THE 



GEOLO&ICAL MAGAZINE. 



No. LXXX.— FEBRUARY, 1871. 



OK,iC3-in:sr^^Xj -A-iaTioxiiES. 



I. — On the Diamond Fields of South Africa. 



By T. EupERT Jones, F.G.S., Professor of Geology, Eoyal Military and Staff 

 Colleges, Sandhurst. 



Diamond Eegion. — The diamond-bearing region in South Africa, 

 as at present known, is chiefly within the valley of the Vaal Eiver 

 and some of its tributaries (as the Modder and the Vet) ; but it is 

 known also to extend down the Orange (Gariep) Valley for a few 

 miles after the junction of its two great branches, the Ky Gariep 

 (Vaal) and the Nu Gariep (Cradock Eiver). Bloemhof on the 

 Vaal, two hours (12 miles) south-west of Potscherfstroom (Trans- 

 vaal), is the reported locality of the most northern diamond-find. 

 Below, for a distance of 370 miles, the plain has yielded diamonds, 

 at several places, on both sides of the river, at Hebron, Klipdrift 

 (near Pniel), Zitzikamma, Vogelstruis Pan, Sitlacomie's Village, 

 Sikoneli's Village, Nicholson's Farm, Kalk Farm (near Litkatlong), 

 etc. ; and on the south side of the Orange Eiver, they have been 

 found some miles north-west of Hopetown, at Probeerfontein, Eoode- 

 kop, David's Pan, etc. Diamonds are also said to have been found 

 a few miles east of Fauresmith, on a branch of the Modder, about 

 100 miles south by east of Litkatlong ; also a few miles south of 

 Winburg (also in the Orange Eiver Free State), in the upper 

 drainage of the Vet Eiver, about 80 miles from the Vaal. 



Geology of the Diamond Eegion. — Owing to the country being 

 mostly flat and very much coated with loose sand, its geological 

 structure has not been fully understood as yet ; and the endeavours 

 of travellers and colonists to describe the rocks and minerals they 

 have met with on the Vaal are, with few exceptions, so much en- 

 feebled by want of exact knowledge, both of geology and mineralogy, 

 that the very numerous and indifierently printed letters, lectures, 

 and notices in the colonial periodicals fail to give us more than 

 an imperfect sketch of the geological features and characters of this 

 interesting region. 



Among those who have contributed to our knowledge of the 

 geology of the Orange and Vaal Valleys, are Mr. A. G. Bain, Dr. 

 E. N. Eubidge, Mr. Wyley, Dr. W. G. Atherstone, Mr. Higson, Dr. 

 John Shaw, Dr. Exton, Dr. Muskett, Dr. G. Grey, Mr. E. T. Cooper, 

 Mr. Gilfillan, Mr. G. W. Stow, and Mr. C. L. Griesbach. 



TOL. VIII.— NO. LXXX. 4 



