IIUA SECTIONS. 43 



II— THE WESTERN BASINS, BELONGING TO THE RER RIVER SYSTEM. 



A. — Iria River Sections. 

 The country between Dhamni and Karamdiha forming the watershed 

 between the Banki aud Iria nullahs is very difficult of access ; dense jungles 

 cover most of the ground^ and great deposits of alluvial sands and clays 

 extend all over that part of the field, so that the nullahs seldom expose 

 rock in sitn, and that only at long intervals.^ 



10. — Regai Nullah and neighbotinng coxmtry. 



In the Regai nullah, near the village, I met with clayey sandstones 

 with marly partings of a dense red brick colour, which I noticed in many 

 sections intercalated between the Panchets and Mahadeva sandstone, and 

 which I connect with the former. They are lithologically identical with 

 the Panchets near Chumra and near Lawa already noticed, and I have 

 also met them in great force in the southern outcrops of the basin near 

 Kachia, overlying the Raniganj series ; all are most probably to be corre- 

 lated with the red and purple clays of Lawa. Between the Regai and 

 Iria nullahs calcareous gritty sandstones, very soft, alternate with and 

 pass into this red sandstone. Partings of ferruginous plates of slag- 

 like appearance remind one of the Mahadeva sandstone, but still I separ- 

 ate the group from the overlying sandstone of that period. 



These sandstones all show false bedding, sometimes as much as 45° 

 with the plane of stratification ; an overlap occurs in every section, so 

 that it is veiy difiicult to correlate beds of even adjoining sections. The 

 red clays usually appear between the sandstone beds as thin partings and 

 often as lenticular masses of considerable dimensions. Here and there 

 the red clay passes into motley lavender-coloured clay shales in which I 

 found fossils a short distance down the river. 



A long fault of east-by-north direction separates the mass of 

 Panchet sandstones and shales, and along this line of fracture a narrow 



1 Several names that have to be used in describing this wild country are only marked 

 on the 1-inch maps. Special copies of those maps can be obtained at the Geologictil Survey 

 Office by any one wishing for the detailed information. 



■ ( 171 ) 



