CONTENTS-. 



XV 



PA&E 



The Copper Mountain dyke . , . . . . • • 162 

 Great dyke west of Kudatani . . . . . . . .162 



Kapgal dyke and prehistoric settlement 163 



The " blotchy " dyke series south of the Virapur Railway Station . 164 

 The Permadevanhalli dyke 164 



Breccia texture 



Chapter VI.-INTRUSIVE ROCKS IN THE ARCH^AN AREA. 



Sub-division into 



(A) Trap dykes ...... 



(B) Brecciated quartz-runs .... 



(C) Pegmatite veins ..... 



(D) Epidote-granite veins .... 



(E) Enstatite rocks, veins and necks . 

 A. The Trap dykes — Prevalence of dioritic dykes • 



Some are augitic ...... 



Grouping of dykes by their courses . 



Distribution of the dykes .... 



Size and length of the dykes .... 



Harapanahalli dyke ..... 



Very few quarries in the trap dykes . 



No really columnar cleavage seen . 



Porphyritic dykes ...... 



At Hurrihal and Kalla Kurti a 

 B.. Brecciated quartz-runs (Fault rocks) — Colour and 



The quartz runs true dykes .... 



Their dimensions ...... 



Their age ....... 



Their number and grouping .... 



Accessory minerals mostly wanting . 



Occurrence of copper carbonate at Harapanahalli 



A smooth ridge ...... 



Excessive jointing ...... 



Unusually white quartz ..... 



The great run at Harapanahalli • . 



Kanch Kerra runs . ..... 



Nellapur run ....... 



Dark coloured runs of Jitna Katti hill and Tellamatti 



Hatti Bellagal run and extension 



Siddapan Konda run, traces of copper 



Other important runs south of Harapanahalli . 



Ujinni and Nimbalgiri runs .... 



Niddagurti hill run ..... 



Great run south of Yemmiganur 

 C. Pegmatite veins . • • • • 



hills 



165 



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 1/2 

 172 

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173 

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