The Great Escarpment in eastern
Australia is an
escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...
that runs east of the
Great Dividing Range along most of the east of the continent. It was created due to formation of a new
continental margin
A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margi ...
in the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...
, followed by
tectonic uplift
Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal th ...
ing of the divide and then
scarp retreat
Scarp retreat is a geological process through which the location of an escarpment changes over time. Typically the cliff is undermined, rocks fall and form a talus slope, the talus is chemically or mechanically weathered and then removed through ...
.
[ The escarpment is estimated to be approximately in length, from north to south.][
]
Formation
The Great Escarpment formed about 80 million years ago due to scarp retreat
Scarp retreat is a geological process through which the location of an escarpment changes over time. Typically the cliff is undermined, rocks fall and form a talus slope, the talus is chemically or mechanically weathered and then removed through ...
from a new continental edge formed by rifting.[
This was similar to the model in the western rift of East Africa.][ The Great Divide is an upwarp that lies tens or hundreds of kilometers from the chasmic fault of the continental margin, creating a drainage divide.
The sequence of formation appears to have started with erosion of the plain and formation of a river pattern.][ The traces of these rivers can still be seen.][
]
Description
The Great Escarpment rises to several hundred meters. To the east, the coastal zone is relatively flat with fast erosional process rate and few landscape palaeoforms. To the west there are many palaeoforms and process rates are slow.tableland
A table or tableland is a butte, flank of a mountain, or mountain, that has a flat top.
This kind of landform has numerous names, including:
* Butte
* Mesa
*
* Potrero
* Tepui
* Terrace
* Tuya
A tuya is a flat-topped, steep-sided vo ...
between the Great Divide and the escarpment, sometimes leaving parts of the plateau standing out in isolation to the east.[ Escarpment retreat along the river valleys in the ]New England
New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the Can ...
region appears to be progressing at about per million years.
See also
*Geography of Australia
The geography of Australia encompasses a wide variety of biogeographic regions being the world's smallest continent, while comprising the territory of the sixth-largest country in the world. The population of Australia is concentrated along ...
References
{{reflist
Landforms of Queensland
Landforms of New South Wales
Landforms of Victoria (Australia)
Escarpments