PEOCEEDIKGS OP THE OEOLOGICAL SOCIETY. 



ern side being very precipitous. Its formation is also calcareous. 

 It consists of a very compact limestone, generally of a red colour, 

 owing to the great proportion of peroxide of iron which it contains. 

 It makes a very good building-material, and has been largely employed 

 in the construction of Antequera. On the eastern side it reposes 

 in conformable stratification on a fine-grained and white oolitic 

 marble, which attains a considerable thickness, the extent of which I 

 was not able to determine with any degree of precision, although it 

 appeared to me that it could not be less than 1000 feet. In the 

 divisional line between the two formations there were many Ammo- 

 nites, lying in a position perfectly parallel to the plane of stratifica- 

 tion, and in the same place in which they were originally deposited, 

 without having suffered the slightest disturbance. It is the red 

 marble that presents the fantastic forms alluded to before. 



At the top of the ridge there are large platforms surrounded 

 by vertical rocks, which are scooped out horizontally in a continuous 

 direction, being principally grooved at their base — so much so that 

 in some places the top greatly projects, making the rock assume the 

 form of a great table, while in other places the grooving is reduced 

 to three or four yards above the level of the plateau, whilst the rest 

 of the cliff remains vertical, having the appearance of long continuous 

 caves. The platforms ai'e generally perfectly plane and horizontal, 

 although full of crevices and faults, which are sometimes of consider- 

 able depth. Large angular masses of detached rocks are found in all 

 parts of these basins ; these, however, are more rounded; that is, their 

 angles are not so sharp as those of the cliffs. We received the 

 impression that these platforms had been the beds of ancient lakes, 

 the water of which had subsided at certain intervals, but not in a 

 gradual and uniform manner, causing certain levels to remain 

 longer stationary than others, the lower ones enduring the longest. 

 In support of this view, we found that the basins have generally 

 an outlet through which they have been drained, so that we could 

 easily trace to a considerable distance the direction of the current 

 as it escaped from the lake. In many of these lakes (if I may so call 

 them) there exist vertical caverns of great depth. The strata dip to 

 the south-west at a very slight angle ; and the declivities of the 

 mountain in that direction are those which present the grandest 

 points of scenery. They contain an immense labyrinth of small 

 valleys and ravines, in the mazes of which we should have lost our- 

 selves had we not been accompanied by a local guide. It is in this 

 locality that the rocks assume their wildest and most fantastic ap- 

 pearance. I calculate that these windings extend for a distance of 

 three or four miles at the least ; and the whole length of the Torcal 

 will be about two leagues. In its upper part, there exist veins of 

 laminated peroxide of iron ; and on the slopes we found a great many 

 crystals of carbonate of lime, some of the common rhombohedral type 

 (ealcite), while a great majority had a very fibrous structure. 



This mountain-chain must have risen from the valley of Antequera ; 

 but its upheaval must have been exceedingly gradual and gentle, as 

 its planes of stratification run perfectly parallel throughout, and we 



