THE TRIASSIC PERIOD. 35 



"covered a large part of England, and seem to have extended north into 

 southern Scotland and across the area of the Irish Sea into the northeast coast 

 of Ireland. It is possible also that the same sea stretched across what is now 

 the English Channel into northern France. Another lake is indicated by the 

 red sandstones of Elgin (northeastern Scotland). The lands surrounding these 

 lakes were clothed with cypress like evergreens, and their shores were frequented 

 by the labyrinthodonts and various reptiles — the highest forms of vertebrate 

 life being represented by small marsupials. The briny waters were unfavorable 

 to life, and we have consequently but little trace of any aquatic fauna. . . . 

 Eventually the lacustrine areas became largely silted up, and then subsidence 

 of the land took place, so that the sea invaded the area and occupied some of 

 the shallow depressions. In these marine areas the Rhsetic deposits accumu- 

 lated. 



" On the continent, the evidence supplied by the German Trias shows that 

 during a large part of the period an extensive inland sea extended westwards 

 from Thuringerwald across the Vosges into France, and stretched northwards 

 from the confines of Switzerland over what are now the low grounds of Holland 

 and northern Germany. In this ancient sea, the Harz Mountains formed a rocky 

 island. In the earlier stages of the period the conditions seem to have been 

 much the same as in the English area, but the thick Muschelkalk, with its num- 

 erous marine forms, seems to indicate an influx of water from the open sea. 

 Afterwards, however, this connection was closed, and the subsequent accumula- 

 tions point to an increasing salinity, during which depositions of gypsum, rock- 

 salt, etc., took place, while the marine fauna disappeared. Towards the close 

 of the period, after the great lake had been largely silted up, a partial influx 

 of the sea took place, when deposits containing a fauna comparable to that of 

 the English Rhsetic were laid down in some areas." 1 



This citation perhaps fails to recognize adequately the probable 

 subaerial origin of some parts of the Triassic system. 



Southern Europe. — In contrast with the Triassic phase of the 

 system, the alpine or marine phase, which has its best development 

 in the eastern and southern Alps, is made up of thick beds of lime- 

 stone (often clolomitic), alternating with thinner beds of clastic rock. 

 The limestone and dolomite are much more resistant than the asso- 

 ciated shales, and as a result, erosion has developed a striking topog- 

 raphy at several points in the Triassic terranes of the southern Alps 

 — a topography so striking that the localities where it is seen have 

 become the objective point of travel, not only for geologists, but for 

 lovers of wild and picturesque scenery. In these regions the dolo- 

 mite (limestone) stands up in bare, bold-faced walls, peaks, and towers, 



1 James Geikie, Outlines of Geology, pp. 311-312. 



