﻿1850.] MURCHISON ON THE MINERAL SPRINGS OF VICHY. 79 



chiefly composed of arragonite ; nor do they advert to the abrupt 

 contrast between the absolutely vertical strata of the Celestins, and 

 the horizontal strata of the town with which they come in contact. 

 In their day, in fact, it is to be presumed that the rock was not so 

 freed from superincumbent rubbish as it now is, nor had the junction 

 I describe been laid open. 



That the present spring of the Celestins cannot explain the origin 

 of the vertical strata is clear from the fact, that the water rises in very 

 minute quantities at 10 feet below the bottom of the outermost of 

 the vertical layers. In other words, these strata form a cliff about 

 40 to 50 feet high above the pavement of the well-house (see fig. 1). 



On further examination I found these vertical beds ranging on 

 their strike to the S.S.E. for the space of 250 paces, though at a 

 diminishing and very varied altitude, to a spot where they terminate 

 in large slabs 18 to 20 feet high, which stand out like monumental 

 stones, the direction of their faces coinciding with the surfaces of 

 the rocks on which the convent stands. The sketch annexed 

 (fig. 2), which is taken from near this spot, in giving some idea of 

 the scene, indicates a cavity between two of the vertical sets of stone* 



Fig. 2. — Vertical Strata of Limestone and Travertine, as seen in 

 looking towards the Old Convent of the Celestins from the S.S.E. 



a' a' 

 a, a 1 . Vertical travertine rocks. 



b. Mass of drift gravel ; vertical section seen at V . 



c. Flat, occasionally inundated by river-floods. 



The position of the fault is marked by the dark vertical cleft. 



* In this sketch the spectator is supposed to be standing on the jagged tops 

 of some of the strata («') near to their S.S.E. end, and to have behind him the 



