1859.] Carter on the Persian Gulf \ 45 



which is here raised up into a hill 330 feet high, and on the top of 

 which is the fort of Kalah Leshtan. As at Kishm, 30 feet of the top 

 consist of a coarse, shelly detritus, and the 300 feet below of clay 

 thickly veined with fibrous gypsum. Still further on, at Jilla el- 

 Abed, which is opposite the island of Khaia, we have trap-diorite 

 again and specular iron-ore with rock salt. 



Beyond this, at Assaloo, we have the characteristic gypseous for- 

 mations of the coast, viz. earthy and massive white, crypto-crystal- 

 line gypsum ; and at Tahree again, we meet with the " Milliolite," 

 sloping up from the shore a little distance from the sea, so as to 

 form an inclined plane with a scarp behind, in which an innumerable 

 quantity of troughs of different lengths have been cut at right angles 

 to the inclination, and which, from the number of wells present, 

 would appear at some remote period to have been used as a garden, 

 perhaps for supplying the town, which now lies in extensive ruins a 

 little distance off on the shore ; there are also holes in the precipi- 

 tous parts of this incline, where it has been cut through by ravines, 

 which appear to have been used for sepulchral purposes ; but Lieut. 

 Constable, who has a full description of the whole, will one day, I 

 trust, lay his interesting account of this locality before the public. 



Lastly, at Bushire we have the same kind of fine sandy deposit 

 capped by shell-detritus or shell-concrete as that of Karrack, indicat- 

 ing that the nearer we get to the Shat el Arab, from which the 

 whole has probably been derived, the coarser the sediment becomes, 

 while the further off we go, as at Kishm, the more subtle it is. 

 At Bushire there also appears to be a still more modern shell- 

 concrete. 



Observations. — Hence we learn that there are two striking geolo- 

 gical features at least in the Persian Gulf. One the presence of a 

 sedimentary formation of more than 500 feet thickness, which has 

 been raised above the level of the sea ; and the other, the existence 

 of a volcanic area, including all the islands at the eastern end of the 

 Gulf and part of the mainland, which is characterized by the presence 

 of trap-diorite and a great development of rock-salt, gypsum, sul- 

 phur, pyrites, specular iron-ore, &c. 



The type of the sedimentary deposit we have found to be upwards 

 of 500 feet of fine calcareous clay veined with fibrous gypsum, and 



