C— GKOLOGY. 81 



freight to March 31, 1928. Besides tliis, the Railway Department has 

 obtained large sums for freight on the great quantities of mining machinery, 

 building materials and supplies transported from Sekondi to the mine. 



In addition to the profit the Railway Department has made on freight 

 of ore and supplies between the port and the mine, the Government gets 

 a royalty of five per cent, on the profits of the company that owns the 

 deposit. The mining royalty for the year 1927-28 was £10,000. 



During the last three years the average number of Europeans engaged 

 on the mine staff was 52, and of natives, 2,000. 



Diamonds were first discovered in February, 1919. These diamonds, 

 though small, are of very good quality, and have a ready sale for industrial 

 purposes and ieweller)^ 



Since mining operations were commenced in 1921 there has been a large 

 progressive increase each year till, for the year ended March 31, 192ft, the 

 figures are ; production, 648,343 carats ; value £538,860 ; export duty 

 paid, nearly £27,000. The total weight of diamonds produced is 1,824,630 

 carats, valued at £1,758,348, on which the Government has received 

 roundly £87,900 from the export duty of five per cent, on the total value. 

 The annual average for the past three years is : production, 520,572 

 carats ; value, £482,157 ; export duty, £24,108 ; mine staff — Europeans, 

 21 ; natives, 1,163 ; cost of the Geological Survey, £9,342. The export 

 duty received by Government for last year was nearly 2J times the cost of 

 the Geological Survey for that year. 



The benefit, therefore, that has accrued to the Gold Coast, directly 

 and indirectly, from these two discoveries by the Geological Survey is 

 apparent, and it will continue for a long period. 



The Gold Coast has a great potential asset in its huge deposits of high 

 grade bauxite- — the total conservatively estimated quantity being upwards 

 of 250 million tons. These deposits are not yet developed, owing mainly 

 to the high cost of transport of bauxite to a port of shipment. Bauxite is 

 an ore of low value and so cannot bear heavy charges for freight, but, with 

 extension of railway communication and reduction of freight charges, the 

 Colony should see a great development of this particular source of wealth, 

 and a further mineral example be added to revenue from Geological Survey 

 discoveries. 



The Survey is also responsible for finding many occurrences of alluvial 

 gold and some of reef gold, large deposits of iron ore (haematite), and good 

 limestone, pottery, tile and brick clays, ornamental and general con- 

 structional stones, refractory substances, and smaller occurrences of tin, 

 arsenic, molybdenum, copper, and platinum. None of these is as yet 

 developed. 



Sierra Leone. — The Geological Survey of this Colony is much younger 

 than those of Nigeria and the Gold Coast. The Director has discovered 

 large deposits of iron ore (haematite) of good quality, and considerable 

 deposits of alluvial platinum and gold — all now being developed — besides 

 occurrences of chromite, corimdum, ilmenite, rutile, manganese, and 

 graphite, all of them also minerals of economic value. If found on further 

 examination to occur in promising quantities these deposits should prove 

 to be of commercial value. 



The West African Geological Surveys have no ofiices and laboratories 



1929 a 



