71 



Geological Features of Part of eyre 

 Peninsula. 



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



[Read November 6, 1906.] 



Contents, 

 section. page. 



I. Introduction ... ... ... ... ••• ••• "1 



II. Physiography ... ... ... ... •. ••• "1 



III. Geological Features ... ... ... ... .• 72 



(a) Recent. 



(bj Miocene(?) 



(cj The Pre-Cambrian Complex. 



IV. Economic Mineral Resources 75 



I. Introduction. 



The following remarks on the geological features of 

 southern Eyre Peninsula are but cursory, the data having 

 been collected during several short visits only. The publi- 

 cation of such hasty observations, however, seems amply 

 justified, as no geological reports,"^ so far as I can ascertain 

 have yet been furnished on this area. 



The field examination was conducted from two centres, 

 Port Lincoln and Tumby Bay. 



II. Physiography. 



The topographical features in the neighbourhood of Port 

 Lincoln tend to a north-and-south development, conforming 

 to the trend of the strata. Hilly country, of varying width, 

 skirts the Gulf shores from Port Lincoln to Lipson's Cove on 

 the north, a distance of forty miles ; at some distance to the 

 south, also, precipitous sea cliffs are developed. 



It is the Port Lincoln to Lipson Cove belt that has 

 come under immediate observation. The hills in this stretch 

 of country reach a fairly uniform height of 800 to 1,000 feet. 

 Beyond the coast range, two miles west of Port Lincoln, the 

 country falls steeply into a low swampy area, running paral- 

 lel with the high ground. Pinch Swamp occupies the mcit 

 depressed portion of this belt, which extends towards the 

 Southern Ocean. 



* A few odd statements referring to this region may be 

 culled from the reports of the Mines Department of South 

 Australia, but they do not pretend to geological detail. 



