274 Prof. Hausraann on the Geographical Characters 



tions, is wanting in Spain, as is also the case in England. The 

 sandstone and marl is rich in gypsum and masses of rock-salt. 

 At Vallecas, near to Madrid, and in some other places, there 

 rests upon it, in single beds, that rare deposite consisting of 

 meerschaum, with nests of siliceous minerals. It is to this for- 

 mation, which occurs widely spread over the high table-lands of 

 Old and New Castile, that these countries owe the reddish-brown 

 colour of their soil, and the tiresome uniformity of their surface. 

 The lias formation is widely distributed in the northern provinces 

 of Spain. It appears to reach a considerable height on the Spa- 

 nish side of the Pyrenees. In the Biscayan provinces, it exhibits 

 the same characters as the gryphite limestone of the Weser, 

 and is so widely distributed that nearly all the older rocks 

 are covered by it. Here it is remarkably prolific in an excellent 

 iron-ore. The immense mass of sparry iron-ore, converted by 

 decomposition into brown and red iron-ores, of Somorostro, near 

 to Bilboa, and which probably forms the ironstone hills men- 

 tioned by Pliny in the 34th Book of his Natural History, be- 

 longs to this formation. Probably also the vast beds of coal in 

 the Austurias are subordinate to it. The white Jura limestone^ 

 which is one of the most widely distributed formations, is also 

 of great geognostical importance in Spain. It forms, in most 

 places, the immediate cover of the variegated sandstone and 

 marl, and occurs in the north, and also in the south of Spain,^ 

 in single ridges, and great mountain masses. This formation is 

 exhibited in its most characteristic forms in the narrow pass of 

 Pancorbo, in Old Castile, in the lacerated mountains of Jaen, 

 and the isolated rocky wall of Gibraltar. Wherever it occurs, 

 its presence is announced by the yellowish-brown colour of the 

 soil with which it is covered. 



Some members also of the chalk formation occur in Spain. 

 The sandstone of the rocky ridge of the southern coast, between 

 Cadiz and Gibraltar, and the limestone in the district of Los 

 Barios, bring to our recollection the rocks of the Saxon Switzer- 

 land. The first agrees with the German quadersanclstein^ the 

 latter with the Saxon planer limestone, an equivalent for impure 

 chalk. 



Tertiary deposifes do not appear to be particularly abundant 

 in Spain. In the south, particularly near the sea-coast, there is 



