110 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



(2) the apparent absence of the felsite and haematite beneath the 

 Trias limestone in a north-easterly direction towards Dhumtour 

 where the Infra-Trias is also absent. In this connection it may be 

 also noted as peculiar that, beyond Kakool in the Turnawaee direc- 

 tion, the felsite and haematite are always present between the Infra- 

 Trias and the Trias, but never present at the base of the Trias when 

 all representatives of the Infra-Trias are absent. 



The north-easterly part of the Sirban hill-mass is chiefly com- 

 posed of the great Nummulitic formation. 

 The Jurassic, Cretaceous, 



and Nummulitic rocks of The very top of the Sirban ridge itself, east 



Sirban. , 



of the 6,243 f eet summit, is also crowned by 



an outlier of this formation. These two separated areas are shewn 

 as one on Waagen and Wynne's map, whereas in reality the outlier 

 on the top of the ridge is completely cut off by a band of Trias lime- 

 stone as shewn on my map. 



In this Sirban section as over a large part of Hazara the limits of 

 the Nummulitic formation in a descending order are very plainly 

 indicated by the characteristic appearance of the Jura-Cretaceous 

 rocks at its base. The black shales known as the Spiti shales are 

 very generally distinguishable either in situ or in the form of debris 

 which has slipped down the slope or been washed by rain into the 

 stream or torrent beds. The Spiti shales also make a marked 

 break on the hill-sides in many places, as for instance on the slope 

 east of the stream running north-east to Shakur Bandee, and near 

 Shawali on the eastern side of the Sirban mass. Very often, too, 

 the outcrop of the Spiti shales is marked by a line of springs as on 

 the south-east side of the high ridge. 



It is chiefly owing to these marked surface features of the Spiti 

 shales and the Cretaceous band that the working out and mapping of 

 much of the geology of Hazara has been rendered easier than it 

 would otherwise have been ; in especial the difficulty of distinguish- 

 ing readily in the field the different members of the great limestone 

 formations has thus been greatly reduced. 



The section indicated in the margin gives a fair idea of the 



( MO ) 



