A Manual of Elementary Geology Part 55

CAMBRIAN GROUP.

Below the Silurian strata in North Wales, and in the region of the c.u.mberland lakes, there are some slaty rocks, devoid of organic remains, or in which a few obscure traces only of fossils have been detected (for which the names of Cambrian and c.u.mbrian have been proposed). Whether these will ever be ent.i.tled by the specific distinctness of their fossils to rank as independent groups, we have not yet sufficient data to determine.

TABULAR VIEW OF FOSSILIFEROUS STRATA,

_Showing the Order of Superposition or Chronological Succession of the princ.i.p.al European Groups_.

I. POST-TERTIARY.

A. POST-PLIOCENE.

Periods and Groups. Examples. Observations.

1. Recent. { Peat mosses and sh.e.l.l-marl, } All the imbedded sh.e.l.ls, { with bones of land animals, } freshwater and marine, { human remains, and works } of living species, { of art. } with occasional { } human remains and { Newer parts of modern deltas } works of art.

{ and coral reefs. }

2. Post-Pliocene. { Clay, marl, and volcanic tuff } All the sh.e.l.ls of living { of Ischia, p. 113. } species. No human { } remains or works { Loess of the Rhine, p. 117. } of art. Bones of { } quadrupeds, partly { Newer part of boulder } of extinct species.

{ formation, with erratics, } { p. 124. }

II. TERTIARY.

B. PLIOCENE.

3. Newer Pliocene { Boulder formation or drift of { Three-fourths of the or Pleistocene. { northern Europe and North { fossil sh.e.l.ls of { America, chaps. 11. & 12. { existing species.

{ { { Cavern deposits and osseous { A majority of the { breccias, p. 153. { mammalia extinct; { { but the genera { Fluvio-marine crag of Norwich, { corresponding with { p. 148. { those now surviving in { { the same great { Limestone of Girgenti, { geographical and { in Sicily, p. 152. { zoological province, { p. 157.

{ { During part of this { period icebergs { frequent in the seas { of the northern { hemisphere, and { glaciers on hills { of moderate height.

4. Older Pliocene. { Red and Coralline crag of { A third or more of the { Suffolk, p. 162. { species of mollusca { { extinct.

{ Subapennine beds, p. 166. { { Nearly, if not all, the { mammalia extinct.

C. MIOCENE.

5. Miocene. { Faluns of Touraine, p. 168. { About two-thirds of the { { species of sh.e.l.ls { Part of Bordeaux beds, p. 171. { extinct.

{ { { Part of Mola.s.se of { The recent species of { Switzerland, p. 171. { sh.e.l.ls often not { found in the { adjoining seas, but { in warmer lat.i.tudes.

{ { All the mammalia { extinct.

D. EOCENE.

6. Upper Eocene. { Upper marine of Paris basin, } Fossil sh.e.l.ls of the { Fontainebleau sandstone, } Eocene period, with { p. 175. } very few exceptions, { } extinct. Those which { Upper freshwater and millstone } are identified with { of same. } living species rarely { Kleyn Spauwen beds, p. 176. } belong to neighbouring { } regions.

{ Hermsdorf tile-clay, near } { Berlin. } All the mammalia of { } extinct species, and { Mayence tertiary strata, } the greater part of { p. 177. } them of extinct { } genera.

{ Freshwater beds of Limagne } { d'Auvergne, p. 181. } Plants of Upper Eocene, } indicating a south 7. Middle Eocene. { Paris gypsum with } European or { Paleotherium, &c., p. 191. } Mediterranean climate; { } those of Lower Eocene, { Freshwater and fluvio-marine } a tropical climate.

{ beds of Headon Hill, Isle } { of Wight, p. 197. } { } { Barton beds, Hants, p. 198. } { } { Calcaire Grossier, Paris, } { p. 193. } { } { Bagshot and Bracklesham beds, } { Surrey and Suss.e.x, p. 198. } } 8. Lower Eocene. { London clay proper of Highgate } { Hill and Sheppey,--Bognor } { beds, Suss.e.x, p. 200. } { } { Sables inferieurs, and lits } { coquilliers of Paris basin, } { p. 196. } { } { Mottled and plastic clays and } { sands of the Hamps.h.i.+re and } { London basins, p. 203. } { } { Sables inferieurs and argiles } { plastiques of Paris basin, } { p. 196. } { } { Nummulitic formation of the } { Alps, p. 205. }

III. SECONDARY.

E. CRETACEOUS.

-- UPPER CRETACEOUS.

9. Maestricht { Yellowish white limestone of { Ammonite, Baculite, and beds. { Maestricht, p. 209. { Belemnite, a.s.sociated { { with Cypraea, Oliva, { Coralline limestone of Faxoe, { Mitra, Trochus, &c.

