618 Transactions. 
and cliff that bounds it, as shown in fig. 2. At the south-east side of this 
syncline there has been a small amount of differential rock-movement, 
and the limestone has moved slightly over the greensand. There has been 
no movement of this kind at the north-west side, and there the limestone 
shows gradations to the greensand. 
At a third point, between Mr. Blackwell's house and Tokatapu, opposite 
Colbeck's Landing, on the west side of the Pahi arm, the hydraulic lime- 
stone is again seen to rest on a highly arenaceous greensand, which is pro- 
bably a local equivalent of the Pahi greensand. Again at Portland, near 
Whangarei, about fifty miles distant, on the downthrow side of a fault 
which shows clearly in a cutting on the railway-line, the greensand has 
been lowered so as to be brought into contact with the limestone. In 
these four localities it is clear that the hydraulic limestone is a higher — 
horizon than the greensand. 
BEP CASE 
———— n Сы 
Greensand (Eocene) 
Ето. 1.— Hydraulic limestone between Pahi and Arapaoa arm. 
Palaeontological evidence of the age of the limestone is very scanty. 
he greensand which lies below it at Pahi contains a considerable variety 
of fossil Mollusca, including an Aturia, and is probably the equivalent of 
the European Eocene—-certainly not Cretaceous. Tt follows that the 
анк limestone in this locality at least is not older than the Upper 
ocene. 
Н ydvauke Limestone 
Stratification abse uve 
Greensand (E ocevia) EX & eee 
~ ae 
- „= 
T a e 
Fic. 2.—Syncline on foreshore north-west of Arapaoa arm. 
a shark’s tooth obtained from the hydraulic limestone near Batley, about 
* 
B 
six miles from Pahi. 
re is also in the Auckland Museum a tring of six similar vertebrae 
from the hydraulic limestone at Portland, and, like the previous one, these - 
"A. — Carcharodon. ; 
palaeontological and stratigraphical evidence seems to me to prove - 
that. the hydraulic limestone at Portland, Pahi, and Batley is certainly of. 
Tertiary age, and not older than the Upper Eocene. : 
