This magical treasure of moss covered cannonball concretions
forest in Mangaweka, a small township of Manawatu-Wanganui region located in North Island of New Zealand, is a natural wonder. A narrow gravel winding road with
beautiful countryside views takes you to the gates of the White cliffs farm.
This self-guided walk has several orange arrows posted along the route and
sheep poo for GPS. The downhill walk past the magnificent Rangitikei River
is a beauty of its own. Hills with pastures and forests line the side of the
valley across the winding river.
You might be walking alongside the company of some fellow New
Zealand sheep as the locale is a private farm property. There is an honesty
box for a decent five dollar donation. It takes almost 45 minutes for a one side walk across these lovely farmlands with some of the most spectacular views of the Rangitikei River before arriving at the
boulders.
A short stroll from the cliff tops down to the river and you feel
like you are stepping back in time. Blue waters of the river stroll past
thousands of grey stones as we walk towards the forest. The White cliffs forest
containing the boulders is situated on a raised land mass with a short uphill
approach track.
These magnificent boulders are set amongst native trees with
almost a Hobbiton ambience. Don’t be surprised if Bilbo Baggins or even Gollum
might haunt you for the Precious from amidst the deep green dungeons of these
boulders. The native bush is rich with a variety of birds, natural flora and fauna, covered in green moss, giving it an enchanted feel. It’s enough to make you imagine you were walking through a giant’s marble collection.
You would be surprised to discover a flushing toilet in the middle
of the Boulders bushes. The walk back up the hill can be a
little steep and might be worth taking a water bottle. The area is perfect for
a picnic with options near the boulders on the outskirts of the forest or
somewhere with a view of the river and may be a swim in the clear river on a
hot summer's day.
White Cliffs Boulders: (Visitors Information Board)
''Take nothing but photos, Leave nothing but footprints''
The Whitecliffs Boulders are called concretions and have formed
within the rocks where they are found. In this case, the rock type is the
Mangaweka mudstone, which was deposited off the coast of an older version of
N.Z. from 2.5 to 3 million years ago. The mudstone came from
sediments dropped by rivers eroding land into the sea. The rivers carried more
than sediments, which was key to the creation of the boulders.
Shells and trees were also carried out to sea and were trapped in
the sediment. The mud was full of water and as new sediments were deposited on
top of the mud, the water was squeezed out. The water contained dissolved
chemicals that dropped out of solution and formed cement around what was left
of the buried shells and plant material. The organic material seems to create a
node for this process to occur.
Layer after layer, calcium carbonate wrapped around the shells and
trees to form cement concretions. Concretions can come in several shapes, but
the round Whitecliffs Boulders are called cannonball concretions (it would take
one huge cannon to fire the biggest boulders).
These concretions are called cannon ball concretions and are
particularly large. There are larger ones in the USA that are 10 meters in
diameter. The size is related to how much dissolved chemicals were in the water
and the volume of water that flowed past the nodes. In this case, there must
have been a lot. Specific conditions needed to be present for the boulders to be created and they definitely feel special up close.
Cannonball concretions are large spherical concretions, which resemble cannonballs. They often outwardly resemble fossils or rocks that look as if they do not belong to the stratum in which they were found. Occasionally, concretions contain a fossil; either as its nucleus or as a component that was incorporated during its growth but concretions are not fossils themselves.
Small hematite concretions, dubbed "blueberries" due to their
resemblance to blueberries in a muffin, have been observed by the Opportunity
rover in the Eagle crater on Mars. Concretions have long been regarded as
geological curiosities. Because of the variety of unusual shapes, sizes and
compositions, concretions have been interpreted to be dinosaur eggs, animal and
plant fossils, extraterrestrial debris or human artifacts.
Getting
there:
Mangaweka, Manawatu-Wanganui, North Island - New Zealand
Enjoy the walk down to the Boulders over farm land with amazing
views. Approximately 2 km walk down into the Boulders from the car park. Access
is from the southern end of Whitecliffs Farm, 12km off SH 1 (Otara Rd
which is 7 km south of Mangaweka) to the carpark. Open all
year, no bookings necessary. This is a self-guided walk. 4WD
transport is provided by prior arrangement for an extra cost. A reasonable degree of fitness is
required for all walks/hikes/trail rides.
Click www.whitecliffsboulders.co.nz for visiting the Official Page
