364 Transactions. 



rivers, spread on a sea-bottom, and. levelled finally by the action of the 

 waves, even if there were not strong and independent evidence to the 

 contrary. 



The pit under consideration affords no evidence of the downward move- 

 ment of the land, since the floor on which the trees grew is 50 ft. above the 

 present high-water mark, but there is no evidence which is opposed to that 

 hypothesis. 



It is impossible to say definitely how long ago this forest grew, but since 

 its existence at least 12 ft. of gravel has been deposited on the area, and, 

 judging from the present rate of deposit in the Canterbury area, the time 

 since it grew must be considered in hundreds if not in thousands of years. 

 The sound condition of the totara draws attention to the extreme dura- 

 bility of that wood even under conditions which are not altogether favour- 

 able for its preservation. On the clay substratum on which it lies it would 

 be exposed to continual alternations of drying and wetting, and the loose 

 texture of the gravel would allow free access of air, so that the present 

 sound condition of the timber is reallv surprising. (See Plate XXIII, 

 fig. 2.) 



The occurrence of the forest serves to draw attention to another point. 

 In an article on the " Post-glacial Climate of Canterbury " {Trans. N.Z. 

 Inst., vol. 43, 1911, p. 408) I put forward the hypothesis that these old 

 forests were established during a pluvial climate, and that their disappear- 

 ance was not due to fire, but to a gradual desiccation of the region. We 

 have here a forest whose destruction was certainly not due to the former 

 of these agencies, so there were conditions previous to the arrival of man 

 which were inimical to the free growth of these totara forests, and the 

 destruction of the patch which covered the site of the old gravel-pit may 

 have been due to a widespread cause of regional and climatic character, 

 and not due to a local accident destroying a mere fragment of a once much 

 more extended forest formation. 



Bibliography. 



1. Haast, Julius. Eeport on the Formation of the Canterbury Plains, 



Canterbury Provincial Repiort, 1864. 



2. Haast, Julius von. Geology of Canterbury and Westland, 1879, p. 396. 



3. Doyne, W. J. Report on the Plains and Kivers of Canterbury, Canter- 



bury Provincial Report, 1864. 



4. Second Report upon the River Waimakariri and Lower Plains of 



Canterburv, Canterbury Provincial Report, 1864. 



5. Hutton, F. W. Rep. Geol. Explor. dur. 1873-74, 1877, p. 56. 



6. Formation of the Canterbury Plains, Trans. N.Z. Inst., vol. 16, 



1884, p. 449, and vol. 37, 1905, p. 465. 



7. Speight, R. Some Aspects of the Terrace-development in the Valleys of 



the Canterbury Rivers, Trans. N.Z. Inst., vol. 40, 1908, p. 16. 



8. Preliminary Account of the Geological Features of the Christchurch 



Artesian Area, Trans. N.Z. Inst, vol. 43, 1911, p. 420. 



