Prof. J. Park — Younger ForTnations of New Zealand. 439 



districts, and their apparent stratigraphical conformity led him in the 

 early seventies to establish his Cretaceo-Tertiary System. Even at 

 that time he clearly recognized the purely secondary character of the 

 fauna of the Cretaceous element of the succession, and the equally 

 distinctive Tertiary facies of that prevailing in the uppermost strata. 

 There was no commingling of Cretaceous and Tertiary types, and, 

 realizing that a Cretaceo-Tertiary System could not he maintained on 

 purely stratigraphical grounds, he unhesitatingly abandoned his own 

 creation. 



The Geological Survey, which adopted Hutton's Cretaceo-Tertiary 

 System from the first, continued to support it for some years ; but for 

 the past quarter of a century the Survey has offered no defence of it. 



Dr. Marshall viewed the Weka Pass sections two or three years 

 ago, and in his maiden flight in the domain of classification ' lumped ' 

 all the Cretaceous and Tertiary strata into one system, which he 

 designated his " Oamaru System (Cainozoic — mostly early) ". A 

 Tertiary system containing Baculites, Ammonites, Inoeeramus, Belem- 

 nites, as well as Plesiosaurus, Mosasaurus, and other secondary reptiles, 

 is a geological curiosity of a very novel kind. This is a grave 

 blunder which fortunately carries its own correction. It appears 

 to have arisen from an exaggerated notion of the value of physical 

 conformity in the role of classification. For the past century the 

 main and minor subdivisions of the geological record have been based 

 on palaeontological grounds alone. No dependence can be placed on 

 physical conformities and unconformities, which are simply an 

 expression of local geographical conditions. 



2. So much for the general discussion. Turning to some details in 

 Dr. Marshall's letter in your June number, he states that " where 

 the Amuri Limestone has been found there is a thickness of 500 to 

 2,000 feet of strata that have up to the present time yielded no fossils ". 

 This is an error, and apparently made in ignorance of the fact that the 

 Geological Survey has found Cretaceous fossils right up to the base of 

 the Amuri Limestone in the Clarence Valley and at Amuri Bluff, 

 Moreover, Dr. Marshall omits to mention the fact that no Tertiary 

 fossils have ever been found below the Amuri Limestone in any part 

 of New Zealand. 



3. Dr. Marshall states that_the stratigraphical break between the 

 Cretaceous and Lower Tertiary strata as exposed at Orewa and 

 Kaipara is due to slipped gi'ound. The too frequent appeal to the 

 hypothetical slip lacks conviction. These sections were first described 

 and figured by me over twenty-five years ago, and on account of their 

 important bearing on the relationship of the Tertiary and Cretaceous 

 systems were subsequently critically examined by Sir James Hector 

 and Alex. McKay. These experienced geologists made no attempt to 

 evade the obvious evidence of unconformity. 



4. Dr. Marsliall represents me as saying that I had not previously 

 to 1912 critically examined the surface of the Amuri Limestone for 

 Hutton's unconformity. My paper on the '' Lower Tertiary Rocks of 

 Kew Zealand",^ with my description and sections of the Weka Pass 

 district, should have made it clear enough that I did not refer to the 



^ Trans. N.Z. Institute, vol. xxxvii, 1904. 



