Liverpool is a

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

situated in

Arnhem Land Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...

within the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

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 ...

. It was named after the nearby Liverpool River. Liverpool is remote and difficult to access. The crater has a raised, near-circular rim averaging about 1.6 km in diameter. It was first noticed by geologists during reconnaissance geological mapping in the 1960s, and although an impact origin was considered possible, this was not confirmed until a more detailed study was undertaken in 1970.
Abstract
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Description

The crater lies within flat-lying

Paleoproterozoic The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions (eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

of the

McArthur Basin The McArthur Basin is a large intracratonic sedimentary basin in northern Australia, with an exposed area of about 180,000 km2. Most of it lies within the northeastern Northern Territory, but extends over the border into the state of Qu ...

. This sandstone has been fractured and

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

ted by the impact event to form the rim. Flat-lying and non-deformed sandstone that must have been deposited after the impact event is exposed within the crater's center. Because the crater is quite well preserved, it can be argued that it was buried by younger

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

soon after the impact event; this younger rock has now been mostly eroded away except in the crater center. The crater-filling sandstone was originally thought to be of

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

age, leading to the Cretaceous age listed for the crater in older literature sources. But more recent studies suggest that the infilling rock is more likely to be of

Neoproterozoic The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. It is ...

age (1000-543 Ma),PDF
br/>Abstract
br/> and therefore the crater is more likely to have formed at some time during the Neoproterozoic. No meteorite fragments have been found at the site. This is not surprising considering its great age; such fragments would have weathered away. Evidence supporting an impact origin includes the geological structure of the crater, and the discovery of

shocked quartz Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure (but limited temperature), the crystalline structure of quartz is deformed along planes inside the crystal. These pla ...

. The crater is not perfectly circular, but is about 6% broader in a northeast–southwest direction. And the internal parts of the crater are asymmetric in such a way as to imply that the impact was oblique from the southwest.

Aboriginal significance

The Aboriginal people of Western

named Liverpool crater Yingundji and describe it as the nest of a giant catfish. This is supported by pictographs of giant catfish on the walls of a rock shelter within the crater.Abstract
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References

{{DEFAULTSORT:Liverpool Crater Impact craters of the Northern Territory Mesozoic impact craters Mesozoic Australia Geology of the Northern Territory

Description

Aboriginal significance

See also

References