GEOLOGY OF CENTRAL INDIA. 51 



The boundary range runs in a direction nearly north and south 

 as far as Chitor, where it takes a turn to the east, and in inarching 

 from the last place towards Nimach, the route running parallel to — and 

 at no great distance from — the base of the hills, the line of demarkation 

 betwixt the two varieties of rock forming them could be distinctly traced, 

 and it appeared to me that the superior strata had accommodated them- 

 selves to the form of a previously existing range, tilling up all irregulari- 

 ties, and presenting at their summits, the even line before described. 

 The base and lower portions of the hills are covered with vegetation, 

 owing to the softer and less durable nature of the sandstones, &c. forming 

 them ; and the crags rising abruptly above this jungle, appear like huga 

 walls raised artificially, presenting to the view the bare rock, apparently 

 arranged in horizontal strata, but which, in fact, presents the waved 

 aspect just described. The rocks so situated, as far as I have had 

 opportunities of examining them, are ferruginous quartz, or a siliceo- 

 ferruginous grit, containing occasional beds of breccia. Many varieties 

 of the series of rocks which I have named quartzose breccia, may probably 

 be found in this range. 



The rocks of the formation thus briefly described are characterized 

 by the large quantities of iron ore contained in them. This ore occurs 

 in small beds, veins, and in the form of embedded nodular concretions. 

 These latter sometimes exhibit a jaspery aspect — Botroidal red hoema- 

 tite, common hcematite, red iron ochre, and sometimes magnetic iron 

 ore— are met with, and the whole surface of the crag frequently assumes 

 an iron-shot appearance. Iron also occurs in minute grains, disseminated 

 through the mass. This rock, either in its purer or brecciated form, 

 never occurs loose or friable. The cementing medium of the brecciated 

 variety is generally siliceo-ferruginous, and some of the specimens greatly 

 resemble the coarse old red sandstones. I have met with no organic 

 remains in this formation. 



