Park. — Birth and Development of New Zealand. 75 



The Cretaceous and Tertiary formations are marginal deposits mainly 

 composed of materials derived from the wear-and-tear of the axial chains. 

 The post-Albian history of New Zealand is a chronicle of denudation, sub- 

 mergence, uplift, faultings, vulcanicity, glaciation, and river erosion, all 

 of which have taken an active part in modifying and shaping the topo- 

 graphical forms with which we are familiar. 



In the early Cretaceous the foothills, transverse chains, and even the 

 lower parts of the axial chains became worn down to a peneplain that 

 bordered the coast on all sides. When the peneplain became submerged 

 by the mid-Cretaceous transgression of the sea, the area of the dry land 

 was correspondingly diminished. It is probable that the New Zealand 

 of this period was represented by a long narrow island, or by a chain of 

 islands, of moderate relief, deeply indented with bays and sounds, and 

 drained by numerous small streams. The submerged peneplain was now 

 a sea-floor, and on it accumulated the marginal pile of Cretaceous and 

 Tertiary sediments, which as partially consolidated and elevated strata 

 may now be seen fringing many parts of the sea-coast in both Islands, and 

 as down-faulted blocks on the flanks of the alpine chains. When we 

 speak of the marginal pile of Cretaceous and Tertiary strata we do not 

 wish it to' be inferred that deposition was continuous. As a matter of 

 fact, we know that it was broken by a considerable hiatus in the early 

 Eocene. 



The Cenomanian transgression was preceded by the deposition of deltaic 

 and estuarine silts and muds, on the emergent surface of which there 

 grew a dense jungle vegetation. The vegetable remains were subsequently 

 buried by the sediments laid down by the advancing sea, and afterwards 

 formed the coal-seams of our Upper Cretaceous measures. The Upper 

 Cretaceous strata constitute what is called the Waipara formation. 



At the close of the Cretaceous there was a general uplift which lasted 

 well into the Eocene. During this uplift the greater part of the newly 

 formed Cretaceous sediments was removed by denudation, thereby uncover- 

 ing the pre-Albian peneplain. 



Towards the close of the Eocene there took place another transgression 

 of the sea, which was preceded by the deposition of deltaic sediments 

 on the surface of the recently uncovered peneplain. A jungle vegetation 

 nourished for some time on the emergent deltaic flats. Afterwards the 

 marine sediments laid down by the advancing Miocene sea covered and 

 preserved the vegetable remains. 



The late Cretaceous and older Tertiary movements were unaccompanied 

 by crustal folding, and as a consequence the strati graphical break between 

 the Upper Cretaceous and Lower Tertiary formations is generally insignificant. 

 But in New Zealand, as elsewhere, the close of the Cretaceous witnessed 

 momentous faunal changes. 



The Miocene coal-measures and the associated marine strata that cover 

 them constitute the well-known Oamaruian formation. 



In the central, or Cook Strait, area deposition continued uninterruptedly 

 till the close of the Pliocene, but in the north Auckland region and in that 

 part of the South Island lying to the south of the Trelissick Basin marine 

 strata of Pliocene age are absent. So far as we know, the Tertiary succes- 

 sion of marine strata in the far north and south of New Zealand ended with 

 the deposition of the Awamoan beds, of Upper Miocene age. The Awamoan 

 is the closing member of the great Oamaruian formation as developed in 

 north Auckland, south Canterbury, Otago, and Southland. The abrupt 



