74 Colonel Silver top on the Lacustrine Basins of 



put beyond doubt their respective superposition ♦. Facing the 

 hill, whose geological structure I have attempted to sketch, 

 there is a tract of high ground on the opposite or right bank of 

 the rivulet, or Rio de Alhama, which is a continuation of the 

 table-land along the summit of the ridge between the villages of 

 Cacin and Alhama noticed in describing the line of road from 

 Granada to Alhama. 



In proceeding from the hill of El Majar de en Medio to this 

 high ground, a ford was crossed in the rivulet, at a point about 

 two miles below the mineral-baths of Alhama, which take their 

 rise in an insulated mass of secondary nummulitef limestone, 

 confining there for a short space its banks, and at about the 

 same distance above the little village of Santa Cruz, situated up- 

 on the same stream. The valley here becomes more expanded, 

 and a jK)rizontal flat of some extent borders the right bank of 

 the rivulet. A long cultivated slope succeeds J, At about 

 two-thirds of the ascent, the compact limestone, with its usual 

 paludinae, makes its appearance in thick horizontal strata, and 

 continues to manifest itself in low irregular escarpments to the 

 summit of the hill. Here there is an extensive tract of level 

 ground, varied by some undulations and hollows, and covered 

 with short herbage, wild plants and shrubs, analogous, both in 

 physical character and geological relations, to the eminence on 

 the opposite side of the valley. During three hours which I was 

 riding in various directions over this table-land tract, spread 

 over with a scanty covering of vegetable soil, I constantly ob- 

 served the compact limestone, and no other rock ; but, at about 

 the distance of three miles in an easterly direction, and towards 

 the line of road from Cacin to Alhama, the shelly marly pla- 



• The shelly marly planorbis limestone, observed to rest upon lime- 

 stone 4, near the village of Cacin, and in the ridge between Cacin and Al- 

 hama, was not observed here. 



•f- 1 believe these mineral waters take their origin in a red sandstone, upon 

 which the secondary nummulite hmestone rests. 



X Although I did not observe any beds of gypsum here, I was assured by 

 different peasants, that it is met with in several places, but not worked, as 

 the neighbouring villages are supplied abundantly with this mineral, from 

 the quarries noticed in the hill of El Major de en Medio, on the opposite 

 side of the rivulet. 



