Waihi Beach

BY JULIAN THOMSON (OUT THERE LEARNING)
Accessibility: EASY
Waihi Beach, Photo J.Thomson @ GNS Science
The rocks of these crumbling cliffs reveal changes in environments caused by tectonic uplift.
Waihi Beach, Photo J.Thomson @ GNS Science
Seen from the beach, the cliffs have two main layers. The lower layer is a grey mudstone, with an upper section that is darker brown and softer. The two layers are separated by a very distinct boundary that can be followed for a long way along the cliffs.
Waihi Beach, Photo J.Thomson @ GNS Science
The cliff that you first see on the left (before getting to the beach) allows good access to the boundary layer (unconformity) between the two main rock units.
Look also for particles of volcanic material in the sedimentary rocks.
There are good fossils to be found along this beach. A hammer (and protective glasses) are useful to break open the mudstone nodules that often contain fossils. As well as scallops and oysters, vertebrate fossils have also been found here.
Take note of the advisory section - these cliffs are prone to rockfalls and collapses, and it is best to search for fossils in loose boulders a a safe distance from the cliffs, when the tide is going out.
Directions/Advisory

Head for the car park at the end of Denby Road, near Hawera. Follow the obvious track down to the beach. The outcrop on the left just before the beach is a good place to access sediments and fossils before descending to the beach itself.

These sea cliffs can be very dangerous due to the frequency of rockfalls, expecially during or after wet weather. It is highly recommended that you keep away from the vertical cliffs as much as possible. The boulders on the beach are derived directly from the cliffs, so if you time your visit at low tide, you can search at a safe distance for the good fossil material.

Google Directions

Click here for Google driving directions

Accessibility: EASY

From the car park descend the track for about 5 minutes to the beach. The cliff that you first see on the left (before getting to the beach) allows good access to the boundary layer (unconformity) between the two main rock units.

Features
Sedimentary Fossils
Geological Age
The lower mudstones are about 3.5 million years old, whilst the upper sandy layers are about 125 000 years old.
Zealandia Evolution Sequence
Pākihi Supergoup: 5 million years ago – present
Links
This GNS Science video explains the geology of Waihi Beach: https://youtu.be/rGikHmpNetA