Fox. — The Waitemata Series. 453 



sandstones and the overlying tuffs and lava-streams, which are 

 of Pliocene or later age. The lower limit is not so certain. 

 In this paper it is taken to be the Papakura limestone, which 

 crops out along the Palaeozoic ranges to the east of the Waite- 

 mata Harbour, lying unconformably on the upturned and de- 

 nuded edges of ancient slates and phyllites. This limestone 

 is considered by Captain Hutton to be Oligocene in age, while 

 the beds in the vicinity of Auckland are classed as Lower 

 Miocene. If this classification be accepted the volcanic beds 

 with which this paper deals are Lower Miocene, some of them 

 Oligocene perhaps. 



Above the limestone lies a thick group of greensands. 

 These are succeeded by sandstones and shales, evidently 

 deposited in somewhat shallow water, for ripple-marks and 

 current bedding may frequently be observed in them. There 

 is some doubt as to whether an unconformability exists 

 between the greensands and the overlying beds, Captain 

 Hutton and Mr. S. H. Cox, F.G.S., both holding that 

 there is one," while Mr. James Park, F.G.S., believes the 

 evidence to point to a regular succession. i At least the un- 

 conformability cannot be very great if we judge by fossil 

 evidence. 



About the time when the limestone was being formed 

 to the east of the Waitemata there rose through the Oligo- 

 cene sea to the westward a long line of volcanic vents, now 

 denuded and overgrown with dense forest, and known as the 

 Waitakerei Eange. There is no means of ascertaining its 

 exact extent or the nature and position of the vents. These 

 Waitakerei outbursts gave rise to a thick bed of coarse vol- 

 canic fragments. As the bed occurs typically at Cheltenham, 

 it may be called the Cheltenham breccia. This is the oldest 

 of the volcanic beds of the series. 



Twenty or thirty miles to the eastward another line of 

 vents became active at nearly the same time, on Coromandel 

 Peninsula. The Coromandel eruptions, however, would seem 

 to have commenced rather earlier than those at the Waitakerei, 

 and to have continued for some time after the western vents 

 had become quiescent. The debris from the Coromandel vol- 

 canoes was spread over the floor of the sea, and possibly it was 

 these eruptions which supplied the material for the Parnell 

 grit, the youngest volcanic bed of the series. 



Between these two main beds, the Cheltenham breccia and 

 the Parnell grit, there are other but less important beds of 

 volcanic origin which seem to have been all derived from the 

 Waitakerei outbursts. Each of these seems to be less coarse 



* Trans. N.Z. Inst., 1884. 

 f Trans. N.Z. lust., 1889. 



