Williamsdale, New South Wales
Encyclopedia
Williamsdale is a village on the New South Wales
- Australian Capital Territory
border in Australia
on the Monaro Highway
. The postcode is 2620.
tuff
. The crystals are sized from 0.3 mm to 1 mm and are embedded in a fine matrix. Quartz crystals make up 25%, plagioclase
5%, alkali feldspar
10%, biotite
5-10% which is altered to chlorite
, epidote
and leucoxene
.
Middle Silurian
Colinton Volcanics foliated dacite
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
and at least as far south as Bredbo
.
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
. 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
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
following on the east side of the Murrumbidgee River.
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
- Australian Capital Territory
Australian Capital Territory
The Australian Capital Territory, often abbreviated ACT, is the capital territory of the Commonwealth of Australia and is the smallest self-governing internal territory...
border in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
on the Monaro Highway
Monaro Highway
The Monaro Highway is a state highway in New South Wales, the Australian Capital Territory and Victoria, Australia. The Victorian section was formerly known as the Cann Valley Highway until the 1980s....
. The postcode is 2620.
Geology
To the east of Williamsdale is the Williamsdale Volcanics. These are made up from blue-green crystalCrystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
tuff
Tuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
. 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
Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...
5%, alkali feldspar
Feldspar
Feldspars are a group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust....
10%, biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
5-10% which is altered to chlorite
Chlorite
The chlorite ion is ClO2−. A chlorite is a compound that contains this group,with chlorine in oxidation state +3. Chlorites are also known as salts of chlorous acid.-Oxidation states:...
, epidote
Epidote
Epidote is a calcium aluminium iron sorosilicate mineral, Ca2Al2O, crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often...
and leucoxene
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...
.
Middle Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
Colinton Volcanics foliated dacite
Dacite
Dacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...
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, New South Wales
Michelago is a small settlement in the Monaro region of New South Wales, Australia, in the Cooma-Monaro Shire, approximately 54 km south of Canberra on the Monaro Highway. It was founded in the 1820s, on the main route from Sydney to the Snowy Mountains...
and at least as far south as Bredbo
Bredbo, New South Wales
Bredbo is a village on the Monaro plains of New South Wales, Australia. The village is on the Monaro Highway 33 kilometers north of Cooma. The village is in the Cooma-Monaro Shire shire and had a population of 169 people in 2006....
.
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
Mount Stromlo is situated a short drive west of the centre of Canberra, Australia, near the district of Weston Creek. Its peak is at approximately 770m AHD....
. 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
Burra, New South Wales
Burra is an Australian district and parish of rural smallholdings lying 20 kilometres to the south of Queanbeyan, New South Wales in Palerang Council, postcode 2620. In 2006, Burra had a population of 480 people...
, and south to Michelago.
On the west side of the Murrumbidgee River
Murrumbidgee River
The Murrumbidgee River is a major river in the state of New South Wales, Australia, and the Australian Capital Territory . A major tributary of the Murray River, the Murrumbidgee flows in a west-northwesterly direction from the foot of Peppercorn Hill in the Fiery Range of the Snowy Mountains,...
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, New South Wales
-Education: is Cooma's only public high school, it serves the town and seven of the neighbouring rural towns and villages such as Berridale, Jindabyne, Nimmitabel, Bredbo and Dalgety....
following on the east side of the Murrumbidgee River.