Geology of New South Wales
Encyclopedia
Geologically the Australian state of New South Wales consists of seven main regions: Lachlan Fold Belt
, the Hunter-Bowen Orogeny
or New England Orogen (NEO), the Delamerian Orogeny, the Clarence Moreton Basin
, the Great Artesian Basin
, the Sydney Basin
, and the Murray Basin
.
There are a few other sedimentary basins, the Great Artesian Basin can be broken into the Eromanga Basin
in the west and the Surat Basin
to the east. The Sydney Basin extends north into the Gunnedah Basin, which goes even further north into the Bowen Basin
which extends into Queensland, under the Surat Basin. The New England Orogen has a few small Basins included, such as the Lorne Basin, the Myall Syncline, and Gloucester Basin. The Oaklands Basin in in the south of the state under the Murray Basin. The Darling Basin is in the state's west, but mostly covered by the Murray Basin. Gilgandra Sub-Basin and Paka Tank Trough are potential places for coal and gas.
New South Wales is home to some important mining operations including Broken Hill and coal mining and burning in the Hunter and Illawarra.
and the Sydney and Murray Basins at depth. The region is currently 1000 km wide, but was originally 2000 to 3000 km. The Lachlan Fold Belt was formed in the Middle Paleozoic from 450 to 340 Mya. It lies on a basement of Cambrian
oceanic floor, however, most of this has been subducted leaving the sediment veneer scraped off in chevron folds. It was compressed as the Pacific plate subducted beneath the Australian continent margin. Over time the hinge point, at which the ocean bed was bend down, changed to be more out to the east, and additional ocean bed sediment was added to the continent. This also means that there is a failed subduction zone extending through New South Wales.
The Australian Capital Territory is embedded in New South Wales in the Lachlan Fold Belt. The Narooma Terrane
is another terrane abutted on the southeast corner of New South Wales which can be considered as a component of the Lachlan Fold Belt.
to early Mesozoic
times. It was formed as an arc-forearc zone as the Pacific Plate
was subducted to the west.
. Stretching the crust led to the formation of basins such as the Cobar Basin, Mount Hope Trough, Melrose Trough and Rast Trough. Where stretching was less, shelves were formed instead: Kopyje Shelf, Mouramba Shelf, Walters Range Shelf and Winduck Shelf. The Cobar Supergroup is the term used for the infill in these shelves and troughs which consisted of sediment and volcanics.
The deeper basins included turbidite
s. Felsic volcanic material was also erupted in the Rast and Mount Hope Troughs. The Florida, Babinda, Majuba and Mineral Hill Volcanics are found on the East side of the Kopyje Shelf. Most of the sediment however is quartz sand.
Subsequently in the early Devonian the basin content was pushed back up, and the Mulga Downs Group was deposited by rivers up until the Carboniferous
Period. This formed the Barka Basin. Rock from this group is mostly quartz sandstone, with a small amount of siltstone.
and Triassic
sedimentary rock
s stretching from Newcastle
to Batemans Bay. The land component covers 44000 km2, but there is another 5000 km2 underwater on the continental shelf. The basement consists of the Lachlan Fold Belt
, and the New England Fold Belt is found to the north across the Hunter Thrust. It is a foreland basin
, likely to be formed by compression loading.
The first rocks formed in the Permian
were the Dalwood Group and lower Shoalhaven Group. Material for this came from basaltic volcanoes to the north in the Hunter region. The Greta Coal Measures then formed in the north side in an alluvial fan from the mountains of the New England Orogen. The basin sank lower and sea water came much further inland, covering the Permian sediments and the basement further west, and the Maitland Group and upper Shoalhaven Group were deposited. The Muree/Nowra Sandstone formed in the centre of the basin.
In the next stage the Hunter – Bowen Orogeny cause faulting and folding on the north side of the basin. In the Late Permian river and delta deposition formed the Tomago and Whittingham Coal Measures in the north. But deepening seawater formed the Kulnura Marine Tongue and Bulga Formation. In the southern part of the basin a delta formed the lower Illawarra Coal Measures. The Erins Vale Formation interrupts this. Marine transgression formed Dempsey Formation, Denman Formation, Bargo Claystone, and Ball Bone Formation. Beach deposition then formed Waratah/Watts Sandstone and the Darkes Forest Sandstone and Angus Place Sandstone. Over the beach land formed again with the Newcastle and Wollombi Coal Measures in the north, and upper Illawarra Coal Measures in the south. Early in the Triassic
the New England Fold Belt was uplifted and an alluvial flood plain formed the Narrabeen group
. The Bald Hill Claystone, which is a redbed containing laterite
was formed by weathering of the Gerringong Volcanics.
The Hawkesbury sandstone is the prominent rock found in Sydney, and also forming the top of escarpments in the area, such as the Illawarra escarpment
. This is overlain by the fine sandstone of the Mittagong Formation
and the Wianamatta shale
.
The basin was later buried under 1 to 4 km of Jurassic
and Cretaceous
sediments. The Tasman Sea formed by rifting and underplating
of the basin may have happened in Aptian
times. This resulted in the upper sediment being completely eroded off.
is along the northern border of New South Wales and also extends north into Queensland. This is also known as Surat Basin. It occupies one fifth of the state of New South Wales. The eastern border extends from Bebo to Narrabri to Murrurundi to Dunedoo to Narromine. The basin was formed in the Jurassic
and Cretaceous
periods.
The oldest Jurassic rocks in the basin are found in the northeast near the Queensland border. They are called Precipice Sandstone, Evergreen Shale and Boxvale Sandstone, Hutton Sandstone from Pliensbachian
to Aalenian
in age. In the south east of the basin these deposits are known as Purlawaugh Formation which are aged between Pliensbachian
to Bathonian
. The northern parts are then covered with coal and shale from the Injune Creek Group. In the east they are covered with quartz sand, at the point where run off entered the basin called Blythesdale Group between Tithonian
and Barremian
or Pillaga Sandstone which is now known as Pilliga Sandstone.
