JO M1DDLEMISS: GFOLOGY OF HAZARA AND BLACK MOUNTAIN. 



evidence for discordance is afforded by the abrupt petrological 

 change from hard compact limestone to friable shale. 



Northern Section. 



The Jurassics exposed in the Slate zone, and in the more northern 

 parts of the Nummulitic zone, differ considerably from those to the 

 south. The former comprise : — 



(2) Gieimal sandstone } 30 



(passage) > to 



(1) Spiti shales ) 200 feet. 



The bottom bed of the Spiti shales is a layer of cystalline mar- 

 tite, 5 to 6 inches thick, and more or less changed to earthy and brown 

 haematite and limonite. Above this the normal Spiti shales set in. 

 They consist of jet-black or soot-black slightly micaceous shales, 

 very fissile, and often with shining lamination surfaces. 



Ferruginous and slightly sandy concretions run through the shales 



arranged in lines with the bedding. When split 

 Concretions. & & r 



open they shew red, black, and yellow concen- 

 tric coats. They vary in size up to a foot in diameter, and in shape 

 from a flattened ovoid to irregular sub-angular masses. These con- 

 cretions are unlike those of Spiti and Kumaun, and they have no fossil 

 as a nucleus. 



By common consent these densely black and extremely fissile 



shales have been called after their namesake 



Correlation with in Spiti. I have not myself seen the Spiti 



Spiti shales of Spiti, . " 



and Central Himalaya sections, but Mr. Onesbach named rocks 01 

 Kumau 3 n a . rhWal *"* the same petrological characters and pal aeon - 

 tological horizon in the Central Himalaya of 

 Garhwal and Kumaun after the Spiti shales of Spiti ; and having 

 myself seen the Central Himalayan sections I can vouch for their 

 identity of facies with my Hazara Spiti shales. There are two or 

 three points that may be specially noted about these shales. 



1. They cannot possibly be confounded anywhere with the slates 

 of the Slate series. The latter very rarely are of such a deep black 

 colour; and whilst they ring under the hammer and weather into a 

 ( 30 ) 



