tower hill, volcano, volcanic ash, volcanic ash layers, geology, koroit

Colour photographs of the volcanic ash layers at Tower Hill.tower hill, volcanic ash, ash layers

Tower Hill is a volcanic formation believed to have erupted about 32,000 years ago. Its formation is known as a "nested maar" and it is the largest example of its type in Victoria. During formation, molten lava pushed its way up through the Earth’s crust and encountered a layer of water-bearing rock. Violent explosions followed creating a shallow crater which later filled with water to form the lake. Further eruptions occurred in the centre of this crater, creating the islands and cone shaped hills. In 1892 Tower Hill became Victoria’s first National Park. In 1961, Tower Hill became a State Game Reserve under the then Fisheries and Wildlife Department and a major re-vegetation program began. (https://www.towerhill.org.au/index.php/about-reserve/history, accessed 23 December 2019)A number of photographs taken at Tower Hill, including the lakes, volcanic ash layer, and koala.tower hill, ash layer, volcano

The Tower Hill Reserve is located inside a dormant volcano, and features a lake and wetlands. It became Victoria's first national park in 1892, but by the 1930s the early settlers had cleared much of the land for grazing, cropping and quarrying. In the 1960s the bare hills and islands were revegetated based in species identified from Eugene von Guerard's painting of Tower Hill. Tower Hill was formed around 30,000 years ago in a violent volcanic eruption. The initial eruption created the outer rim of the volcano, and later smaller eruptions formed the internal hills that are evident today. The layers of volcanic ash layers include artefacts relating to indigenous communites.A series of colour digital photographs showing Tower Hill, near Port Fairy, Victoria. Tower Hill is an extinct volcano.tower hill, volcano, extinct

Thunderegg Agates are formed within rhyolite volcanic ash layers. They are rough spherical shapes, varying in size from less than an inch to over a metre long. Thundereggs usually contain centres of chalcedony which may have been fractured followed by deposition of agate, jasper or opal, either uniquely or in combination. A unique characteristic that these specimens have is the fact that they often look like ordinary rocks on the outside, but slicing them in half and polishing them may reveal intricate patterns and colours. These particular specimens are examples of thunderegg agates. Agate is a variety of chalcedony, a cryptocrystalline form of quartz. The agate component contributes to the intriguing internal patterns of the specimens. The specific locality of these specimens is unknown but they can be found in flows of rhyolite lava. They are formed in gas pockets in the lava, which act as moulds. These specimens can be found globally, with specific locations in Germany being particularly abundant. This specimen is part of a larger collection of geological and mineral specimens collected from around Australia (and some parts of the world) and donated to the Burke Museum between 1868-1880. A large percentage of these specimens were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush) to study and map the geology of Victoria. Collecting geological specimens was an important part of mapping and understanding the scientific makeup of the earth. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study.Two small solid specimens with pale, sandy-coloured exteriors and fractured internal patterns. burke museum, beechworth, geological, geological specimen, thundereggs, thundereggs agate, agate, rhyolite, rhyolite lava, volcanic ash, chalcedony, cryptocrystalline

A fossil refers to any remains or traces of past life that are preserved in the rock. It could be remains of plants or animals. Fossil leaves are commonly found on different types of rocks. These fossils can go as far back as the Triassic Age just like the series of fossil plants collected at Denmark Hill, Ipswich in Queensland. Fossils leaves are formed when dead plants get buried by sediments like mud, sand, or volcanic ash. Often, it gets detached cleanly from stems along a special layer of weak cells, then twigs, and, less commonly, cones of conifers and fruits and seeds of flowering plants. Over time, the leaves or pieces of leaves get buried by more sediments and eventually gets 'lithified' or hardened into a rock. Erosions and mining can cause the rocks to break and reveal the fossils buried in it. Fossilisation frequently takes place at sites in the lowlands where deposits of clay, silt, sand are found. This is usually due to weathering and erosion of rocks. Fossil leaves can provide information about ancient Australia's way of living. It contributes to Victorian biodiversity records and its botanical collections. It also contributes information on the geographical profile of Victoria as fossilisation usually occur at estuaries and deltas of rivers, river flood plains, ponds and lakes. This specimen is part of a larger collection of geological and mineral specimens collected from around Australia (and some parts of the world) and donated to the Burke Museum between 1868-1880. A large percentage of these specimens were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush) to study and map the geology of Victoria. Collecting geological specimens was an important part of mapping and understanding the scientific makeup of the earth. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study.Piece of light brown rock with fossilised leaves in shades of golden yellow and brown.Existing label: Fossil Leaves / Locality unknown / might be worth checking if this is Glossopteris, a Permian age plant. / C. William 16/4/21 geological specimen, geology, geology collection, burke museum, beechworth, fossil leaves, fossilization, 1868 geological survey of victoria, lithified, rocks, fossilised leaf, rock, fossils, leaves