In the Cretaceous sea water entered and deposited shale from the Rolling Downs Group which also contains some calcareous sandstone. Continental sediment also occasionally show in the Cretaceous.
Most of the basin is covered by alluvium and lake deposits from the Cainozoic period, and this deposition continues till this day.
Because the basin is an important site for artesian wells, it has been extensively drilled and much is known about the structure of the basement and geothermal temperature gradients. Prominent subsurface features are the Coonamble lobe of the Surat Basin
, round around Moree and Coonamble. The Culgoa Ridge is underlain by metamorphic rocks, and is near Brewarrina. The Lila Trough is north of Bourke
. The Eulo Shelf is underlain by granite and is southeast of Hungerford. The Bulloo Embayment north of White Cliffs
is over 300 m deep and is disrupted on its west side by the Warratta Fault. The Quinyamble Trough extends in from South Australia.
and Grafton
. It formed by oblique extension of the underlying Paleozoic New England Orogen basement. It consists of continental deposits, starting with a small amount of Triassic
coal beds, and then mostly Jurassic
and Cretaceous
sedimentary rocks. The basin covers 16000 square kilometers. The basin was named when the Clarence Basin (named after the Clarence River
and Moreton Basin in Queensland were proved to be one structure.
The first rocks in the Clarence Moreton Basin of New South Wales are the Chillingham Volcanics. These are from some time in the Triassic period, and for a band north and south of Chillingham
. They consist of cobbles at the base, Rhyolite, lithic rhyolitic tuff, and shale. The Nymboida Coal measures extend from Nymboida
to Kangaroo Creek. They consist of lithic sandstones (wackes, minor arenites), siltstone, polymictic conglomerate, coal, rhyolitic tuff, and basalt. The total thickness is over 1000 meters. The outcrop is 90 square kilometers, and it forms a north west trending band 29 km long on the southwest tip of the basin. Fossils reveal a date of middle Triassic. A lower part is called Cloughers Creek Formation. The Basin Creek Formation includes the coal mined at Nymboida. The Bardool Conglomerate forming a 180 m thick layer, is also a unit in the coal measures. The conglomerate includes a 15 m thick layer of basalt exposed at Copes Creek.
The Red Cliff Coal Measures are from late Triassic. It forms a belt 2.5 km wide and 19 km long from Buchanans Head trough Red Cliff. The Evans Head Coal measure are correlated with these, but are further up the north coast at Evans Head
.
The basin was next uplifted and eroded and then deepened considerably and Bundamba group rocks form a complete V shape on both sides of the basin. In the northern parts the rock is mostly friable sandstone, but in the south it is divided into conglomerate below and siltstone above. The Laytons Range Conglomerate rests on the basin floor and extends from Baryulgil, to Nymboida. The conglomerate often appears as a cliff. The Corindi Conglomerate is a local name for a hailstone sized gravel near Corindi. The Mill Creek Siltstone. are often olive green or yellow-brown with bright red joint planes.
The Marburg subgroup extends for 225 km along the western side of the basin into Queensland from Corindi. It is mostly clay cemented cross bedded quartz sandstone, but this is interbedded with claystone
and shale. At the base is the Blaxland Fossil Wood Conglomerate Member at Blaxlands Creek. The fossil wood is in the form of horizontal tree trunks up to 18 m long and 600 mm diameter. The fossilization process replaced the wood with limonite
and hematite
. The Towallum Basalt is a 15 meter thick layer near Nymboida, Glenreagh and Moleton trig station overlying the Marburg formation. The Walloon Coal Measures forms a U shape around the east, south and west sides of the basin. It consists of claystone, shale, siltstone, arenite
s, and coal seams and the plant fossils in it show a Jurassic age.
The next layer of rocks in the basin forming a nested U shape in its exposure is the Kangaroo Creek Sandstone. This sandstone has saccharoidal texture, and glistens white and cream. This is not due to angular sand grains, but results from silica crystallization. It is up to 150 m thick.
The Grafton Formation is the sedimentary unit in the core of the basin. It is the youngest of the beds being between Late Jurassic and early Cretaceous. It occurs from Grafton
to Casino
consisting of soft sandstone, siltstone and claystone. Dolerite has intruded this at Glenugie Peak, and near Banyabba.
Rifting along the east coast of Australia commenced and uplifted the eastern side of the Clarence Moreton Basin. This resulted in the splitting off of the Lord Howe Rise
and the opening of the ocean floor.
From Paleocene
to Eocene
the western side was flooded with sea water and deposited the Warina sand. The sea withdrew and later in the Eocene silt and clay of the Olney Formation were deposited. One minor sea incursion resulted in late Eocene resulted in the Buccleuch Formation in South Australia. The is group of deposits is termed the Renmark Group and was earlier known as Knight Group.
The sea level rose again in Late Oligocene
to mid Miocene forming the Murray Group of sediments, with marl
and limestone
in the deeper locations, and the Geera Clay in the shallow waters. The rock units formed in the deeper water included the Ettric Formation, the Winnanbool Formation and the Mannum Formation limestone with Gambier Limestone in South Australia. When sea level fell again in mid Miocene the deposited Geera clay and Olney Formation moved westward over the limestone.
During Upper Miocene to Pliocene
the sea rose and fell several times. The first sea rise formed the Murravian Gulf and resulted in clay and marl in the west called the Bookpurnong Formation, and Calivil Formation river and lake sand in the east. When the sea retreated in Early Pliocene, the Loxton Sands also informally known as Loxton-Parilla Sands were formed on the beach on the shore of the emergent land. Locally heavy minerals
have been concentrated by wave action including rutile
zircon
and ilmenite
forming economic mining opportunities.
