10 mallet: geology of darjiling and western duars. 



If a section be drawn from south to north, from the Terai to the 



' , Rammk river, through Karsiang and Darjiling-, 



General stratigraphy ' ° ° J ° J 



of formations. ( v ifo M ap j^ ft w ^ ^ f oun( j ^hat the entire 



succession of rocks has prima facie the appearance of a great synclinal. 

 In the southern part of the section, all the strata are inclined towards 

 the north at rather high angles. Towards the centre, the dips are 

 rolling and irregular, while between Darjiling and the Ramman they are 

 southerly. It is scarcely necessary to say, however, that this appearance 

 is deceptive as far as the Tertiary rocks are concerned ; their northerly 

 dip is a constant feature along the Himalayas as far as they have been 

 examined, and it has been usually assumed that they are faulted against 

 the older rocks. It is more probable, however, as pointed out by Mr. 

 H. B. Medlicott with respect to this formation as developed between the 

 Ganges and Ravi,* that the present boundary marks an original limit of 

 deposition against the older rocks, which has been subsequently modified 

 by crushing and local faulting of the strata. 



North of the soft massive sandstones and clunch beds which make 

 up the Tertiaries, we come on a narrow band of Damiidas in a more or 

 less altered condition, and including various alternations of sandstone 

 or quartzite, shales, slates, and beds of friable anthracitic coal. Over- 

 lying these, without apparent unconformity, are some thousand feet of 

 slates, mostly of grey and green tints, and including here and there a 

 band of quartzite. As we ascend the hills these slates are found to pass, 

 more or less gradually, through mica-schist into gneiss. That the gneiss 

 should be the oldest rock, and either inverted on to the slates, and they 

 in their turn on to the Damiidas, or else that the boundaries should be 

 faulted ones, or finally that the relations of these formations to each 

 other should resemble those of the Tertiaries to the Damiidas, as indicated 

 above, is what will naturally suggest itself. Strange as it may appear, 



* Vol. Ill, pt. 2. 

 ( L0 ) 



