KALADGI SERIES. 131 



It will be observed that all the basins and ridges formed by the 

 upper series are broken through by small streams flowing northward into 

 the Ghatprabha. From the great height to which the upper quartzite 

 outcrop ridges rise above the surrounding country^ it becomes evident 

 that the valleys must have been formed when the denuding forces had 

 not as yet cut so deeply into the lower limestone series and formed the 

 longitudinal valleys now running parallel with the quartzite ridges. 

 The hardness of the quartzite is such that the drainage would not have 



Drainage along lines *^^®^ P^^^® transversely across them unless lines 

 of weakness. of weakness had occurred here and there. Such 



lines of weakness were in some cases certainly due to comminution of 

 the rock by excessive jointing. 



In the ease of the nullah draining the Anathilli basin_, this weakness 



of the quartzites along their southern wall is abundantly evident. A 



close examination of the lines of jointing there prevalent showed them to 



belong to the following systems, which are either wanting on the ridges 



east and west of the depression through which the stream in question 



^ flows or much less developed than in the inter- 



Weakness due to ex- 

 cessive jointing. vening valley. Three systems of jointing are 



especially marked ; they are — \stl^, a joint running north b^ east to 



south 5° west, with an average dip of 45° west by north ; 'indly, a 



joint striking north 15° — 17° east to south IS'^ — 17° west, and dipping 



55° east by south; and K>rdly, a joint striking north-north-west to 



south-south-east, with a dip of 30° west-south-west. The joint fissures 



are mostly close together, so that the rock is cut up into small fragments 



which can offer no great resistance to a rush of water. The brecciation 



of the quartzites at the apices of sharp flexures is in part due to ordinary 



systems of jointing, and in part also to systems of cleavage planes, but 



irregular conchoidal fracture is observable as well in numerous fragments. 



The largest of the synclinal basins may well be called the Shima- 



keri basin after the village of that name, which is 



Shimakeri basin. 



the largest place standing withm its limits. The 



( 131 ) 