The Murray River
became dammed by uplift of over 250 meters in the Grampians
in Victoria during the Pleistocene
about 2.5 Mya. The dam formed Lake Bungunnia, which reached 40000 km2 and deposited the Blanchetown Clay therein. Higher rainfall of at least 500 mm per year kept the lake filled at first, but during later times rainfall was insufficient and saline lakes formed, depositing dolomite. Even today some saline lakes remain as a remanent of the vast lake. The Murray River carved out a new path to the sea via Murray Bridge replacing its previous exit at Portland, Victoria
. The lake was gone by about 0.7 Mya.
The Pooraka Formation formed in the north west due to increased erosion resulting in colluvium
depositing. The colluvium forms fans, cones and scree slopes, and often contains clay and breccia. In the flat areas the Shepparton Formation also resulted from river deposits of floodplain clay.
Most of the existing surface dates from Quaternary
period. The river deposits from the east have been progressively overlaying the marine deposits further west, as the shore line receded. Within the Pleistocene
deposits are three layers of sand that are aquifers, deposited during higher rainfall periods of the interglacial
s. The floodplain deposits from the current rivers are the Coonambidgal Formation, however this term is used informally for the older Pleistocene flood deposits as well. During the dryer glacial periods the area was arid.
and south to Armidale, the Liverpool Range
, Barrington Tops, Nandewar Range
near Narrabri, the Warrumbungles
, and the Tweed Volcano
.
supercontinent
. North America was detached opening up the Pacific Ocean
. In the Ordovician
period, sediment deposited on the newly formed sea floor, and in the Silurian
a back arc basin behind a chain of volcanoes was formed and then accreted back onto the east coast of Australia to form the Lachlan Fold Belt
. The main structure in this is north-south, and this is reflected nowadays with the orientation of rivers and mountain ranges.
Opalised fossils about 100 Mya occur at Lightning Ridge.
The Wellington Caves contain megafauna fossils from 4 Mya to 30,000 years old. These include the marsupial lion
and giant kangaroo.
At Canowindra is the most important fish fossil site in the world. It dates from 360 Mya in the Devonian
and includes Groenlandaspis
, Canowindra grossi, Remigolepis walkeri and Bothriolepis yeungae. A museum is there called Age of Fishes Museum. At Cuddie Springs
is a fossil site containing Diprotodon
and the Thunder Bird
.
The Griman Creek Formation
contains Cretaceous dinosaur fossils.
the world's richest zinc and silver mine; Bowdens Silver Deposits near Mudgee; Cadia-Ridgeway Mine 20 km south of Orange
; Lake Cowal Campaign and Barrick Gold
125 km sw of Parkes
; CSA Mine near Cobar mines copper; Endeavour Mine extracts zinc, is 43 km nw of Cobar; Ginko Mineral Sand Deposit is 30 km west of Pooncarie; Murrawombie Mine; Hillgrove Gold Mine 23 km east of Armidale; Mineral Hill 67 km NNW of Condobolin; Northparkes is 26 km north of Parkes mining copper; Peak Gold Mine 8 km southeast of Cobar; Peak Hill Gold Mine 50 km north of Parkes; Prungle Mineral Sand Project 50 km north east of Euston
; Tritton 18 km north of Hermidale; Twelve Mile Mineral Sand Project 40 km east of Pooncarie.
near Wingen, New South Wales
.
The Newcastle earthquake killed 13 people on 28 December 1989.
was its first supervisor.
in 1950s to 1970s the administering body for mines was the New South Wales Department of Mines or New South Wales Department of Mines and Agriculture.
Before 2004 New South Wales Department of Mineral Resource
After 2004 until July 2009 mining in New South Wales was administered by the New South Wales Department of Primary Industries
. and then New South Wales Department of Industry & Investment.
Lachlan Fold Belt
The Lachlan Fold Belt or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria, also extending into Tasmania, the Australian Capital Territory and Queensland. It was formed in...
, the Hunter-Bowen Orogeny
Hunter-Bowen orogeny
The Hunter-Bowen Orogeny was a significant arc accretion event in the Permian and Triassic periods affecting approximately 2,500 km of the Australian continental margin....
or New England Orogen (NEO), the Delamerian Orogeny, the Clarence Moreton Basin
Clarence Moreton Basin
The Clarence Moreton Basin is a Mesozoic sedimentary basin on the easternmost part of the Australian continent. It is located in the far north east of the state of New South Wales around Lismore and Grafton and in the south east corner of Queensland. It formed by oblique extension of the...
, the Great Artesian Basin
Great Artesian Basin
The Great Artesian Basin provides the only reliable source of freshwater through much of inland Australia. The basin is the largest and deepest artesian basin in the world, stretching over a total of , with temperatures measured ranging from 30°C to 100°C...
, the Sydney Basin
Sydney Basin
The Sydney Basin is a sedimentary basin on the east coast of New South Wales, Australia consisting of Permian and Triassic sedimentary rocks...
, and the Murray Basin
Murray Basin
The Murray Basin is a Cenozoic sedimentary basin in south eastern Australia. The basin is only shallow, but extends into New South Wales, Victoria and South Australia. It takes its name from the Murray River which traverses the Basin from east to west....
.
There are a few other sedimentary basins, the Great Artesian Basin can be broken into the Eromanga Basin
Eromanga Basin
The Eromanga Basin is a large Mesozoic sedimentary basin in central and northern Australia. It covers parts of Queensland, the Northern Territory, South Australia, and New South Wales, and is a major component of the Great Artesian Basin...
in the west and the Surat Basin
Surat Basin
The Surat Basin is a part of the Great Artesian Basin of Australia. The Surat Basin extends across an area of 270,000 square kilometres and the southern third of the basin occupies a large part of northern New South Wales, the remainder is in Queensland. It comprises Jurassic through to Cretaceous...
to the east. The Sydney Basin extends north into the Gunnedah Basin, which goes even further north into the Bowen Basin
Bowen Basin
The Bowen Basin contains the largest coal reserves in Australia. This major coal producing region contains one of the world's largest deposits of bituminous coal. The Basin contains much of the known Permian coal resources in Queensland including virtually all of the known mineable prime coking coal...
which extends into Queensland, under the Surat Basin. The New England Orogen has a few small Basins included, such as the Lorne Basin, the Myall Syncline, and Gloucester Basin. The Oaklands Basin in in the south of the state under the Murray Basin. The Darling Basin is in the state's west, but mostly covered by the Murray Basin. Gilgandra Sub-Basin and Paka Tank Trough are potential places for coal and gas.
