impact craters

IMPACT CRATERS


Oldest Crater

Scientist found evidence of what could be the oldest proven meteorite site on Earth. The exact place and time is unknown. There is a possibility that the meteorite crater is located over two continents. (Africa and Australia)

They base their evidence on geochemical analysis of rock samples collected from two ancient formations well known to geologist:  South Africa’s Barberton Greenstone belt and Australia’s Pilbara block.  Both sites contain 3.5 billion year old layers of rock embedded with “spherules” – tiny spherical particles that are frequently a by product of meteorite collisions.

Scientist speculate the meteorite was 20 km (12 mile) wide, and hit the Earth approximately 3.47 billion years ago.

Sources:-Oldest Meteorite Collision on Earth, MNASSA, Vol. 61, Nos. 9 & 10, October 2002, pp.122 – 125.


Vredefort Crater

Located in the Free State; > 250km, 2023 millenia old. (Gould 2000)


Tswaing Meteor Crater

Pretoria Salt Pan; 56km NW of Pretoria. 1.13km across, 220 000 years old (Gould 2000)

Also see Gaylard (1996).


Morokweng

West of Vryburg; 70-340 km across, 145 millenia old (Gould 2000


Kaalkop

Located in the Eastern Cape; 0.64km across; less than 5 millenia old. (Gould 2000)


Roter Kamm

Located in southern Namibia; 2.5km across; 3.7 +/- 0.3 millenia old. (Gould 2000)


Highbury

Located in Zimbabwe; 20km across; 1000-1800 millenia old. (Gould 2000)


Sinamwenda

Located in Zimbabwe; 220m across; less than 10 millenia old. (Gould 2000)


ReferencesGaylard, M. (1996) The Tswaing Meteor Crater. MNASSA, 55, 182.
Gould, T. (2000) The Oldest and Largest Impact Crater on Earth. MNASSA, 59, February Centrepiece.