Entries about nambung national park

The North or Western Australia is a vast area of diverse landscape and stunning scenery. the Indian Ocean Coastline offers uninhabited islands, coral reefs, breath taking cliffs and sandy beaches.

Nambung National Park is an unusual park composed of beach and dunes, with the dunes extending inland from the coast. The park is famous for the Pinnacles, a region of curious limestone pillars, the tallest of which is 4m high.

Visitors can take a 3km driving trail

or a shorter walk we of course, did both!

It was great to be able to walk between the pinnacles, and not be fenced off. so we had a bit of fun...

Despite their spectacular and widespread occurrence in the region, little if any scientific research has been dedicated to understanding how and when the pinnacles formed. Nearly all geological aspects related to their formation are controversial...

Noongars knew this place, the Pinnacles Desert, as Werinitj Devil places, because of the sinking sands... the young men were told not to come here as they would disappear into the sand. But some did not listen to their elders, and when they got here they vanished into the dunes. The pinnacles are their fingertips, trying to grasp hold of something so they can drag themselves out of the sand Yued elder in 2006.

In geological terms, the pinnacles are very young and scientists today are just beginning to unravel their many mysteries. The pinnacles are believed to have formed underground, possibly up to 500,000 years ago during the Ice ages of the Quanternary period. they may have remained buried for most of this time, or have been repeatedly exposed and buried again over the millennia. Evidence suggests that they were exposed around 6,000 years ago, but were again covered by shifting sands until only a few hundred years ago.

Scientists believe that the story of the pinnacles off shore, where shell fragments break down to form fine-grained sand rich in calcium carbonate (lime).
At the water's edge the beach sands accumulate as a mixture of shell-based sands from the ocean floor and quartz sands carried by the rivers from the hinterlands. Blown by strong winds, the beach sands form extensive dunes along much of the coastline.

As rainwater comes into contact with the dune sands, it dissolves the calcium carbonate grains. As the dunes dry out, the calcium carbonate recrystallizes and cements nearby sand grains together, forming limestone. This process underlies the formation of the pinnacles.

Just how the limestone formed in the shape of pinnacles continues to puzzle scientists. Current research favours two explanations. In both, plants act as a critical catalyst. Both also remain controversial and may be challenged as new research takes place.
One theory argues that pinnacles are the calcified remains of ancient tree trunks, another that the pinnacles formed from the roots of trees and other plants.

Fossil Pupal Cases

These small egg-shaped objects, up to 5cm in length, are fossilised pupal cases of the weevil Leptopius. Formed over the past 200,000 years during periods when ancient dunes were stabilised by vegetation, they can be seen today commented to the sides of pinnacles. some show the hole where the adult weevil emerged.

Fire plays a critical role, destroying or thinning plant life on the dunes. Stripped of vegetation, the loose sands are blown away by the strong coastal winds to expose - and at times, rebury - the pinnacles. this is a process that continues to this day.

You can get an idea of scale in the image below if you can spot the cars (black dot top left)

The drive to and from Nambung national Park was a long one, but made easier with a stop off at the beach on the way there

and a beer on the way back

with some great music in a great setting

and the company of the usual seagulls

and this magpie lark

Other wildlife was possible

but all we saw were these catapillars - no it's not Chinese writing!