123 



mile soufh of Eoll's Point, and inland is traceable over a 

 limited area by the presence of a white travertine limestone 

 crust, chemically deposited from the underlying organic lime- 

 stone. Both these formations are evidently referred to by 

 Peron in the following passage: — -"At many points of Bougain- 

 ville Bay there occur two kinds of calcareous rocks ; the one 

 harder in the grain, of a more homogenous nature, approaching 

 in nature some sandstones ; the other more like chalk. These 

 calcareous stones are ordinarily superposed upon the schistose 

 rocks, as well as upon the primitive sandstone ; they may be 

 seen at 50 or 60 feet above sea level, and at this elevation con- 

 tain a great quantity of detritus and debris of petrified shells." 



Pliocexe Drift. — In the small bight on the west side of 

 E-oll's Point, Kingscote, there may be seen resting against, and 

 partially overlying the Miocene limestone, red loams and 

 mottled clays, which have been shed from the metamorphie 

 rocks constituting the elevated ground which terminates sea- 

 ward at Kingscote Point. Similar beds are exposed on the 

 western flank of the same ridge, along the east shore of the 

 Bay of Shoals. But the most extensive section is that pre- 

 sented by the sea-cliffs, called "Eed-banks" from the prevail- 

 ing colour of the formation, which has a depth above sea level 

 of about 100 feet. At this place we have evidently the remnant 

 of an extensive plain constituted of the residuum of disinte- 

 grated rocks and of the diluvium brought down by surface 

 drainage from the rocks forming the high lands to the east and 

 south. Similarly the valley of the lower part of the Cygnet 

 Eiver is composed of loams, varying from clayey to sandy, as 

 is shown in the deep banks confining the river and by the cha- 

 racter of the soil. This formation is destined to play an im- 

 portant part in the role of the future agricultural history of 

 the island, as it has done already in a slight measure. It 

 affords the only soil of value, and I am sorry to have to say 

 that its superficial area is comparatively small. On the map 

 are indicated the chief Pliocene basins. One other claims 

 special reference, it is that resting on the north flank of the 

 Preestone Eange, which owes its more argillaceous character to 

 the disintegration of the diorite which forms the axis of that 

 elevated track. The Pliocene Drift of Kangaroo Island i& 

 judged, by its mode of occurrence and by its lithological cha- 

 racter, to be of pluvial origin — certainly not aerial as is the 

 "loess" of some parts of this colony; and the absence o£ 

 organic remains favours this assumption. Excepting in this 

 last particular, it so much resembles the " drift" of the Ade- 

 laide Plain, and of others similarly constituted, that it may be 

 relegated to the same period of time. 



Pleistocei^e. — Much of the littoral tracts about \YesteriL 



