INTRUSIVE ROCKS IN THE ARCH/EAN AREA, 



167 



In order of the number of dykes belonging to them, the 14 systems 

 just referred to stand as follows : — 



I 



W. N. W. 



to 



E. S. E. 



45 dykes 



2 



N. W. 



!■ 



S. E. 



44 



>i 



3 



N. W. by W. 



II 



S. E. by E. 



3o 



ji 



4 



W. by N. 



J> 



S. by E. 



30 



„ 



5 



W. S. W. 



Ji 



E. N. E, 



21 



i» 



6 



W. 



»1 



E. 



20 



n 



7 



W. by S. 



,, 



E. by N. 



20 



11 



8 



N. N. W. 



)) 



S. S. E. 



15 



11 



9 



S. W. by W. 



M 



N. E. by E. 



11 



11 



10 



S. W. 



U 



N. E. 



10 



11 



11 



N. by W. 



)) 



S.byE. 



6 



ji 



12 



N. W. by N. 



JI 



S. W. by S. 



5 



n 



13 



S. W. by S. 



'1 



N. E. by N. 



2 



11 



»4 



S. by W. 



„ 



N. by E. 



1 



11 



Of the dykes belonging to the first system (W. N. W. to E. S. E.) 

 by far the larger number occur in the north-eastern part of the 

 district ; and the remainder mostly in the south-western part. Of 

 the second system (N. VV. to S. E,) a third part occurs in the 

 westernmost Archaean area and another third in the west central 

 part. In the case of the third system the majority of the dykes are 

 found in the central and eastern part of the district. In the case of 

 the remaining systems the majority of the dykes lie in the western 

 half of the district. In point of size the most important dykes 

 belong to the following 7 directional groups : — 



N. W. by W. 

 Group 



N. W. 

 Group. 



N. by W. 

 Group 

 W. by N. 

 Group 

 W. S. W. 

 Group 



1. The Avinmadagu dyke 1 



2. The Annampur dyke 



. ) 



> Raidrug area 



3. The Waddarhalli south dyke .) „ „ 



4. „ „ north dyke . j Hos P et area - 



5. The Kapgal dyke . 



6. The Adoni dyke 



1. The Harapanahalli dyke 



2. The Uchingi Drug dyke 



3. The Murvani dyke 



1. The Kailasa Konda dyke 



2. The Venkatapur E. dyke 



1. The Kamalapur N. dyke . 



2. n ), O. ,| . 



] I. The Tambrahalli dyke . 



Bellary area. 

 . Adoni area. 



' I Harapanahalli area. 



Adoni area. 

 . Rat Drug area. 

 Hospet area. 



' > Hospet area. 

 . Kudligi area. 



1 The Avinmadagu and Waddarhalli south dyke are the eastern and western 

 extensions respectively of the great Joga dyke which traverses the Joga-Sultanpur 

 tract of the Sandur and Copper Mountain Dharwar.area. 



( 167 ) 



