184 WYNNE : GEOLOGY OF KUTCH. [PART II. 



A singular section is exposed at the north base of Katrol Hill 

 Infra-trappean beds, between the higher Jurassic beds of the plain and 



north of Katrol Hill. ^-^^ j^^^^. ^^^^^ ^^^^^ ^^ ^j^^ ^-^^ ^^ dislocation. 



The upper beds here, consisting of coarse, white, felspathic, varie- 

 gated and brown sandstones, frequently conglomeritic, with some beds 

 of shale, have a general dip to the south-30°-west at angles under 20°, 

 and terminate suddenly at a line of disturbance, beyond which for about 

 300 yards occurs a strange assemblage of what have been elsewhere 

 termed infra-trappean grits. They are generally very open and inco- 

 herent, but their trappean or coarse ashy aspect is quite as constant 

 as their granular mechanical structure, some portions passing into 

 sandstone or from sandstone into solid amygdaloidal trap. Towards 

 the north side of their exposure they are distinctly stratified, dipping 

 south by east at angles varying from horizontal to 12° or 20°. For 

 some distance they become obscured by thick sub-recent concrete, adding 

 greatly to the difficulty of understanding the section, but southward 

 beyond this they are more trappean looking and decomposed, with 

 gritty and earthy portions and the transition abovementioned. Some 

 hard calcareous sandstone occurs here (much resembling that of Katrol 

 Hill) either vertical or dipping at a very high angle to the north. South 

 of it is a vesicular basaltic trap, perhaps a dyke, and the ground is again 

 so obscured by sub-recent rock and debris from the hill that nothing 

 further regarding the arrangement of the rocks can be made out. Both 

 ends of this section appear to be in faulty ground, and it is probable 

 that the line of the great Katrol fault here comprises more fractures 

 than one, the intervening spaces being occupied by some of the infra- 

 trappean rock which probably once extended over the Katrol summit. 



The rocks on the south side of this portion of the range are, gene- 

 . , f TT t 1 r^lly speaking, coarse sandstones and compact 

 range. flags, with shaly partings, one bed containing 



easts of small bivalve shells. 



( 184 ) 



