Minerals and Origin of the Moon

Triana Henz

Formation Theories

• Fission

• Capture

• Co-formation

• Giant Impact

Data

• High angular momentum

• Low iron core

• Identical abundances of oxygen isotopes

Giant Impact Exchange

Giant Impact Uncertainty

• Faster cooling rate

• Rotation of disk might have inhibited radial diffusion

• Either enrich or same as the Earth in REE, thorium, uranium, zirconium and FeO

Mineral Make up

• Thick crust has feldspar and pyroxene

• Feldspar is mainly anorthite (CaAl2Si2O8 ) , especially if the melt is pyroxene and olivine rich

• Low density means that it most likely doesn’t have an iron core

• Same density as ordinary rock

Phenomenon

• Pristine highland rocks are extremely rare• Probably due to “gardening” of the surface• Highland is made from molten lunar

material that crystallized slowly from deep inside

• Magma ocean froze over• Radioactive isotopes decayed, warming up

interior• Basalt erupted to low areas

Composition

• Olivine: dense, in interiors and lava

• Pyroxene: constituent in interiors where metallic iron is present

• Feldspar: less dense, crust

• Ilmenite: lava, titanium bearing

Composition

• Eutectic composition can shift with pressure

• Determine depth of lava source

Composition

• REE fit in where they can• Feldspars rejects lighter

REE • Feldspars accepts denser

REE• Pyroxene is opposite• Olivine rejects all• Europium (Eu) is a

characteristic of feldspars

References

• Taylor, G. J. (2008). "Compositional Balancing Before Moon Formation." Planetary Science Research Discoveries. http://www.psrd.hawaii.edu/Feb08/EarthMoonFormation.html