Vol. 6$.~] THE POST-CEETACEOUS OF SOUTHERN NIGERIA. 311 



stream-beds, the members of the Lignite Series x above mentioned 

 may be seen ; but, as the country is densely clothed with forest, the 

 range of the beds can only be discovered by an exhaustive search, 

 for which so far there has been no time. 



Except for the obscure remains of some plants, no fossils were 

 found in the Lignite Series. 



This district differs from the Central Province, (1) in that the 

 boundary between the crystalline rocks and the sedimentary deposits 

 lies farther north ; and (2) that the sedimentary beds lying between 

 the basement-floor of crystalline rocks and the Benin Sands are, 

 on the whole, better exposed. 



(c) The Calabar District. 



The Benin Sands in the neighbourhood of Calabar vary con- 

 siderably in composition. Near the ferry on the Kwa Biver, 

 en route to Calabar, a section is exposed at the side of the path 

 a few hundred yards from the river. We have here a reddish, 

 somewhat argillaceous sand, showing no sign of stratification as 

 seen, composed principally of angular quartz-grains and sub- 

 angular pebbles. At Calabar, on the other hand, we find a 

 variable deposit more argillaceous than the sands at Benin or on 

 the Kwa, either homogeneous and structureless or finely bedded, 

 exceedingly quartzose, and not uncommonly pebbly. The colour of 

 the deposit varies strikingly from place to place, being charac- 

 teristically purplish, reddish, or yellowish, owing to the state of 

 oxidation of the iron, or possibly to the presence of manganese. 

 The quartz-grains are coarse and sharp. 



The Calabar rock is seen still better at Adiabo, about 10 miles up 

 the Calabar River. The sand here forms a conspicuous rounded 

 hill, presenting a vertical cliff-face to the river, and descending 

 rapidly on either side to the swamps. Traces of stratification show 

 that the sands are approximately horizontal, or, in places, false- 

 bedded. They are usually yellow or mauve in colour, and consist 

 of quartz-grains, subangular and having pitted surfaces. 



Prom a short excursion which I made to Oron and thence for a 

 few miles along the Eket road, I think it probable that the Benin 

 Sands have a not unimportant extension on the western side of the 

 estuary of the Calabar Biver. 



The banks of the lower Cross Biver between Ikeritu and 

 Ikorofiong provide excellent sections of the Benin Sands. The 

 beds vary from yellow sand to grey and red clay, and harden near 

 the water-line into a blotched or mottled rock of vesicular habit. 

 A section on the Kwa River below Abuton shows a precisely- 

 similar rock. At Ikorofiong the high bank is composed of a red 

 sandy clay, locally containing multitudes of quartz-pebbles up to 

 4 inches in length, not very conspicuously rounded and occasionally 

 subrectangular in form. This pebble-bed shows distinct signs of 

 stratification : whether it is an integral part of the Benin Sands, 



1 For analyses and calorific values, see Colonial Reports — Miscellaneous. 

 No. 33. — Southern Nigeria: 'Reports on the Mineral Survey of Southern 

 Nigeria for 1903-4 and 1904-5 ' pp. 18-20 ; & ' Government Gazette, Protectorate 

 of Southern Nigeria' vol. vi (1905) p. 288. 



