60 
AUSTRALASIAN ANTARCTIC EXPEDITION. 
Jurassic (Hokonui) sediments into an alpine range of which the present New Zealand Alps 
are the diminished representatives. Recent stratigraphical and physiographical studies 
emphasise the importance of this great post-Hokonui deformation, but demonstrate 
quite decisively that the majority of the present mountain ranges are due to a much 
later Kaikoura deformation commencing in the late Tertiary and perhaps not yet 
exhausted. Between these two major deformations peneplanation of the Hokonui 
mountains ensued, and the land was nearly all submerged in the Oamaruian (Oligocene- 
Miocene). Within the central part of New Zealand the Cretaceous and Tertiary beds 
are accordant, and any possible break between them is a disconformity and not an 
unconformity. There has been no mountain-forming diastrophism in New Zealand 
between the post-Hokonui and Kaikoura deformations. In one part or another of the 
area now New Zealand there was practically continuous deposition between these two 
major epochs of diastrophism, resulting in a series of beds from Middle Cretaceous to 
probably Upper Pliocene, which in their totality I have termed the Notocene 
(Thomson, 1917, No. 2.). In the middle of the Oamaruian the sea transgressed on 
both the east and the west coasts of both islands so that the land was at a minimum, 
and during this period any connections with Australia are most improbable. The 
Cretaceous transgressions, however, affected only the eastern coasts except in the north 
of Auckland, and during this period the land may have extended far to the west and 
north-west, and may have continued to do so during the Eocene. 
Diastrophic considerations in distant correlation have not yet been fully 
appraised, but their value in the form advocated by Willis (1910), in which distinct 
dynamic districts bordering the different oceans are recognised, seems to be considerable. 
No geological facts known to me controvert the probability that the diastrophic history 
of the New Zealand area in its major outlines is also that of eastern Australia and 
western America, both North and South, in fact of the circum-Pacific lands.* 
According to this view, the late Jurassic or early Cretaceous was a period of major 
diastrophism with emergent lands around the Pacific, coupled with diversities of 
climate similar to those of the present. Base-levelling and rise of the strand-line, the 
latter modified by local warpings, and perhaps intermittent owing to the different 
diastrophic history of other connecting oceans, followed throughout the Cretaceous and 
Eocene, and attained its climax in the Oligocene-Miocene, when the continents were 
low-lying and peneplained, and their margins largely overflowed by the ocean. At 
the same time the climate, which in the New Zealand Senonian had well-contrasted 
seasons (Stopes, 1914), had altered to become more uniform and mild. With the early 
stages of the Kaikoura deformation the land areas were again increased, and the 
climate became diversified, the climate of the New Zealand Wanganuian not being 
greatly different from that of the present day. With the full attainment of the 
* vSince the above was written, A. Windhousen (Am. .Joii'rn. Sci., ser. 4, vol. xlv, pp. 1-53, 1018) has discussed the 
problem of the Cretaceous-Tertiary boundary in South America, and concludes that both in Chile and Patagonia there is 
a hiatus between Cretaceous and Tertiary sediments, corresponding to the first phase of the Aniline orogenetic movements. 
The latter, therefore, seem to be earlier in inception that the Kaikoura deformation. Nevertheless, the transgressions in 
Patagonia increase in area from the Cretaceous to the Oligocene-Miocene, as in New Zealand, and the diastrophic history 
of the two areas is broadly parallel. 
