TALCHIR GROUP. 39 



Talchirs appear to me to be separated by a greater hiatus from the 

 overlying coal measures than is implied by speaking of them respectively 

 as being consecutive groups of the same series.* 



The Talchir rocks in our area, though nowhere exposed over so 

 extensive a tract as they occupy in the Daltonganj field, are still, in all 

 probability, widely spread under the newer deposits. 



Their presence is indicated by narrow marginal strips at separated in- 

 tervals along the boundaries of the Aurunga field, and in more steadily con- 

 tinuous exposures round the limits of the coal measures of the Hutar field. 

 They occur also on the eastern margins of the Tatapani and Bisrampur fields. 

 Several detached outliers in the vicinity of the Aurunga field are partly, 

 or altogether, made up of rocks of this age, and at Satbarwah, in the bed 

 of the Maila (or Mylee) river, they occupy an area of about three square 

 miles, being unaccompanied there by any more recent deposits. 



As this Satbarwah area is about centrically situated with reference 



to the three coal fields of Daltonganj, Hutar and 

 Talchirs at Satbarwah. , . . 



Aurunga, it can scarcely be regarded as pertaining 



more to one than to another. The rocks there occurring may, there- 

 fore, most fittingly be described in this place. The fact of their exist- 

 ence has already been noted by Mr. Hughes in his report on the Dal- 

 tonganj field'' and by Mr. Forbes in his settlement report. 



The area occupied by these beds extends as an irregular strip for 

 nearly five miles along the bed of the Maila, with an average width 

 of about two-thirds of a mile. East of the village of Bari the boundary is 

 concealed by alluvium, and it may be that the Talchir rocks extend for 

 some distance under th.e cultivated plain in that neighbourhood. 



The ordinary varieties of sandstones, shales and boulder conglome- 

 rates represent the group in this area ; but it is noteworthy that in some 

 of the last-mentioned beds, in addition to rounded boulders of metamor- 



* This question has many points in common with the difficult one as to the limits of 

 the terms 'genus ' and 'species.' 



" Memoirs, G, S. I., vol, VIII, page 22. 



( 39 ) 



