Bartrum. — Intrusive Igneous Rocks from West port District. 263 



previously from the river-gravels and old moraines of Central Otago, has 

 not as yet been recorded from the West Coast district. This monchiquite 

 was found by Mr. P. Gr. Morgan in the boulders of Rider Creek, a small 

 headwaters tributary of the Blackwater River, and, although the outcrop 



Locality Map, Westpokt District. 

 (Scale, 1 in. to 10 miles.) 



of the dyke shedding these boulders was not located, a similar type and 

 several camptonites were traced by Mr. Morgan to their parent dykes in 

 the vicinity. 



Camptonites have been recorded by Bell and Fraser* from the Hokitika 

 district, and Dr. J. Hendersonf has determined these and other types of 

 lamprophyres in gravels near Reefton ; it is only during the past year, 

 however, that any of these rocks have been discovered in situ around either 

 Reefton or Westport. 



* Bull. No. 1 (n.s.), N.Z. Geol. Surv., pp. 82-83, 1906. 



t Personal communication (see also Trans. N.Z. Inst., vol. 45, 1913, p. 315). 



