40^ Geological Society :^ 



the old river-courses that formed the gully-drifts, and caused the 

 drainage water of the region to be accumulated in lakes. 



The next deposit is a coarse ochreous quartzose drift, considered 

 by the author to be the effect of some sweeping deluge ; and this is 

 also overlaid by a third bed of trap-rock, with the charred remains 

 of a forest intervening. This trap is covered by a mottled clay of 

 pure quality, also regarded as lacustrine. 



A fourth trap succeeds, covered by a superficial quartzose drift (of 

 diluvial origin, according to the author), and lying on one side of 

 the schistose hills, which are clearly denuded on the other. 



In the basin of the Yarrowee, which is covered chiefly with this 

 gravel, the author traces the run of the " gold-leads " or old gullies, 

 which have only an approximative resemblance to the ramifications 

 of the present river. These ancient gullies or leads had a very uni- 

 form fall, which, from the smallness of the contents of the gullies, 

 must have been as rapid as 16 in 1000, while the fall of the present 

 Yarrowee has only a fall of 8 in 1000. 



Mr, Phillips urges that all the basin between the gold-leads may 

 be wrought by the aid of the water power of the Yarrowee ; a thou- 

 sand horse-power being now allowed to run waste, which, by means 

 of reservoirs, could be made available. 



The author adds that silver-nuggets have been reported on good 

 authority to have been found within thirty miles of Ballaarat. He 

 further observes, that, whilst surveying the district, oscillations of 

 the spirit-bubble indicated a rocking of the earth ; and that the 

 country in places sounds hollow, like a wooden bridge, horses even 

 noticing it in passing. 



3. "Notes on the Gold-diggings at Creswick Creek and Ballaarat." 

 By Mr. W. Redaway. 



Mr. Redaway noticed first the "bluestone" or concretionary 

 basaltic lava at Creswick Creek, which composes also the rough 

 bouldered surface of the country to a great extent. In the plains 

 formed of this volcanic rock, small lakes or water-holes, from 3 to 

 12 feet in diameter, are in some places frequent. 



At Creswick Creek the different diggings perforate varying thick- 

 nesses of the bluestone, from 17 to 20 feet. Under this is 30 feet 

 of solid clay ; then darkish-coloured quartzose gravel, with abundant 

 remains of wood, to a depth of about 80 feet ; and under this the 

 " gutters," "leads," or " runs" of auriferous quartzose gravel — or 

 " wash-dirt " — are met with on the surface of the slate or ou pipe- 

 clay; The pits vary considerably in the sections they afford. 



The fragments of wood in the gravel are of all sizes, from tree- 

 trunks, 3 or 4 feet in diameter, to branches and twigs ; and this 

 drift is throughout impregnated with woody particles, giving it a 

 black appearance, esjjecially towards the bottom. The cones of the 

 " honeysuckle," or Banksia, have been found not unfrequently in 

 this drift. These are very brittle, but the wood is often well pre- 

 served. Thin horizontal layers of very hard rock are imbedded in 

 the gravel. 



Some of the " gutters " or " leads " were traced by the author 

 on plans showing their course beneath this drift across the present 



