100 WYNNE : GEOLOGY OF THE SALT EAN6E IN THE PUNJAB. 



also occur in Cheshire above the salt^ and in Germany in the Keuper 



formation overlying the salt-bearing Muschelkalk, He explains their 



occurrence by the evaporation of brine^ the crystals being formed partly 



in mud left dry sufficiently long to harden. ' Salt 

 Formation. i i • • n • 



water or weaker brine again flowing over this mud 



would dissolve the salt and deposit mud or sand in its place, forming 

 casts of the crystal moulds, which would adhere to the under surface of 

 the upper layers. In the cases quoted first, however^ the casts were 

 observed both on the upper and under surfaces of the layers, from 

 which it would appear that the crystals were enclosed before they were 

 dissolved, or were developed near the surfaces subsequently to the depo- 

 sition of these layers, their adhering to one surface or the other being 

 a matter of accident. 



The only organic traces observed in these beds were obscure fucoid 



impressions, or tracks like those of worms. They 

 Organic traces. p • i 



frequently exhibit very perfect ripple marks, some- 

 times crossing each other in different directions. 



Whatever may be its precise place in the general series, the group 



is a local one. It is present from Mount Tilla to 

 Distribution. 



Makrach in one direction, appears at Diljaba on 



one side, but is absent at Chambal Mountain (east) upon the other, and 



attains its greatest thickness near Bhaganwala about midway between 



these points. Here unfortunately the beds undulate greatly at low 



angles, so as to render observations of the thickness uncertain, but 



measured sections across the strike, reduced to 

 Thickness. 



compensate for possible error, gave a thickness of 



over three hundred feet for the upper earthy portion and one hundred and 



fifty feet or more for the sandstone and flags below, so that from four to five 



hundred feet may be a fair estimate. Where the group is thinner, as at 



Mount Tilla, Diljaba, and towards Makrach, it may vary from one 



hundred to fifty feet and even less where dying out both to the east 



and west. 



( 100 ) 