New South Wales is home to some important mining operations including Broken Hill and coal mining and burning in the Hunter and Illawarra.
Lachlan Fold Belt
Rocks from the Lachlan Fold Belt are exposed through the south east and central parts of NSW, and underlie the Great Artesian BasinGreat Artesian Basin
The Great Artesian Basin provides the only reliable source of freshwater through much of inland Australia. The basin is the largest and deepest artesian basin in the world, stretching over a total of , with temperatures measured ranging from 30°C to 100°C...
and the Sydney and Murray Basins at depth. The region is currently 1000 km wide, but was originally 2000 to 3000 km. The Lachlan Fold Belt was formed in the Middle Paleozoic from 450 to 340 Mya. It lies on a basement of Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
oceanic floor, however, most of this has been subducted leaving the sediment veneer scraped off in chevron folds. It was compressed as the Pacific plate subducted beneath the Australian continent margin. Over time the hinge point, at which the ocean bed was bend down, changed to be more out to the east, and additional ocean bed sediment was added to the continent. This also means that there is a failed subduction zone extending through New South Wales.
The Australian Capital Territory is embedded in New South Wales in the Lachlan Fold Belt. The Narooma Terrane
Narooma Terrane
The Narooma Accretionary Complex or Narooma Terrane is a geological structural region on the south coast of New South Wales, Australia that is the remains of a subduction zone or an oceanic terrane...
is another terrane abutted on the southeast corner of New South Wales which can be considered as a component of the Lachlan Fold Belt.
Hunter-Bowen orogeny
The Hunter-Bowen orogeny also known as the New England Orogen contains rocks from Late PaleozoicPaleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
to early Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
times. It was formed as an arc-forearc zone as the Pacific Plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
was subducted to the west.
Darling and Barka Basins
The Darling basin formed in the very early DevonianDevonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
. Stretching the crust led to the formation of basins such as the Cobar Basin, Mount Hope Trough, Melrose Trough and Rast Trough. Where stretching was less, shelves were formed instead: Kopyje Shelf, Mouramba Shelf, Walters Range Shelf and Winduck Shelf. The Cobar Supergroup is the term used for the infill in these shelves and troughs which consisted of sediment and volcanics.
The deeper basins included turbidite
Turbidite
Turbidite geological formations have their origins in turbidity current deposits, which are deposits from a form of underwater avalanche that are responsible for distributing vast amounts of clastic sediment into the deep ocean.-The ideal turbidite sequence:...
s. Felsic volcanic material was also erupted in the Rast and Mount Hope Troughs. The Florida, Babinda, Majuba and Mineral Hill Volcanics are found on the East side of the Kopyje Shelf. Most of the sediment however is quartz sand.
Subsequently in the early Devonian the basin content was pushed back up, and the Mulga Downs Group was deposited by rivers up until the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
Period. This formed the Barka Basin. Rock from this group is mostly quartz sandstone, with a small amount of siltstone.
Sydney Basin
The Sydney Basin consists of PermianPermian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
and Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
sedimentary rock
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
s stretching from Newcastle
Newcastle, New South Wales
The Newcastle metropolitan area is the second most populated area in the Australian state of New South Wales and includes most of the Newcastle and Lake Macquarie Local Government Areas...
to Batemans Bay. The land component covers 44000 km2, but there is another 5000 km2 underwater on the continental shelf. The basement consists of the Lachlan Fold Belt
Lachlan Fold Belt
The Lachlan Fold Belt or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria, also extending into Tasmania, the Australian Capital Territory and Queensland. It was formed in...
, and the New England Fold Belt is found to the north across the Hunter Thrust. It is a foreland basin
Foreland basin
A foreland basin is a depression that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure...
, likely to be formed by compression loading.
The first rocks formed in the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
were the Dalwood Group and lower Shoalhaven Group. Material for this came from basaltic volcanoes to the north in the Hunter region. The Greta Coal Measures then formed in the north side in an alluvial fan from the mountains of the New England Orogen. The basin sank lower and sea water came much further inland, covering the Permian sediments and the basement further west, and the Maitland Group and upper Shoalhaven Group were deposited. The Muree/Nowra Sandstone formed in the centre of the basin.
In the next stage the Hunter – Bowen Orogeny cause faulting and folding on the north side of the basin. In the Late Permian river and delta deposition formed the Tomago and Whittingham Coal Measures in the north. But deepening seawater formed the Kulnura Marine Tongue and Bulga Formation. In the southern part of the basin a delta formed the lower Illawarra Coal Measures. The Erins Vale Formation interrupts this. Marine transgression formed Dempsey Formation, Denman Formation, Bargo Claystone, and Ball Bone Formation. Beach deposition then formed Waratah/Watts Sandstone and the Darkes Forest Sandstone and Angus Place Sandstone. Over the beach land formed again with the Newcastle and Wollombi Coal Measures in the north, and upper Illawarra Coal Measures in the south. Early in the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
the New England Fold Belt was uplifted and an alluvial flood plain formed the Narrabeen group
Narrabeen group
The Narrabeen group of sedimentary rocks occurs in the Sydney Basin in eastern Australia. This series of rocks was formed in the triassic period....
. The Bald Hill Claystone, which is a redbed containing laterite
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...
was formed by weathering of the Gerringong Volcanics.
