Feb. 1848. SOANE PEBBLES. 33 



gneiss, come (in order of superposition) shivered and 

 undulating strata of metamorphic quartz, hornstone, horn- 

 stone-porphyry, jaspers, &c. These are thrown up, by 

 greenstone I believe, along the north and north-west 

 boundary of the gneiss range, and are to be recognised as 

 forming the rocks of Colgong, of Sultangunj, and of 

 Monghyr, on the Ganges, as also various detached hills 

 near Gyah, and along the upper course of the Soane. 

 From these are derived the beautiful agates and cornelians, 

 so famous under the name of Soane pebbles, and they are 

 equally common on the Curruckpore range, as on the 

 south bank of the Soane, so much so in the former position 

 as to have been used in the decoration of the walls of the 

 now ruined palaces near Bhagulpore. 



In the route I had taken, I had crossed the eastern 

 extremity alone of the range, commencing with a very 

 gradual ascent, over the alluvial plains of the west bank of 

 the Hoogly, then over laterite, succeeded by sandstone of 

 the Indian coal era, which is succeeded by the granite 

 table-land, properly so called. A little beyond the coal 

 fields, the table-land reaches an average height of 1130 

 feet, which is continued for upwards of 100 miles, to the 

 Dunwah pass. Here the descent is sudden to plains, 

 which, continuous with those of the Ganges, run up the 

 Soane till beyond Rotasghur. Except for the occasional 

 ridges of metamorphic rocks mentioned above, and some 

 hills of intruded greenstone, the lower plain is stoneless, 

 its subjacent rocks being covered with a thicker stratum of 

 the same alluvium which is thinly spread over the higher 

 table -land above. This range is of great interest from its 

 being the source of many important rivers,* and of all 



* The chief rivers from this, the great water-shed of Western Bengal, flow north- 

 west and south-east ; a few comparatively insignificant streams running north to 

 VOL. i. d 