{ Denmark, p. 210. { Large marine saurians.

10. Upper White { White chalk with flints of } Marine limestone Chalk. { North and South } formed in part of { Downs,--Surrey and Suss.e.x, } decomposed corals.

{ p. 211. }

11. Lower White { Chalk without flints, and } Chalk. { chalk marl, ibid. }

12. Upper { Loose sand, with bright green } Greensand. { particles, ibid. } { } { Firestone of Merstham, Kent, } { p. 218. } { } { Marly stone, with layers of } { chert, south of Isle of } { Wight. }

13. Gault. { Dark blue marl at base of { Numerous extinct genera { chalk escarpment,--Kent { of conchiferous { and Suss.e.x, p. 218. { cephalopoda, Hamite, { Scaphite, Ammonite, &c.

---- LOWER CRETACEOUS.

14. Lower { Sand with green matter,--Weald } Species of sh.e.l.ls, &c., Greensand. { of Kent and Suss.e.x, } nearly all distinct { p. 219. } from those of Upper { } Cretaceous; most of { White, yellowish, and } the genera the same.

{ ferruginous sand, with } { concretions of limestone and } { chert,--Atherfield, Isle } { of Wight. } { } { Limestone called Kentish Rag }

F. WEALDEN.

15. Weald Clay. { Clay with occasional bands of { Of freshwater origin.

{ limestone,--Weald of Kent, { Sh.e.l.ls of { Surrey, and Suss.e.x, p. 227. { pulmoniferous { mollusca, and of { Cypris. Land reptiles.

16. Hastings Sand. { Sand with calciferous grit and { Freshwater with { clay,--Hastings, Suss.e.x, { intercalated bed of { Cuckfield, Kent, p. 229. { brackish and salt { water origin. Sh.e.l.ls { of fluviatile and { lacustrine genera.

{ Reptiles of the genera { Pterodactyle, { Iguanodon, { Megalosaurus, { Plesiosaurus, Trionyx, { and Emys.

17. Purbeck Beds. Limestones, calcareous slates { Chiefly freshwater, and and marls, p. 231. { divisible into three { groups, each { containing distinct { species of freshwater { mollusca and of { entomostraca.

{ Alternations of { deposits formed in { fresh, brackish, and { marine water, and of { ancient soils formed { on land and retaining { roots of trees.

{ Plants chiefly cycads { and conifers, p. 231.

G. OOLITE.

18. Upper Oolite. { _a._ Portland building stone, } Ammonites and Belemnites { p. 259. } numerous.

{ } { _b._ Portland sand. } Large saurians, as { } Pterodactyles, { _c._ Kimmeridge clay, } Plesiosaurs, { Dorsets.h.i.+re, p. 260. } Ichthyosaurs.

} 19. Middle Oolite. { _a._ Coral Rag, p. 260. } No cetaceans yet known, { Calcareous freestones, } but three species of { oolitic, often full of } terrestrial mammalia, { corals. Oxfords.h.i.+re. } p. 267, 268.

{ } Preponderance of { _b._ Oxford clay--Dark blue } ganoid fish. The { clay,--Oxfords.h.i.+re and } plants chiefly cycads, { midland counties, p. 262. } conifers, and ferns, } with a few palms.

20. Lower Oolite. { _a._ Cornbrash and forest } { marble, Wilts.h.i.+re, p. 263. } { } { _b._ Great oolite and } { Stonesfield slate,--Bath, } { Bradford, Stonesfield near } { Woodstock, Oxfords.h.i.+re, } { p. 266. } { } { _c._ Fuller's earth,--Clay } { containing fuller's earth } { near Bath, p. 272. } { } { _d._ Inferior oolite, } { calcareous freestone, and } { yellow sands,--Cotteswold } { Hills, Dundry Hill, near } { Bristol, p. 272. }

H. LIAS.

21. Lias. { Argillaceous limestone, marl { Mollusca, reptiles, { and clay,--Lyme Regis, { and fish of genera { Dorsets.h.i.+re, p. 273. { a.n.a.logous to the { oolitic.

I. TRIAS.

22. Upper Trias. { Keuper of Germany, or } Batrachian reptiles, { variegated marls--Red, grey, } _e.g._ Labyrinthodon, { green, blue, and white marls } Rhyncosaurus, &c.

{ and sandstones with } Cephalopoda: { gypsum--Wurtemberg, bone-bed } Cerat.i.tes. No { of Axmouth, Dorset, p. 289. } Belemnites. Plants: } Ferns, Cycads, } Conifers.