1859.] SELWYX GEOLOGY OF VICTORIA. 147 



a letter from my friend Mr. Bland, the manager of the Port Phillip 

 Company. The figures there given show what can be done in gold- 

 (juartz-mining with efficient machinery and proper management. The 

 ('Inner Gold Mine is. I consider, the only mine at present in Victoria 

 where the requisites indispensable for success in this branch of gold- 

 mining are to be found. They have good management and efficient 

 machinery, and it being on private property, they are not hampered 

 by the very obstructive rules and regulations made by the Govern- 

 ment and the local Mining Boards applicable to the Crown -lands. 

 Since the date of Mr. Bland's letter the " reefs " have been cut in 

 two tunnels at the respective depths of 200 and 230 feet ; in one 

 the reef is 6 feet thick, and in both the quartz contains as much 

 gold as it did at the surface. At Maryborough, 400 feet has been 

 reached with a similar result ; but in almost every case the yield has 

 been neither steadily increasing nor steadily diminishing, but fluc- 

 tuating. There are also many instances of quartz-veins having 

 contained no gold on the surface, and having proved remunerative 

 when followed to greater depths. 



I have no satisfactory evidence for supposing any of our gold- 

 drifts to be older than Lower Pliocene. With the Paper above 

 mentioned I have sent you a ' Handbook to Australasia,' recently 

 published here. In the article on Geology you will see, by what I 

 have said on this subject, that I think they are all of Pliocene and 

 Post-Pliocene age, with enormous contemporaneous basaltic lava- 

 flows. The divisions I am provisionally adopting for the tertiaries 

 in the maps about to be published are as under : — 



1. Alluvial Recent fluviatile deposits, &c. 



2. Post- Pliocene ... Upper Gold-drift (angular, with recent Unios), 



Raised beaches, and Estuary beds (the shells 

 all recent). 



3. Newer Pliocene... Middle Gold-drift with bones (rounded) of living 



and extinct mammals, Flemington red Ter- 

 tiaries, Marine (like the Red Crag). 



4. Older Pliocene... Lower Gold-drift (with pounded bones of living 



and extinct animals), Upper Brighton Tertia- 

 ries. Marine (Lignite-beds, with lixuksiu). 



5. Miocene Corio Bay, Cape Otway Coast. Murray Basin, 



and Lower Brighton-beds. (All marine, with 

 characteristic Suooene fossils.) 

 G. Eocene East shore of Port Phillip, Muddy Creek, Hamil- 

 ton, A.e. (Blue elavs. with selenite and charac- 

 teristic Eocene fossils.) 



I have not yd been able to obtain any mure satisfactory evidence 

 respecting the probable age of our ooal-bearing rocks: if the mass 

 of them be Oolitic, there are certainly others in the eastern districts 

 of the colony which contain true •'Carboniferous" plants. Bo Ear 

 as I could make out in Tasmania, the ooal-bearing beds there rest 

 quite conformably on, and pass downwards into, Calcareous beds, the 

 basils from which are, [ believe, nearly all Carboniferous or Devo- 

 nian forms. With the exception of a single specimen of a bivalve 

 mollusk, I have not been able to find any fossil fauna in 001 Odal- 



bearing beds. 



VOL. XVI. PART I. M 



