GEOLOGY. 29 



broken hilly ground or disturbed masses of clay, the soft strata below 

 the nummulitic limestone, or under quantities of superficial debris, 

 deeply cut ravines sometimes expose the salt along their precipitous sides 

 for considerable distances. In other places the local fall of a portion of 

 the clay and debris at the head of a small nallah may allow the salt to 

 be seen, the action of rain water sometimes tending to enlarge the ex- 

 posure, sometimes to cover and conceal the salt again. 



In most places it presents vertical or approximately vertical faces 

 from the rapidity with which it yields to the action of the atmospheric 

 water, which also cuts it into pillars, spires, and strangely fluted or sys- 

 tematically grooved forms, with sharp edged dividing reliefs, the hollows 

 all leading up to points. At some favourable situations where th* salt 

 contains a percentage of clay, the slow solution of the former leaves this 

 behind, and thus the rock-salt becomes covered by a heap of dark gray 

 saline earth forming a coating which must ultimately act as a protection 

 to the mineral beneath. 



Joints or such divisional planes are rare in the mass, yet some 

 strongly developed, approximately horizontal, joints have been observed, 

 traversing salt escarpments or outcrops. 



Strata that m.ay underlie the salt unhwwn. — The exposures of the 

 salt are not such as to enable any satisfactory observations to be made 

 with regard to the possibility of some of the soft associated strata really 

 underlying it. In but one instance did the quarrymen admit that this 

 had ever been penetrated by their working. The statement was founded 

 much on hearsay, and to the effect that below the salt at one of the 

 Jatta quarries ' sheenkow, ' the ordinary gray, gypseous clay found with 

 the gypsum had been reached. There is perhaps some probability that 

 in so disturbed a region, if there existed any strong zone of gypsum 

 or harder rock immediately below the lowest visible salt, it would make 

 its appearance in one locality or another, but there being absolutely no 

 data to limit the depth of the nearly horizontally bedded salt over a 

 great portion of the ground in which it is seen, speculation as to what 

 mav underlie it becomes involved in the greatest uncertainty. 



( 133 ) 



