In physical geography, a dune is a hill of sand built by either wind or water flow. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. When wind creates a sand dune, the sheltered side of the dune is steeper than the windward side, the valley or trough between dunes is called a slack, most prevailing winds are South Westerly.
The Cresenct Dune or known as the Barchand Dune is the most common type of sand dune. As its name suggests, this dune is shaped like a crescent moon with points at each end, and it is usually wider than it is long. Crescentic dunes form when winds blow from one direction. This dune traverses desert surfaces faster than any other type of dune.
The Linear Dune is straighter than the crescentic dune with ridges as its prominent feature. Unlike crescentic dunes, linear dunes are longer than they are wide -- in fact, some are more than 100 miles (about 160 kilometers) long. The ridges are long and snakelike, and these dunes usually occur in parallel sets separated by other sand, gravel or rocky corridors.
The Star Dune has arms that radiate out from a center pyramid-shaped mound, hence the descriptive name. Star dunes grow upward instead of outward and are a result of multidirectional winds.
The Dome Dune is rare, oval- or circular-shaped and has no slip face. Dome dunes sometimes appear at the ends of crescentic dunes. Most dome dunes are low only a few feet high.
The Parabolic Dune is U-shaped, but differs from the crescentic dune because its crests point upward, with elongated arms that follow behind. A parabolic dune's trailing arms are typically anchored by vegetation.
According to geologists, the Perry Sandhills originated after an ice age 40,000 years ago and are formed by wind erosion over thousands of years. The dunes are located just outside of Wentworth 6km from PO, and are a unique land formation of 822 acres of continuously shifting sand dunes.
Skeleton remains of giant mega-fauna kangaroos, emus and wombats have been found there. Replicas of these animals are now on show at the Pioneer Museum in Wentworth.
When at the Sandhills standing at the shelter look to your right about 2 oclock and you will see a River red Gum that has the trunk completely covered in by the sand which is well worth the walk to it. It feels unusual to be standing at the top of it canopy and the tree is said to be over 500 years old.
At the listed coordinates please answer the following questions and email them to us to be able to log the cache.
Q1: which direction is the Sandhill drifting?
Q2: what type of sand dune is this?
Q3: is the sand fine, medium or coarse in texture and your thought why it is?
Feel free to log your find immediately however after a few weeks if the answers have not been submitted I will delete the log. If for some reason I don’t reply to your answers you can safely assume your answers were correct.
For those who may be towing a Caravan there is not problems turning or parking and it is a great spot to stop for lunch, however there is no toilets but a good size shelter to sit in.
We hope you enjoy our Earthcache and please have fun and drive carefully in this area especially at Dusk.
Regards
The Coffee’s
Reference:
http://www.resourcesandenergy.nsw.gov.au/miners-and-explorers/geoscience-information/services/online-services/digs
http://www.visitnsw.com/destinations/country-nsw/the-murray/wentworth/attractions/perry-sandhills.
http://crcleme.org.au/
http://geography.howstuffworks.com/