Evidence for a basalt-free surface on Mercury and implications for internal heat.
Microwave and mid-infrared observations reveal that Mercury's surface contains less FeO + TiO2 and at least as much feldspar as the lunar highlands. The results are compatible with the high albedo (brightness) of Mercury's surface at visible wavelengths in suggesting a rock and soil composition that is devoid of basalt, the primary differentiate of terrestrial mantles. The occurrence of a basalt-free, highly differentiated crust is in accord with recent models of the planet's thermal evolution and suggests that Mercury has retained a hot interior as a result of a combination of inefficient mantle convection and minimal volcanic heat loss.
Jeanloz
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Department of Geology and Geophysics, University of California, Berkeley 94720, USA.
Mitchell
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Sprague
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de Pater
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D005296:Ferrous Compounds / Q000032:analysis*; D006358:Hot Temperature; D018537:Mercury, Planet; D008903:Minerals / Q000032:analysis*; D017640:Silicates / Q000032:analysis*; D014025:Titanium / Q000032:analysis*
D005296:Ferrous Compounds; D008903:Minerals; D017640:Silicates; C060346:basalt; C009495:titanium dioxide; D014025:Titanium; C034236:ferrous oxide