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THE Wadella Springs and associated Bog-Iron 



ORE Deposit. 



By D. Mawson, B.E., B.Sc. 



[Read November 6, 1906.] 



The Wadella S^Driugs are located on Eyre Peninsula, 

 about seven miles west-north-west of Tumby Bay. Their 

 present aspect is more of the nature of a soakage, water ooz- 

 ing to the surface over an area several hundred yards in 

 length. Coarse reedy grass grows along the creek- bed, drain- 

 ing the boggy ground, and directs attention to the presence 

 of moisture. 



The rocks in the vicinity are highly metamorphic schists 

 and gneisses, regarded as of Pre-Cambrian age, intruded by 

 numerous pegmatitic granite dykes. In close proximity, also, 

 is a large body of iron ore, forming a flattish-topped knoll, 

 whose upper surface is elevated about 700 feet above sea 

 level. The creek draining the springs has cut away the 

 southern end of the deposit in its work of channel develop- 

 ment. The limonite composing the ore-body is exception- 

 ally pure, and different in character from that usually found 

 composing ironstone outcrops in South Australia. A syndi- 

 cate that one time held the property sank several shafts, and 

 proved the body to be comparatively shallow. The excava- 

 tions also showed it to be composed in the main of large 

 masses of solid limonite, breaking with a varnish-like frac- 

 ture, set in a matrix of an impure earthy variety; this latter 

 increases in relative bulk towards the base of the deposit, 

 depreciating its value. 



An approximate estimate of the thickness of the mass 

 is some 30 feet towards the centre, gradually decreasing in 

 saucer fashion towards the margin. The superficial area 

 is, roughly, a couple of acres. 



The springs are situated about 50 feet below the top of 

 this ironstone rise, on its western and southern borders. 

 When making geological investigations in the district, my 

 interest was enlisted by Mr. G. Carr, the farmer in posses- 

 sion. This gentleman assured me that he had a petroleum 

 spring on his property. He further described it as not any 

 ordinary type, but one which is in the habit of changing its 

 affluent liquid to milk m wet weather, and, at all times, having 

 a powerful corrosive action on rock fragments placed in its 

 waters. With this air of mystery, no further inducement 

 was necessary for me to arrange a visit to the enchanted 



