Lunar Igneous Rocks and the Nature of the Lunar Interior

James Fred Hays; David Walker

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NASA NTRS · 19780004989

Lunar Igneous Rocks and the Nature of the Lunar Interior

James Fred Hays·David Walker

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Abstract

Lunar igneous rocks, properly interpreted, can give useful information about mineral assemblages and mineral chemistry as a function of depth in the lunar interior. Though intensely brecciated, terra rocks reveal, in their chemistry, evidence for a magmatic history. Partial melting of feldspathic lunar crustal material occurred in the interval 4.6 to 3.9 Gy. Melting of ilmenite-bearing cumulates at depths near 100 km produced parent magmas for Apollo 11 and 17 titaniferous mare basalts in the interval 3.8 to 3.6 Gy. Melting of ilmenite-free olivine pyroxenites (also cumulates?) at depths greater than 200 km produced low-titanium mare basalts in the interval 3.4 to 3.1 Gy. No younger igneous rocks have yet been recognized among the lunar samples and present-day melting seems to be limited to depths greater than 1000 km.

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James Fred Hays, David Walker. 1977-01-01. Lunar Igneous Rocks and the Nature of the Lunar Interior. https://ntrs.nasa.gov/citations/19780004989

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