The Hawkesbury sandstone is the prominent rock found in Sydney, and also forming the top of escarpments in the area, such as the Illawarra escarpment
Illawarra escarpment
The Illawarra Escarpment is the fold created cliffs and plateau eroded outcrop mountain range west of the Illawarra coastal plain south of Sydney, Australia, enclosing the region known as the Illawarra which stretches from Stanwell Park in the north to Kiama, Gerringong and the Shoalhaven river in...
. This is overlain by the fine sandstone of the Mittagong Formation
Mittagong Formation
The Mittagong Formation is a type of sedimentary rock occurring in the Sydney Basin in eastern Australia. Formed in the triassic period. It may be seen as a narrow band of fine grained sandstone between the shale and the Hawkesbury sandstone . The maximum thickness is ten metres.In northern Sydney...
and the Wianamatta shale
Wianamatta shale
Wianamatta Shale is the uppermost outcropping unit in the Sydney Basin in New South Wales, Australia. It dates from the Triassic Period and generally comprises fine grained sedimentary rocks such as shales and laminites with less common sandstone units...
.
The basin was later buried under 1 to 4 km of Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
sediments. The Tasman Sea formed by rifting and underplating
Underplating
Underplating is the accumulaton of partial melts at the base the crust where an ocean plate is subducting under continental crust. Underplating is the result of partial melts being produced in the mantle wedge above a subducting plate. The partial melting is induced by a lowering of the solidus by...
of the basin may have happened in Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...
times. This resulted in the upper sediment being completely eroded off.
Great Artesian Basin
Part of the Great Artesian BasinGreat Artesian Basin
The Great Artesian Basin provides the only reliable source of freshwater through much of inland Australia. The basin is the largest and deepest artesian basin in the world, stretching over a total of , with temperatures measured ranging from 30°C to 100°C...
is along the northern border of New South Wales and also extends north into Queensland. This is also known as Surat Basin. It occupies one fifth of the state of New South Wales. The eastern border extends from Bebo to Narrabri to Murrurundi to Dunedoo to Narromine. The basin was formed in the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
periods.
The oldest Jurassic rocks in the basin are found in the northeast near the Queensland border. They are called Precipice Sandstone, Evergreen Shale and Boxvale Sandstone, Hutton Sandstone from Pliensbachian
Pliensbachian
The Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the Early or Lower Jurassic epoch or series and spans the time between 189.6 ± 1.5 Ma and 183 ± 1.5 Ma . The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.The...
to Aalenian
Aalenian
The Aalenian is a subdivision of the Middle Jurassic epoch/series of the geologic timescale that extends from about 175.6 Ma to about 171.6 Ma . It was preceded by the Toarcian and succeeded by the Bajocian.-Stratigraphic definitions:...
in age. In the south east of the basin these deposits are known as Purlawaugh Formation which are aged between Pliensbachian
Pliensbachian
The Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the Early or Lower Jurassic epoch or series and spans the time between 189.6 ± 1.5 Ma and 183 ± 1.5 Ma . The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.The...
to Bathonian
Bathonian
In the geologic timescale the Bathonian is an age or stage of the Middle Jurassic. It lasted from approximately 167.7 Ma to around 164.7 Ma...
. The northern parts are then covered with coal and shale from the Injune Creek Group. In the east they are covered with quartz sand, at the point where run off entered the basin called Blythesdale Group between Tithonian
Tithonian
In the geologic timescale the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. It spans the time between 150.8 ± 4 Ma and 145.5 ± 4 Ma...
and Barremian
Barremian
The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...
or Pillaga Sandstone which is now known as Pilliga Sandstone.
In the Cretaceous sea water entered and deposited shale from the Rolling Downs Group which also contains some calcareous sandstone. Continental sediment also occasionally show in the Cretaceous.
Most of the basin is covered by alluvium and lake deposits from the Cainozoic period, and this deposition continues till this day.
Because the basin is an important site for artesian wells, it has been extensively drilled and much is known about the structure of the basement and geothermal temperature gradients. Prominent subsurface features are the Coonamble lobe of the Surat Basin
Surat Basin
The Surat Basin is a part of the Great Artesian Basin of Australia. The Surat Basin extends across an area of 270,000 square kilometres and the southern third of the basin occupies a large part of northern New South Wales, the remainder is in Queensland. It comprises Jurassic through to Cretaceous...
, round around Moree and Coonamble. The Culgoa Ridge is underlain by metamorphic rocks, and is near Brewarrina. The Lila Trough is north of Bourke
Bourke, New South Wales
-Transportation:Bourke can be reached by the Mitchell Highway, with additional sealed roads from town to the north , east and south . The town is also served by Bourke Airport and has Countrylink bus service to other regional centres, like Dubbo...
. The Eulo Shelf is underlain by granite and is southeast of Hungerford. The Bulloo Embayment north of White Cliffs
White Cliffs, New South Wales
White Cliffs is a small town in outback New South Wales in Australia, in Central Darling Shire. White Cliffs is around 255 km northeast of Broken Hill, 93 km north of Wilcannia. At the 2006 census, White Cliffs had a population of 119....
is over 300 m deep and is disrupted on its west side by the Warratta Fault. The Quinyamble Trough extends in from South Australia.
Clarence Moreton Basin
The Clarence Moreton Basin is in the far north east of the state around LismoreLismore, New South Wales
Lismore is a subtropical town in northeastern New South Wales, Australia. Lismore is the main population centre in the City of Lismore local government area. Lismore is a regional centre in the Northern Rivers region of the State.-History:...
and Grafton
Grafton, New South Wales
The city of Grafton is the commercial hub of the Clarence River Valley. Established in 1851, Grafton features many historic buildings and tree-lined streets. Located approximately 630 kilometres north of Sydney and 340 km south of Brisbane, Grafton and the Clarence Valley can be reached...
