Amelia Creek crater is an

impact structure An impact structure is a generally circular or craterlike geologic structure of deformed bedrock or sediment produced by impact on a planetary surface, whatever the stage of erosion of the structure. In contrast, an impact crater is the surfa ...

(or astrobleme), the eroded remnant of a former

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 crater ...

, located in the Davenport Range,

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Aust ...

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

. It lies within a low range of

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 ...

sedimentary 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 ...

and

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plat ...

rocks, which are extensively folded and faulted, thus making an eroded impact crater difficult to recognize. It was only discovered by the identification of

shatter cone Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the rang ...

s near its centre.Conference abstract
br/> The central shatter cone locality is surrounded by a area of anomalous deformation, the asymmetry being possibly related to very oblique impact, but may be at least partly due to the preexisting structural complexity of the rocks. This deformed zone gives the best estimate for the original size of the crater. Impact took place after folding of the

rocks but before deposition 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 prec ...

and

Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago ...

rocks which overlie them, thus constraining the impact event to the interval between about 1660 and 600 Ma.

References

{{Impact cratering on Earth Impact craters of the Northern Territory Proterozoic impact craters Precambrian Australia

See also

References