[17] From ἠως, eos, the dawn or commencement, and recent.
Obs.—The marine are often associated with fresh-water deposits, and the general characters of the Tertiary system are alternations of marine and lacustrine strata. In England the most important Tertiary deposits are those of the London basin, the Isle of Sheppey, the south-western coasts of Sussex and Hampshire, the north of the Isle of Wight, and the eastern coasts of Essex, Norfolk, Suffolk. (Wond. p. 226.)
The Cretaceous or Chalk Formation. (Wond. p. 296). A marine formation, comprising a vast series of beds of limestone, sandstone, marl, and clay, &c.; characterized by remains of extinct zoophytes, mollusks, cephalopods, echinoderms, crustaceans, fishes, &c.; lacertians, crocodilians, chelonians, and other extinct reptiles; drifted coniferous and dicotyledonous wood and foliage, fuci, &c.
Subdivisions:—
| 1. | The Maestricht beds. Friable coralline and shelly limestones, with flints and chert. | ||
| 2. | Upper Chalk, with flints | } | Craie blanche of the French geologists. |
| 3. | Lower Chalk, without flints | ||
| 4. | Chalk-marl | Craie tufeau. | |
| 5. | Firestone, Malm-rock, Upper Greensand, or Glauconite | } | Glauconie crayeuse. |
| 6. | Galt, or Folkstone-marl | Glauconie sableuse. | |
| 7. | Shanklin, or Lower Greensand. | { | Formation néocomien; which is divided into N. supérieur, the English upper divisions of the Greensand or Kentish rag; and N. inférieur, the lower beds of sand and clay, of the southern shore of the Isle of Wight, at Atherfield.[18] |
[18] Another subdivision, with other names (chiefly derived from French localities), has lately been proposed by M. D'Orbigny; which I notice with the more regret, since this eminent naturalist formerly repudiated the censurable practice of many modern systematists, of changing established names of strata and fossils, without any just cause. The British geologist will smile to see the Wealden Formation—so eminently distinguished in England and Germany by its extent, thickness, and remarkable fauna and flora,—ranked as a subordinate member of the "Formation néocomien," of France.
Obs.—The Maestricht beds are chiefly composed of fawn-coloured limestones of friable texture; containing peculiar species of corals, shells, fishes, reptiles, &c. The Chalk is generally white, but in some localities is of a deep red, in others of a yellow colour; nodules, layers, and veins of flint occur in the upper, but are seldom present in the lower chalk. The Marl is an argillaceous limestone, which generally prevails beneath the white chalk; it sometimes contains a large intermixture of green or chlorite sand, and then is called Firestone, or Glauconite. The Galt is a stiff, blue or blackish clay, abounding in shells which frequently retain their pearly lustre. The Greensand is a triple alternation of sands and sandstones with clays; and beds of cherty limestone called Kentish Rag.