[ 653 ] 

 LXX. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from p. 448.] 



November 17th, 1909.— Prof. W. J. Sollas, LL.D., Sc.D., F.R.S., 

 President, in the Chair. 



r PHE following communications were read : — 



1. ' The Geology of Nyasaland.' By Arthur R. Andrew, F.G.S., 

 and T. Esmond Geoffrey Bailey, B.A., F.G.S. With a Description 

 of the Fossil Flora, by E. A. Newell Arber, M.A., F.G.S. ; Notes on 

 the Non-Marine Fossil Mollusca, by Richard Bullen Newton, F.G.S. ; 

 and a Description of the Fish-Scales of Colobodus, etc. by Ramsay 

 Heatley Traquair, M.D., F.R.S., F.G.S. 



1. The greater part of Nyasaland consists of crystalline rocks, 

 which comprise : — 



(a) Highly metamorphosed sedimentary beds, including 

 graphitic gneisses with limestones, and muscovite-schist?. 



(6) Foliated igneous rocks, especially augen-gneiss, derived 

 from granite or syenite. 



(c) Plutonic intrusions, usually granite or syenite, more 

 rarely gabbro. In two localities nepheline and sodalite- 

 syenites are found ; these are perhaps of the same age as 

 the similar post-Waterberg and pre-Karoo syenites of the 

 Transvaal. 



2. In the north-western corner of Nyasaland is a somewhat altered 

 sedimentary series, which forms the Mafingi Hills. It consists of 

 a thick accumulation of quarlzites, grits, and sandstones of pre- 

 Karoo age. 



3. The Karoo System is represented both in the north and in the 

 south of Nyasaland ; in the north it occurs in patches, which owe 

 their preservation to faulting. It has afforded remains of freshwater 

 lamellibranchs (Palceomvtela), nsh-scales(cVo/>ocZ'ws), and species of 

 Glossopteris. 



4. Recent lacustrine marls and sands are found at great heights 

 above the present level of the lake, and as much as 15 miles away 

 from its margin. 



5. Pumiceous tuff's, associated with recent gravels containing 

 pebbles of Tertiary lava, are found in the extreme north of the 

 country ; across the border, in German East Africa, Tertiary and 

 recent lavas and tuffs are widely distributed. 



6. Nyasaland consists of high plateaux rising irregularly one 

 above the other. The Nyika and Vipya plateaux were doubtless at 

 one time continuous as ' a platform of erosion,' which originated 

 after the main faulting of the Karoo in Northern Nyasaland, and 

 before the formation of the great Nyasa fault-trough. 



2. ' The Faunal Succession of the Upper Bernician.' Bv Stanley 

 Smith, M.Sc, F.G.S. 



