Search This Blog

Saturday 31 August 2013

LAKE HART SA

 
This Free Camp over looks Lake Hart, a reasonably sized Salt Lake of 16000 hectares in area. The Lake is part of the Lake Eyre feeder system and is usually dry but I was lucky, there was water in it today. Being close to Woomera Rocket Range, parts of Lake Hart are restricted with entry prohibited. Apparently, it was part of the Blue Streak Missile Project testing range. Information about the place is hard to come by probably because it is still a restricted area. I did find out that it was one of the last inland lakes to be mined for it's salt. The last shipment was due to leave in 1934 but was never moved and is still here. Although the bags that contained the salt have rotted away and it is now a solid mound of the stuff. I was surprised to also learn that Murray Cod had been caught or seen in the salty brine, amazing that fish could tolerate such conditions.


Remnants of the 1934 shipment
  It is quite a pretty  down near the shore line. The puzzle of the railway line was solved when a goods train rolled by every couple of hours each hauling 120 or so waggons and about 1.5 km long. As it turns out, it is the Ghan railway to Alice Springs. The famous Train didn't pay a visit this time unfortunately.


 Through here to the shoreline

















I am sure that this picture features in many a Visitor's photo gallery

More views of the Lake



























And at Sunset






  Well dear Reader, you have caught up to me. It is Saturday 31st August 2013 and I am still at Lake Hart. I am also a bit injured. A couple of days ago I spilled an entire mug of boiling hot coffee on my leg and that produced a decent burn with a blister about 4" square. Jules has bandaged it for my so as to keep the millions of flies off it. I am hoping that it will heal before any infection sets in. No need for a Doctor unless that happens.
We will leave tomorrow to continue south towards port Augusta with a stop at Woomera Township for a look around and a possible overnight at Pimba on the Stuart Hwy.

Friday 30 August 2013

SOMETHING ABOUT OPALS

  Australia has around 90% of the World's Opal with the majority coming from Coober Pedy. (0% of Opal found is common Opal with only the remaining 10% showing colour.
he Mining of Opal begins with a mining permit with which a Miner can peg a claim 50m x 50m or 50m x 100m from where he will search. Today, mine prospecting shafts are made by using a Calwell type drill to excavate holes about 1 metre in diameter. The drills can reach a depth of 28 to 30 metres. the Opal fields are pitted with thousands of abandoned Calwell shafts. The earlier form of mining was to sink a shaft with a pick and shovel then driving a tunnel along the level in the same way. Traces of Opal were then removed by hand with a pick or screwdriver. Waste material or mullock was originally lifted to the surface from shafts by hand windless, then later by power winches called Yorke Hoists or bucket tippers. Today, truck mounted blowers, which operated like vacuum cleaners are more commonly used to bring mullock to the surface. Since the 1970's more modern methods of mining have been introduced with tunnelling machines and small underground front end loaders or bloggers now in use. All Opal fields have restricted entry due to the thousands of open shafts that exist. permission must be obtained. The is a strict rule around here "NEVER WALK BACKWARDS".
  Another type of mining called "Noodling" is carried out by many locals for a living and is also popular with tourists. the process is that of simply searching through heaps of Mullock for pieces of opal that miners may have missed. Permission must be obtained from the claim owner to fossick on his claim. Noodling machines in which Mullock is passed through a darkroom on a conveyour belt beneath ultra violet lights are often used to detect Opal.
  what about Opal itself? It is a form of Silica, similar to Quartz but with water in it's molecular structure. Opal occurs either as Precious Opal or Common Opal known as Potch. precious Opal in general has 6 - 10 % water content. The colour is caused by a regular array of Silica spheres diffracting white light into the various colours of the spectrum. The and spacing of the spheres controls the colour range. Opal colours also depend on the angle of light incidence and they can change or disappear when the gem is rotated. In Potch, the silica spheres are irregular in shape and molecular structure and are unable to diffract light and consequently there is no colour.
  The main factors influencing the price of an Opal are:

Base Colour: Black Opal is more valuable than Crystal Opal which is more valuable than White or Milky Opal.

Dominant colour:  Red-fire Opal is more valuable than a predominately Green Opal which is more valuable than an Opal which is only Blue.

Colour Pattern: Harlequin Opal, where the colour is in defined patches is usually more valuable than Pin Fire Opal where the colour is in small specks.

There is a big difference in the value of Cut and Uncut Opal as one would expect. There are three main ways that Opals are cut and polished:

Solid (Cabochon): Opals that naturally occur in one piece having been cut and polished from rough Opal.

Doublet: When there is only a thin veneer of Opal, it's co;lour may be enhanced by cementing either black or grey silica, glass or a thin slice of Potch to the back of the coloured Opal.

Triplet: To protect the Opal from damage, a slice of Quartz Crystal is used to cap the thin Opal veneer on a Doublet, thus producing a three tier gem. this can produce a brilliant display of colours and is a cheaper method of presentation that can enhance the appearance of the Gem.

Finally, The "Olympic" from Coober Pedy is said to be the World's largest piece of uncut Precious opal and weighs 3.5 kgs. It is so named because it was found in 1956, the year of the Olympic games held in Melbourne.

