40 Transactions. 



not have been any recent elevation of more than a few feet. 

 The general recent direction of land movement has been down- 

 ward, and this is indicated also by the aggradation going on 

 in the Lower Waimakariri and Rakaia. 



The evidence afforded by Otago, where river- terracing is 

 also shown on a gigantic scale, points distinctly to a sinking- 

 land. Unless there has been at the same time an increase in 

 the rainfall — and as long as conditions have been the same over 

 the Tasman Sea there seems to be no reason why this should 

 have increased on the mountains — we are at once driven to con- 

 sider the supply of waste to be a predominating factor in ter- 

 race-formation in the valleys of the Canterbury rivers. If we 

 consider those parts of the world where terraces are greatly 

 developed— e.g., British Columbia, the Rocky Mountains region, 

 the Himalayas, and Patagonia — we must be struck by the fact 

 that they have all passed through a severe glaciation, when 

 waste filled the valleys, and now terracing is actively going on. 

 Elevation of the land has had an important effect in some cases, 

 but not in all. It seems that too little consideration has been 

 given to the control exerted by excessive waste- supply. 



Note. 

 I have omitted mention in the above of the effect which sag- 

 ging of the coast-line might have had on the formation of terraces. 

 Owing to the loading of the coast-line with enormous quantities 

 of waste from the land, it is highly likely that differential lowering 

 of the crust has taken place, and is probably going on now ; 

 perhaps the general lowering since the glacier maximum may be 

 intensified in the coastal regions by this process. It is highly 

 likely that a large syncline has been forming under the Canter- 

 bury Plains and to seaward of them, dating from some time 

 posterior to the Upper Cretaceous period, and that the coal- 

 measures and overlying limestones and other beds have ex- 

 perienced the results of this movement. Very interesting evi- 

 dence on this point has been afforded by the cruise of the 

 steam-trawler " Nora Niven." Mr. Edgar Waite, Curator of the 

 Canterbury Museum, informs me that at certain positions along 

 the coast large pieces of brown coal were brought up in the 

 trawl. They were frequently from 2 ft. to 3 ft. in length, and 

 weighed at times over 1 cwt. They were obtained from the 

 following stations : No. 39, twenty-six miles east of Timaru ; 

 depth, 28-31 fathoms. No. 42, thirty-one miles north-east 

 of Timaru ; depth, 21-24 fathoms. No. 54, twenty-seven miles 

 north-east of Godley Head; depth, 21-27 fathoms. No. 57, 

 four miles east-south-east of Waiau River ; depth, 26 43 Eathoms. 

 Their occurrence at such a uniform depth, their absence else- 



