y2 SCIENCE IN AFRICA 



sheet showing the areas for which data are available. The merits 

 of the individual surveys vary considerably, but data sufficent for 

 mapping on the scale of i :5, 000,000 are available for the whole 

 continent, with the sole exceptions of the Rio de Oro and Kenya. 

 The international map itself will cover the whole continent in 

 nine sheets and is now in course of publication. 



The International Geological Congress of 1929 also appointed 

 a Sub-Commission of African Geological Surveys, comprising the 

 Directors of the Geological Surveys concerned. This sub-com- 

 mission met in 1931, and as a result published an International 

 Geological Map of Southern Equatorial Africa on the scale of 

 1 :5,ooo,ooo. These international maps include full references to 

 all previous maps of special areas which have been used in com- 

 pilation, so it is unnecessary to go into details here; but certain 

 particular mapping activities deserve notice. 



In the Union of South Africa the mapping programme has been 

 accelerated recently, especially in areas which are of potential 

 mineral value. In addition to a 1:1,000,000 map of the whole 

 Union, the geological department has published large-scale maps 

 at approximately i inch to the mile of the principal mineral- 

 bearing areas; and there are also twenty-one sheet maps on a scale 

 of 1 1148,750, and five sheet maps on a scale of 1 1238,000 (now dis- 

 carded). All these publications are accompanied by the necessary 

 explanations. 



Geological maps of the territories have been published in recent 

 reports of the geological departments in Uganda and Tanganyika, 

 and some important areas have been mapped in considerable 

 detail; for instance the Uganda Geological Survey has issued maps 

 on scales of from i to 3 miles to the inch for the Ankole tin- 

 fields (Combe and Groves 1932), the Bufumbira volcanic region 

 and parts of the eastern province. In the Gold Coast, regional 

 geology has been worked out perhaps in greater detail than in the 

 other British colonies, partly owing to its small area and to the 

 relatively larger staff that it has been able to maintain. A revised 

 geological map (i : 1,500, 000) of the whole colony and protectorate 

 was prepared for the Gold Coast Atlas (1935), and the southern 

 section is covered by a more detailed published map on a scale of 

 1 :500,ooo. 



