GEOLOGY. 43 



frequent repetition of discontinuity, there is from the lowest to the 

 highest groups in some regions such an absence of unconformity that 

 through the long list of periods down to tertiary times results of any 

 violent local disturbances are unknown, these only being referable to 

 causes connected with Himalayan elevation and dating from the eocene 

 age.* 



In such a vast succession of comparative tranquillity (if the absence 

 of older rocks than nummulitic could be explained) , time might have been 

 adequate and ample for the accumulations of a thickness of salt rivalling 

 that of all the known palaeozoic fossiliferous accumulations of the Salt 

 Kange and far exceeding in depth many of its separate groups, some of 

 which might even be supposed represented in time by part of this great salt^ 

 series ; were it not that even after making allowance for formerly greater 

 superficial expansion of the country, there are still no reasonable grounds 

 for the belief in such a permanent ' Swatch of no ground/ and of no 

 deposits existing between the points where mesozoic or more ancient 

 deposition is known to have been taking place. 



If we turn to the known natural salt pans of the present day for 

 an illustration of the method by which such enormous deposits of rock- 

 salt as these were accumulated, it may be strongly doubted whether the 

 whole world affords anything approaching a parallel case likely to pro- 

 duce a similar result. The Runn of Kutch is a favourite example of the 

 natural formation of salt from sea- water on a large scale, under conditions 

 of intermittent floodings by saline water, yet the salt formed there by 

 evaporation is only a few inches thick and not sufficient to cover the 

 whole of its surface, while the formation (even if accompanied to some 

 extent by re-solution) has been going on for an indefinitely vast period, 

 but little interfered with by one of the greatest earthquakes of the 

 present country. 



* The occurrence of boulders of foreign rocks is not here contemplated. Although 

 these occur in some of the oldest groups, they are no evidence of local disturbance, but 

 rather of tranquillity enabling them to subside. 



( 147 ) 



