HILLS BETWEEN TUZ KHURMATU AND KLFRI. 49 



The Naft Dagh and its continuation the Karach Dagh form the 

 core of a N.W. — S.E. sinuous anticline, overfolded towards the 

 south-west, and, at least in places, fold-faulted. Furthermore it is 

 not a simple fold, but is contorted in varying degrees. It is tightly 

 isoclinal, and actual crests either of the parent anticline or of its 

 minor puckers are very seldom visible. Most of the contortion in 

 the vicinity of the Palkanah oil pits can be followed ; some idea of 

 it is given in the sketch sections. 



Rocks. 



The rocks consist of a core of Fars beds comprising the usual 

 bands of gypsum, limestone, and green and red clays, succeeded by 

 the red clays and sandstones of the Kurd series. The rocks of the 

 latter series have been described in former reports and can be divided 

 into 4 or 5 more or less distinct phases or zones, each one passing 

 gradually up into the other. The lowest three zones form what 

 I have alluded to as the Lower stage of the series. In the Upper 

 or Conglomeratic stage two phases can, I think, be recognized and 

 there may be higher zones not yet seen. The beds may be tabulated 

 thus : — 



Kurd series — 



Upper (Conglomeratic) stage j 7 ° ne j' 



fZone c. 

 Lower stage . . . . . . . . .< Zone b. 



\JZone a. 



Zone " a " is characterised by abundance of red clay with compara- 

 tively few sandstone bands, which are thinner, more argillaceous 

 and therefore finer in texture, and more deeply iron-stained than 

 those of the succeeding zone. These characteristics are not always 

 simultaneously present. Sometimes sandstone is almost as plenti- 

 ful as it is in the " b " zone, but the bands are less massive and redder 

 in colour (as in the Aq Su section), or they consist of numerous 

 thin iron-stained bands with a considerable proportion of argillace- 

 ous material. This zone coincides with a belt of lower-lying 

 and less rugged country between the range of the Fars outcrop on 

 the one hand and the series of sandstone ridges forming zone " b " 

 on the other ; it is usually occupied by a large, open, winding, longi- 

 tudinal, compound valley. Thin layers of selenite derived from the 

 Fars gypsum, and often a thin layer of marl are found among the 



