Obituary— S. L. Tornquist. 52*1 



only an increasing interest by the mining community in tlie geology 

 of the Nigerian tinfields, but also, I hope, an increasing disposition 

 to publish geological observations thereon. Major WilUams, how- 

 ever, will agree that in view of local controversies it is important 

 that facts and conclusions should be correctly stated and deduced, 

 and I may therefore perhaps be allowed to make the following 

 remarks upon his paper. 



Major WilUams makes no mention of the fact that I mapped and 

 described in 1911, in my " Geology and Geography of Northern 

 Nigeria", the younger riebeckite - granites of Ningi, Kila, and 

 Fagam, with which a portion of his paper is concerned. Of the 

 country between Buji and Ningi, I have little personal knowledge, 

 but from what I have gathered in conversation with capable observers 

 who have repeatedly traversed it, and from what I know of 

 the adjoining parts of the tinfields, I feel sure that there are there 

 not extensive outcrops of an older riebeckitic Sabon Garri granite, 

 but a number of outcrops of younger riebeckite-granite projecting 

 through older micaceous gneisses of various types. In spite of the 

 a.ssertion to the contrary in the appendix on p. 446, the petrographical 

 descriptions do not confirm the hypothesis of an older series of 

 intrusions '' specially characterized by perthite, riebeckite, and 

 segirine ". Of the sections quoted in support Nos. 106, 108, 110, 

 C.C. 3, and C.C. 4 contain no perthite, riebeckite, or segirine ; No. 113 

 is valueless as evidence ; No. 115 is said on one page to be " slightly 

 crushed " and on another to show " no sign of crushing " and to 

 belong " to the younger series ", while Nos. 100 and 105 are simply 

 sections of normal younger granite. 



It would also be interesting to know how Major Williams arrives at 

 his belief that the younger granites of Nigeria are of Mesozoic age. 

 It may be on account of the relative freshness of their outcrops, as 

 in the case of the Tertiary (?) gabbro dyke of Keffi Filani. In any 

 case the distinction of Archaean and Mesozoic soda - granites in 

 Nigeria cannot be considered established, while the generalization 

 that " tin is only found in granites that contain riebeckite " is true 

 only in the sense that tinstone is associated with the younger granites, 

 which may or may not carry riebeckite. 



J. D. Falconer. 



London. 



October 13, 1920. 



OBITUARY. 



Sven Leonhard Tornquist, Ph.D., F.M.G.S. 



BoKN March 6, 1840. Died September 6, 1920. 



The study of Graptolites has in the last few years suffered the loss 

 of some of its veteran workers, and to the names of Hopkinson and 

 Lapworth must now be added that of the Swedish geologist, 

 S. L. Tornquist. Born at Uddevalla in 1840, he proceeded in due 



