M Mr Hardie o?i the Geologij of the 



brown scoriae, and seems rather to be a variety of epidote ; it is 

 intimately associated with the quartz-rocks, and is isomorphous 

 with and passes into them. As we proceed west, the quartz- 

 rocks pass into micaceous schists which alternate with hornblende 

 schists. A variety of the last mentioned rock consists of a basis 

 of a dark colour resembling the more compact hornblende schist, 

 or rather greenstones, through which are distributed numerous 

 scales of mica. It forms the link between the micaceous and 

 hornblende schists, and may be termed a micaceous hornblende 

 schist. 



We have now approached close upon the base of the boun- 

 dary ranges, and the rocks have been gradually becoming more 

 and more allied to the rocks of the argillaceous schist series. 

 The strata which constitute the most eastern of the boundary 

 ranges consist of quartz-rock, alternating to the westward with 

 argillaceous schists. A similar quartz-reck also occupies the 

 plain in the immediate neighbourhood of the eastern slope of 

 the barrier range. The first indication of the occurrence of 

 rocks of this nature may be traced in a series of strata observed 

 immediately to the eastward of the quartz-rocks. The strata 

 in this position consist of a light greyish-coloured rock, some- 

 what friable, and in appearance and texture resembling the 

 finer freestones. It is more or less schistose, can be scratched 

 by the knife, and the finer varieties have a slightly soapy feel ; 

 the coarser, on the other hand, are gritty en masse, but when 

 reduced to powder have also a soapy feel. This rock seems to 

 consist of quartz, or rather silica, intimately blended with tal- 

 cose matter, the magnesia of which has probably operated in 

 preventing a more perfect crystallization. It passes insensibly 

 into the quartz-rock of the barrier range, the geology of which 

 we shall now proceed to examine, merely premising, that the ap- 

 proach to this range is marked by the occurrence of several de- 

 tached ranges and outlines composed of the rocks we have just 

 described. 



At the bund of the Oodissagor, we have an excellent opportu- 

 nity of studying the internal structure of the most eastern of the 

 barrier ranges of the Valley of Oodipoor. The range in this 

 position is traversed by a ravine or narrow cross valley which 

 originally gave issue to the Bedus, but which is now obstructed 



