LOWER TRANSITION ROCKS. l6l 



A large dyke which cuts through the Dharwars or stands up 

 Uchingi Drug dyke. " inlier fashion " surrounded by them, and tra- 

 verses the Uchingi side band (p. 167) diagonally from south-east to 

 north-west, next requires notice, because of its doubtful relations to 

 the country rock, no contacts with which could be seen unfortu- 

 nately. 



Proceeding northward to the Mallapangudda division of the 



Dykes in the Malla- Dambal-Chik Nayakanhalli band, only two 



pangudda band. dykeg of interest were observed. They occur on 



the eastern side of the band to the west of Maithur (Mydoor) in the 

 Harapanahalli taluq. The first of them forms two striking ridges of 

 The north dyke at black large-blocked hornblendic trap (diorite?) 

 1 ur ' which run nearly parallel with the eastern 



boundary of the Dharwars from Maithur north-westward and then 

 north-north-westward for 10 miles close up to Varrakanhalli. In 

 the middle part of its course it sinks down below the cotton soil 

 spread lying to the south of Nandi Bevur, and is covered up for nearly 

 a mile ; only cropping out at intervals. In the southern part of its 

 course it presents much of the appearance of being a trap-flow 

 uptilted to a high angle and running parallel to all appearance with 

 the trappoids, hornblendic schists, and poor haematitic beds, which 

 make up the mass of the Dharwars in that corner. In the northern 

 half of its course it presents the ordinary sharp-cut appearance of a 

 true dyke. Its southern end is cut off by an important fault imme- 

 diately west of the village of Maithur, while its northern end is lost 

 sight of in the trap-flow forming the hilly corner east of Varrakan- 

 halli. 



At its southern extremity it appears to abut, nearly at a right 

 The Maithur south angle, on the great south dyke which is a 



dyke. . 



genuine intrusive dyke of post-Dharwar age. 

 The contact of the two dykes is unfortunately, however, invisible. 

 This southern dyke runs west-south-west from close west of the 

 village of Maithur, and traverses the Dharwars to high up on the 

 eastern flank of Jajkalgudda. 



L ( 161 ) 



