109 



Section of a Well-bore at Mulgundawa, 

 near Wellington, South Australia. 



By Professor Ralph Tate. 



[Read September 3, 1900.] 



In the latter part of 1899 Dr. Stirling, on behalf of Mr. 

 Knight, of Mulgundawa, handed me some siftings of certain 

 fossil-developments obtained from a well-boring (the further 

 sinking of which had to be abandoned), with the view to an 

 opinion as to the probability of reaching water at no inconsider- 

 able depth, if a second venture should be decided on. 



Well No. 1 was sunk to a depth of 214 feet. At 213 feet a 

 shell-bed, rich in fossils, was penetrated. The fosssils are mainly 

 identical with those of the chief fossil-bed in the Kent Town 

 bore, and with those from 380 to 424 feet (=312 to 356 above 

 sea-level) at the Ki-Ki bore, in the Ninety-Mile Desert. 



The Mulgundawa bore is about ten miles west from Welling- 

 ton, near the lake-mouth of the Murray River, and one and a 

 half miles from the shore of Lake Alexandrina. Its elevation 

 above sea-level has not been ascertained, but it is not likely to 

 exceed 20 or 30 feet. It is situated about 40 miles N.W. from 

 Ki-Ki, which yielded water at 312 feet below sea-level.* There 

 is great similarity in the beds yielding water in the Ninety-Mile 

 Desert, which agree with those at Mulgundawa — a contemporane- 

 ity which is proved by identity of fossil-contents. This led me 

 to express the opinion that water would be found at a depth 

 below 214 feet; and making allowance that the Eocene beds 

 were rising in their westerly extension, I assigned a less depth to 

 reach water than obtained at Ki-Ki. 



Bore No. 2 was sunk close to the site of No. 1, and in a letter, 

 dated July 14, 1900, Mr. John S. Knight advises that "At a 

 depth of 292 feet we struck water, which rose to, and is still 

 flowing, from the casing within 3 feet 6 inches of the surface ; 

 consider it middling stock water." Thus has been demonstrated 

 the feasibility of an economic application of a detailed know- 

 ledge of the actual similitudes of fossiliferous horizons. An 

 increase of like results may lead to the determination of the 

 actual source of water supply contained in the basal beds of the 

 Eocene in the vast area of country extending eastward from the 



*See Clark, Trans. Roy Soc., S. Aust, XX., 1896, p. 112. 



