BY A. MONTGOMERY, M.A. 



193 



streams of basalt crossing the road, the first about a quarter 

 of a mile wide, the second about half that width. It occurs 

 again at 21 miles from Corinna on the road to the Heazlewood, 

 and on the track to the Specimen Reef at about one and a half 

 and quarter miles from Hall's Creek. Round Waratah it is 

 rather extensively developed. Looking southward from the 

 top of Mount Bischoff it appears likely that the plateau, out of 

 which Mount Pearse stands up like an island from the sea, is 

 all basalt. If this is the case there is a very interesting 

 geological problem here, to determine as far as possible the 

 configuration of the country previous to the lava flow. This 

 Way have important economical results in leading to the 

 discovery of buried tin-bearing leads heading from Mount 

 Bischoff. Ever since the discovery of this wonderful ore 

 deposit, the small quantity of alluvial tin ore found in the 

 creeks running from it has been a subject of surprise to 

 observers, and the existence of leads buried under the basalt 

 has frequently been conjectured. The interesting leaf beds 

 underlying the basalts at Waratah have more than once been 

 brought under the notice of this Society. As usual, the 

 basaltic soil appears to be very fertile, and in the event of a 

 targe population becoming established on the West Coast, 

 these strips of good land will doubtless be very valuable for 

 farming purposes. 



The questions connected with the igneous rocks are by no 

 Weans the only interesting geological problems that present 

 themselves. Others there are in profusion, apparent even 

 to the cursory glance of the passing traveller. I may mention 

 some of these, not to throw any light upon them, but merely 

 to direct attention to them. The Tertiary leaf beds fringing 

 Macquarie Harbour have been scarcely at all studied as yet, 

 though Dr. Milligan and Mr. R, M. Johnston have made a 

 valuable beginning and given us a glimpse of the riches 

 here awaiting both botanist and geologist. The sand dunes 

 through which the railway passes between Strahan and the 

 flenty River also deserve some attention. They extend inland 

 rom the beach for a very considerable distance, and are now 

 covered with a dense growth of ti-tree scrub. Are they 

 ov erly ln g t^g leaf be( j gj or < j tldey lie aga i ngt ^g face of an 



escarpment of these such as we see at Strahan ? The latter 

 eems to me at present the more likely. But apart from 

 r geological age these dunes suggest some interesting 

 1 estions : How have they been formed ? Have they been 

 aused by the sand being blown inland from the beach, as we 

 ow sand dunes frequently are formed, encroaching on low- 

 er ^? oas t ^ ari ds and gradually covering them, or has their 

 S owth been quite in the opposite direction by the sand 

 fuflf 1 tias 0n the beach g ra duallv extending further and 

 "her seaward, and so reclaiming a* strip of shore ? If, as 



