Page:A Handbook for Travellers in Spain - Vol 1.djvu/79

Rh Español de Antigüedades, fol. Rivadeneyra, Autores Españoles, and the excellent reprints of rare works, brought out by the Bibliofilos Españoles; Libros de Antaño; Coleccion de libros españoles raros y curiosos, appear at intervals.

The student who wishes to have an idea of the geological structure of the Spanish Peninsula must consult the 2nd Edition of ‘Carte Géologique de l’Espagne et du Portugal,’ by Messrs. M. de Verneuil and Collomb, with the ‘Explication sommaire de la carte,’ which accompanies it, and Señor Botella’s ‘Mapa Geologico.’

Amongst the principal modifications which the researches of Spanish and Portuguese geologists have introduced in M. Verneuil’s map, are to be mentioned the great development of Cambrian strata in the west of Portugal and Estremadura in Spain (see Egozcoue and Mallada, and Rebeiro and Delgado’s works on the subject), and the perhaps too great reduction of what had hitherto been considered as Silurian deposits. The Cambrian formation is traversed by great intrusive masses of granite. The principal rocks found in this formation are a great thickness of slates and mica-schists, which in the province of Caceres appear to attain a thickness of thousands of feet. In this formation are found some very important veins of lead and silver ores, as well as some of the richest deposits of phosphate of lime of Estremadura. The Silurian deposits are constituted at their base by a great thickness of greywacke and slates, followed by large masses of quarizite and limestone, on which repose a succession of fossiliferous slates. In the parts of the country already studied these deposits follow generally a (. 36° .) direction. Likewise, a great part of the Silurian of the south of Portugal and the province of Huelva in Spain has been seen to belong to the lower Carboniferous or culm of Silesia, the Posydonomia Becheri having been abundantly found. Carboniferous deposits have been signalled by Mallada in the Spanish Pyrenees of the province of Huesca. What is marked as Permian in M. de Verneuil’s map in the province of Cuenca, has been questioned, probably with reason, by M. Cortazar in his ‘Descripcion geologica de la provincia de Cuenca;’ whilst Señor Botella, in his map, considers Permian the dolomitic limestone of Sierra Nevada.

In the secondary formations some alterations have also been made. The Triassic fauna has been greatly enriched, and Sr. Mallada mentions twenty-nine species found in the provinces of Jaen, Albacete, Teruel, Palencia, &c. Probably some of what is represented by M. Verneuil as Triassic in his map, will be found to belong to other formations; as the researches of Messrs. MacPherson and Calderon in the provinces of Cadiz and Santander make it likely. Jurassic deposits have also suffered some modifications. The small patch in the west of the province of Santander is also extended. Wealden, and probably Purbeck deposits, have been discovered in the Peninsula by M. Delgado in Portugal, from Setubal to Cape Mondego, and by MM. Linares and