 

COOBER PEDY SA

 
At last we made it! A long 1200 km trek from Alice Springs (that includes the 500 km round trip to Ayers Rock). The minute we arrived at Coober Pedy I knew that I would like it. Like Lightning Ridge, this place has characteristics that only an Opal mining Town has. In my opinion, its a sense of "lawlessness" or at least that there are very few rules that apply here other than the general rule of law etc. Or maybe its the "Cowboy" feel that appeals. All that I know is that I am comfortable here. Others had painted a picture of a dangerous or at least unpredictable place but if one is sensible all if fine. Like all Towns, the locals are proud of what they have achieved in setting up in such a harsh environment and rightly so.
There is much to talk about here so this post may be a little longer than usual.
  I did mention that "Coober"  has a similar feel to "The Ridge" and yet it is unique in it's own way. Maybe a little more structured, or controlled, or planned? Certainly, the underground buildings and homes are not a feature of Lightning Ridge and there is less evidence of actual mining in the Township here. At Lightning Ridge the norm is to find a spot that looks interesting, even if it is near the main street, buy a claim, find or build something to live in and dig a hole looking for Opal. There is one similarity though, Coober is also full of junk, old cars, buses, trucks, mining machinery. It appears that nothing is thrown away. Maybe things where so hard to come by in the past that everything is kept that may be useful at a latter time. Rather than make the place look bad, I reckon it just adds to the charm. The "noodling" fields around the place and the famous underground buildings and houses also add to the atmosphere.
  Now some facts. the most important is the origin of the name, Coober Pedy. Now, I thought that it was most likely the name of a pioneer or early Opal miner. Not so, it is fact derived from a word from the Aboriginal, Anangu words "kupa" and "pita" meaning "white man" and "hole in the ground". Well there you go! Until 1920 it was called the Stuart Range Opal Fields when it was renamed Coober Pedy. The first European explorer to reach the area was John Stuart in 1858. The first Opal was discovered in 1915 by a 14 year old Will Hutchison, a member of his father's gold prospecting party. The story goes that Willie strayed from camp, against orders to search for water. When he finally returned he had not only found a waterhole but also showed a sugar bag full of Opal. The first Opal rush didn't occur until 1919, probably because of the remoteness of the place and the lack of water. In 1924 the water issue was partially solved when the Government built a 2 million litre water tank and introduced a water ration of 110 litres per person per week. Today water is pumped 23 kms from a 60 metre deep artesian bore and then is treated using Reverse Osmosis, making it of excellent drinking quality.
  Well things developed rapidly, with many European Migrants arriving to make their fortune. Now the town has a population of around 3500 that includes around 45 different nationalities. There is also a sizable Aboriginal community.
  The Climate here is harsh to say the least, although it is really pleasant at this time of year. It was around 29 c and dry today. The weather does warm up however with temps from 35c to a whopping 48c in summer! It doesn't rain much either with an average of only 5" or 175mm a year. Consequently, nothing much grows around here, there are no naturally occurring trees in Town, The surrounding country too it treeless and about as desolate as it can be without actually being sandy.The whole area sits on a bed of sand and siltstone 100 feet thick that's topped with a stony desert.















 












What about the dugouts. "It is said that dugout living began in Coober Pedy when Soldiers returned from the trenches in France in 1918." The temperature in the dugouts varies only about 5 c all year round and remains at around 23 c, very comfortable indeed. Town  planning did not exist but that has been rectified with the entire town now having been surveyed and divided up into building blocks and allotments. To construct a dugout one must first buy a piece of land but as all dugouts are excavated from the inside of a natural hill, the block must therefore include at least part of a hill. after designing a layout a contractor is used to excavate the house at a cost of between $20,000 and $120,000, depending on its size. Then plumbing, electrics and "wet areas' are added, the latter near the front so as to dispose of waste by gravity feed. Dividing walls are about 2 metres thick to support the roof, lighting is either natural or artificial and roof vents, that can be seen all around Town and added for ventilation. The cost of a modern underground home today would be about $80,000 to $250,000. Some are very large and luxurious I am told.




 That's about it for delightful Coober Pedy, another "Bucket List" entrant for me. For those that want to know something about Opals and Opal mining, I will include another post that deals with that specifically.
 

A CORRECTION to RECENT POSTS

OOps, I just discovered that I have been referring to the correct Stuart Hwy as the incorrect Sturt Hwy in recent posts. This extends right back to the Three Ways Roadhouse. Rather than go back and edit all of the posts I will use this posting to do the same. Sorry!

THE BREAKAWAYS via COOBER PEDY SA

 Nearly at Cooper Pedy. but first a side trip along an 11 km dirt road just before Town to The Breakaways.
The following description taken from information available in Coober Pedy describes the Breakaways probably better than I:
"The Breakaways Reserve lies 32 km north of Coober Pedy. It consists of colourful low hills which have broken away from the Stuart Range, hence their name “The Breakaways”There are two lookout points which highlight the open spaces and colourful environment, leaving an impression of the long gone inland sea that our early explorers dreamt of. From the lookout, the locally named “Castle” or “Salt & Pepper” can be seen in an easterly direction. This outcrop has been used in a number of films and advertisements, while Panorama Hill situated in the middle, features in Mad Max Beyond Thunderdome and Ground Zero. As the day goes by, the passing of the sun changes the desert colours, creating photogenic scenes that appear surreal. The 70 km round trip back to Coober Pedy takes you east along the hills to the dog fence. This 2m high wire barrier stretches for over 5,300km across three States, to protect the sheep country in the south from the native dog, the Dingo. The desert-like moonscape along the fence, with its fossilised shells, grey, soft clay dirt and cracks that appear to be bottomless, has been nicknamed the “moon plain”. It too has been the scene for numerous movies".
Latest news is that the Breakaways Reserve has been handed back to the traditional owners, the Antakirinja Matu Yunkunytjatjara (AMY) people with whom a Native Title Agreement has recently been struck.
 I found this place well worth the short but dusty road trip and recommend a visit to anyone out this way.

 "Eat my dust" says Billy