Craters, spherules and ancient terrestrial impactors

New publication from Geology Professor Bruce Simonson:

Spherule layers, crater scaling laws, and the population of ancient terrestrial impactors

Johnson, Brandon C.; Collins, Gareth S.; Minton, David A.; Bowling,
Timothy J.; Simonson, Bruce M.; Zuber, Maria T.

ICARUS, 271 350-359; 10.1016/j.icarus.2016.02.023 JUN 1 2016

Partial abstract:
"Ancient layers of impact spherules provide a record of Earth's early bombardment history. Here, we compare different bombardment histories to the spherule layer record and show that …the flux of large impactors …was likely 20-40 times higher than today." (C) 2016 Elsevier Inc.
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