56 WYNNE : TRANS-INDUS SALT REGION, KOHAT DISTRICT. 



(fig. 17) and (fig. 18), may be compared with those on the Kurshru Algud 

 near Bahadur Khel, (fig. 36), and near Giiruza, (fig. 42.) 



Sandstone hands similar to tertiary sandstones. — Apparently about 

 the place of No. 7 in the foregoing list, there are sometimes a few beds 

 of purple sandstone and clay present, very much resembling those of 

 the succeeding tertiary sandstone group. In several instances such 

 bands, apparently within the limestone group, have been found to belong 

 to the series above misplaced by dislocation, or brought in by both 

 curvature and faulting, but in other cases, from the apparent regularity 

 with which these bands seem to be included, it would be unsafe to assume 

 that they are never really intercalated with the limestones. 



Concealment by debris. — If the nummulitie limestone affords a key 

 to the structure of the country, on the other hand, the quantity of hard 

 debris which it forms overshooting the slopes of the hills mostly on 

 the outcrop side, adds greatly to the difficulty of seeing the complete 

 succession of the rocks, many miles of hill side being covered, and the 

 rock beneath almost entirely concealed by this debris, from the limestone 

 of the ridge to the foot of the declivity, and frequently in situations 

 where only a few projections of gypsum serve to indicate the interest 

 of sections which the ground might otherwise afford. 



Varieties in succession.— The lower rocks are gray shales or clays 

 with occasional calcareous bands. They take a greenish olive colour 

 where weathered, and are not unfrequently gypseous^ being then undis- 

 tinguishable from the l Sheenkoura' beds of the gypsum series below. 

 In these clays or shales fossils are often rare for a depth of very many 

 feet, but become suddenly abundant in thin or flaggy layers of limestone 

 largely made up of Nummulites. Thicker beds of limestone occur irre- 

 gularly higher up containing numerous fragments of oyster-like shells 

 and sometimes a few corals. 



At about this position the greater portion of the shales of some 

 localities underlie strong brown sandstones of soft texture and light 

 colour, in parts conglomeratic and enclosing nummulitie pebbles as well 



( 160 ) 



