Reports & Proceedings — Geological Society of London. 381 



ordinary supra-glacial moraine, and the collection of remains of 

 fauna from different depths in one horizon. 



2. June 25, 1919.— Mr. G. W. Lamplugh, F.H.S., President, in 



the Chair. 



The following communications were read: — 



1. "Outlines of the Geology of Southern Nigeria (British "West 

 Africa), with especial reference to the Tertiary Deposits." By 

 Albert Ernest Kitson, C.B.E., F.G.S., Director of the Geological 

 Survey of the Gold Coast. 



The oldest rocks in Southern Nigeria comprise a series of 

 quartzites, schists of various kinds, blue and white marble, grey 

 limestones, altered tuffs and lavas, amphibolites and gneisses. Their 

 strike varies from west-north-west and east-south-east to north-east 

 and south-west. They occur in the north-western portion of the 

 country (Yorubaland), north of lat. 7° N., and in the Oban Hills 

 region in the east. They, may be classed provisionally as Pre- 

 Cambrian. Intruded into these are large masses of granites of 

 various kinds, syenite and diorite, with pegmatite and aplite dykes. 

 In some parts these rocks have shared in the dynamic alteration to 

 which the oldest series has been subjected ; but usually they are 

 practically unchanged. There is no definite evidence to show to 

 what period they belong, but they are certainly Pre-Cretaceous, 

 probably Middle and Early Palaeozoic. 



So far as observed, there is a great hiatus between the Pre- 

 Cambrian and the next known sediments, the Upper Cretaceous. 

 Normally, these are slightly inclined rocks : they include (1) Marine 

 fossiliferous shales, mudstones, limestones, and sandstones in the 

 great valley between the Oban Hills and the Udi plateau. The 

 fossils are principally ammonites and mollusca ; (2) Estuarine 

 fossiliferous carbonaceous shales, mudstones, and sandstones along 

 the eastern foot of the Udi escarpment ; (3) Lacustrine sandstones, 

 shales, and black coal-seams, with numerous plant-remains; and (4) 

 Pluvio-lacustrine sands, shales, and pebble-bands in the lower and 

 upper parts of the Upi plateau. 



Flanking this plateau on the south and south-east, and extending 

 thence over the southern part of the great valley to the Cross River, 

 is a series of Eocene estuarine shales, clays, and marls, with septarian 

 nodules and pieces of coal and resin, and a rich fauna consisting 

 principally of mollusca, but including fragmentary remains of whales, 

 birds, fishes, and turtles. 



A thick series of sandstones, mudstones, shales, and seams of 

 brown coal forms a large portion of the basin of the Niger, west of 

 the Udi plateau. These rocks appear to be of lacustrine origin, and 

 are probably Eocene. They contain numerous remains of un- 

 determined plants, largely of dicotyledonous types, Their relation 

 to the Cretaceous and to the Eocene estuarine series is uncertain. 



In the Ijebu Jebu district are bituminiferous sands and clays with 

 Pliocene estuarine shells. 



Extending over practically the whole of the country south of 

 lat. 7° 10' N., and west of the great valley of the marine Cretaceous 



