264 PROCEEDINGS OF THE GEOLOGICAL, SOCIETY. 



south by the range of Tang i Khashow, and on the north by that of 

 Deh 1 Liz. These ranges are composed of the Nummuhtic forma- 

 tion ; but the centre of the valley shows a thick series of bituminous 

 blue shales (fig. 4, 4d), dipping conformably under the limestones, 

 and probably of the age of the Chalk. 



The descent from Deh i Liz is covered by a thick oak-forest, 

 growing upon limestone-debris, which entirely conceals the stratifica- 

 tion to the north of the Pass ; but, soon after leaving the plain of 

 Jeudiki, the marls and gypsum with soft sands appear, dipping at an 

 angle of 30° towards the chain of Deh i Liz. Some of these beds 

 afterwards attain a great development, and rising into considerable 

 mountains studded with oak, are traversed by several large streams, 

 which form magnificent gorges, and are bounded by high perpendi- 

 cular cliffs of blue and red marl, and red sand-rocks, in which gypsum 

 does not appear. 



This order prevails until the limestone is again thrust up at Tang 

 1 Chemish, with a dip of about 45° to the S.W. 



North of this chain, the strata are concealed by debris, as in the 

 same position at Deh i Liz. As soon, however, as this debris ceases, 

 contorted beds of sands, marls, and gypsum, the last being less 

 abundant, occupy the trough between Tang i Chemish and Kiih i 

 Dadawa, a distance of about three miles. The limestone then rises 

 in high undulations, which, forming the Kuh i Bebbe, finally slope 

 down at Tang i Sibbiir into the alluvial plain of Khorremabad. The 

 last appearance of the gypsiferous series to the N.E. in this part of 

 the Zagros is on the southern base of the cretaceous limestone-range 

 of Yaftah Kiih, which thrusts up the red sands and marls at an angle 

 of 35° towards the south. 



It would be useless to enumerate the various sections in which the 

 rocks composing the gypsum-series present the same order of suc- 

 cession. It is sufficient to have shown that such order is universally 

 preserved. To trace the numerous beds throughout their whole 

 extent, would be a work extremely minute in detail, which would 

 require much time and labour without affording (that I can see) 

 adequate remuneration. The absence of nearly all trace of organic 

 Hfe would render such an investigation in all respects unsatisfactory ; 

 and, moreover, the numerous layers of the sandstones, marls, or 

 gypsums so exactly resemble each other, as to render the discrimina- 

 tion of any one of them a matter of great difficulty, if not of utter 

 impossibility. It is true that in some localities among the marls are 

 a few bands of impure limestone containing an assemblage of crushed 

 shells, which are probably large Cyclades or Cyrence ; but, as the 

 characteristic features are in all cases destroyed, they would afford 

 little or no assistance. 



The total thickness of these deposits must be very great, certainly 

 not less than 2000 feet ; but, never having seen a perpendicular 

 section through them, I can only give this as a somewhat rough 

 approximation. 



