Zhamanshin is a meteorite crater in

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

. It is in

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid fo ...

and the age is estimated to be 900,000 ± 100,000 years (

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

). The crater is exposed at the surface.

Description

It is believed that the Zhamanshin crater is the site of the most recent meteorite impact event of the magnitude that could have produced a disruption comparable to that of a

nuclear winter Nuclear winter is a severe and prolonged global climatic cooling effect that is hypothesized to occur after widespread firestorms following a large-scale nuclear war. The hypothesis is based on the fact that such fires can inject soot into t ...

, but it was not sufficiently large enough to have caused a

mass extinction An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. I ...

. Preliminary papers in the late 1970s suggested either Elgygytgyn, or Zhamanshin,B.P. Glass (1979), Zhamanshin crater, a possible source of Australasian tektites? Geology, July 1979, v. 7, p. 351-353 as the source of the

Australasian strewnfield The Australasian strewnfield is the youngest and largest of the tektite strewnfields, with recent estimates suggesting it might cover 10%–30% of the Earth's surface.Glass, B.P. and Wu, J., 1993. ''Coesite and shocked quartz discovered in the, A ...

References

Impact craters of Kazakhstan Pleistocene impact craters Pleistocene Asia Aktobe Region {{Kazakhstan-geo-stub