408 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 8, 



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 are annually extracted. This is the whole extent of the true 

 Carboniferous system in Spain. 



The New Red Sandstone formation contains an extensive develop- 

 ment of the Zechstein limestone, which forms almost the sole consti- 

 tuent of the Sierras of Alcazar, of the Sagra, of Cazorla, and of Castril, 

 in the provinces of Jaen, Albacete, and Murcia. The marnes irisees 

 have not yet been clearly made out ; this is a great deficiency in our 

 geology. There may be perhaps some traces in Moncayo, near Calcena 

 in Aragon, and also in the mountains of Leon, and possibly in the 

 province of Guadalaxara, towards Tamajon, with shght traces of coal. 

 It is said that in La Mancha (now the province of Ciudad Real) the 

 zechstein occurs mth its marnes irisees and todt-liegendes, resting 

 against the northern slope of the Sierra Morena ; I have not seen it. 

 At San Juan d'Alcaraz, in the Sierra of the same name, near the 

 village of Riopar, the marls and dolomites are well characterized, and 

 contain a rich deposit of Calamine, the working of which is every day 

 becoming more productive. I think I have discovered the Kupfer- 

 schiefer of the Germans near Archidona,', between Sierra de Lucena 

 and Sierra d'Antequera. 



The Jurassic or Oolitic formations constituted, to all appearances, 

 the bottom of the sea during the cretaceous period, inasmuch as it 

 everywhere rises above the surface when the cretaceous formation is 

 interrupted. There is, however, a considerable extent of it exposed, 

 as e. g. the whole mountain range, which, commencing near Burgos, 

 continues towards the east through the province of Soria, as far as 

 Moncayo, and thence into Aragon, passing near Arina, as far as 

 Feruel. This ridge of oolitic rock is slightly interrupted by the 

 chalk and tertiary beds, but it again appears in the kingdom of 

 Valencia as far as the town of the same name ; so that, in fact, 

 the oolitic formation can be traced from Yalencia to Burgos for a 

 distance of 180 Spanish leagues (900 kil.) forming an obtuse angle 

 at the culminating-point of Moncayo. I have obsen^ed the same beds 

 at Siguenza and Torremocha, in the province of Guadalaxara, in 

 Andalusia near Cabra, in the province of Cordova, and in the Basque 

 provinces, as is laid down in the Geological Map of France. It pro- 

 bably exists in other localities not yet accurately investigated. 



The oolitic formations of Spain have in my opinion some remark- 

 able featm'es. They abound in metalliferous deposits of all kinds, 

 generally scattered in small isolated masses, and seldom in veins. 

 These beds were formerly worked with a profit when mining was 

 carried on on a small scale, and with the help of slaves. Now, how- 

 ever, minerals must be very rich and abundant to enable the com- 

 panies to make any return. Almost all those who have worked in 

 the Jurassic formation have been ruined. Cuivre gris or grey copper 

 ore of good quality is found here as well as copper pyrites, both very 

 argentiferous, but soon worked out. Near Barbadillo, at the extre- 

 mity of the province of Burgos, at the foot of the Sierra de San 

 Lorengo, a bed of this description is now worked, which, both for the 



