8 I'ASCOE: GEOLOGICAL NOTES ON MESOPOTAMIA. 



Since neither range is penetrated very deeply by streams, not 

 more than abont GOO ieet of the Fars are exposed in the Jabal 

 Hamrin and between GOO and 700 feet in the Jabal Makhul. 



Kurd {VBakhtiyari) series. — The Fars is succeeded by thick beds 

 of somewhat sandy soft red clay containing near the base two or 

 three isolated layers, an in. h or two thick, of selenite derived from the 

 gypsum below ; these follow the dip of the clays. One characteristic 

 band, occurring within the first 50 feet, is that of a light bluish un- 

 fossiliferous marl, less than a foot thick ; this was observed in widely 

 separated areas, for instance at Ain Khalid (near Ain Nukhailah) 

 and near Qal'at-al-Bint some 1G miles N.N.W. of Fathah. Bands 

 ■of red brown sandstone, at first very thin and argillaceous soon 

 appear, and increase in size and purity further up in the series 

 until they predominate over the clays in massive current-bedded 

 sand-rock of medium to coarse texture. Near Ain Nukhailah 

 incipient root-like concretions produce a fretted weathered surface 

 on this sand-rock. Thin gravel or conglomerate bands next appear 

 and one of these forms the line of low mound-like hills which stretches 

 practically continuous from the north of Ain Nukhailah to the neigh- 

 bourhood of the river, where it swings round to the north-west. These 

 mounds have evidently been submerged beneath the alluvial waters and 

 are loosely strewn with gravel which largely conceals the Tertiary 

 beds beneath. This is the highest Tertiary horizon properly ex- 

 posed, the Alluvium sweeping up its dip-slope. The pebbles in 

 the conglomerates are mostly of siliceous sandstone, chert and 

 white quartz ; they are the same as those in the Pleistocene conglo- 

 merate and the recent gravels, which have already been described. 

 The whole of this series seems to have offered a surprisingly feeble 

 resistance to erosion, and is nearly always largely masked by alluvium, 

 outcrops of sandstone appearing here, and there iu the deeper stream- 

 courses. 



There is occasionally a decrease in dip passing from the Fars 

 to the red clays of the Kurd series, but in this area there is usually 

 no such change in dip ; the highest bed of the Fars, a band of white 

 gypsum, is succeeded by a bed of red clay containing one or two 

 thin layers of selenite and a thin band of bluish marl, and there is 

 the appearance of conformity. I say " appearance," because, al- 

 though my cursory survey with small scale maps was unable to show 

 that any extensive erosion of the Fars took place before the deposi- 

 tion of the younger series, the change from one to the other is 



