Palliser Bay is an isolated sweep of coastline about 2 hours drive from Wellington. It is separated from New Zealand's busy capital city by the Rimutaka Range. Yesterday I visited the area with a group of Lower Hutt school children as part of their Year Seven geology camp. 
A striking feature that we noticed straight away was the flat topped escarpment that runs along much of the coast. This is a raised marine terrace that was at sea level about 80 000 years ago. It indicates that the whole area has been undergoing an enormous amount of uplift which continues to this day. 
First stop was Hurupi Stream. (This is described in detail in the "Kiwi Fossils Hunter's Guide"). The soft mudstones at the sides of the stream were deposited under the sea in the Miocene Epoch (sometime between 11 and 7 million years ago) , when the Aorangi Range just to the North was an island, separated from other parts of the North Island by a shallow sea. We found quite a few marine molluscs that are very well preserved and easily spotted. 
Not far along the coast road are the Putangirua Pinnacles. These spectacular features have been eroded out of a thick sequence of conglomerate. Hard layers or large individual boulders within the conglomerate form a protective cap at the tip of each pinnacle. The ground is strewn with loose rubble - testament to the fact that the erosion here is still very active. This might not be the best place to visit in a rainstorm! 
A few kilometers along the coast road, there is a dramatic example of coastal erosion where a whole section of the original road itself has disappeared! 
We followed the coast past the small settlement of Ngawi, and a huge tilted slab of fossiliferous sandsone called Kupe's Sail, to the Cape Palliser lighthouse. This is built on a cliff of volcanic rock that was erupted under the sea as pillow lavas about 100 million years ago. The long staircase up to the lighthouse leads up to a great viewpoint. 
This is the Southeastern tip of the North Island of New Zealand, with nothing but ocean between here and Antarctica or South America. Just a few kilometres out to sea is the Hikurangi Trench, the collision boundary between the Pacific and Australian tectonic plates. The connection between uplifted terraces, fossils, erosion, earthquakes and volcanoes gave us all something to think about to round off our geological excursion.
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.
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.
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.
ray.merchant said...
Hi Julian
How did you create the cool rotatable feature for Joans fossil please. What software created it
Thanks
Ray
ray.merchant said...
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jules said...
Hi Ray - You are referring to the images on our website at http://www.gns.cri.nz/paleontology/Fossil.html
Here are the technical details:
The 3D scan was created using a laser scanner called NextEngine Desktop 3D Scanner. It captures a 2D still photograph, and then, using a bunch of lasers, captures the topography of the object, after which it overlays the colour photo with the laser topography to recreate the surface and colour of the object. You can either scan a single shot, 3-image shot, or a 360 deg shot of an item, where you can control for the lens (macro/wide), exposure and quality of scan (standard definition to HD). The software it uses is called ScanStudio, and this is where, in the case of images composing of more than one shot, you can align your parts of the model, brush them up (e.g., remove unwanted parts, etc.), and seal them together to form a water-tight model of the whole object. You can then export the file as an OBJ format, and using Adobe Acrobat versions 8 or higher, you can create a PDF of your 3D model. We've been able to scan objects as small as 4cm to as large as 35cm (the latter was done by scanning the object in 2 halves and then aligning them together).
Cheers
Julian
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.
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.Labels: arches, limestone cave, Oparara Karamea
Our "Discover Ancient Worlds" holiday programme finished this week, with a presentation from the participants of some of their activities and discoveries. Feedback from each of them has been very positive - particularly about the many hands on challenges they were involved with. Here are some examples:
We also investigated possible causes of sea level change. Here the participants are heating water whilst measuring the resulting thermal expansion. 
This test was to find out the effect on sea level of melting ice caps compared to melting sea ice or ice shelves.
On one of our days we went to drill our own sediment core from Petone Wharf. 
The samples were then studied to look for microfossils and other features.
The JOIDES Resolution drill ship is back in Wellington after spending the last two months recovering sediment cores from off the east coast of the South Island. The photo shows the ship being loaded with fresh supplies in the Port of Wellington.
GNS Science is running a 7 day holiday programme for school students that is investigating the science of ocean floor geology. 
The students were amongst a priveleged few New Zealanders allowed to visit the ship today. They were able to ask all sorts of questions of a number of scientists and technicians.
Young scientist Thomas Seaton is admiring the
Imaging specialist Bill Crawford explains the process for making high resolution digital images of the rock cores.Labels: Ocean Dilling science holiday programme
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