Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments / by Sir Charles Lyell.

  • Lyell, Charles, Sir, 1797-1875.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments / by Sir Charles Lyell. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    317/822 (page 295)
    not constitute simply narrow littoral zones, such as we might look for on an ancient sea-shore. In reply, Mr. Prestwich has suggested that such zones of shingle may have been slowly formed on a large scale at the period of the Thanet sands (C. 3., p. 279.), and while the land was sinking the well-rolled pebbles may have been dispersed simultaneously over considerable areas, and exposed during gradual submergence to the action of the waves of the sea, aided occasionally by tidal currents and river floods. Thanet sands (C. 3., p. 279.).—The mottled or plastic clay of the Isle of Wight and Hampshire is often seen in actual contact with the chalk, constituting in such places the lowest member of the British Eocene series. But at other points another formation of marine origin, characterized by a somewhat different assemblage of organic remains, has been shown by Mr. Prestwich to intervene between the chalk and the Woolwich series. For these beds he has proposed the name of “ Thanet Sands,” because they are well seen in the Isle of Thanet, in the northern part of Kent, and on the sea- coast between Herne Bay and the Reculvers, where they consist of i sands with a few concretionary masses of sandstone, and contain among other fossils Pholadomya cuneata, Cyprina Morrisii, Corbula longirostris, Scalaria Bowerbankii, &c. The greatest thickness of these beds is about 90 feet. GENERAL TABLE OF FRENCH EOCENE STRATA. UPPER EOCENE. French subdivisions. English equivalents. A. 1. Gypseous series of Montmartre. 1. Bembridge series, p. 279. A. 2. Calcaire siliceux, or Travertin 2. Osborne and Headon series, p. 282. Inferieur. A. 3. Gres de Beauchamp, or Sables 3. White sand and clay of Barton Cliff, Moyens. Hants. MIDDLE EOCENE. B. 1. Calcaire Grossier. I. Bagshot and Bracklesham beds. B. 2. Soissonnais Sands, or Bits Coquil- 2. Wanting. liers. LOWER EOCENE. C. 1. Argile de Londres at base of Hill I. London Clay. of Cassel, near Dunkirk. 2. Plastic clay and sand with lignite C. 2. Argile plastique and lignite. (Woolwich and Reading series). C. 3. Sables de Bracheux. 3. Thanet sands. The tertiary formations in the neighbourhood of Paris consist of a series of marine and freshwater strata, alternating with each other, and filling up a depression in the chalk. The area which they occupy has been called the Paris basin, and is about 180 miles in its greatest length from north to south, and about 90 miles in breadth from east to west (see Map, p. 219.). MM. Cuvier and Brongniart attempted, in 1810, to distinguish five different groups, comprising three freshwater and two marine, which were supposed so imply