1859.] Carter on the Persian Gulf. 43 



Passing on to the island of Kishm, which is within ten miles of 

 Hormuz, and the largest by far in the Persian Gulf, being about 

 55 miles long, but very narrow ; the specimens and descriptions of 

 this island show that it presents the same kinds of rocks as those 

 of Hormuz and Larrack, but in addition to these there is a stratified 

 sedimentary formation upon it of great extent, and upwards of 500 

 feet in thickness. 



The latter is particularly well seen about the town of Kishra, 

 which is situated at the eastern end of the island, in long inclines 

 terminating in bluff precipices, some of which are 570 feet high. 

 Again at Bassadore, which is situated at the opposite or western end 

 of the island, it is equally well seen in the form of flat-topped pre- 

 cipitous elevations called the "Great" and "Little Hummucks," 

 of which the former is 500 feet high. 



This formation consists of upwards of 500 feet of calcareous clay, 

 capped by from 30 to 40 feet of a more or less coarse, and more or 

 less consolidated, detritus of shells and calcareous grit. 



The clay is of a light grey colour, very fine consistence, effervesces 

 violently with acids, and is veined throughout with fibrous gypsum. 

 Jt is also very plastic, and is used extensively in Kishm for pottery. 

 Some portions bear impressions of bivalves, but those which I have 

 are too imperfect for description. 



The detritus of shells, again, may be coarse or fine to almost chalky. 

 The shells are semifossilized, easily separated from the mass in which 

 they are imbedded, and bear such a resemblance to those of the 

 present day that they appear to be the last raised from the bottom 

 and sides of the Gulf. Whether this formation is conformable to 

 the clay beneath, and whether the two belong to the same, or to 

 two different geological epochs, further observation must determine. 



Thirteen miles from Bassadore on the same island, are " the Salt 

 Caverns" where a green trap-diorite is found, specular iron-ore, 

 sulphur, &c. as at the islands of Larrack and Hormuz, and these 

 volcanic products, as well as the sedimentary formation, we shall 

 presently see, are also extended to the mainland or coast opposite. 



After the island of Kishm, we come to the great and Little Tombs, 

 Polior Nobflure and Surree ; the furthest not more than 55, and the 

 nearest only 15 miles from the western end of Kishm ; and here 



G 2 



