Beal. — On the Alluvial Deposits of Otago. 333 



and the large amount of debris carried by the ice in this 

 glacial epoch, will well account for the wearing-power we see 

 in the ranges of mountains, in the vast accumulations and 

 the different varieties of rocks and soils that fill our valleys, 

 and in the equally extensive appearance of flowing water 

 that has so fully sorted them during their deposition. 



To-day we observe iu valleys running east and west very 

 strong evidence of their shady and sunny sides in the differ- 

 ence in the growth of vegetable life ; and in the glacial epoch 

 this difference between the shady and sunny sides I imagine 

 to be equally observable. The shady side, facing the south, 

 would be the last home of the glaciers, and thus account for 

 the greater quantity of deposit which we call the terraces of 

 to-day; whilst the sunny side, facing the north, being more 

 under the influence of water caused by the melting snow, has 

 been scoured out, and has thus prevented the debris being of 

 equal height on both sides of such valleys. Every valley thus 

 tells its own geological story, a large one like the Clutha or 

 Molyneux Valley having, of course, more to tell us than its 

 smaller companions. 



When considering this subject we must bear well in mind 

 the difference between the very gradual melting of snow and 

 the more powerful water-scouring of our present rainfall — 

 sometimes light, sometimes heavy, especially during tropical 

 and thunder storms. The persistent, steady melting of the 

 snow, no matter of what magnitude the snowfalls might be, 

 would give us those regular or almost regular and light bands 

 which we see in the banks of the Molyneux Eiver, my lowest 

 point of observation, and in the photograph which I show of 

 the celebrated Mount Burster Claim, in the Kyeburn Eanges, 

 some 4,000ft. above the level of the sea, which forms my 

 highest point of observation. The deposits at the Blue Spur, 

 Tuapeka, and other large sluicing-claims at lower elevations, 

 tell the same story. The consideration of this subject is 

 necessarily very absorbing to us as dwellers in this land 

 of golden deposits. It indicates and points to the evidence 

 of old channels of rivers, the objects of search to the 

 miner and of possession to the speculator and capitalist ; 

 and it will not be denied that wherever the bed-rock in the 

 Silurian formation has been reached large deposits of the 

 precious metal have been found, as at Gabriel's Gully, Tua- 

 peka, Butcher, and Conroy Gullies, adjoining the Manuherikia 

 Eiver, in the Molyneux Valley. Occasionally, also, rich de- 

 posits have been found when sinking in the terrace-formation, 

 as at Eoss Flat, on the west coast, and in the Cardrona 

 Valley. These two latter may be pictured to our minds by 

 considering the river-features of to-day — say, for instance, in 

 the lower part of the Shag Valley, where the Shag Eiver 



