LOFTUS TURKO-PERSIAN FRONTIER. 281 



region under consideration, and he classifies them provisionally as 

 *' Lower Secondary." At first meeting with these rocks, I was in- 

 duced to regard them in the same light, but after having examined 

 them in various localities and under various conditions, I am satisfied 

 that the most considerable portion is referable to the Nummulitic age, 

 and that other portions belong to the Secondary and even Palaeozoic 

 Series. 



The lithological character and homogeneous structure of these 

 rocks are everywhere, however, so precisely similar, as utterly to pre- 

 clude the possibility of my pointing out any decided line of geological 

 demarkation (although their western boundary is tolerably well de- 

 fined) ; and it is to the fossil contents, therefore, that we must look 

 for information. 



It may be imagined that in deposits so altered and metamorphosed 

 as these are, the presence of organic remains is exceedingly rare. I 

 have been so fortunate, however, as to meet with a few fossils ; and, 

 although these are very indistinct and contorted, I satisfied myself at 

 the spots in which they occur (except in one instance *), that they 

 rather belong to the Tertiary, than to any earlier geological period. 

 The really characteristic forms of Nummulites and their allies it is 

 true are absent, but so are also Ammonites and the peculiar fossils of 

 the secondary and older rocks. At Bisiitun I observed a large 

 buccinoid shell, — at Persepolis, near the tombs of the kings, are 

 Ostrea, Cardium, Turritella, Fusus ?, Echinites, and Zoophyta more 

 abundant than in any other observed locality of this rock. 



It may be objected to my supposition of these rocks chiefly belong- 

 ing to the Tertiary period, that they for the most part rise too boldly 

 from the plain, and constitute a too well-defined N.W. and S.E. line 

 invariably to the east of the undoubtedly Cretaceous deposits ; — that, 

 while the mountains composed of Nummulitic rocks have their sides 

 and frequently their summits clothed with rich forest-trees, the blue 

 crystalline limestone is totally devoid of trees, and generally of vege- 

 tation ; — and that the jagged and serrated crests of the latter form a 

 remarkable contrast with the smooth and regular outline of the former. 

 These differences might appear to point to a difference in the geolo- 

 gical age of the two rocks, but they may surely be accounted for by 

 the abrupt fracture and separation of their masses during elevation 

 and crystallization, and by the altered state of those portions in proxi- 

 mity to the igneous axis. 



I do not, however, insist upon the correctness of my assumption ; it 

 must rather be considered as a provisional arrangement, until further 

 information is obtained to enable us to decide satisfactorily on the sub- 

 ject. At present we have very insufficient data to enable us to de- 

 termine the question. 



The section (fig. 10) between Kermanshah and Asavla shows the 

 eruption of granite and syenite (accompanied by green porphyry and 

 serpentine, and trap-rocks) through the limestone which I believe to be 

 of the tertiary age. In rising the Mewari Pass we find the limestone 

 is so altered by the intrusion of trap-veins as to be converted into 



* See page 290. 



