2 
4 THE GEOLOGICAL FORMATIONS OF ZEW ZEALAND 
from its containing the richest eens of alluvial gold that form 
th 
_ the distribution of which, and as a rule the mineral ¢ ik ne, a8 a 
indicates that they were related to a closely adjust shore line, 
New 
sll, of which 120 have been found in this format 
the fauna of this formation indicate a 
the mountain range of a greatly extended land area, and iene 
the North Island, the voleanic forces had their greatest activity, 
attended with the rapid elevation of local areas of fossiliferous — 
deposits that were forming in adjacent seas. In the South Island — 
no marine deposits of importance, belonging to this period, are 
present, but the great area of land above the shore line intensified 
the erosive action of the glaciers radiating from the mountain — 
centres, and gave rise to enormous deposits of gravel, such, for 
instance, as compose the pe part of the Canterbury pee 
and the Montere hills in Nelso 
In the North Island this formation is, to a large exten 
marine origin, with 90 per cent. of existing mollusea, characterized — 
by the grea eat tai of Rotella TRS with Dosinea a 
Strutholaria fraseri, Chione assimilis, and a large form 
cctnum maculatum, with many other r forms. 
The economic importance of this formation is very considerable, — 
Se 
the support of the mining populati In both New Zealand and “ 
Australia the natural drainage ae of the country hada Vay 
different arrangement during pliocene* times from pia 
obtaining, the ancient river courses constituting the “deep i 
and “made hills” of the gold-miners. 
Bee 
IIL—Uprrer Miocene. 
a. Wanganui series. 
b. Manawatu Gorge. 
c. Castle Point. 
d. Taerua and Ross. 
e. Waitotara and Awatere beds. 
These beds consist of a series of sandy and argillace 
to at 
they often pass, almost suddenly, from coarse conglomers i 
narrow strips of fine mud and clay, such as are deposi e 
centres of deep channels and inlets 7 oe 
and seas have salind about 350 —_ med . 
ich are now extinct. 
Ain “ apes characterized by the occurrence of : 
octagonus, Fusus ro echelon Sal lt 
Chios Fricsterth and Pecten. gemmulatus 
De cp! on pin of el 
similar 
the great shell-limestone formation of the South Australian 
