Mystery of Lake Acraman, cosmic catastrophe in the South Australia and it impact on the natural environment in late Proterozoic – Ediacaran 1300-WTJAP

Results of investigation of the largest meteorite crater in Australia will be discussed. This crater, 95 km in diameter is identify with wide and radially spread distal ejecta which extends from the central point of this cosmic impact to distance of 600 km.
The geological impact structure Acraman was generated in effect of exogenic processes associated with Asteroidal impact of cosmic body estimated on 4.5 km in diameter. This late Neoproterozoic (Ediacaran) catastrophical event has important influence on contemporary natural environment.
Research since 1995 has verified Acraman as a complex impact structure that has undergone as much as 3-5 km of denudation and which originally had a transient cavity up to 40 km in diameter and a final structural rim possibly 85-90 km in diameter. The estimated impact energy of 5.2 x 106 Mt (TNT) for Acraman exceeds the threshold of 1 x 106 Mt (TNT) nominally set for global catastrophe, and the impact probably caused a severe perturbation of the Ediacara environment. The occurrence of the impact at a low paleolatitude (12.5 ± 7o) may have magnified the environmental effects by perturbing the atmosphere in both hemispheres. These findings are consistent with independent data from the Ediacaran palynology of Australia and from isotope and biomarker chemostratigraphy that the Acraman impact induced major biotic change.
New field and laboratory methods employed in the impact events identification associated with crushing the large celestial body onto the Earth surface will be discussed.