Morokweng crater
Coordinates: 26 ° 28 ' S , 23 ° 32' E
The Morokweng crater is a 70 km large impact craters , which under the Kalahari Desert is hidden. It is located near the town of Morokweng in the South African province of Northwest near the border with Botswana .
The crater was created by the impact of an asteroid five to ten kilometers in diameter. Its age is estimated to be around 145 million years. The impact structure was discovered in 1994, but is not visible on the earth's surface; it could be proven by gravimetric measurements . Drill cores have shown that the crater was formed by the impact of an L-Chondritic asteroid.
In May 2006, a group of scientists who were drilling in the area of Morokweng Crater announced that a fragment of the original asteroid had been found at a depth of 770 meters, as well as other tiny pieces at varying depths. This discovery was unexpected, because up to now, wells in large impact structures had not uncovered any fragments, and it was assumed that the asteroid must have completely evaporated.
See also
Individual evidence
- ^ Christian Koeberl, Bernhard Peucker-Ehrenbrink, Wolf Uwe Reimold: Meteoric component in impact melt rocks from the Morokweng, South Africa, impact structure: An OS isotopic study . (PDF) In: Lunar and Planetary Science . August 31.
- ↑ WD Maier, Andreoli MA, McDonald I, Higgins MD, Boyce AJ, Shukolyukov A, Lugmair GW, Ashwal LD, Graser P, Ripley EM, Hart RJ: Discovery of a 25-cm asteroid clast in the giant Morokweng impact crater, South Africa . In: Nature . 441, No. 7090, pp. 203-206. doi : 10.1038 / nature04751 . PMID 16688173 .