40 BALL : GEOLOGY OF AURUNGA AND HUTAE COAL FIELDS, 



phic rocks, larg-e-sized angular fragments of vein-granite and gneiss 

 occur in some abundance. 



In the Daltonganj field Mr. Hughes estimates the thickness of the 



Talchirs at 500 feet. In the area under description 

 Thickness. 



they probably do not exceed a total of 300 feet. 



The members of this group, within the limits of the Aurunga and 



Hutar fields, possess lithological characters whichj 

 Abnormal rocks. ... 



as a general rule, may be described as being 



normal. There are some exceptions to this rule, however, which merit 

 particular notice. In the Aurunga field near Latiahar there are some 

 sandy and fibrous shales, with papery carbonaceous layers, which for rea- 

 sons given further on I refer to this age. In the Hutar field in some 

 instances there is found to be in the boulder bed a preponderance of red 

 (Vindhyan) quartzite boulders over those derived from the neighbouring 

 metamorphie rocks. 



Besides the areas herein described it is not improbable that other 

 detached patches of Talchirs may be found in the hilly broken ground 

 surrounding the coal fields. 



Section 3. — Baeakar Geoup. 



The lithological characters of the rocks of this group vary very much 

 in the different coal fields of Palamow. 



In the Daltonganj field Mr. Hughes found* that the typical Barakar 

 sandstone of the eastern fields is replaced by " a false-bedded rock with 

 fine and coarse layers of sand deposited often at an angle of 50° with 

 the plane of the bedding." It is friable, earthy and slightly calcareous 

 and consequently rather resembles a common form of sandstone in the 

 Baniganj group than it does any normal Barakar form previously met with. 



In the Aurunga field the rocks of this group may, in general terms, 



Lithological characters ^^ described as being normal, perhaps even more so 



of Aurunga Barakars. ^-^^^ ^-^^^ ^^^ ^^ ^^^ Karanpura field. The ordi- 



« Memoirs, G. S. I., yoI. VIII,, page 333. 

 ( 40 ) 



