C— GEOLOGY. 83 



Uganda. — The operations of this Survey comprise mainly the 

 geological mapping of the country. During such work areas likely to 

 prove mineral-bearing are noted and mining companies and individual 

 prospectors advised to test them. The Survey, has, however, made 

 discoveries directly, or through prospectors acting on advice given. In 

 one such instance it was proved that owing to earth-movements the 

 drainage of a stream had been reversed, and the source of the gold in it 

 was found to be down, instead of up, the course of the stream. Another 

 interesting discovery, a recent one, which may prove to be valuable, was 

 the occurrence, in considerable quantity, of a bismuth-tantalum mineral, 

 new to science, in pegmatite. 



A unique adjunct is a branch of seismological research, with a view to 

 possible prediction of earthquakes, since Uganda is situated on an unstable 

 portion of the earth's crust. 



Ceylon. — The Mineral Survey of Ceylon made numbers of discoveries 

 ■of valuable minerals, including deposits of limestone, mica, iron 

 ore, nionazite, corundum, gemstones, and various rarer minerals with 

 radio-active properties, notably one new to science — ^thorianite (thorium 

 oxide), which occurs both in gravels of streams and in dykes of pegmatite. 

 Occurrences of platinum, and of manganese, chromium, molybdenum and 

 copper minerals were noted, and hot saline springs found. 



Jamaica. — Valuable stratigraphical work was done by this Survey 

 through its discovery of fossils. By their aid the various zones of the 

 strata were revealed, and the nature and occurrence of underground 

 supplies of water determined. Numerous dykes and sills of basic rocks, 

 from which can be obtained vast quantities of road-metal, much more 

 durable than the limestone then being used, were discovered by the 

 Survey. 



British Honduras. — The operations of the Mineral Survey embraced 

 the geological mapping of the country, and the preparation and publication 

 of a useful geological sketch map. Large deposits of limestone were 

 discovered, and occurrences of tinstone and molybdenite noted. 



British Guiana. — Following the original survey already mentioned, 

 much important work was done and reports published by the late Sir 

 John Harrison, describing valuable occurrences of bauxite, diamonds, gold 

 and palladium. Other useful reports issued later were by Messrs. H. J. C. 

 Connolly and Smith Brace well, on the geology and economic features of 

 the gold and diamond fields. 



Gambia. — A rapid geological survey of this small colony has been 

 made by Dr. W. G. G. Cooper of the Gold Coast Geological Survey, and a 

 ■comprehensive report with map, sections and photographs published. 

 Many interesting features were noted, and useful information given, 

 specially with regard to water-supply and brick and pottery clays. 



Somaliland. — A brief examination by Mr. R. A. Farquharson of a 

 portion of this Protectorate resulted in his discovery of seams of black coal 

 and lignite, and of occurrences of lead and strontium minerals. Other 

 minerals and rocks were noted — among them salt, barite, oil-shale, marble 

 and large deposits of gypsum. Many useful remarks were also made 

 regarding water-supplies and soil, and a report with sketch map published. 



Zanzibar. — An important report with map, sections and photographs 



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