1854.] LOFTUS — TURKO-PERSIAN FRONTIER. 465 



Further northwards similar rocks occur, hut the igneous eruptions 

 have greatly altered and contorted the sedimentary deposits. Some 

 of the sections in this more northerly region are pointed out hy the 

 author as throwing much light on the age of the disturbing forces. 



The several geological formations described by Mr. Loftus are as 

 follows : — 



I. Recent Deposits. 



1. The alluvial deposits consist, 1st, of narrow tracks of fluviatile 

 clay, sand, and gravel, now forming along the rivers and canals, and 

 containing recent land and freshwater shells ; 2ndly, of marine 

 sands and marls, of greater extent, reaching into the desert at some 

 distance from the rivers, and containing marine shells ajid corals of 

 recent forms. This marine alluvium is represented by Colonel Raw- 

 linson and Mr. Ainsworth as increasing at the rate of a mile in thirty 

 years, at the head of the Persian Gulf. 



2. Lacustrine deposits are very rare in the southern portion of the 

 tract referred to in this paper, one patch only of soft limestone with 

 Plmiorbis and Limnceus occurring in the mountains of Lauristan. 

 Calcareous tufa forms an important feature, however, in the northern 

 district, near Lake Van and elsewhere. 



3. Limestone gravel, with a few sandstone and quartz pebbles. 

 Enormous accumulations of this gravel, sometimes passing into a 

 conglomerate, abut against the hills skirting the plain, particularly 

 at Dizful, &c., where they are deeply ravined by the streams from 

 the hills. The pebbles are derived from the adjacent mountains. 



IL Tertiary Deposits. 



A. The gypsum series. This presents in descending order, — 



1 . Fine gravel, passing into 



2. Friable, red, calcareous sandstone. 



3. Variegated marls, frequently saliferous ; with vast deposits of 



gypsum, and thin beds of impure limestone. 



The approximate thickness of the whole is not less than 2000 feet. 



The gravel and sandstone are unfossiliferous ; the marls locally 

 contain fossils, viz. masses of crushed shells resembling Cyrence. But 

 at Kirrind, where some of the lower portion of the series is exposed, 

 the marls and sandstone have no gypsum, and are fossiliferous, con- 

 taining, — 



Jaw and teeth of a 



small 



Natica. 



Cardium. 



Reptile. 





Mytilus? 



Cardita. 



Remains of Crustacea. 



Astarte, 2 sp. 



Pinna. 



Balanus. 





Modiola. 



Area, 2 sp. 



Cerithium. 





Pholas ? 



Anomia. 



Murex. 





Lucina. 



Flustra. 



OUva. 





Nucula ? 



Sei-pida. 



Calyptraea. 





Chama. 



Astraea. 



Bitumen and naphtha springs occur in the gypsiferous series, but 

 are very rare in the next succeeding series — the nummulitic rocks. 

 The gypsiferous series was traced by Mr. Loftus for nearly 700 



