320 Transactions. — Geology. 



reason is there to look for the cause of either in conditions of 

 a general rather than of a local nature. The suggestion I 

 have to offer is that there is a class of evidence \vhich might 

 be usefully sought for, as calculated to finally settle the ques- 

 tion of elevation, if found. We can have no direct proofs of 

 great elevation, such as would be sufficient to produce severe 

 climates on our present lowlands. But there might be found 

 proofs that the country was not thus elevated while a severe 

 climate prevailed. The recognition of a raised beach contem- 

 porary with the red gravels, or an interstratification of these 

 gravels with marine beds, would give a datum line of first im- 

 portance. Is any instance of either known ? There is none 

 in South Canterbury, for the country here is lower now than 

 it has ever been since the red gravels began to be laid. 



The red gravels being completed, there ensued a long 

 period of time after which we find fan-building resumed under 

 the influence of a second age of cold. The climatic history of 

 the interval is not written here in any new deposits, but, and 

 only vaguely, in alteration of the gravels previously laid down. 

 The record tells clearly of a long lapse of time; but whether 

 the climate was on the whole, or ever, as warm as or warmer, 

 say, than our present climate, I know of no evidence to show. 

 Possibly some information on this head could be obtained from 

 the North Island, where, if I have not misunderstood some 

 geological reports, portions of the Wanganui and Hawke's 

 Bay country were submerged after the first cold period, which 

 is registered there, as here, in red gravels. The fossils of the 

 beds of submergence should give some intelligible evidence as 

 to the climate during their deposition. Certainly the climate 

 became warmer, for the process of fan-building ceased. 



In this district — and was it not so in many other districts 

 also ?- — the long warm interval was made more noteworthy by 

 important seismic operations. The shingle-fans here were 

 disturbed in various degrees near the ranges, and subsequently 

 or simultaneously, probably the latter, and as a result of the 

 same subterranean movements, volcanic action was set up at 

 two points, on what are now known as the Timaru and 

 Geraldine downs. At Mount Horrible, in the former case, an 

 explosive volcano burst forth, which discharged dust and grit 

 in such quantity as to bury the country at the present coast- 

 line, seven or eight miles from Mount Horrible, to a depth of 

 about lOin. Two miles inland, at the Harbour Quarry, the 

 tuff is din. or 5in. deeper. At the south-west corner of 

 Mount Horrible it is 2ft. deep, with no grit so coarse a§ at the 

 coast. The explosive eruption was followed by an emission 

 of lava, which consolidated into the well-known Timani 

 dolerite or bluestone. This rock is 100ft. to 150ft. thick at 

 Mount Horrible, where it has been enormously cut away,. 



