TALCHEER COAL FIELD. 47 



they have not been in all cases removed by denudation previously to the 



deposition of the overlying strata. Thus each member of the series may 



have been, and probably was, originally much thicker than it now appears. 



In describing these beds more minutely, it will be found most 



Order of description : Convenient to proceed in order of ascent and to 

 aseen mg. Commence therefore with what have been called the 



Talcheer Group. These beds are seen in the South-east portion of the 

 field, where they occupy a tract of variable width, extending Westward 

 about 20 miles from the Brahmini River, and being terminated on the 

 West by a fault, which brings the middle or Damoodah Group in 

 contact with the gneiss. The boundary of these lower beds and the gneiss 

 is, as may be seen by a reference to the map, very much complicated by 

 a number of small faults,* which render it very difficult to obtain good 

 sections or continuous measurements. The lowest bed, which we find 

 resting on the gneiss, is most generally the " boulder bed," which 

 occasionally assumes the local form of a coarse conglomerate. But 

 at times this bed is entirely wanting, and the tesselated sandstone rests 

 immediately on the gneiss. This " boulder bed" is a peculiar one. It 



The boulder ted (3 c consists essentially of boulders of granite and 

 of section.) gneiss, those of the former comparatively small 



and the latter of much larger size, frequently from 4 to 5 feet in diameter, 

 imbedded in a matrix, which varies from a coarse sandstone to the 

 very finest shale. In some places (as e. g. near Purongo) the matrix 

 is a dark-green sOt, without any admixture of sand, but full of boulders 

 of all sizes. Occasionally it is very fine in grain and sometimes assumes 

 a shaley structure. A good instance of this, and one in which the 

 boulder bed is seen resting on the gneiss, is shown in the accompanying 



* These may often be Mlacious, and the gneiss seen abutting against the beds above the 

 "boulder bed" may be merely the top of hard knolls in situ, rising through the boulder 

 bed, which has spread over an in-egular and knoUy bottom. {W. T. Jim.) 



