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Magma Ascent and Eruption Triggered by Cratering on the Moon
Author(s) -
Michaut Chloé,
Pinel Virginie
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl078150
Subject(s) - impact crater , geology , crust , magmatism , magma , lithosphere , petrology , volcanism , lunar craters , geophysics , overpressure , volcanology , volcano , astrobiology , geochemistry , seismology , tectonics , physics , thermodynamics
On the Moon, the low‐density crust exerts a strong filter to magma ascent. Many lunar craters are filled with mare, and evidence of pyroclastic activity and shallow magmatism is often located within craters called floor‐fractured craters (FFCs). Interpreting quantitative observations on mare‐filled craters and FFCs based on mechanical models, we show that a surface unloading caused by an impact crater provides a driving overpressure to the magma stalling at depth. This overpressure counterbalances the melt negative buoyancy, favoring its ascent through the crust. Providing a large unloading and a thin crust, magma can ascend up to the crater floor. FFC characteristics are consistent with a magma denser than the crust by 200–300 kg/m 3 and an elastic lithosphere thickness larger than 70 km. Our study suggests that small impact cratering likely induced magmatism and thereby crustal evolution in the early times of terrestrial planets.