I 



AUSTRALASIA. 161 



of 900 ft. The MetamorpMc Rod:s consist of foliated gneissose schist, 

 passing into gneiss, L. Silurian, or perhaps older ; they pass into un- 

 altered fissile shales and thin sandstones, and decompose quickly into a 

 soft white rock. The Older Pliocene consists of ferruginous sandstones 

 and grits, and conglomerates of quarte-pebbles, ifcc, forming nearly 

 level plains. Thin beds of concretionary ironstone (" pot-metal") occur, 

 some containing marine fossils — the only known instances of such in 

 connexion with gold drifts. L. Newer Pliocene^ represented by the 

 Deep Lead, from 40 to 100 ft. deep, and Commercial Street Lead with 

 their tributaries. Up. Newer Pliocene^ beds of ferruginous grit and 

 semiangular quartz-conglomerate occurring at higher levels than the 

 older Tertiaries. Pleistocene^ or cemented granitic detritus in hori- 

 zontal beds probably occupying the whole width of the valleys running 

 from the granite. 



4. Krause, P. M. Notes on the Geological Survey of Ararat, 

 pp. 93-99. — Post Pliocene, most recent gold drift, or alluvium of the 

 gullies and creeks, consisting chiefly of mud and clay with sand and 

 gravel sparingly distributed, and barren of gold, with a few exceptions. — 

 U. Newer Pliocene. Recent Gold Drift, equally distributed drifts left by 

 a receding sea and composed of clay and angular gravel, from a 

 " capping " to over 100 feet thick, and layers of ferruginous cement ; 

 the whole sparingly auriferous. — L. Newer Pliocene. Older Gold Drift, 

 most of the " deep leads " are referable to this ; they rise to a height 

 of 1250 feet above the sea-level, and have been traced down to 800 

 feet. They are fluviatile, and contain subfossil trunks of trees. — Newer 

 ■ Volcanic Uoclcs. Two extensions of the great Warrnambool volcanic 

 area extend to within 7 miles E. of Ararat. Borings along the river 

 Hopkins show that there are 3 layers of lava (cellular dolerite) with 

 intervening beds of clay and scoriae. — Older Pliocene. Oldest Gold Drift. 

 These drifts occur as outliers capping hills at a height of 1100 feet 

 above the sea-level, and finally form an unbroken gently sloping plain 

 down to the Wimmera basin; they are marine. — Silurian. The Palae- 

 ozoic rocks are presumed to be of this age ; there seems to be a per- 

 sistent W. dip for 4 miles. — MetamorpMc. Near the granite-boundary 

 the Palaeozoic rock changes into mica-schist, diorite, &c. — Porphyritie 

 Roclcs. Dj'kes of quartz and felspar-porphyry occur from 3 to 30 feet 

 thick, and can be traced for 3 or 4 miles. They correspond to the 

 strike and dip of iihe altered Silurian, and in one case penetrate the 

 granite. — Quartz Reefs. None of the woU-defined reefs have been 

 found to be payably auriferous. — Granite, a fine-grained ternary rock. 



5, 6, 7. Reports by Messrs. Murray, Etheridge, and Nicholas. 

 See Geological Record for 1874, pp. 150, 155. 



8. W. Nicholas. Report on the Geological Features of the country 

 near Mount Piper, pp. 121-125, plate v. (Plan of the U. Silurian and 

 Newer Volcanic Rocks between Tullarook and Kilmore). The oountiy 

 surrounding Mt. Piper consists of U. Silurian strata, overlain in parts 

 by the newer Volcanic Lava. The hills on the left of the Goulburn 

 River are covered by quartz-gravel. Just S. of Tullarook a patch of 



1875. M 



