The Great Western Tiers are a collection of

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

bluffs that form the northern edge of the Central Highlands

plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ha ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, Australia. The bluffs are contained within the

Tasmanian Wilderness The Tasmanian Wilderness World Heritage Area, abbreviated to TWWHA, is a World Heritage Site in Tasmania, Australia. It is one of the largest conservation areas in Australia, covering , or almost 25% of Tasmania. It is also one of the last ex ...

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

. The bluffs stretch northwest to southeast over from the Western Bluff near the town of

Mole Creek Mole Creek is a town in the upper Mersey Valley, in the central north of Tasmania, Australia. Mole Creek is well known for its honey and accounts for about 35 percent of Tasmania's honey production. The locality is in the Meander Valley Counc ...

to the Millers Bluff, approximately west of

Campbell Town Campbell Town is a town in Tasmania, Australia, on the Midland Highway. At the 2021 census, the town had a population of 823. History Traditional owners of the Campbell Town area The traditional custodians of the Campbell Town area were t ...

.Lloyd, p.1 During the late 19th century the Tiers were known as the Great Western Range.

Features

The Central Highlands, or Tasmanian central plateau, was uplifted from the lower Meander Valley, most probably in the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

epoch though possibly earlier, forming the Tiers' escarpment. The plateau's north-east boundary, which ranges from –, originated in extensive Tertiary faulting. This escarpment divides the high, rocky, sparsely inhabited central plateau from the fertile lower land of the

Meander Valley Meander Valley Council is a local government body in northern Tasmania. It covers the western outskirts of Launceston, and further westward along the Meander River. Meander Valley Council is classified as a rural local government area and h ...

and the northern midlands. The edge of the tiers have prominent cliffs and columns of

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

dolerite Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained ...

. The highest peak in the tiers is the

Ironstone Mountain The Ironstone Mountain is a mountain located in the Central Highlands region of Tasmania, Australia. Part of Great Western Tiers escarpment, the mountain is situated south of the small country village of Mole Creek. With an elevation of ab ...

. Unlike most of the bluffs this mountain is not visible from the Meander Valley, but is south of the escarpment. The escarpment has a distinct concave profile. Cliffs and scree slopes are common features. The dolerite is so prominent as the older rocks that overlay them are softer and have been eroded away. In places dolerite columns have collapsed into

scree slope Scree is a collection of broken Rock (geology), rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus depos ...

s. The face of the tiers has been eroded and retreated approximately since their formation, leaving the mountain Quamby Bluff as a solitary outlier. The central plateau's landform has been changed by glaciation. Valleys under the tiers are filled with talus, mostly bounders with a 25% mix of soil formed from boulder weathering.

Peaks

The

peaks Peak or The Peak may refer to: Basic meanings Geology * Mountain peak ** Pyramidal peak, a mountaintop that has been sculpted by erosion to form a point Mathematics * Peak hour or rush hour, in traffic congestion * Peak (geometry), an (''n''-3)-d ...

and bluffs of the Great Western Tiers include: * Brady's lookout, at . Named after the bushranger Matthew Brady. * Billop Bluff *

Dry's Bluff Dry's Bluff is a mountain in the Great Western Tiers Range in Tasmania. The walk to its summit is listed in The Abels as one of the hardest day walks in Tasmania with an elevation gain of over 1000m from the base of the plateau. Access to the st ...

at . Origin of the

Liffey River The River Liffey (Irish: ''An Life'', historically ''An Ruirthe(a)ch'') is a river in eastern Ireland that ultimately flows through the centre of Dublin to its mouth within Dublin Bay. Its major tributaries include the River Dodder, the River ...

. *

, at * Millers Bluff, at *

Mother Cummings Peak The Mother Cummings Peak is one of the prominent peaks on the Great Western Tiers located in the Central Highlands region of Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , ...

, at * Mount Blackwood * Mount Parmeener * Neals Bluff * Panorama Hill * Projection Bluff *

Quamby Bluff Quamby Bluff is a mountain in Northern Tasmania, Australia that is an outlying part of the Great Western Tiers mountain range. Geography and Geology Quamby Bluff lies from Deloraine by road, just north of the main escarpment of the Great We ...

, at Forestry Commission of Tasmania, p.9 * Western Bluff, at

Gallery

References

Bibliography

* * * * {{CentralHighlandsTasmania , state=autocollapse Central Highlands (Tasmania) Mountains of Tasmania

Features

Peaks

Gallery

See also

References

Bibliography