DESCRIPTIVE GEOLOGY : SLATE ZONE. 121 



There seems to be no reason for the idea that this plain was 

 once a lake basin, because, as I have already explained, the altitude 

 of the surface of the alluvium varies within large limits, and there is 

 a gradual change of level (without any sudden drop) from 4.000 feet 

 at Abbottabad to 1,100 at Turbeluh. 



The portion of the Slate zone, in which one or two typical sections 



will now be taken for description, comprises the 



strip of country south-east of the great Crystal- 

 line and metamorphic zone, extending from Meerpoor to Gurhee- 

 Hubeebooluh and with a width of from two to four miles. It is 

 chiefly remarkable for the narrow width of the outcrops of sharply- 

 folded repetitions of Infra-Trias and Trias. Rocks younger than the 

 Trias are scarcely visible in this little bit of country, but they come 

 in strongly to the south-east of it on the Abbottabad side of the 

 Tandiani ridge. It is apparent, therefore, that this area, which for 

 convenience is placed with the Slate zone, might with equal propriety 

 be represented as a sub-zone of Trias and Infra-Trias rocks among 

 the Slate zone. I have already remarked that the four great dis- 

 turbance zones into which I have divided the district mav sometimes 

 be again divided into smaller subdivisions, and the present is an 

 instance in point. The north slopes of Sirban hill, in like manner 

 might also be placed in a sub -zone, which is the precise equivalent 

 of this. 



It is a difficult and out-of-the-way bit of country to penetrate 



into. The great complex of folds and faults are all striking N.E. 



S.W. or N.N E.— S.S.W. Beyond Meerpoor the Slate series is not 

 in evidence until the Koonhar river is reached. The boundary line 

 between the Slate zone and the Crystalline and metamorphic zone 

 is a sharply-faulted one. 



About one mile N.N.W. of Meerpoor village and a short distance 



to the east of the Abbottabad-Mansehruh road 

 po!r e and n Ka n kool. Meer * we find a section which is the counterpart of 



the one at Koti-ki-Khubbur (Sirban sections). 

 Beneath high scarped cliffs of the Infra-Trias limestone presenting 



( 121 ) 



