46 GLACIAL BEDS, LITTLE PEPPERMINT BAY. 



boulder was seen which was more than one foot in its 

 longest dimension. The colour of the rock varied in 

 places, but, except on the sea-beach, the prevailing tint was 

 grey, with patches of pui'ple-coloured clay in places. The 

 clay, except for its greater tenacity, has many points in 

 common with the glacial beds of Coimaidai, near Bacchus 

 Marsh. 



Among the included boulders are black, grey, and white 

 quartzite, chert, coarse-grained granite, sandstone, slate 

 (unfossiliferous), white and rose quartz, mica-schist, 

 micaceous sandstone. quartz-porphyry, quartz-felspar- 

 porphyry, and quartz- felspar-horn blende-porphyry. A 

 large number of microscope slides were prepared from the 

 igneous rocks for the purj)osff of compai'ison with the Port 

 Cygnet and Oyster Cove igneous rocks — a very necessary 

 pohit to determine if, as it would appear, certain of the 

 Port Cygnet rocks are contemporaneous with the mai'ine 

 beds of Port Cygnet. However, a comparison of the slides 

 of rocks taken from the glacial beds, and of over 100 

 slides taken from the Port Cygnet and Oyster Cove 

 igneous rocks, appears to lead to the conclusion that the 

 igneous rocks found as boulders in the glacial beds do not 

 belong to the Port Cygnet and Oyster Cove series, and 

 that we must look elsewhere for the origin of these rocks. 

 From the granite specimens no conclusion can be drawn. 

 It is worth mentioning that, so far as the author is aware, 

 the nearest granite in situ is at the Hippolyte Rocks, south 

 of Maria Island, on the east coast of Tasmania. 



Among the included blocks was a piece of hard, dark- 

 blue limestone, containing a fossil, which Mr. R. M.John- 

 ston, F.L.S., has kindly identified for me as a form of 

 Telhnomaya, probably of Upper Silurian age. The fossil 

 is not in a state to admit of specific determination. 



Where exposed on the beach in Little Peppermint Bay 

 the glacial beds are pierced by three well-marked parallel 

 dykes and an irregular dyke, all bearing S. 30° E. The 

 dyke material is much weathered, but on the whole it 

 appears probable that the dyke belongs to the Oyster 

 Cove porphyry series. 



The occurrence of glacial beds at the horizon of the 

 Permo-Carboniferous series exposed at Little Peppermint 

 Bay is of the greatest interest. The glacial conglomerates 

 exposed at the north end of Maria Island lie nearly, if not 



