MALLET, VINDIIYAN SERIES. 19 



the scarp is shale and the upper sandstone exhibits an under-clifF of about 

 30° inclination, with a vertical precipice above ; the relative magnitude 

 of cliff and under-cliff depending chiefly on the ratio of shale to sandstone. 

 When the latter is absent, the scarp preserves a uniform slope from top 

 to bottom, while the boldest precipices are found where the scarp is entirely 

 sandstone, the under-cliff then being made up of a talus from above. 

 Where, as sometimes occurs, there are two bands of sandstone separated 

 by shale, the escarpment is usually divided into two distinct terraces. 

 The other condition, the inclination of the strata, also greatly affects 

 the form. The beds may be either horizontal, dip from the face of 

 the escarpment, or dip towards it, and, as a general rule, the cliff of 

 the escarpment is perpendicular to the stratification, and the surface in 

 from the edge or glacis, parallel to it. Hence, in the first case, the cliff is 

 found to be vertical and the country above the escarpment horizontal. In 

 the second, the cliff is not quite so steep, and the country slopes from the 

 edge with an inclination equal to that of the bedding, whilst in the third 

 case, the escarpment degenerates into an easy slope without cliff of 

 any kind. The combination of the above elements produces every variety 

 of form met with, and a geologist acquainted with the country could 

 accurately picture to himself the outline of any escarpment, without 

 seeing it, if he were told of what rocks it was made and how they were 

 disposed. / 



Along some lines of scarp outlying hills are very frequent, whose 

 elevation is equal to, or greater than, that of the 

 main scarp, according as the stratification is per- 

 fectly horizontal or dips gently from the outlier. On such eminences, 

 either wholly or semi-detached, have been constructed those hill forts 

 which once played such a prominent part in Indian history. Amongst 

 many others may be mentioned Rotasgurh, Chunar, Kallinjer and 



Gwalior. 



c { 19 ) 



