114 The N.Z. Journal of Science and Technology. [Mar. 
shales containing Inoceramus and other fossils. These rocks outcrop for 
nearly two miles along the road that follows the eastern or Te Kuiti side 
of the valley, and again appear for half a mile along the roadside in Pangaki 
Creek several miles nearer Te Kuiti. Similar rocks were observed on the 
Hauturu road twelve miles north-west of Te Kuiti, and between two and 
three miles south-west of Hauturu Trig. In both localities the beds strike 
in a north-north-easterly direction, and dip steeply. These rocks are con¬ 
sidered to be of Lower Cretaceous age. 
The Mesozoic rocks above described are unconformably overlain by 
Tertiary strata, of which the most characteristic beds are calcareous. In 
its lower portion the limestone is massive and decidedly arenaceous, but 
towards the top the rock consists of tabular layers of nearly pure calcareous 
material. The limestone is overlain by blue arenaceous mudstone con¬ 
taining shell-fragments and Foraminifera. In several localities the basal 
rock is separated from the limestone by thin deposits of fine conglomerate; 
in others, beds of blue mudstone intervene ; and in others, grits, shales, 
and carbonaceous mudstone, with seams of brown coal, are to be found. 
Locks of this series, which is probably of Oamaruian age, cover a con¬ 
siderable area to the eastward of Te Kuiti, but their chief occurrence is 
along the eastern side of the Tawairoa Range, where they are exposed 
continuously over a wide belt for more than twenty miles. 
Overlying the Oamaruian beds is a series of sandstones which on the 
one hand grade into mudstones and on the other into limestones. These 
rocks form the main portion of the hills lying westward of the railway in 
the neighbourhood of Te Kuiti, but do not appear to cover a large area in 
the district. The limestone, which is more or less tufaceous, is typically 
exposed in the neighbourhood of Oparure, a native settlement three miles 
north-west of Te Kuiti. Whether these beds are conformable or uncon- 
formable to the Oamaruian is unknown. They contain fossils at many 
points, but these are fragile and broken. 
A still younger series of Tertiary rocks, consisting almost entirely of 
thick massive beds of sandstone, occurs in the district. The lowest beds 
contain numerous pebble-bands in which the pebbles are usually of grey- 
wacke, although waterworn fragments of soft calcareous and argillaceous 
sandstone are to be found in some localities. These beds undoubtedly 
lie unconformably upon the older Tertiary rocks. They cover a consider¬ 
able area along the centre of the depression between the Tawairoa and 
Rangitoto-Tuhua ranges. 
Rhyolitic tuff has a wide distribution in the district. The commonest 
form is a breccia consisting of a fine-grained matrix containing numerous 
fragments of pumice. It recalls to some extent the “ wilsonite ” of the 
Waihi district. Crystal tuff is also found occasionally. Although beds of 
fine-grained tuff evidently laid down under water occur, it is evident that 
the bulk of this rock is of subaerial deposition. The Te Kuiti district is 
near the western fringe of the area smothered during the great explosive 
outbursts of the volcanoes of the Taupo zone. 
Economic Geology. 
The Public Works Department has long quarried the limestone from 
the cliff on the western side of the Mangaokewa, a mile and a half south¬ 
east of Te Kuiti. The rock is broken and used for railway-ballast. Two 
plants for the production of ground limestone for use in agriculture have 
been erected within the last few years, one immediately to the north of the 
