21. Rocking On – Vanished World Paleontology Trail

From Mt Cook village, we headed down the Waitaki Valley, intending to take lots of sideshoots to see more lakes, hydro dams and features of the Vanished World self-guided trail which shows some of the ancient geological features of this area.
After dropping the caravan off at Ohau B Canal, we drove along the edge of lovely Lake Ohau. There were several camping areas with both campervans and tents. One site had a display about the native mistletoe you can find in the bush, and showing photos of what it looks like.

Back at the caravan we enjoyed a delicious sunset, late at night – it’s so lovely being able to relax through these long days and evenings of summer without having to rush to get all our jobs done and be ready for work each day – still deeply appreciating being able to take a whole year off work!

Next morning we opened the door to see two crested grebes/kamana on the canal. They move fast, so I only managed to get this unsatisfactory photo of just one. These birds are endemic to the South Island, and are amazing as they spend their entire lives on the same stretch of water – literally from birth as they hatch out on floating nests and are raised there too. Not once in their lives do they ever step onto land. I’ve only ever seen one other crested grebe/kamana before now, which was on Lake MacKenzie near Tekapo.

We set off again, and stopped almost immediately to take a look at Lake Ruataniwha which is one of New Zealand’s man-made lakes for producing electricity. I think I’ve mentioned before that there are eight power stations in the Waitaki Hydro Scheme leading from Lake Tekapo down into the Waitaki River – Lake Ruataniwha lies between the third and fourth of them.

We visited the local salmon farm where there was a whole flock of NZ’s smallest native duck, the scaup/papango. This one is a boy as it has yellow eyes and black feathers. The girls have much paler eyes and also lighter feathers.

Kevin tossed pieces of food to the salmon while I tried to get a photo – this was the best one! I bought a small packet of salmon to try but it made me feel sick – knowing what wild river bred salmon tastes like has ruined my appetite for farmed fish. Kevin never touches fish – I think he’s allergic to it as he gets sick even if it’s fresh and wild.

We headed downriver to Lake Benmore and the Benmore power station/hydro dam. Kevin stood in this short length of penstock which was next to the carpark – for people like us to play in, we thought! A penstock is a concrete pipe that carries the water downhill from the upper level to the lower level of a hydro dam.

Benmore, which is part of the Waitaki Hydro Scheme, is the biggest man-made dam in the country, and is the second largest producer of electricity after Manapouri, which is west of here. We talked with a couple here, on a biking trip, who had been part of building the dam. They told us that tonnes and tonnes of soil from near the township of Otematata was trucked in and built up and up, and packed down every bit of the way.

Looking out over the power station from the upper level of the Benmore Hydro Dam.
The upper dam.
The road across the dam.
Looking out over the penstocks to the lower level of the dam.
The earth wall between the upper and lower levels, with the road along the top. The construction of the earth wall was a significant achievement when the dam was built; and there’s none other as big in NZ.

After leaving the hydro dams behind, we were stoked to find our first site on the Vanished World Trail – basalt columns from past volcanic activity in the Eocene.

These basalt columns have been cut down and used to build a fence…
…and to sit a mailbox on!

We found some fossil shells – bivalves, and possibly bracchiopods – in the rocks on the side of the road.

This fossil whale is fenced in at the Vanished World site known as ‘Earthquakes’. Otago University has taken many fossils over the years from this area and a lot of information is known about the creatures that lived in the seas in the ancient past.

We stopped in Duntroon as that’s where the main museum and information centre for the Vanished World Trail is situated. The museum is amazing with many fossils on display from the rocks in Otago and Southland. We bought a coloured chart there too, that shows all the sites you can visit.

Walking among the information boards and relics on the street outside the museum, we climbed a short way down a hole in the ground to see this spring of fresh, clear water. Apparently it was used as a mirror back before you could buy glass mirrors in NZ – cool!

We continued on to the Elephant Rocks, where there were a lot of people dotted around taking selfies – one person using a drone. These rocks are remnants of sea floor from more than 20 million years ago, at a time when NZ was largely covered in sea.

Kevin stood on one of the limestone formations that makes up the ‘Elephant Rocks’.

Next we moved on to Anatini which, like the Elephant Rocks, was more of the same limestone formation.

Sea floor ripples preserved in the limestone at Anatini.
This was cute and funny – they find lots of whale bones in the rocks of this area, and here was a piece of limestone in the shape of a whale!
Honeycomb patterning in the limestone.
Rain provides acid that reacts with limestone to eat the rock into both weird and wonderful patterns and shapes. What does this one remind you of?

Driving on, we passed these lovely limestone bluffs – you can see these in a lot of places around the Waitaki Valley and beyond.

We went a very short way along the road towards Danseys Pass, and saw this near vertical sedimentary bedding – imagine the forces pushing bedding that was once flat into this kind of a tilt! There are plenty of faultlines around here…I’m glad it all happens extremely slowly!

Continuing on down the Waitaki Valley, we knew we were getting close to Oamaru when we started seeing quite a few buildings built from the lovely Oamaru Limestone. Oamaru Limestone will be mined for many years yet around this region, and is sold all around the world.

An old barn building of limestone.
Every church we saw was built from it…

Sad to leave this beautiful and interesting area – we saw many of the Vanished World sites but did manage to miss a few!

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