110 MIDDLEMISS: THE GEOLOGY OF IDAR STATE. 



Aravalli rocks below. Here, whenever we study the possible terms 

 of this relationship, as made evident from the preceding details, 

 we are brought face to face with amazing irregularities of juxta- 

 position that at first sight appear irreconcilable on any simple 

 hypothesis of folding, even allowing as much as possible for the 

 fact that actual junctions are almost always obscured by the allu- 

 vium of the valleys, or by debris from the quartzite scarps. The 

 most noticeable phenomenon in this connection is the puzzling 

 way in which long or short ridge-masses (strike-masses) of the 

 quartzite end in sudden, blunt, or even expanded processes directed 

 towards the south-west or tail away in long slender ones among 

 the basement of Aravalli rocks. 



On the theory that these quartzites have been simply or com - 



Not ex ilioable b • P^ ca t e lv folded superpositionally with regard 



simple folding above to the Aravallis, these sudden endings ought 



Aravallis. ^ s ] low concentric outcrops of sharply rising 



eynclines of the quartzite to the Aravallis, the exact counterpart 

 of their sharply pitching anticlines as regards the overlying 

 phyllites. But all evidence whatever of this is entirely lacking, 

 whilst not infrequently the evidence is the other way, and as we 

 have seen in descriptions given above the separated arms of 

 anticlines or of vertical strata (probably isoclines) of the quartzite 

 splay out, or end in a fringe, against the Aravallis as though they 

 had sunk down, been engulfed in, or become frayed awav by some 

 process. It is easily recognised as a startling but undoubted fact, 

 that no single one of the many quartzite hill-masses that mapping 

 has revealed, ever displays anything that could be construed as 

 a regular synclinal trough upon the surface of the Aravallis, as do 

 the phyllites above them. On the other hand an instance has been 

 given near Samalpar of a brachy-anticline in the Delhis with its 

 central portion missing as if it had mysteriously disappeared or 

 been effaced by the Aravallis below. 



Were the underlying Aravallis consistently composed of igneous 

 rock, we should recognise this anomaly now-a- 

 J^HSSnmt£ da V s as due to _ dismemberment of the quartzite 

 by the solution, stoping away, or under- 

 cutting and sinking of the broken ends in the igneous magma. 

 In other words we should admit it as a complicated eruptive 

 unconformity. The stoped contacts near Walren and Dijio are 

 especially instructive instances of such a supposititious process. 