. It formed by oblique extension of the underlying Paleozoic New England Orogen basement. It consists of continental deposits, starting with a small amount of Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
coal beds, and then mostly Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
sedimentary rocks. The basin covers 16000 square kilometers. The basin was named when the Clarence Basin (named after the Clarence River
Clarence River (New South Wales)
The Clarence River is situated in northeastern New South Wales, Australia. The river originates on the watershed that marks the Queensland border. After flowing south and northeast for 394 km it then empties into the Pacific Ocean at Iluka/Yamba. On its journey it passes through the towns of...
and Moreton Basin in Queensland were proved to be one structure.
The first rocks in the Clarence Moreton Basin of New South Wales are the Chillingham Volcanics. These are from some time in the Triassic period, and for a band north and south of Chillingham
Chillingham, New South Wales
Chillingham is a small village approximately 14 km northwest of Murwillumbah in the Tweed Valley, New South Wales, Australia. The Rous River, a tributary of the Tweed River, flows through the town....
. They consist of cobbles at the base, Rhyolite, lithic rhyolitic tuff, and shale. The Nymboida Coal measures extend from Nymboida
Nymboida, New South Wales
Nymboida is a rural village located in the Northern Rivers region of New South Wales, Australia. It is located about 21 kilometres south-west of Coutts Crossing, 44 kilometres south-west of Grafton and approximately 687 km north of Sydney. Nymboida is close to the challenging and popular white...
to Kangaroo Creek. They consist of lithic sandstones (wackes, minor arenites), siltstone, polymictic conglomerate, coal, rhyolitic tuff, and basalt. The total thickness is over 1000 meters. The outcrop is 90 square kilometers, and it forms a north west trending band 29 km long on the southwest tip of the basin. Fossils reveal a date of middle Triassic. A lower part is called Cloughers Creek Formation. The Basin Creek Formation includes the coal mined at Nymboida. The Bardool Conglomerate forming a 180 m thick layer, is also a unit in the coal measures. The conglomerate includes a 15 m thick layer of basalt exposed at Copes Creek.
The Red Cliff Coal Measures are from late Triassic. It forms a belt 2.5 km wide and 19 km long from Buchanans Head trough Red Cliff. The Evans Head Coal measure are correlated with these, but are further up the north coast at Evans Head
Evans Head, New South Wales
Evans Head is a town in the Northern Rivers region of New South Wales, Australia in Richmond Valley Shire. At the 2006 census, Evans Head had a population of 2,631 people. It is 726 kilometres north of Sydney, and 11 kilometres east off the Pacific Highway from Woodburn...
.
The basin was next uplifted and eroded and then deepened considerably and Bundamba group rocks form a complete V shape on both sides of the basin. In the northern parts the rock is mostly friable sandstone, but in the south it is divided into conglomerate below and siltstone above. The Laytons Range Conglomerate rests on the basin floor and extends from Baryulgil, to Nymboida. The conglomerate often appears as a cliff. The Corindi Conglomerate is a local name for a hailstone sized gravel near Corindi. The Mill Creek Siltstone. are often olive green or yellow-brown with bright red joint planes.
The Marburg subgroup extends for 225 km along the western side of the basin into Queensland from Corindi. It is mostly clay cemented cross bedded quartz sandstone, but this is interbedded with claystone
Claystone
Claystone is a geological term used to describe a clastic sedimentary rock that is composed primarily of clay-sized particles ....
and shale. At the base is the Blaxland Fossil Wood Conglomerate Member at Blaxlands Creek. The fossil wood is in the form of horizontal tree trunks up to 18 m long and 600 mm diameter. The fossilization process replaced the wood with limonite
Limonite
Limonite is an ore consisting in a mixture of hydrated iron oxide-hydroxide of varying composition. The generic formula is frequently written as FeO·nH2O, although this is not entirely accurate as limonite often contains a varying amount of oxide compared to hydroxide.Together with hematite, it has...
and hematite
Hematite
Hematite, also spelled as haematite, is the mineral form of iron oxide , one of several iron oxides. Hematite crystallizes in the rhombohedral system, and it has the same crystal structure as ilmenite and corundum...
. The Towallum Basalt is a 15 meter thick layer near Nymboida, Glenreagh and Moleton trig station overlying the Marburg formation. The Walloon Coal Measures forms a U shape around the east, south and west sides of the basin. It consists of claystone, shale, siltstone, arenite
Arenite
Arenite is a sedimentary clastic rock with sand grain size between 0.0625 mm and 2 mm and contain less than 15% matrix. The related adjective is arenaceous...
s, and coal seams and the plant fossils in it show a Jurassic age.
The next layer of rocks in the basin forming a nested U shape in its exposure is the Kangaroo Creek Sandstone. This sandstone has saccharoidal texture, and glistens white and cream. This is not due to angular sand grains, but results from silica crystallization. It is up to 150 m thick.
The Grafton Formation is the sedimentary unit in the core of the basin. It is the youngest of the beds being between Late Jurassic and early Cretaceous. It occurs from Grafton
Grafton, New South Wales
The city of Grafton is the commercial hub of the Clarence River Valley. Established in 1851, Grafton features many historic buildings and tree-lined streets. Located approximately 630 kilometres north of Sydney and 340 km south of Brisbane, Grafton and the Clarence Valley can be reached...
to Casino
Casino, New South Wales
Casino is a town in the Northern Rivers area of New South Wales, Australia, with a population of 9,400 people . It lies on the banks of the Richmond River and is situated at the junction of the Bruxner Highway and the Summerland Way....
consisting of soft sandstone, siltstone and claystone. Dolerite has intruded this at Glenugie Peak, and near Banyabba.
Rifting along the east coast of Australia commenced and uplifted the eastern side of the Clarence Moreton Basin. This resulted in the splitting off of the Lord Howe Rise
Lord Howe Rise
The Lord Howe Rise is an underwater plateau that extends from southwest of New Caledonia to the Challenger Plateau, west of New Zealand. To its west is the Tasman Basin and to the east is the New Caledonia Basin. Lord Howe Rise has a total area of about 1,500,000 square km, and generally lies about...
and the opening of the ocean floor.
