J 859.] Carter on the Persian Gulf. 4*7 



this area towards the sea, and from thence, as I have stated in my 

 u Summary of the Geology of India," is continued on into Lower Sind. 



But what struck me forcibly in the portions of mud from these 

 mud-volcanoes, which were sent to the Society by Mr. H. B. Erere, 

 Commissioner in Sind, was the presence of calcareous matter mixed 

 with sulphur and passing into gypsum or sulphate of lime, — con- 

 nected with the great development of impure rock gypsum (that 

 is gypsum veining an aluminous, earthy, consolidated base, which, 

 from Lieut. Constable's specimen, appears to exist throughout 

 the sub-range of mountains between the highland and the sea all 

 along the north-eastern side of the Persian Gulf, indicating that 

 this has been formed in a similar way, and that the process above 

 described is going on now and has existed for ages. 



Now carrying our speculation out a little further, and going to 

 the upper end of the Gulf, we may reasonably infer that as the 

 same range of mountains bordering the north-eastern Coast of the 

 Persian Gulf is continued on into Persia, and up into Khourdistan 

 under the name of the Khourd Mountains, forming the north-eastern 

 boundary of the vale of Mesopotamia, in which springs of asphalt 

 abound, — the same source of subterranean disturbance, (probably a 

 carboniferous deposit mixed with pyrites) exists throughout ; and 

 finds its different outlets all along the great crack or fault in the 

 earth, which must accompany the precipitous or south-western face 

 of this highland tract. 



Furthermore, it is not improbable that the so called "marbles" 

 of Nimroud and of all the great cities which have existed in this 

 vale that have been brought to light, and which are chiefly compos- 

 ed of mottled impure rock-gypsum, precisely like that of the hills 

 on the shores of the Persian Gulf, have been obtained from quarries 

 in the sub-ranges of the Khourd Mountains. Lastly, might it not 

 have been the outburst of volcanic matter which we now know to 

 have been that which threw up the Miocene formation of the 

 Persian Gulf, and the last upheaval, apparently, of any consequence 

 in this sea, that caused the disturbance of level in the vale of 

 Mesopotamia, which led to the overflowing of these cities with the 

 mud under which they now lie buried and thus concealed from view. 



Perhaps in no part of the world could the phenomena connected 



