oo 
Mineralogy and Geology. 261 
mabar, It also occurs in the mountain-chain of Asturia, which contains 
coal of good quality. 
he secondary formations, which are shut in between the older rocks 
and the sea, occupy a great area in the centre of Spain, extending to 
the north and to the eastern coast. The greater part of these second- 
ary rocks belong to oolitic and cretaceous periods; all the members 
of the series are fully developed except the Muschelkalk. 
_ The Devonian formation is very limited. Some traces of it occur 
in the centre of the Asturias, and a still larger development occurs in 
the northern part of the province of Léon, which extends as far as 
Galicia, following a line parallel with the mountain-chain of Cantabria. 
n both these localities the Devonian rocks abound with coal of an ex- 
cellent quality. That of the Austurias, which was already known at the 
close of the last century, not only in the Devonian, but in other forma- 
tions, will hardly come into competition with other coals, unless the com- 
pany by which it is worked agree to lay out larger sums in working it. 
That of Léon is more easily obtained, and although it has been known 
only for a few years, it is already a source of considerable industry in 
Castille. It is taken to Madrid for the cast-iron foundries and other 
works, as gas-lighting, &c. 
n the Silurian rocks of the Sierra Morena, which we have alluded 
Espiel and Belsuez, which may be called the basin of the Guadiato, the 
tiver by which it is traversed. This formation may be traced for a dis- 
t 
coal, exten ing over near! square league of ground. is coal is 
not of very good quality, being friable and dusty ; nevertheless, owing 
to its situation so near the river and Seville, many thousand quintals 
*lopar, the marls and dolomites are well characterized, and contain 
8 rich deposit of calamine, the working of which is every day becom 
ae productive. I think I have discovered the upferschiefer of 
the Germans near Archidona, between Sierra de Lucena and Sierra 
4\ntequera, 
the p> Burassic or Oolitic formation constituted, to all appearances, 
‘bottom of the sea during the cretaceous period, inas as it 
* 