Murray basin
After Australia separated from Antarctica the Murray basin was formed. The basin floor only subsided slowly over time. The basin became filled with up to 600 m of sediments during the Cenozoic.From Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
to Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
the western side was flooded with sea water and deposited the Warina sand. The sea withdrew and later in the Eocene silt and clay of the Olney Formation were deposited. One minor sea incursion resulted in late Eocene resulted in the Buccleuch Formation in South Australia. The is group of deposits is termed the Renmark Group and was earlier known as Knight Group.
The sea level rose again in Late Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
to mid Miocene forming the Murray Group of sediments, with marl
Marl
Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...
and limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
in the deeper locations, and the Geera Clay in the shallow waters. The rock units formed in the deeper water included the Ettric Formation, the Winnanbool Formation and the Mannum Formation limestone with Gambier Limestone in South Australia. When sea level fell again in mid Miocene the deposited Geera clay and Olney Formation moved westward over the limestone.
During Upper Miocene to Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
the sea rose and fell several times. The first sea rise formed the Murravian Gulf and resulted in clay and marl in the west called the Bookpurnong Formation, and Calivil Formation river and lake sand in the east. When the sea retreated in Early Pliocene, the Loxton Sands also informally known as Loxton-Parilla Sands were formed on the beach on the shore of the emergent land. Locally heavy minerals
Heavy mineral sands ore deposits
Heavy mineral sands are a class of ore deposit which is an important source of zirconium, titanium, thorium, tungsten, rare earth elements, the industrial minerals diamond, sapphire, garnet, and occasionally precious metals or gemstones....
have been concentrated by wave action including rutile
Rutile
Rutile is a mineral composed primarily of titanium dioxide, TiO2.Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiO2 are known:...
zircon
Zircon
Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. A common empirical formula showing some of the range of substitution in zircon is 1–x4x–y...
and ilmenite
Ilmenite
Ilmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide . It crystallizes in the trigonal system, and it has the same crystal structure as corundum and hematite....
forming economic mining opportunities.
The Murray River
Murray River
The Murray River is Australia's longest river. At in length, the Murray rises in the Australian Alps, draining the western side of Australia's highest mountains and, for most of its length, meanders across Australia's inland plains, forming the border between New South Wales and Victoria as it...
became dammed by uplift of over 250 meters in the Grampians
The Grampians
The Grampians are a set of hills in the Nelson region of New Zealand. Frequented by locals and tourists alike, they are covered in a myriad of tracks ranging from leisurely strolls to relatively taxing steep inclines.-Areas of interest:...
in Victoria during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
about 2.5 Mya. The dam formed Lake Bungunnia, which reached 40000 km2 and deposited the Blanchetown Clay therein. Higher rainfall of at least 500 mm per year kept the lake filled at first, but during later times rainfall was insufficient and saline lakes formed, depositing dolomite. Even today some saline lakes remain as a remanent of the vast lake. The Murray River carved out a new path to the sea via Murray Bridge replacing its previous exit at Portland, Victoria
Portland, Victoria
The city of Portland is the oldest European settlement in what is now the state of Victoria, Australia. It is the main urban centre of the Shire of Glenelg. It is located on Portland Bay.-History:...
. The lake was gone by about 0.7 Mya.
The Pooraka Formation formed in the north west due to increased erosion resulting in colluvium
Colluvium
Colluvium is the name for loose bodies of sediment that have been deposited or built up at the bottom of a low-grade slope or against a barrier on that slope, transported by gravity. The deposits that collect at the foot of a steep slope or cliff are also known by the same name. Colluvium often...
depositing. The colluvium forms fans, cones and scree slopes, and often contains clay and breccia. In the flat areas the Shepparton Formation also resulted from river deposits of floodplain clay.
Most of the existing surface dates from Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
period. The river deposits from the east have been progressively overlaying the marine deposits further west, as the shore line receded. Within the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
deposits are three layers of sand that are aquifers, deposited during higher rainfall periods of the interglacial
Interglacial
An Interglacial period is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age...
s. The floodplain deposits from the current rivers are the Coonambidgal Formation, however this term is used informally for the older Pleistocene flood deposits as well. During the dryer glacial periods the area was arid.
Volcanic rocks
New South Wales has 26,000 km2 of volcanic rocks from Cainozoic period. In the north east major outcrops of volcanic rocks are found between Warialda to Glen InnesGlen Innes, New South Wales
Glen Innes is a parish and town on the Northern Tablelands, in the New England region of New South Wales, Australia. It is the centre of the Glen Innes Severn Shire Council. The town is located at the intersection of the New England Highway and the Gwydir Highway...
and south to Armidale, the Liverpool Range
Liverpool Range
The Liverpool Range is a mountain range and a lava-field province in New South Wales, Australia.The Liverpool Range starts from the volcanic plateau known as the Barrington Tops and runs for about 100 km westwards, forming the northern boundary of the Hunter Valley district...
, Barrington Tops, Nandewar Range
Nandewar Range
The Nandewar Range is a mountain range east of Narrabri in New South Wales, Australia. John Oxley was the first European to see the range in 1818 as he explored the New South Wales Northern Tablelands....
near Narrabri, the Warrumbungles
Warrumbungles
The Warrumbungles is the name of a mountain range and National Park located in northern New South Wales, Australia. The nearest town to the Warrumbungles is Coonabarabran...
, and the Tweed Volcano
Tweed Volcano
Tweed Volcano was an early Miocene shield volcano in northeastern New South Wales, Australia. In the course of about three million years, Tweed Volcano was formed over the East Australia hotspot when this part of the continent passed over it around 23 million years ago...
.
Geological history
In the Cambrian and earlier period only the far west of New South Wales existed in its present form. It was joined to what is now Western North America in the RodiniaRodinia
In geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era...
supercontinent
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
. North America was detached opening up the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. In the Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
period, sediment deposited on the newly formed sea floor, and in the 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...
a back arc basin behind a chain of volcanoes was formed and then accreted back onto the east coast of Australia to form the Lachlan Fold Belt
Lachlan Fold Belt
The Lachlan Fold Belt or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria, also extending into Tasmania, the Australian Capital Territory and Queensland. It was formed in...
