LOFTUS — TXJRKO-PERSIAN FRONTIER. 309 



and, as any one is at liberty to dig how and where he pleases, it may 

 be well imagined what a " warren " the Salt Hill is become. 



At the base of the hill the hard crystalline limestone is completely 

 filled with fossils, especially beautiful and perfectly preserved Corals, 

 together with casts of shells, among which are an Ai'ca, LithodomuSy 

 and Trochiis. The Corals agree in species generally with those from 

 Guverjin Kalah, and many of them present a remarkable resemblance 

 to species from the European deposits of Gosau. 



Quantities of massive gypsum and crystals of selenite are im- 

 bedded in the sandstones and loose gravel. The surface of the Salt 

 Hill is of rotten blue marl and sand, apparently derived from the 

 melting of the mineral and the decomposition of the matrix, by 

 atmospheric causes. Gypsum and selenite also lie strewed in great 

 abundance on this decayed soil. 



The Plain of Khoi would appear to be an horizontal deposit of 

 the above-mentioned sandstone and gravel. 



In accounting for the origin and saltness of the Lake of Uriimia, 

 I have concluded that these are due to the recent eruption of the 

 igneous rocks, p. 307. I believe that the red and blue marls con- 

 taining the rock-salt (together with the associated sand and gravel 

 deposits at the Diizlak, in the Plain of Khoi) were in process of 

 formation at the period when the igneous rocks were intruded from 

 beneath the bed of the then existing ocean, carrying with them 

 portions of the stratified deposits, — and that the intensity of volcanic 

 action was such as to produce solidified rock-salt from the depths of 

 the sea in the pure state here met with. By the same action, the 

 sands saturated with sea water would be converted into such a rock 

 as the saliferous sandstone of the Diizlak. The portion of the 

 liquid mass which remained after the disturbance unevaporated, from 

 depth or other cause, constituted the modern Lake of Uriimia, and 

 I imagine that similar salt-lakes were formed in a like manner, vary- 

 ing however in their saltness according to circumstances, — viz. depth, 

 intensity of volcanic action, &c. In favour of this view, it is worthy 

 of remark, that the most pure and perfect crystals are at the greatest 

 depth, where of course the pressure from above and the internal 

 heat must have been greatest ; while the least compact salt is at the 

 surface. 



The above theory appears to me to be the most simple in account- 

 ing for the origin of rock-salt in this region, and for the intense salt- 

 ness of the Lake of Uriimia. That the streams flowing from the 

 neighbourhood of salt-deposits have no influence on the quality of 

 the water of the Lake itself is evident, since they are drinkable, and 

 at Shabani, half a mile from the Diizlak, the water, though brackish, 

 is by no means disagreeable. That a vast amount of rock-salt exists 

 beneath the Lake and surrounding plains is almost certain. 



The isolation and elevation of the Diizlak are not difficult to explain, 

 seeing the proximity of the igneous chain, and the probability of its 

 being a dome, forced up in the centre of the basin. 



