Dating terrestrial impact structures goranga dating system v1 01

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If uncertainties regarding its age are resolved, then the largest in the last 10 million years would be the 52-km Karakul crater which is listed in EID with an age of less than 5 Ma, or the Pliocene.The large but apparently craterless Eltanin impact (2.5 Ma) into the Pacific Ocean has been suggested as contributing to the glaciations and cooling during the Pliocene.Due to this, dating on whole rock samples or insufficiently pure mineral fractions often yielded ambiguous results that set broad age limits but are not sufficient to answer reliably questions such as a possible periodicity in cratering on Earth, or correlation of impact events with mass extinctions.

For eroded or buried craters, the stated diameter typically refers to the best available estimate of the original rim diameter, and may not correspond to present surface features.In the early 1990s, the subsurface Chicxulub structure in Mexico (slide #37) was confirmed as the long-sought Cretaceous-Tertiary boundary impact crater.An environmental crisis, triggered by the gigantic collision, contributed to the extinctions.This rate estimate is equivalent to that based on astronomical observations of Earth-crossing bodies.These rates are a factor of two higher, however, than the estimated post-mare cratering rate on the moon but the large uncertainties preclude definitive conclusions as to the significance of this observation.

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