Col. Silvertop on the Basins of Baza and Alhamu. 337 



presenting in a portion of their respective areas, beds of the 

 tertiary age, and of lacustrine origin. One of these lies between 

 the towns of Baza and Huescar, the other between the city of 

 Granada, capital of the province of the same name, and the 

 large village of Alhama, celebrated for its mineral waters. I 

 have further observed vestiges of similar beds in other parts of 

 Spain, which will be subsequently noticed. 



In order to facilitate the labours of future investigators, I 

 shall point out a few circumstances connected with these two 

 tracts, and offer such observations with respect to their geognos- 

 tical relations, as a cursory inspection of them enabled me to 

 make. I shall designate the basins by the names of the towns 

 of Baza and Alhama, to which they are respectively contiguous, 

 and commence with the former. 



1. Basin of Ba^u. 



Section across the Basin of Baza from south to north nearly, or from 



near Baza to Huescar. 

 ^. Jv. 



Sierra de Baza- Sierra de Huescar. 



1. 1. Transition Limestone. 



2. Secondary Nummulite Limestone. 



3. Gypsiferous Marls. 



4. Compact Paludina Limestone. 



Previous to entering into a detail of the beds in this basin, 

 I beg leave to give the following rough sketch of the structure 

 of the country between Granada and Baza. For the first eight 

 leagues after leaving Granada, the road follows an irregular hol- 

 low along the northern base of the Sierra * Nevada, a magni- 

 ficent mountain, composed of primitive rocks, and rising in two 

 of its peaks, called La Veleta and Muleihassen, to the elevation 



• Sierra Nevada. This name, in Spain, designates and is confined to one 

 immense mountain mass, which extends longitudinally from near Granada to 

 the vicinity of Guadiz, but which is only a portion of a chain of mountains 

 bordering the Mediterranean from Gibraltar to the Cabo de Palos. I de- 

 signate the vhole of this nearly continuous range as the Sierra Nevada Clutin. 



