EXPLANATION OF THE PLATES. 



ture of the chain was obtained by consulting an original map of great merit, 

 executed many years since by Mr. Greenough : much assistance has also been 

 received from M. P. Partsch of Vienna, and great obligations are due to Mons. 

 de Buch, the reputed author of the general map of Martin Schropp & Co. 

 The geological features of the southern part of Styria, including the Bacher and 

 Matzel Gebirge, are chiefly taken from an original map executed by several Au- 

 strian geologists, under the direction of His Imperial Highness the Archduke 

 John, and presented by him to the Geological Society of London-. For the map 

 of all those parts of Styria which lie within, or surround the basin of Gratz, the 

 authors are, however, personally responsible. 



A tertiary deposit is marked at Guttaring, far within the area of the primary rocks, 

 on the authority of M. Keferstein, whose general maps have also been consulted. 

 M, Necker de Saussure has pointed out the occurrence of a tertiary deposit at 

 Kropp on the Save in the Alps of Carniola, where it reposes on secondary lime- 

 stone (At/n. dcs Sciences Nalurelles, vol. viii.). The same author has also shown 

 the existence of a ridge of primary rocks, succeeded, between Schio and Recoaro, 

 by others of various secondary ages. This remarkable outbreak takes place on 

 the confines of the cretaceous series being accompanied by new porphyritic rocks 

 which overlie the scaglia, and are probably of the same age as the Euganean 

 trachytes. A phenomenon similar in many respects, though on a smaller scale, 

 is seen in the northern flank of the Alps (Sonthofen, Bavaria), which is de- 

 scribed in detail in this Memoir, p. 333, 334. Section, PI. XXXVI. fig. 4. 



The great expanse of green-sand and "scaglia" in the neighbourhood of Feltre, is 

 inserted from the works of Professor CatuUo *. 



In the highest group, No. 1. of the map, are comprehended all the accumulations from 

 the most recent alluvions down to the coralline, tertiary limestone of the Leitha 

 hills near Vienna, and of Wildon &c. near Gratz. Under this colour, therefore, 

 is represented the greatest superficial range of tertiary deposits around the Alps, 

 particularly all those at a considerable distance from the edges of the chain. 



No. 2. represents the middle and older tertiary formations, and is supposed to com- 

 mence with deposits of the age of those of " Bourdeaux," and to end in the 

 period of the " calcaire grossier." This group is found in bands and patches 

 close along the edges of the Alps (from Bregenz to Fiissen, for example,) in the 

 forms of molasse, sandstone and conglomerate, and again in various parts of the 

 valley of the Danube, usually in the state of marl with shells, as near Traunstein 

 on the Alpine side, or near Ortenburgh and Pielach on the flanks of the Bohemian 

 chain. The coal-field of Hiiring is assigned to the lower part of this group. 



On the southern flank of the Alps the shelly deposits of the Vicentin, described by 

 M. Brongniart, and those of Bassano, by Mr. Murchison, are amongst the most 

 unequivocal exhibitions of these formations. 



No. 3. The copperas green colour marks a peculiar shelly deposit unknown in 



* The colours are only intended to indicate great groups of strata, the subdivisions of which, 

 whether in the secondary or tertiary system, will be found in the Plate of Sections. 



