SECONDARY EPOCH.
During the Primary Epoch our globe would appear to have been chiefly appropriated to beings which lived in the waters—above all, to the Crustaceans and Fishes; during the Secondary Epoch Reptiles seem to have been its prevailing inhabitants. Animals of this class assumed astonishing dimensions, and would seem to have multiplied in a most singular manner; they were, apparently, the kings of the earth. At the same time, however, that the animal kingdom thus developed itself, the vegetation lost much of its importance.
Geologists have agreed among themselves to divide the Secondary epoch into three periods: 1, the Cretaceous; 2, the Jurassic; 3, the Triassic—a division which it is convenient to adopt.
The Triassic, or New Red Period.
This period has received the name of Triassic because the rocks of which it is composed, which are more fully developed in Germany than either in England or France, were called the Trias (or Triple Group), by German writers, from its division into three groups, as follows, in descending order:—
| England. | France. | Germany. | ||||
| Saliferous and gypseous shales and sandstone | – | Marnes irisées | – | Keuper. 1,000 feet. | ||
| Wanting | – | Muschelkalk or Calcaire coquillier | – | Muschelkalk. 600 feet. | ||
| Sandstone and quartzose conglomerate | – | Grès bigarré | – | Bunter-Sandstein. 1,500 ft. | ||
The following has been shown by Mr. Ed. Hull to be the general succession of the Triassic formation in the midland and north-western counties of England, where it attains its greatest vertical development, thinning away in the direction of the mouth of the Thames:—
| Foreign Equivalents. | ||||||||||
| TRIASSIC SERIES. | – | New Red Marl. | Red and grey shales and marls, sometimes micaceous, with beds of rock-salt and gypsum, containingEstheria and Foraminifera (Chellaston). | Keuper. | Marnes irisées. | |||||
| Lower Keuper Sandstone. | Thinly-laminated micaceous sandstones and marls (waterstones); passing downwards into white, brown,or reddish sandstone, with a base of calcareous conglomerate or breccia. | Letten Kohle (?) | „ | |||||||
| Wanting in England. | ... | Muschelkalk. | Calcaire coquillier. | |||||||
| Upper Mottled Sandstone. | Soft, bright-red and variegated sandstone (without pebbles). | – | Bunter Sandstein. | Grès bigarré, or Grès des Vosges (in part). | ||||||
| Pebble Beds. | Harder reddish-brown sandstones with quartzose pebbles, passing into conglomerate; with a base ofcalcareous breccia. | |||||||||
| Lower Mottled Sandstone. | Soft bright-red and variegated sandstone (without pebbles). | |||||||||
| PERMIAN SERIES. | – | Upper Permian. | Red marls, with thin-bedded fossiliferous limestones (Manchester). | Zechstein. | ||||||
| Lower | – | Red and variegated sandstone (Collyhurst, Manchester) represented by [...]. | – | Rothe-todte-liegende. | Grès des Vosges (in part). | |||||
| Reddish-brown and purple sandstones and marls, with calcareous conglomerates and trappoid breccia.(Central counties). | ||||||||||