Impacts and tectonism in Earth and Moon history of the past 3800 million years

Abstract

The Moon's surface, unlike the Earth's, displays a comparatively clear record of its past bombardment history for the last 3800 Myr, the time since active lunar tectonism under the massive pre-mare bombardment ended. From Baldwin's tabulation of estimated ages for a representative sample of large lunar craters younger than 3800Ma, six major cratering episodes can be discerned. These six bombardment episodes, which must have affected the Earth too, appear to match in time the six major episodes of erogenic tectonism on Earth, despite typical resolution errors of al00 Myr and the great uncertainties of the two chronologies. Since more highly resolved events during the Cenozoic and Mesozoic Eras suggest the same correlation, it is possible that large impacts have influenced plate tectonics and other aspects of geologic history, perhaps by triggering flood basalt eruptions.

The limitations of NEO-uniformitarianism

“…However, there is evidence for six major cratering episodes over the past 3800 Myr. Stothers (1992) has correlated these with the six major episodes of erogenic tectonism on Earth, which is of interest with regard to the Earth's history, but also may be interpreted as (i) Providing supportive evidence that the approximate dating of the lunar cratering is correct; and (ii) Indicating that on the longest time-scales (hundreds of Myr) th e errestrial influx is variable. t On time-scales of tens of Myr the influx is also variable.…”