A NEW CAPE THERMAL CHALYBEATE SPRING. 



By JOHN Geokc;e Rose, F.C.S. 



In 1906 a syndicate was formed for the purpose of borings for 

 oil in the neighbourhood of Port Elizabeth. A borehole 404 feet 

 deep was put down ; but, as no definite information was obtained 

 thereby, a company with a capital of ;;(ii3,ooo was floated, and 

 in April, 1908, boring- operations were beg-un in the Zwartkops 

 Valley with a most modern outfit on the jumper principle capable 

 of boring to 5,000 feet if necessary. The drill was of the type 

 known on the Boryslaw oil fields as the Canadian Galician, iron 

 rods 38 feet in length being used in its working. The initial 

 diameter of the bore was 18 inches, decreasing gradually to 6 

 inches as the depth increased beyond 3,000 feet. It was lined 

 throughout with artesian casing, and so true was the bore that at 

 a depth of 3,400 feet the entire casing, weighing some 60 tons, 

 was lifted and turned daily. Red clays, shales and sandstones 

 were passed through up to 3,234 feet, when a very hard, coarse, 

 yellow sandstone was entered, which gave great trouble in drill- 

 ing, getting harder and harder as the depth increased. On the 

 29th May, 1909, a spring of hot water was struck at a depth of 

 3,400 feet. Its temperature was loSOp., and the water flowed 

 freely from the borehole at the rate of 35,000 gallons per diem. 

 At the request of the company, the author visited the spring on 

 the 15th July, 1909, for the purpose of taking samples for 

 analysis. The bore had then reached a depth of 3,450 feet. A 

 temperature of 125OF. was found at the surface, the daily yield 

 being 130,000 gallons. The bottom temperature had been taken 

 the day previously bv Mr. G. W. Smith, of Port Elizabeth, who 

 found it to be 4°F. greater than at the surface,, .viz., 

 129OF. Analysis showed the water to be that of a thermal 

 chalybeate spring, and the company were advised accordingly. 

 It was also suggested to them that, as the prospects of finding oil 

 were not very encouraging, boring should be stopped, and the 

 medicinal properties of the spring exploited. Boring was, how- 

 ever, continued until November, 1909, when a depth slightly in 

 excess of 3,460 feet had been reached, and progress had become 

 extremely slow owing to the increasing hardness of the rock. 



On the 2nd of that month the author paid his third visit to 

 the spring, and found that the temperature had risen to i28.5°F 

 and the yield increased to 250,000 gallons per diem. 



The chemical composition of the water was as follows :— 



Common Salt ... 25.71 grains per gallon. 



Sulphate of Magnesia ... 3.07 ,, ,, ,, 



Carbonate of Magnesia... 2.10 ,, ,, ,, 



Carbonate of Lime 2.06 ,, ,, ,, 



Bicarbonate of Iron ... 1.66 ,, ,, ,, 



Alumina ... 02 ,, ,, ,, 



Silica I -60 ,, ,, ,, 



