SEC. 10.] NOUTH-WESTERN ETJTCH. 239 



The country south of tliis is an oiaen plain covered by detrital de- 

 posits^ concealing the boundary between the Jurassic and overlying beds. • 

 The hilly ground to which the name of the Gaira hills has been 

 „ . , . given for want of any other^ has been regarded by 



Gaira hills. . a J 



General Sir Le G. Jacob as the continuation 

 of the Abrassa chain^ but it forms a much broader group attaining the 

 most lofty elevations in Western Kutch. At the time when this part of 

 the district was examined, a long continued drought had rendered the 

 country so uninhabitable that much of it was deserted, and those parts 

 only could be explored where water was obtainable. The examination 

 was with difficulty carried round the base of these hills, and as they 

 were always found to be composed of the bedded traps, it is believed that 

 any details which may have escaped notice would not affect the general 

 accuracy of the conclusions arrived at with regard to the structure of 

 this part of the country. 



The trap flows of these hills were seen in many places to undulate 

 horizontally, the outer portion always passing with various inclinations 

 beneath the sub-nummulitie rocks. The old surface formed by the flows 

 appears to have had some irregularities, as hollows were found here and 

 there occuj)ied by the newer group, but not to such an extent as would 

 indicate total unconformity. It could hardly be expected that such 

 accumulations as the traps would everywhere present a perfectly level 

 floor to receive the nest deposits, but that they did so generally is 

 shown by the persistence of the sub-nunimulitic band along their upper 

 boundary, whether locally thick or thin, and the conformity between 

 the general inclination of the beds of both groups.* 



* While it is admitted that perfect coincidence of stratification is no proof of con- 

 formity, — these same sub-nummulitic rocks and the Jurassic heds of Eastern Kutch and 

 the Runn Islands affording a striking instance to the contrary — it must he borne in mind, 

 that the newer group of the locality under notice contains no such evidence of uncon- 

 formity as would he afforded by detrital conglomeritic beds composed of trap fragments, 

 while its connexion with the trappean group is strengthened by the occurrence of certain 

 earthy rocks which must be looked upon as volcanic ; specimens undistiuguishable from 

 them having been taken from intrusive di/l-es occurring either alone or associated with 

 the doleritic traps of the interior of Kutch. 



2y ( 239 ) 



