82 BLANFORD : GEOLOGY OF WESTERN Sim>. 



Feet, 

 Brought forward ... 80 



10. Dark -olive shales with calcareous hands containing oysters, &c. 30 



11. Pale-olive calcareous sandstone weathering hrown . . .10 



12. Olive-green, red-ochrey and purple shales (some of them 



containing iron pyrites and with an efflorescence of alum) and 

 rather hard whitish sandstone. Some of the shales are fossili- 

 ferous and contain Leda, Ostrea, Turritella, &c. Approximate 

 thickness ...„.,.... 100 



220 



Above this the Sita Nai traverses a deep glen between cliffs of the 



massive Nari sandstones. At least 3,000 feet of 

 Section on Sita Nai. 



these beds are exposed, and then comes a consider- 

 able thickness of dark-eoloured shales (700 or 800 feet) associated with 

 the characteristic brown limestones. These last beds form the Piro range, 

 round the north end of which the Sita stream runs in a deep curve, 

 exposing a fine section of the shales in the cliff north of the stream. 

 West of the Piro range, which rises rapidly to the southward, runs the 

 fault already described, bringing down the upper Nari sandstones to the 

 west of the range. These dip eastward at from 10° to 20°, and continue 

 for about 2 miles till the Khirthars crop out at the foot of the main 

 range, the brown limestones at the base of the Nari group running up 

 the slopes as usual. Most of the water in the Sita stream comes from 

 hot springs (temp. 91°) situated not on the fault west of the Piro range, 

 but on the eastern side of the latter. 



In the Piro range, south of the Sita Nai, Khirthar limestones appear 



from beneath the Nari beds near Eedo, and again 

 Piro range. 



to the southward, where the next stream, the Ma- 



zarani Nai, cuts- through the ridge by an impassable gorge. From this 



point the crest of the Piro ridge consists of Khirthar beds, except just 



north of the Sahar Dat. West of the Piro ridge, the Karch valley, 



running nearly north and south on the upper part of the Mazarani 



stream, is cut out of the soft Nari sandstones. 



( 82 ) 



