Yol. 6t,.~] the crystalline rocks of the kuktjrtjku hills. 317 



19. The Crystalline Eocks of the Kukcruku Hills (Southern 

 Nigeria). By John Parkinson, B.A., F.G.S. (Bead 

 December 19th, 1906.) 



[Abstract.] 



In this paper a preliminary account is given of the crystalline 

 rocks lying to the north of the Benin Sands of the Central Province 

 of Southern Nigeria, and between 5° 20' and 6° long. E. (for route, 

 see map, p. 310). 



Comparison of this district with that of the Oban Hills goes 

 to show that we have to deal with differences rather of degree than 

 of kind. In each area we find a group of schists intruded into by a 

 series of later gneisses of acid composition ; in each the latter are 

 associated with pegmatites and basaltic dykes. 



In the Kukuruku district (Owo, Otua, etc.) there is a striking- 

 development of quartz-schists, unknown up to the present in the 

 Oban Hills; a difference to be naturally accounted for by the condi- 

 tions under which the original sediments were deposited. 



The evidence for the intrusive nature of the gneisses of the 

 Kukuruku Hills rests upon sections along the banks of the Ayi-ossi 

 and the Ossi. 



The petrographical characters of the schists (quartz-schists, 

 sillimanite-schists, etc.) show that they were originally sediments. 

 A partial analysis of a very ferriferous mica-schist from Otua yielded: 



Per cent. 



SiO, 15-10 



Fe 2 3 67-77 



(47-44 Fe) 

 A1 2 3 4-83 



In many respects the gneisses recall those of the Eastern 

 Province. 



Near Utchi in the Ogbese Valley the foliation of the gneiss 

 trends N. 45° W. (true), and on the Ossi west of Iduani the trend 

 of the foliation is approximately the same. 



Discussion (on the three foregoing Papers). 



Dr. J.W.Evans referred to the advantages of the system, by which 

 the members of the Mineralogical Surveys of Northern and Southern 

 Nigeria spent the winter in the field in the Protectorates, and the 

 summer in this country, reviewing their work. The crystalline 

 rocks showed considerable resemblance to those of Central Africa, 

 so far as they were known ; and similar types were largely repre- 

 sented in the southern portion of peninsular India. 



Mr. E. B. Newton suggested that some proof should be given, in 

 the Author's second paper, as to the presence of Cretaceous rocks in 

 Southern Nigeria. 



