Williamsdale is a locality situated immediately on the south-east side of the

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

border abutting the locality of Williamsdale in south-eastern

Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The

Monaro Highway Monaro Highway is a highway in Victoria, New South Wales, and the Australian Capital Territory, in Australia, linking in Victoria to Canberra in the Australian Capital Territory (ACT) via the Monaro region. From its southern terminus, it foll ...

and the former Bombala railway pass through the village. A railway station saw service from 1891 until 1975. The postcode is 2620. The part of Williamsdale in NSW is itself split up by two

Local Government Areas A local government area (LGA) is an administrative division of a country that a local government is responsible for. The size of an LGA varies by country but it is generally a subdivision of a state, province, division, or territory. The phrase i ...

, in the north to Queanbeyan–Palerang and in the south to Snowy Monaro.

Geology

To the east of Williamsdale is the Williamsdale Volcanics. These are made up from blue-green

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

. The crystals are sized from 0.3 mm to 1 mm and are embedded in a fine matrix. Quartz crystals make up 25%,

plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more prope ...

5%, alkali

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldsp ...

10%,

biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more alumino ...

5–10% which is altered to

chlorite The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous ac ...

epidote Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habi ...

and

leucoxene Leucoxene is a fine granular alteration product of titanium minerals. It varies in color from yellow to brown. It consists mainly of rutile or anatase. It is observed in some igneous rocks and iron ore deposits as the result of the alteration of il ...

. Middle

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

Colinton Volcanics foliated

dacite Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. ...

and tuff is under Williamsdale. A roughly north south band of these acid volcanics extends to the north along the Monaro Highway and then follows the Cooma road to Cottondale. South the volcanics also follow the Monaro Highway in a more complex band through Colinton past

Michelago Michelago is a village in the Monaro region of New South Wales, Australia. The village is in the Snowy Monaro Regional Council local government area, south of Canberra on the Monaro Highway. It was founded in the 1820s, on the main route from ...

and at least as far south as

Bredbo Bredbo is a village on the Monaro plains of New South Wales, Australia. The village is on the Monaro Highway north of Cooma. The village is in the Snowy Monaro Regional Council and had a population of 352 at the . History Located at the junct ...

. To the west of Williamsdale is an outcrop of Upper Silurian Laidlaw Volcanics dark grey rhyodacitic and dacitic crystal tuff. This extends to the west as far as Angle Crossing. This band extends to the north north west as far as

Mount Stromlo Mount Stromlo (formerly Mount Strom ) is a mountain with an elevation of that is situated in the Australian Capital Territory, Australia. The mountain is most notable as the location of the Mount Stromlo Observatory. The mountain forms part ...

. The outcrop finishes a couple of kilometres south, but it is also found to the east, with outcrop from Fernleigh in the north, via Burra, and south to Michelago. On the west side of the

Murrumbidgee River The Murrumbidgee River () is a major tributary of the Murray River within the Murray–Darling basin and the second longest river in Australia. It flows through the Australian state of New South Wales and the Australian Capital Territory, desce ...

around Angle Crossing can be found the Bransby Beds or Goosoon Beds. These beds contain tuff and dacite with some sediments. They form a narrow band extending to the south as far as

Cooma Cooma is a town in the south of New South Wales, Australia. It is located south of the national capital, Canberra, via the Monaro Highway. It is also on the Snowy Mountains Highway, connecting Bega with the Riverina. At the , Cooma had a po ...

following on the east side of the Murrumbidgee River. A quarry is also situated in Williamsdale, New South Wales.

References

External links

Williamsdale Railway Siding
{{authority control Towns in New South Wales Snowy Monaro Regional Council Queanbeyan–Palerang Regional Council