278 GEOLOGY. 



sea extended thence through Moravia, and spread far and wide among 

 the islands of southeastern Europe, over the regions of the Black and 

 Caspian Seas. 1 These great inland seas may be looked upon as the 

 relics of the Tertiary extension of the sea across southern Europe. 



From the distribution of Miocene strata it is inferred that southern 

 Europe was an extensive archipelago, the plateau of Spain, parts of 

 Pyrenees, the Alps, and the Carpathian mountains, and portions of 

 adjacent lands, being islands. Malta and Sicily had probably not 

 appeared, as both are composed chiefly of marine Miocene formations. 

 The borders of the sea were marked by peninsular headlands giving 

 it notable irregularity. The strait of Gibraltar is thought to have 

 been closed, and southern Spain joined to Africa; but there were per- 

 haps straits across Spain, as across southern France, connecting the 

 Atlantic with the southern sea. To the east, the sea was expanded 

 far beyond the limits of the present Mediterranean, but without con- 

 nection with the Indian ocean. Though extensive areas of Europe 

 which are now land were then submerged, some areas which are now 

 submerged, e.g. the eastern part of the Adriatic, are thought to have 

 been land at that time. 



Late in the Miocene period, there was a notable withdrawal of 

 the sea from the land, for many of the late Miocene deposits were laid 

 down in brackish and fresh waters, over marine beds referred to the 

 earlier part of the period. Thus the connection of the Vienna basin 

 with the Mediterranean sea, via the Rhone valley, was closed, or greatly 

 restricted, before the end of the period, and bodies of brackish and 

 fresh water came into existence where the sea had been. Well-defined 

 brackish-water faunas are developed in some places. 



The Miocene formations include all the common sorts of sedimentary 

 rocks common to marine and non-marine deposits. The latter include 

 not a little limestone of fresh-water origin, made partly from the secre- 

 tions of algae. As was natural, too, under the conditions of sedimenta- 

 tion, the limestones of certain localities are made up almost wholly 

 of the secretions of a single type of life. Thus in the Vienna basin, 

 the limestone is made up in some places chiefly of coral, in others of 

 the shells of gastropods, in others of foraminiferal shells, in others 

 of the secretions of algae, etc. The system has great development 

 in Italy, where it attains a thickness of nearly 6000 feet. 



1 Geikie, Text-book of Geology, 4th ed., p. 1261. 



