MESOZOIC TIME — TJKIASSIC AND JUKASSIC. 769 



continental sea. In the earlier and later part of the Triassic, it was very 

 shallow, the conditions those of sea margins and seashore basins, and brack- 

 ish-water flats ; in its middle portion of somewhat deeper waters ; but about 

 the region of the eastern Alps, and along the side of the Alps toward the 

 Mediterranean^ as well as in southern France and Austria, the waters, judg- 

 ing from the prevalence of limestones, their thickness and the fossils, were 

 those of a clear, open sea. This region has been designated the Mediterra- 

 nean region. 



ROCKS — SUBDIVISIONS, KINDS AND DISTRIBUTION. 



1. LowEK Trias or Vosgian. — Eepresented generally by red or 

 variegated sandstones passing to whitish marlytes and pebbly beds ; salt 

 beds are sometimes present, and also gypsum. In England it includes the 

 Lower Eed Sandstone of the Trias, 1000 feet to 2000 feet thick ; in Germany, 

 the Buntersandstein ; in France, the Gres des Vosges and Gres bigarre {hunter 

 and bigarre meaning variegated); but in the eastern Alps, in Lombardy, and 

 the Tyrol, a limestone, the Gutenstein, underlying the Werfen sandstone 

 "with rock salt and gypsum. 



2. Middle Trias or Frakconian. — The rock is limestone in Germany, 

 France, and the Alps ; it is not recognized in England. It is represented by 

 the Muschelkalk of Germany, with the Wellenkalk below, and affords rock 

 salt in Wiirtemberg ; and by the Calcaire Conchylien in France. 



3. Upper Trias. — (1) Keuperian. In England mostly like the Lower 

 Trias in its rocks ; it affords rock salt at Cheshire. In Germany there 

 are, heloio, red shales and marlytes with thin coal seams — the Kohlen- 

 keuper or Lettenkohle ; and above, the Keupermergel, marlytes containing 

 gypsum. Gypsiferous beds and rock salt occur in Lorraine, and at Salz- 

 kammergut, near Salzburg, Austria. In the eastern Alps, there are the St. 

 Cassian beds ; in Sweden, gray and red marlytes, with some good coal. 



(2) The Rhcetic, so-named from the Rhaetic Alps. The beds are limestone 

 or shales. They include the Kossen beds of Germany, the Avicida contorta 

 beds ; the larger part of the Dachstein limestone of the eastern Alps ; and 

 in England the Penarth beds of shales overlying the Trias from Yorkshire 

 to Lyme-Eegis, 50 to 150 feet thick. One to three bone-beds occur in the 

 lower part in England, and also in Bourgogne, Hanover, Brunswick, and 

 Franconia. The Bhsetic is sometimes placed at the base of the Lias. 



The Trias has great thickness in the Alps, especially the Italian, it being 

 nearly 13,000 feet along a belt from Bardonneche (Savoy), by the Mont 

 Cenis tunnel, to Modena. This great thickness is owing to the fact that 

 preparations were in progress, through a geosyncline of accumulation, for the 

 Tertiary mountain making, which took place along the range at the close of 

 the Miocene. 



In peninsular India, the upper part of the Gondwana series, the Panchet group, is 

 Triassic; it is without marine fossils. Outside of the peninsula, Triassic beds occur in 



DANA'S MANUAL — 49 



