PHYSICAL GEOLOGY. 21 



There is often a startling similarity in these inverted sections to a 

 true ascending 1 instead of a descending order, and were it not that within 

 the district at the extremities of some of the anticlinal ridges the rocks 

 are found in their proper or normal order, instances would have to be 

 brought forward from various external localities to show that the ordi- 

 nary appearance of the sections along the flanks of the hills is fallacious. 



The abnormal relations described are not limited to one side of each 

 anticlinal ridge, but seem to be, on the whole, more largely developed 

 along their southern aspects, and though no persistent regularity of the 

 inversion points strongly to overthrow from the north, the balance of 

 evidence may slightly indicate a preponderance of force or thrust from 

 that quarter. 



From what has just been said, it will be seen that, at all events, in 

 the country under notice, the great regularity and steady dip to the 

 north-west asserted to exist in this region (Verchere, Jour. As. Soc, 

 Bengal, 1867, p. 92,) partakes somewhat of an imaginative character. 



In considering the general structure of the country we have thus 

 a large series of sandstones and clays overlying a comparatively narrow 

 but strong zone of nummulitic limestone, both forming open synclinal 

 troughs, between which rise long, narrow, approximately east and westerly 

 anticlinal ellipses, the forms of the latter being well defined by the lime- 

 stone zone coinciding with the hill ranges. Down to this limestone 

 order, though complicated, exists, but below it disorder, and structural 

 obscurity is the rule, the interiors of these ellipses being occupied by 

 disturbed soft strata of clay or shale and sometimes sandstone, by 

 quantities of gypsum and by harder amorphous or distinctly bedded 

 masses of rock-salt. 



The latter is the lowest rock known with any certainty to exist in 

 the district. Such is the state of confusion and concealment however, 

 that the salt might well be locally absent, or lower clays exposed. 



The overlying gypsum is frequently well stratified, but its contor- 

 tion and dislocation diminish its usefulness in explaining the internal 



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