct shells of St. Helena [ 224]
Sedgwick, Professor, on concretions [ 206]
Septaria, in concretions in tuff [198]
Serpulæ on upraised rocks [185]
Seychelles [248]
Shells, colour of, affected by light [ 201]
—— from Van Diemen’s land [ 256]
—— land, extinct, at St. Helena [ 224]
—— particles of, drifted by the wind at St. Helena [223]
Shelly matter deposited by the waves [ 200]
Siau, M., on ripples [254]
Signal Post Hill [168], [ 175], [176]
Silica, deposited by steam [182]
—— large proportion of, in obsidian [206], [208]
—— specific gravity of [246]
Siliceous sinter [196]
Smith, Dr. A., on junction of granite and clay-slate [264]
Spallanzani on decomposed trachyte [182]
Specific gravity of recent calcareous rocks and of limestone [198]
—— of lavas [245]
Sphærulites in glass and in silicified wood [207]
—— in obsidian [204], [210]
Sowerby, Mr. G. B., on fossil-shells from Van Diemen’s land [256]
—— from St. Jago [169]
—— land-shells from St. Helena [ 224]
St. Helena [214]
—— crater of elevation of [ 227]
St. Jago, crater of elevation of [227]
—— effects of calcareous matter on lava [231]
St. Paul’s rocks [187], [ 248]
Stokes, Mr., collections of sphærulites and of obsidians [207], [212]
Stony-top, Little [218], [222]
—— Great [218]
Stratification of sandstone in New South Wales [253], [255]
Streams of obsidian [208]
Stutchbury, Mr., on marine remains at Otaheite [184]
Subsided space at Ascension [192]
Tahiti [183]
Talus, stratified, within tuff craters [ 236]
Terceira [182]
Tertiary deposit of St. Jago [169]
Trachyte, absent at the Galapagos archipelago [ 241]
—— at Ascension [193]
—— at Terceira [182]
—— decomposition of, by steam [ 182]
—— its lamination [200], [210]
—— its separation from basalt [ 244]
—— softened at Ascension [ 194]
—— specific gravity of [245]
—— with singular veins [195]
Trap-dikes in the plutonic series [247]
—— at King George’s sound [ 259]
Travertin at Van Diemen’s land [257]
Tropic-bird, now rare, at St. Helena [ 225]
Tuff, craters of [231], [ 235], [236]
—— their breached state [240]
—— peculiar kind of [231]
Turner, Mr., on the separation of molten metals [244]
Tyerman and Bennett on marine remains at Huaheine [184]
Valleys, gorge-like, at St. Helena [225]
—— in New South Wales [254]
—— in St. Jago [180]
Van Diemen’s land [256]
Veins in trachyte [195]
—— of jasper [195]
Vincent, Bory St., on bombs [190]
Volcanic bombs [189]
—— island in process of formation in the Atlantic [226]
—— islands, their distribution [ 248]
Wacke, its passage into lava [183], [257]
Wackes, argillaceous [168], [178]
Webster, Dr., on a basin-formed island [ 237]
—— on gypsum at Ascension [ 201]
White, Martin, on soundings [254]
Wind, effects of, on the form of craters