Yarrabubba crater refers to an impact structure

Impact structure

The term impact structure is closely related to the terms impact crater or meteorite impact crater, and is used in cases where erosion or burial have destroyed or masked the original topographic feature with which we normally associate the term crater...

 (or astrobleme), the eroded remnant of a former impact crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

, situated in the northern Yilgarn Craton

Yilgarn craton

The Yilgarn Craton is a large craton which constitutes the bulk of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts...

 between the towns of Sandstone and Meekatharra, central Western Australia

Western Australia

Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

.

The original crater has been completely eroded and is not readily visible on aerial or satellite images; the evidence for impact comes rather from the presence of shocked quartz

Shocked quartz

Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure , the crystalline structure of quartz will be deformed along planes inside the crystal...

 and shatter cone

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...

s in outcrops of granite

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

 interpreted the be near the centre of the original crater, and from geophysical

Geophysics

Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...

 data. The diameter of the original crater is uncertain, but has been estimated to be in the range 30 –. The age of the impact event is also uncertain, but it must be younger than the granite that has been shocked, which has been dated at about 2650 Ma (late Archaean). Veins of pseudotachylite

Pseudotachylite

Pseudotachylite is a fault rock that has the appearance of the basaltic glass, tachylyte. It is dark in color and has a glassy appearance. However, the glass has normally been completely devitrified into very fine-grained material with radial and concentric clusters of crystals...

 (rocks melted by friction) in the granite have given a date of 1134±26 Ma using the argon-argon dating

Argon-argon dating

Argon-argon dating is a radiometric dating method invented to supersede potassium-argon dating in accuracy. The older method required two samples for dating while the newer method requires only one...

 method, and although the significance of this age is not fully clear it is currently considered by some to provide the best tentative estimate for the age. The Earth Impact Database

Earth Impact Database

The Earth Impact Database is the authoritative source for information on confirmed impact structures or craters on Earth. It was initiated in 1955 by the Dominion Observatory, Ottawa, under the direction of Dr. Carlyle S. Beals...

 prefers an intermediate estimate of about 2000 Ma.