Western Australia, Australia
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Western Australia covers the western third of the Australian continent. It is sparsely populated, with 2.6 million people, 92% of which live in the far south-west corner of the state.
Most of the state is desert apart from the Kimberley region in the far north, and the far south west area. Due to the lack of tectonic activity over an extended period, the land has been eroded so that now the highest point is only 1245 metres Mt Meharry in the Pilbara. For the same reason the soils are poor, although it has led to an increased adaptability of flora, making especially the southern parts of the state a biological hotspot.
Western Australia has been occupied by aborigines for 40 000 years. Dreamtime stories explain how various landforms came to exist, and was an essential aspect for their world view. Apart from ochre, aborigines took little interest in rocks unless it was important for their day to day survival.
The first Europeans to become aware of Western Australia were the Dutch as they sailed up the coast to their spice colonies in Indonesia. The British established a settlement at Albany in 1826, and then Perth 1829. The colony struggled with a harsh climate, poor soils, and isolation from the rest of the world.
From the early 1890's a series of rich goldfields were discovered starting at Cue, Mount Magnet, Southern Cross, Coolgardie and Kalgoorlie. This led to huge gold rushes, with people travelling to the state from all over the world, in the hope of making their fortune. As time has gone, other mineral riches have come to the fore, like nickel and iron ore, with mining now the mainstay of the Western Australian economy. Western Australia holds 30% of the worlds gold reserves, 20% of its nickel, 80% tantalum, 60% rare earths, the largest diamond mine in the world, major iron ore deposits, significant platinum, vanadium, titanium, bauxite, mineral sands, and natural gas.
The most important geological province in Western Australia is the Yilgarn Craton, covering approximately one third of the state. This is an old land ranging from 4.4 Ga to 2.63 Ga. The craton contains widespread granite, granodiorite, tholeiitic basalt, and komatiite volcanism, regional metamorphism. Further the northern and eastern parts have large scale north north-west to south-south-east greenstone belts, often hundreds of kilometres long, containing many gold and nickel deposits.
South of the craton, and along the south coast is the Albany-Fraser Orogen. West is the Perth Basin, the edge marked by the Darling Scarp. North of the Perth Basin, along the coast to Onslow is the Carnarvon Basin. The north section of the Pilbara holds the Pilbara Craton, immediately south of this is the Hamersley Basin, Ashburton Basin, Capricorn Orogeny, the Bangemall Basin in the northern Mid-West region.
The Great Sandy Desert region holds the Canning Basin (roughly the size of Spain). To the north is the Kimberley Basin of Hart Dolerite and Carson Volcanics. This is bordered to the south in a wide coast to coast arc of a Devonian aged reef system.
Some geological attractions include:
1. The earliest evidence of life on Earth in 3.5 billion year old Pilbara rocks.
2. The oldest dated zircons in the world at Jack Hills leading to new theories about early 'fireball' Earth.
3. Modern stromatolites at Shark Bay and lesser known locations along the west coast.
4. Wheatbelt granites, including one that forms a surreal wave (Wave Rock).
5. Bungle Bungle banded domed rock mountains in the eastern Kimberley, and various gorges in the Karajini National Park.
6. One of the largest Devonian age barrier reef systems in the world, bordering the southern section of the Kimberley.
7. Wolfe Creek Crater, the second largest meteorite crater in the world.
8. Pinnacle Desert north of Perth
9. Mount Augustus, the largest monolith in the world.
10. Variety and number of mines, ranging from old historic gold mining shafts, to industrial scale iron ore mines.
Mineral specimens from Western Australia, are generally large ore types
from oxidised zones. Coffee table gemstone specimens are rare, as most have been weathered to clay over the eons. The State holds several low grade emerald deposits, specimen value only elbaite in restricted locations, and two tightly controlled diamond mines in the Kimberley.
Internationally collectors are most likely to see, tiger iron and tiger eye, zebra stone, various jaspers from the Mid-West region, rare secondary nickel species, large hematite type specimens, and Whim Creek wulfenite/secondary copper specimens. Others do exist but rarely get seen overseas. The collecting community in Western Australia is small and few inhabit the internet. MINSOCWA is the local mineral specimen collecting club, based in Perth.
Mineral ListMineral list contains entries from the region specified including sub-localities
652 valid minerals. 57 (TL) - type locality of valid minerals. 2 (FRL) - first recorded locality of unapproved mineral/variety/etc.
Rock Types RecordedEntries shown in red are rocks recorded for this region.
Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!
Rock list contains entries from the region specified including sub-localities
- Igneous rock
- Normal crystalline igneous rock
- Coarse-grained ("plutonic") crystalline igneous rock
- Fine-grained ("volcanic") normal crystalline igneous rock
- Fine-grained ultramafic-rock
- ⓘ Dolerite
- ⓘ Porphyry
- Exotic crystalline igneous rock
- Volcaniclastic igneous rock and sediment
- ⓘ Pegmatite
- Normal crystalline igneous rock
- Sedimentary rock and sediment
- Siliclastic sedimentary rock
- Carbonate sediment and sedimentary rock
- Iron-sediment and ironstone
- Organic-rich sediment and sedimentary rock
- Non-clastic siliceous sediment and sedimentary rock
- Miscellaneous clay and aluminium-rich sediment and sedimentary rock
- Sediment and sedimentary rock based on grain or crystal size
- Metamorphic rock and metasediment
- Meta-igneous rock
- Metasedimentary rock
- Metasedimentary rock with known protolith
- Metasedimentary rock, undefined protolith, defined by modal composition
- Metamorphic rock with unknown protolith
- High-grade metamorphic rock
- Very low to low-grade metamorphic rock
- ⓘ Gneiss
- Metacarbonate rock
- ⓘ Schist
- Contact metamorphic rock