269 



discovery of extensive deposits of polyzoal limestone of Eocene 

 age between Yorketown and Edithburg has shown this to be 

 the case. 



As these lagoons have been discussed in considerable detail 

 by Mr. W. Howchin we shall confine our attention to the con- 

 sideration of the second class, namely, salt marshes and raised 

 beaches produced by a retreat of the sea consequent on a 

 gradual elevation of the land, which has taken place in recent 

 times. Of the latter class the gi'eat salt marsh known as 

 Peesey Swamp, extending completely across the Peninsula 

 from Sturt to Hardwicke Bay, forms a notable illustration. 



Raised beaches occur aft intervals along the coast from Point 

 Turton at the Northern extremity of Peesey Swamp to Sturt 

 Bay on the south. In many cases these extend a considerable 

 distance inland, their continuity being only broken by ridge-s 

 of calciferous sandstone, terminating in the headlands, some of 

 which attain a height of 300 ft., or occasional cliffs of the same 

 material, which in many cases must have flanked the ancient 

 shore line. 



The most extensive of these marginal raised beaches occupies 

 the area between Point Souttar and Corney Point, extending 

 along the coast for about fifteen miles, and in some instances 

 stretching inland for nearly four miles. Like many of the 

 others, this is flanked by cliffs of calciferous sandstone 60 ft. in 

 height, which at Point Souttar rest directly on a bed of red 

 •clay 2 ft. thick, under which is 6 ft. of greenish clay lying un- 

 conformably on the highly inclined metamorphic rocks. 



A raised beach was also observed overlying the Eocene about 

 one mile west of Point Turton, and separated from it by a 

 l)ed of travertine, which may represent an old land surface. 

 Of the others the following are the principal occurrences : The 

 Drains, Pipeclay Lagoon (Section L, Caribee), Emu Waterhole, 

 Hilderowie Well, chain of salt lagoons lying between Marion 

 B. and Pondalowie Bay, Stone Hut. Swivel's Hut, Maclntyre'a 

 section (Section 6, Moorowie), Tuckok Cowie. 



Recent. 



In an excavation in Section 42, Moorowie, a raised beach was 

 observed, largely composed of the foraminiferal tests of Orhi- 

 folite-^ complanata. Specimens of Area trapezia and the pearl 

 oyster {Maleogrina margaretifera) were also obtained. To-day 

 iDoth the pearl oyster and the OrhitoUtes are only found in 

 warmer seas of Australia and elsewhere, and hence afford 

 striking evidence of the climatic or other chano:es which have 



