T. STEPHENS, M.A., F.G.S. 



'^I^S 



Tlie character of the country from this point may 

 be briefly described. To the West and South-West are 

 lofty ridges of diabase, which is continuous for about 

 three miles on both sides of the gorge occupied by 

 Russell Falls River. The first change is shown in out- 

 crops of thick bedded mudstone and sandstone, and 

 these are succeeded by Permo-Carboniferous marine 

 beds brought into view by strong faults. The same- 

 broken and faulted country continues up to the head of 

 the valley, where these marine beds crop out on the 

 Southern flanks of Mt. Field at an elevation of over 

 2,000 feet. To the east at a lower level are great bands, 

 of Ordovician limestone with a northerly strike, and to 

 the west are rugged ridges of quartzite and conglome- 

 rate, with bands of limestone, and traces of the Cam- 

 brian sandstone which I have elsewhere mentioned as 

 occurring at the head of the Florentine Valley. The 

 discussion of the mutual relations of these rocks is, how- 

 ever, outside the limits of this paper. It may, however, 

 be noted that, as was pointed out in a paper read before- 

 this Society in 1896,* that the valley of the Russell Falls 

 River is the first stage of the only practicable route for 

 communication by road or railway Ijetween Hobart and' 

 the West Coast, whether it be in the near or the far 

 distant future. 



In concluding these somewhat fragmentary notes, it 

 only remains to consider whether this district supplies 

 any proof of g'laciation in past ages, and it must be ad- 

 mitted that the evidence is not very clear. The typical 

 mudstone, which is one of the most widely distributed 

 of South-Eastern sediments, is an upper member of the 

 Permo-Carboniferous marine series. It is noticeable for 

 the number of erratics of large size that are contained in 

 it, and is almost certainly of glacial origin. The stupen- 

 dous intrusion of diabase, which now caps all the moun- 

 tains and most of the hills of Eastern Tasmania, is 

 mostly stripped of its original covering of sediments, 

 the remnants of which are seen in isolated patches, or- 

 abutting against the flanks of the mountains, where 

 they have been protected from erosion by accumula- 

 tions of talus. It is hard to conceive anv agencv but 



*Land routes for exploration of the Western Country. By 

 T. Stephens, M.A., F.G.S. Read loth August. 1896. 