. The main structure in this is north-south, and this is reflected nowadays with the orientation of rivers and mountain ranges.
Fossils
Collecting fossils is legal in New South Wales under the New South Wales Mining Act with ownership applying to the land owner.Opalised fossils about 100 Mya occur at Lightning Ridge.
The Wellington Caves contain megafauna fossils from 4 Mya to 30,000 years old. These include the marsupial lion
Marsupial lion
Thylacoleo is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene...
and giant kangaroo.
At Canowindra is the most important fish fossil site in the world. It dates from 360 Mya in the Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
and includes Groenlandaspis
Groenlandaspis
Groenlandaspis is an extinct genus of armored placoderm.Groenlandaspis was a member of the Order Arthrodira, the most successful group of placoderms which also included the superpredator Dunkleosteus...
, Canowindra grossi, Remigolepis walkeri and Bothriolepis yeungae. A museum is there called Age of Fishes Museum. At Cuddie Springs
Cuddie Springs
Cuddie Springs is a notable archaeological and paleontological site in the semi-arid zone of central northern New South Wales, Australia . Cuddie Springs is an open site, with the fossil deposits preserved in a claypan on the floor of an ancient ephemeral lake...
is a fossil site containing Diprotodon
Diprotodon
Diprotodon, meaning "two forward teeth", sometimes known as the Giant Wombat or the Rhinoceros Wombat, was the largest known marsupial that ever lived...
and the Thunder Bird
Dromornithidae
Dromornithidae — the dromornithids — were a family of large, flightless Australian birds of the Oligocene through Pleistocene epochs. All are now extinct. They were long classified in the order Struthioniformes, but are now usually classified as a family of Anseriformes1...
.
The Griman Creek Formation
Griman Creek Formation
The Griman Creek Formation is a geological formation in New South Wales, Australia whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...
contains Cretaceous dinosaur fossils.
Mining
A variety of mines occur in New South Wales, including Broken Hill Ore DepositBroken Hill Ore Deposit
The Broken Hill Ore Deposit is located underneath Broken Hill in western New South Wales, Australia, and is the namesake for the town. It is arguably the world's richest and largest zinc-lead ore deposit.- Discovery :...
the world's richest zinc and silver mine; Bowdens Silver Deposits near Mudgee; Cadia-Ridgeway Mine 20 km south of Orange
Orange, New South Wales
Orange is a city in the Central West region of New South Wales, Australia. It is west of the state capital, Sydney, at an altitude of . Orange has an estimated population of 39,329 and the city is a major provincial centre....
; Lake Cowal Campaign and Barrick Gold
Lake Cowal
Lake Cowal is the largest inland lake in New South Wales, Australia. The lake is ephemeral, being fed by the small Bland Creek and by the occasional flooding of the Lachlan River. Despite this, it retains a considerable amount of water in about 70% of years....
125 km sw of Parkes
Parkes, New South Wales
- Transport :Parkes has a local bus service provided by Western Road Liners, which acquired Harris Bus Lines in March 2006. The Indian Pacific also stops twice a week, as well as the Broken Hill Outback Xplorer service, run by CountryLink, which heads to Broken Hill on Mondays and Sydney on...
; CSA Mine near Cobar mines copper; Endeavour Mine extracts zinc, is 43 km nw of Cobar; Ginko Mineral Sand Deposit is 30 km west of Pooncarie; Murrawombie Mine; Hillgrove Gold Mine 23 km east of Armidale; Mineral Hill 67 km NNW of Condobolin; Northparkes is 26 km north of Parkes mining copper; Peak Gold Mine 8 km southeast of Cobar; Peak Hill Gold Mine 50 km north of Parkes; Prungle Mineral Sand Project 50 km north east of Euston
Euston, New South Wales
Euston is a small town on the banks of the Murray River, southern New South Wales, Australia in Balranald Shire. The twin town of Robinvale is on the other side of the river in the state of Victoria. At the 2006 census, Euston had a population of 462 people. Until the irrigation development at...
; Tritton 18 km north of Hermidale; Twelve Mile Mineral Sand Project 40 km east of Pooncarie.
Disasters
The oldest coal seam fire in the world has been burning for 6000 years at Burning MountainBurning Mountain
Burning Mountain, the common name for Mount Wingen, is a hill near Wingen, New South Wales, Australia, approximately north of Sydney just off the New England Highway. It takes its name from a smouldering coal seam running underground through the sandstone...
near Wingen, New South Wales
Wingen, New South Wales
Wingen is a village in the Upper Hunter area of the Hunter Valley in New South Wales, Australia. Situated on the New England Highway, it lies about 15 minutes from the town of Scone. It is known for the local "Burning Mountain" tourist attraction, a burning underground coal seam...
.
The Newcastle earthquake killed 13 people on 28 December 1989.
Government
The Department of Mines commenced in late 1874, and the Geological Survey of New South Wales was brought into existence on 1 January 1875. Charles Smith WilkinsonCharles Smith Wilkinson
Charles Smith Wilkinson was an Australian geologist. He became geological surveyor in charge in New South Wales in 1875 and was president of the Royal Society of New South Wales in 1887.-Early life:...
was its first supervisor.
in 1950s to 1970s the administering body for mines was the New South Wales Department of Mines or New South Wales Department of Mines and Agriculture.
Before 2004 New South Wales Department of Mineral Resource
After 2004 until July 2009 mining in New South Wales was administered by the New South Wales Department of Primary Industries
New South Wales Department of Primary Industries
The New South Wales Department of Primary Industries, a division of the New South Wales Government, is responsibile for the administration and development for agriculture, fisheries, aquaculture, state forests, biosecurity, and crown lands in New South Wales...
. and then New South Wales Department of Industry & Investment.