434 PROCEEDINGS OF SECTION ©. 
Summarising the evidence disclosed by the above section, we 
find that there are three great formations of sub-aqueous origin 
represented on the Thames Goldfield. Tabulating them according 
to their probable age, they are as follows :— 
1. Upper Eocene—volcanic breccias and _ tuffs—Mount 
Brown series. 
. Lower Eocene—auriferous series—grey mar] series. 
3. Paleeozoic—slaty shales, &e.—Te Anau series. 
bo 
1.— Upper Eocene. 
This formation covers by far the greater part of the peninsula. 
It consists of a great succession of trachyte tufts, andesite-breccias, 
and fine-grained tufaceous sandstones passing into dirty greenish- 
coloured grit beds. Its thickness varies considerably, but is 
generally between 1200 feet and 1500 feet. It is frequently 
intruded by dykes of hornblende-andesite, augite-andesite, and 
trachyte. A fine example of the former may be seen on the coast 
three miles past Tararu, and of the latter in the valley of the 
Kauaeranga, opposite the Orphanage. Veins of jasperoid, 
chalcedonic and opalline quartz, calcite and ironstone are not 
uncommon in the breccias and finer-grained tufas ; but no gold- 
bearing quartz, so far as I can ascertain, has up to the present 
time been found in this formation. 
In a bed of blue tufaceous clay exposed in a road-cutting on 
the beach, about two miles north of Tararu, there occurs a 
quantity of selenite, as well developed crystals and radiating 
fibrous masses. Near their junction with the underlying 
auriferous series the breccias often contain large quantities of 
silicified wood, as at Hape Creek and Kauaeranga, and thin seams 
of brown coal and coaly shales, as at Paeroa and Owaroa. The 
presence of the latter would indicate an approach to land 
conditions at the close of the Lower Eocene formation, but, as 
has already been stated, there is no stratigraphical break to mark 
an unconformity. At Waiohanga they overlap an isolated rocky 
ridge of the paleozoic rock; elsewhere they rest upon the 
auriferous series. 
Between Cape Colville and Te Aroha this formation is arranged 
as a succession of synclinal and anticlinal folds, the axes of which 
have a general north-east trend. The underlying auriferous 
series at the Thames, Tapu, Puriri, Hikutaia, Karangahake, 
Waitakauri, Te Aroha, and all the other goldfields on the penin- 
sula, are exposed in the denuded cores of the anticlinal folds. 
It may be interesting to note that the Waitakerei range, 
extending between the Kaipara and Manukau harbours, and the 
great Pirongia range, lying between the Waipa and West Coast, 
are composed of similar rocks. It is evident that, during the 
period of their formation, the province of Auckland must have 
