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Project

IMPACT – Identification of Microstructures in Phosphate grains of Apollo 14 breccias and Correlation To precise U-Pb ages. (FWOTM1055)

The impact rate in the inner Solar System in the period between the
formation of the Moon (~ 4.5 Ga) and the first basaltic mare (~3.8
Ga) remains a matter of intense scientific debate. Understanding the
timing and intensity of impact events during the infancy of the Solar
System is not only important for reconstructing the early crustal
evolution of the Moon, but also to determine the formation, evolution
and habitability of planetary bodies.
Uranium-bearing materials, such as the minerals zircon and
phosphate have played a key role in understanding the impact and
magmatic history of the Moon, and several distinct impact events
within the narrow time interval of 3.94 to 3.92 Ga have previously
been identified. However, partial resetting of the U-Pb system may
have disturbed some of the ages.
The IMPACT project combines comprehensive microstructural,
isotopic and geochemical analyses of Ca-phosphates in carefully
selected breccia samples from the Apollo 14 landing site to establish
a precise chronology of impact events. It couples cutting-edge
analytical techniques, such as laser ablation ICP-MS imaging with
microtextural analyses by electron backscatter diffraction analysis. As
a result, the newly obtained U-Pb ages can clearly be interpreted to
result from impact and/or magmatic events or, alternatively, to reflect
partial reset ages. Our novel approach will establish protocols for
future dating of impact events on the Moon.
Date:31 Aug 2023 →  Today
Keywords:Late Heavy Bombardment, Early Solar System, Lunar impact history, Solar system
Disciplines:Extraterrestrial geology, Geochemistry not elsewhere classified, Planetary science, Mineralogy and crystallography, Geochronology