Baza and Alhama, 69 



are first observed to cap some of the low hills and eminences at a 

 little distance from the road towards the left, whose nature will 

 be soon more fully explained. On reaching the highest part of 

 the tract between the Venta and a village called Cacin, distant 

 from the former about six miles, a portion of its summit is ob- 

 served to be crowned by a bed of compact limestone, containing 

 moulds of paludina?, superimposed to which, irregular masses 

 are seen of a marly limestone, almost entirely composed of com- 

 minuted shells, amongst which paludinae, lymneae, and planor- 

 bes, are distinctly visible. But here this calcareous mass has 

 little thickness, not exceeding, I should think, thirty feet ; and, 

 from the irregularity in position of some of the strata, which are 

 from four inches to three feet thick, as well as from th6 state of 

 decomposition of the rock, it has the appearance of having been 

 considerably broken up and affected by external agents. From 

 this point to the little village of Cacin, situated upon the right 

 bank of a stream bearing the same name, there is a long descent, 

 in the first part of which, immediately below the calcareous bed 

 just alluded to, the road for a considerable space passes over a 

 bed of white finely granular gypsum, in strata about an inch 

 thick. The subsequent part of the descent exhibits a marly 

 earthy mass, whose surface is strewed with fragments from the 

 limestone capping the hill ; but gypsum is again observed, and 

 has been worked by perpendicular cuts, along the immediate 

 bank of the rivulet. The bed of this is nearly a quarter of a 

 mile in breadth, a small portion of which only is occupied by two 

 little channels in which the rivulet flows, the remaining portion 

 being partly under cultivation and partly planted with willows 

 and poplars. A low cliff of conglomerate bordering the right 

 bank, and in places abutting against the contiguous gypsum, 

 attests the powerful body of water which in some ancient time 

 has rushed down this little valley of denudation. 



The frequent, almost continued appearance of gypsum, from 

 the rising ground near the village of Gavia to this point, and 

 the similarity in physical character and aspect of the intervening 

 tract, appear to countenance the presumption, that the whole of 

 it is occupied by a deposit of the above-mentioned substance, as- 

 sociated with various proportions of marl in an earthy or indu- 

 rated state. No other rock is seen, until a few strata of fresh- 



