Nigeria and its tin fields

by Albert Frederick Calvert

THE FIRST GEOLOGICAL REPORTS

The geology of the area, as described by Mr. R. C. Nicolaus, is composed of granites, igneous intrusions of diabase and porphyry forming the prominent peaks of the hill range. Near the river a coarse grey gneiss forms a contact with the granite, both of which rocks are traversed by lenticles and gash veins of quartz, and several small igneous dykes cross diagonally the general strike of country, which is north-east and dips west.

Although the stream tin had so far only been prospected in the neighbourhood of the rivers, there was abundant evidence to show that the source of the tin supply came from a stockwork formation in the granite at the slopes and at the base of the foot-hills. A somewhat remarkable feature of this deposit was that a considerable quantity of metallic tin was discovered under the river banks during prospecting operations. It was found in small grains and nodules about the size of a bean, its surface very thinly coated with only a trace of iron. It was very ductile, and emitted, on crushing, the peculiar tin cry. Its mode of occurrence in the gravels, associated with coarse grains of stream tin at a depth of some 15 feet under the surface, did not at first allow its genesis being determinable, but it was unhesitatingly put down as “native tin”—a mineral up to that time of very rare occurrence.

FIRST SHIPMENT OF TIN

Mr. Laws and his engineers were so well satisfied with their work, and the results they produced were so encouraging, that the Niger Company applied in 1905 for a number of mining leases in selected areas. In spite of slight difficulties arising from a scarcity of water in the dry season, a considerable amount of development work was accomplished, and the company secured an output of one ton of black tin per diem. These results proved that the gravels could be worked profitably, while the geological structure of the country compelled experts to the conclusion that the field represented by far the most important discovery of native tin that had been made. Further examination of the district, which fully confirmed the expectations raised by the first reports, has inspired the prediction that this Northern Nigerian tin field is perhaps the richest in the world.

The Niger Company continued to treat the alluvial in the old primitive method, which consists in the main of the use of calabash and sluice boxes, by which they have, up to the present time, secured over 1000 tons of black tin. Still, the mineral resources of the colony were not, until recently, appreciated in accordance with the proved facts. Lord Scarborough year after year had told the British public, in his annual speech to the shareholders of the Niger Company, that there was treasure in Northern Nigeria in the shape of alluvial tin. He told them, in March 1907, that during the previous fifteen months roughly 240 tons of black tin, of the approximate gross value of £30,000, had been obtained from one property, the Naraguta, or an average of 16 tons a month. He told his shareholders in 1908 that the Niger Company had won £29,933 worth of tin for that year. Last year he said: “As regards tin development, we have brought home and marketed an increased quantity of ore compared with the previous year.” This year the chairman of the Niger Company declared a 2s. dividend per share as a result of the sale of a small portion of their mining lands.

OFFICIAL INFORMATION ABOUT THE NEW FIELD

The first official recognition of the importance of the Bauchi tin deposits was conveyed to the public in the Colonial Report on Northern Nigeria in 1905, and in 1906 was published the First Report on the Results of the Mineral Survey of Northern Nigeria, 1904-5. “The mineral resource of Northern Nigeria being virtually unknown” (to quote the report), “a mineral survey of the Protectorate to be carried out under the general supervision of the Director of the Imperial Institute by surveyors nominated by him, was proposed by Sir F. Lugard, the High Commissioner of Northern Nigeria, and sanctioned by the Secretary of State for the Colonies in 1904.” It was arranged that the officers of the Survey should spend about eight months of each year in Northern Nigeria in exploring the mineral deposits of selected districts.

In the general introductory summary of the first report of the surveyors, the prospects of the tin fields of Northern Nigeria are described with the customary official reserve. “Tin, in the form of cassiterite,” the report stated, “has now been found in the stream beds of other districts. It is probable that as soon as suitable transport is provided Northern Nigeria will become an important tin-producing country. Already deposits in the Bauchi Province are being worked by the Niger Company, and the metal smelted on the spot. The first consignment of tin from the Protectorate has reached this country.”

The prospect presented by this information, backed up by substantial shipments of tin, might have been expected to stimulate the curiosity of both prospectors and capitalists, and that other Richmonds would have made an appearance in the Bauchi field. But any hopes of such a result were doomed to disappointment. The Niger Company continued to win mineral, and the Mineral Survey persisted in their efforts to prove the extent of country over which the granites were tin bearing. It is possible that the remoteness and inaccessibility of the Protectorate operated unfavourably in the minds of mining adventurers, and the evil reputation which had been erroneously given to the country may have moved financiers to an excess of cautiousness. The colony made no new friends, and, as will be shown later, it was not until last year and then only by the accident of failure in another direction, that capital was diverted into the new tin field.