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Cove, Nepean Bay, are covered with recent marine deposits in 

 the form of a succession of shell-banks, the most inland being 

 about one mile from the present shore, and not less than about 

 twenty feet above sea level. Around the head of the Bay of 

 Shoals and about Pelican Lagoon the same phenomena are ob- 

 servable. The whole of the southern coast-line is encumbered 

 with cliffs of calcareous sand-rock and recent sand-dunes, and 

 in these respects is similar to other parts of South Australian 

 shores washed by the Southern Ocean, as I have described 

 with some detail in "Trans. Eoy. Soc. S. Aust.," vol. II., pp. 

 67 and 113. The cliffs of calciferous sandrock attain to 

 elevations of 100 to 150 feet or more, and are not infrequently 

 crowned by blown sand. Mounts Mary and Bloomfield, 

 Vivoune Bay, are of this character, and are respectively 272 

 and 224 feet high. By chemical metamorphism, the upper 

 layers of the sandrock are more jfirmly consolidated, and by 

 natural fracture — probably through failure of support — become 

 broken up into rectangular masses, usually of large dimen- 

 sions, which prove most serious obstacles to horse- travel. From 

 Mount Prospect to Cape Willoughby, nearly the whole way is 

 encumbered by this kind of material. Peron investigated 

 closely the nature and origin of this calciferous sandstone, and 

 fully recognised its relationship to the sand of the dunes. I 

 will, therefore, reproduce his most pertinent remarks : — " The 

 sand of the shore is very fine, of a quartzose nature, mixed 

 with about one-fifth part of finely comminuted calcareous 

 matter. It is driven from the sea margin by the winds upon a 

 great part of the shore into dunes 60 to 80 feet high.'* 

 "It is in the midst of this calcareous sandstone that trees 

 are entombed, nay, even some entire portions of petrified 

 forests. In many places, where the dunes are perpendicular, 

 there may be distinguished perfectly the trunks of trees with 

 their branches, and on the level surface they appear like 

 broad mosaics. If these trunks are carefully examined, the 

 several layers of ligneous tissue are discernible." Similar 

 phenomena are stated by Peron to occur at Josephine Islands 

 [Nuyt's Archipelago] and on the adjacent mainland, at 

 Esperance Bay, at Leuwin &c., indeed " throughout a space of 

 25° of latitude and upon as wide extent of longitude the same 

 appearances are reproduced on the south, west, and north-west 

 of New Holland." Flinders describes the same phenomena as 

 observed by him at Bald Hill, King George's Sound, but 

 attributed them to coral reefs. And it has usually been con- 

 sidered that Darwin was the first to present a true explanation 

 of their nature and origin. Nevertheless, in this he was 

 anticipated by Peron, who 40 years earlier advanced the same 

 explanations, though with less chemical exactitude. He says : — 



