The South Australian Museum has a strong and well-regarded reputation for active collection and research, with particular regard to the Minerals Collection.
The collection currently contains over 35,000 registered specimens, with the oldest specimens traced to 1865.
The core of the early collection is based on the purchase in 1906 of part of the John Henry Dunstan Collection, with significant material from the Moonta and Wallaroo Mines. This was arranged by the newly appointed lecturer in mineralogy at the University of Adelaide, a young Douglas Mawson. The Dunstan Collection was at the time the premier private mineral collection in country. During his tenure as Honorary Curator from 1906 to 1958, Mawson was also instrumental in the purchase of the Hall and Watkin Brown Collections, which gave the collection considerable strengths in material from Broken Hill and other significant New South Wales localities.
Interestingly, it took over 100 years to eventually acquire the Dunstan Collection in its entirety. Although the second half was purchased under Mawson’s watch in 1954, the remaining handful of specimens retained by the family were donated by Dunstan’s great grand-daughters in 2011. Much of our knowledge of Dunstan and his collection, and other significant collections such as those acquired from Alfred Fairhall and Thomas Cloud, has come through the dogged perseverance of long-serving Minerals volunteer and historian, Mr David Cowen.
The strengths of the Museum’s collection are undoubtedly the fine suites of specimens from South Australian localities, particularly from the copper mines of Burra, Moonta and Wallaroo, as well as secondary minerals from Broken Hill.
The Museum also has a good representation of opals from South Australian fields. The purchase of the Francis Collection in 1996 yielded a further 2000 specimens to the collection. It included comprehensive coverage of the minerals of the iron formations of the Middleback Ranges, now documented at over 150 species.
The collection has good general coverage of mineral species, with over 1500 represented, and recent research activities have resulted in the deposition of type specimens of 20 new species.
The Meteorite Collection has representative material from more than 150 Australian and overseas meteorites. Highlights of the collection include pieces from two Martian meteorites — the Shergotty and Nakhla — and the amino acid-bearing Murchison meteorite from Victoria.
The collection’s focus is on material from South Australia, due to the Museum’s legal responsibilities. South Australian legislation designates that all meteorites found in the State to be the property of the Crown and any finds must be lodged with the Museum’s collections. The Museum offers monetary rewards for any meteorite finds, as well as the presentation of a personalised meteorite finder’s medallion.
Tektites are small, glassy objects that are the result of a meteorite impact. The force of the impact melts the rocks on the Earth’s surface and this glass is splashed back up into the atmosphere, only to fall back down to Earth again. These molten blobs of glass cool and solidify during their flight through the atmosphere and take on characteristic aerodynamic shapes. They range in size from millimetres to centimetres depending on how far they have travelled from the original impact site.
There are 1500 registered individual specimens and specimen lots in the tektite collection. The majority of these are Australian (australites) and have been acquired chiefly through several large donations, representing material from Central Australia, the Nullarbor Plains, and the Kalgoorlie region.
We also have comparative material from international tektite-strewn fields as well as impact materials from local and international meteorite impact craters, including the famous 580 million year old Acraman impact horizon from the Flinders Ranges.
The Acraman ejecta layer in the Flinders Ranges of South Australia tells a great story of scientific discovery and perseverance.
Scientists searched for rocks that could give a firm age for the layers of sediments that make up the Ranges: a thin bed of angular, red volcanic fragments in the mudstones of the Bunyeroo Formation looked promising.
Dating showed these fragments to be far too old for the sedimentary layers of the Flinders. Further analysis, however, showed them to match – both in age and rock type – those at Lake Acraman on Eyre Peninsula.
Independent geological studies of both localities now show us that the lake is actually the remains of an asteroid impact, some 580 million years old. The fragments of red volcanic rock were hurled up to 300km away into the shallow seas, which today make up the rocks of the Flinders Ranges.
Above the ejecta horizon, sometimes we find a thin second layer — evidence of the tsunami which followed the impact. The mystery was solved!
The Rock Collection has 1700 registered specimens with a good representation of South Australian rocks acquired from Museum field trips, donations, and the South Australian Department of Mines (now the Department for Manufacturing, Innovation, Trade, Resources and Energy) Collection.
The collection also includes Antarctic rocks donated by explorers Sir Earnest Shackleton and Sir Douglas Mawson, and a selection of ore specimens from the Wallaroo Mine at Kadina, donated by the Museum’s first Honorary Curator TC Cloud. The rock collection is largely historical and not an active research collection.