Turning over an old leaf with the Fossil Hunter's Handbook

If you are reading this blog, you presumably like the idea of getting outside and appreciating the landscape and its underlying geological features. James Crampton and Marianna Terezow are paleontologists here at GNS Science. They have just published a great book for fossil enthusiasts called the Kiwi Fossil Hunter's Handbook. It is full of interesting information and highlights a number of prime localities around the country for unearthing nice fossil specimens.

After a conversation with James,, and armed with information from one of the chapters in the book, I recently visited a fossil locality near Murchison in the South Island. About 6.5 kms north of Longford on the main State Highway 6, there is a sign indicating Nuggety Creek Road.

A few hundred metres along the track there are some crumbling cliffs by the roadside. This is a fantastic place to collect fossil leaves from the Miocene (about 16 - 13 million years old). They were deposited in a river valley that was surrounded by a rainforest.

Boulders at the foot of the cliff are absolutely packed with leaves of different plants. There were large trees here as well as smaller plants such as ferns living beneath them. The rock is quite crumbly, so it can take a while to find a lump that is solid enough to stay in one piece.

These fossils are evidence that the climate in New Zealand in Miocene times was very humid and warmer than at present.

As you can see from the last photo, some of the fossil leaves are superficially very similar in appearence to modern leaves found at the same locality today.

Cretaceous Reptiles in Hawkes Bay

Over the last few days I have been with a GNS Science team exploring the remote Mangahouanga Stream in inland Hawkes Bay. This is the area that is famous for the discoveries of dinosaur and other reptile remains by Joan Wiffen (who died in June last year) and her team. It is on private land, deep in the forest and therefore rarely visited. Bones of marine reptiles seem to be relatively common in the hard concretions in the stream bed, but land dwelling dinosaur remains are very rare as they were washed some distance into the sea and separated before being buried in the sediments . An example of a therapod dinosaur toe bone, discovered by Joan Wiffen can be seen as a 3D image here

On the way to explore the river we passed the two expedition huts used by Joan's team . In the picture are Mike Wylde and Tunis Keenan, two Royal Society Primary Teacher Fellows being hosted by GNS Science this year.

 

After following a rough track through the bush, we reached the Mangahouanga Stream. In several of the large boulders we could see bone remnants. In this picture there is a large vertebra (backbone segment) of an unknown species of reptile. If you look carefully at the top of the rock in the right foreground you might see an oval shaped brown lump which is another similar vertebra.

Here John Simes (GNS Science palaeontology collections manager) and Pete Shaw (forestry manager) check out a rock slab containing shells, sharks teeth and fish bones.

Have a look at our video of fossil hunting in Mangahouanga Stream:

Oparara Limestone Arches

On a recent trip up to Karamea on the west coast of the South Island, I went to visit the Oparara Caves. These are a few kilometers inland, and not far from the end of the Heaphy Track. They are an amazing example of limestone erosion...

Huge archways have been cut through the limestone by the Oparara River. The limestone was laid down in the ocean during the Oligocene Epoch, about 34 million years ago.

The third photo shows the largest of the arches (the Oparara Arch). You can see the clear boundary between the limestone and the underlying Karamea Granite. This is about 350 million years old, much older than the limestone. The arch is an impressive 200 metres long and 50 metres across.

There are several accessible caves in the area. The unique geology and ecology is a 'must see' if you ever make the trip to Karamea.