PRESIDENTS ADDRESS — SECTION C. 91 



beds of this sequence in the Waipara district contain about 40 per 

 cent, of Recent forms, and since the beds immediately succeeding 

 contain 70 per cent, of Recent species, it is likely that a re- 

 treat of the sea intervened between the deposition of the Mount 

 Broiwn "Upper Miocene", and the succeeding " Pliocene" beds. 

 The retreat of the sea from the Trelissick basin was apparently 

 somewhat later than that from the Waipara, since the highest 

 member of the conformable sequence is a bed containing Ostrea 

 ingens, such as characterizes formations that are considered as 

 transitional between "Miocene" and "Pliocene." (Park 1905,, 

 Speight 1919, Thomson 1920.) 



The succeeding "Pliocene" transgression, as a result of differen- 

 tial crust-movement, occupied quit^e a different area from that 

 affected by Oamaruian transgression. AH of the South Island re- 

 mained emergent, except the extreme north of Canterbury and 

 the coast of Marlborough, but there it extended beyond the limits^ 

 of the older transgression and rested on the pre-Notocene rocks. 

 Its northern extension is apparently observable at the Palliser Bay 

 in the south of the North Island. The deposits of this trans- 

 gression are gravels, oyster-beds, and sands in the Waipara Dis- 

 trict (Greta beds), but north of the Kaikoura ranges, in the 

 Awatere Valley, they are largely clays with abundant Struthio- 

 laria, as well as sandy and gravelly beds. In the intervening 

 area of the Kaikoura ranges, there is a most remarkable formation 

 which has been termed the " Great Marlborough Conglomerate." 

 According to McKay (1877) "it is a conglomerate, composed in 

 chief part of well-rounded bonlders, but having a large percentage 

 of angular blocks of great size sO' that on the surface they often 

 present the appearance of old morainic accumulations." They 

 are rudely stratified; in the lower parts are enormous blocks of 

 Amuri limestone and masses of soft marly strata, and boulders 

 containing (according to McKay) Awatere fossils, are present. 

 Cotton (1914), supported by Thomson (1920), believes that they 

 lie conformably on "the grey marls/' and are followed, also con- 

 formably, by the Awatere beds, from which the fossiliferous 

 boulders were derived. The Marlborough Conglomerate, on this 

 view, consists of material that was stripped off the block of the 

 Seaward Kaikouras as it rose along a line of faulting, and formed 

 a continuous (confluent) strip of fanglomerate at the foot of the 

 growing fault-scarp. After the lapse of a considerable period, it 

 was cut off, and tilted bv the further development of the faulting 

 and warping in the Landward Kaikouras. Other views, how- 

 ever, have taeen put forward. Park (1910) considers the Great 

 Marlborough Conglomerate to be glacial, but his view demands the 

 acceptance of great-faulting and warping since the glacial period. 

 W'0 may also inquire as to its relations with the Kowhai gravels 

 described by Speight (1919) as formed during the earlier portion 



