Thomson. — Diastrophic Correlation and Districts in the Notocene. 411 



The only possible overlapping of the above names is that the Upper 

 or Lower Kaitangatan coal-measures may correlate with the Paparoan. 

 One is, however, a stage name and the other a group name, and both may 

 still be retained. It is worthy of notice that each of the groups of rocks 

 named above embraces coal-beds in some part of the country. 



V. A New Name for the So-called Quaternary Rocks of New 



Zealand. 



As we have no evidence that the highest Notocene stage, the Castle- 

 cliffian, corresponds exactly to the youngest Pliocene rocks of the Old 

 World, it is undesirable to use such a name as " Quaternary " for the super- 

 ficial rocks such as raised-beach deposits, glacier deposits, alluvial gravels, 

 and loess, of which all we know is that they are post-Castleeliffian, or even 

 only that they are subsequent to the main Kaikoura deformation affecting 

 the area in which they occur. It is still more undesirable to attempt to 

 distinguish between Pleistocene and Recent deposits in New Zealand, where 

 the fossil Mammalia on which these distinctions have been based are not 

 found. New names that do not beg the question of correlation are desir- 

 able. It is quite possible that in time the criteria of correlation will be 

 sufficiently developed to permit the recognition of distinct stages to which 

 local names may be given within the period intended to be covered ; but as 

 there is nowhere, and from the nature of the case hardly can be, in any one 

 locality an accessible complete succession of rocks covering the period to be 

 embraced, no local name is suitable for the totality of rocks to be included, 

 and a descriptive term is preferable. For this Notopleistocene* may be 

 suggested. The Notopleistocene period may be defined as commencing 

 where the Notocene. which has already been defined, leaves off, and con- 

 tinuing to the present day. 



In general there will be no difficulty in the application of the term, and 

 there are important series of rocks, notably in Taranaki, to which it may 

 usefully be applied. In some cases there may be a difficulty. If the Kai- 

 koura orogenic movements commenced very much earlier in one area than 

 another (and we do not know that they have yet ceased everywhere), it is 

 possible that superficial deposits were accumulating unconformably on Noto- 

 cene rocks in the former area while ordinary marine Notocene rocks were being 

 deposited in the latter. These superficial deposits would, by the definitions 

 given above, have to be classed as Notocene in age. Thus in the Waipara 

 district there is a series of terrestrial gravels which overlie the Motunau 

 beds unconformably, but nevertheless share to some extent in the general 

 tilt which the marine Notocene rocks of that district have experienced, 

 having in the Kowhai River a dip of 12° to the south-east. These gravels, 

 in addition to the greywackes of which they are mainly composed, contain 

 boulders not only of the Motunau and Mount Brown beds, but also of 

 the Amuri limestone and underlying greensands. The marine Notocene 

 rocks forming the cover to the greywackes must have been tilted, and in 

 places completely removed by denudation, exposing the underlying grey- 

 wackes, before the gravels were deposited. In other words, the latter are 

 subsequent to the main Kaikoura deformation of the area. They have, 

 however, shared in a later tilting, which is presumably a continuation of 

 the Kaikoura movements, and they are much older than the terrace- 

 gravels of the present Kowhai River. It is an open question whether 

 their age is Notocene or Notopleistocene. McKay has described similar 



* Greek votos, south ; and Pleistocene. 



