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The Student's Elements of Geology

Charles Lyell · 1878

passage 96 of 432 · Chapter I—ON THE DIFFERENT CLASSES OF ROCKS. > Section South of Bristol. (1/4)

↪ you wandered here via “loess land-shell mollusks” — the connecting lines are tinted below

in brief
Lyell explains how to build a chronological succession of fossil-bearing rock strata using superposition, tracing formations from a starting section, and inserting new groups into a tabular scheme.

In order, therefore, to establish a chronological succession of fossiliferous groups, a geologist must begin with a single section in which several sets of strata lie one upon the other. He must then trace these formations, by attention to their mineral character and fossils, continuously, as far as possible, from the starting-point. As often as he meets with new groups, he must ascertain by superposition their age relatively to those first examined, and thus learn how to intercalate them in a tabular arrangement of the whole.

By this means the German, French, and English geologists have determined the succession of strata throughout a great part of Europe, and have adopted pretty generally the following groups, almost all of which have their representatives in the British Islands.

Abridged General Table of Fossiliferous Strata.

TABULAR VIEW OF THE FOSSILIFEROUS STRATA, SHOWING THE ORDER OF SUPERPOSITION OR CHRONOLOGICAL SUCCESSION OF THE PRINCIPAL GROUPS DESCRIBED IN THIS WORK.

POST-TERTIARY EXAMPLES

POST-TERTIARY

EXAMPLES

POST-

TERTIARY 1.

RECENT

Shells and mammals, all of living species. British

Clyde marine strata, with canoes (p. 146).

Foreign

Danish kitchen middens (p. 146).

Lacustrine mud, with remains of Swiss lake-dwellings (p. 148).

Marine strata inclosing Temple of Serapis, at Puzzuoli (p. 146). 2.

POST-

PLIOCENE.

Shells, recent mammalia in part extinct. British

Loam of Brixham cave, with flint implements and bones of extinct and living quadrupeds (p. 157)

Drift near Salisbury, with bones of mammoth, Spermophilus, and stone implements (p. 161).

Glacial drift of Scotland, with marine shells and remains of mammoth (p. 176.

Erratics of Pagham and Selsey Bill (p. 182).

Glacial drift of Wales, with marine fossil shells, about 1400 feet high, on Moel Tryfaen (p. 181).

Foreign

Dordogne caves of the reindeer period (p. 150).

Older valley-gravels of Amiens, with flint implements and bones of extinct mammalia (p. 152).

Loess of Rhine (p. 154).

Ancient Nile-mud forming river-terraces (p. 154).

Loam and breccia of Liege caverns, with human remains (pp. 156, 157).

Australian cave breccias, with bones of extinct marsupials (p. 158).

Glacial drift of Northern Europe (p. 166, p. 174).

TERTIARY OR CAINOZOIC

PLIOCENE 3. NEWER PLIOCENE. The shells almost all of living species. British Bridlington beds, marine Arctic fauna (p. 189). Glacial boulder formation of Norfolk cliffs (p. 190). Forest-bed of Norfolk cliffs, with bones of Elephas meridionalis, etc. (p. 191). Chillesford and Aldeby beds, with marine shells, chiefly Arctic (p. 192). Norwich crag (p. 193). Foreign Eastern base of Mount Etna, with marine shells (p. 204). Sicilian calcareous and tufaceous strata (p. 205, 206). Lacustrine strata of Upper Val d’Arno (p. 207). Madeira leaf-bed and land-shells (p. 532). 4. OLDER PLIOCENE. Extinct species of shells forming a large minority. British Red crag of Suffolk, marine shells, some of northern forms (p. 194, 195). White or coralline crag of Suffolk (p. 197). Foreign Antwerp crag (p. 204). Subapennine marls and sands (p. 208).

EXAMPLES

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topics: logic, method, and demonstration · strata, rocks, and the geological record

The Student's Elements of Geology · Charles Lyell · 1878