Denevi, Brett W., Robinsob, Mark S., Solomon, Sean C., Murchie, Scott L., Blewett, David T., Domingue, Deborah L., McCoy, Timothy J., Ernst, Carolyn M., Head, James W., Watters, Thomas R., and Chabot, Nancy L. 2009. "The Evolution of Mercury's Crust: A Global Perspective from MESSENGER." Science, 324, (5927) 613–618.
Mapping the distribution and extent of major terrain types on a planet's surface helps to constrain the origin and evolution of its crust. Together, MESSENGER and Mariner 10 observations of Mercury now provide a near-global look at the planet, revealing lateral and vertical heterogeneities in the color and thus composition of Mercury's crust. Smooth plains cover approximately 40% of the surface, and evidence for the volcanic origin of large expanses of plains suggests that a substantial portion of the crust originated volcanically. A low-reflectance, relatively blue component affects at least 15% of the surface and is concentrated in crater and basin ejecta. Its spectral characteristics and likely origin at depth are consistent with its apparent excavation from a lower crust or upper mantle enriched in iron- and titanium-bearing oxides.
