Constraints on Mercury's surface composition from MESSENGER neutron spectrometer data
| Autor: | Paul G. Lucey, M. A. Riner, G. J. Taylor, Francis M. McCubbin |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
integumentary system
Spectrometer technology industry and agriculture Partial melting Mineralogy chemistry.chemical_element Crust Mantle (geology) Physics::Geophysics Mercury (element) Neutron capture Geophysics chemistry Space and Planetary Science Geochemistry and Petrology Thermal Earth and Planetary Sciences (miscellaneous) Neutron Astrophysics::Earth and Planetary Astrophysics Geology |
| Zdroj: | Earth and Planetary Science Letters. 308:107-114 |
| ISSN: | 0012-821X |
| Popis: | The composition of Mercury's surface is poorly known, but the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) mission has provided a wealth of new data from three flybys. In particular, MESSENGER Neutron Spectrometer (NS) observations reveal a surface enriched in neutron absorbing elements, consistent with interpretations of color and albedo observations suggesting a surface composition enriched in Fe–Mg–Ti oxides. In this study, we have computed the neutron absorption cross sections for all of the available proposed surface compositions of Mercury and evaluated the plausibility of each surface composition based on the neutron absorption cross section observed by MESSENGER. For identified plausible compositions, the implications for the thermal and magmatic evolution of Mercury are discussed. The measured macroscopic neutron absorption cross section of Mercury is inconsistent with a crust formed from partial melting of plausible bulk mantle compositions, flotation in a magma ocean or adiabatic melting of upwelling cumulates during magma ocean overturn. However, the observed neutron absorption is consistent with model compositions of late-stage magma-ocean cumulates and some proposed compositions from spectral modeling and equilibrium modeling. This suggests that the enrichment of neutron absorbing elements may be indicative of the processes that acted to form Mercury's crust. The enrichment in neutron absorbing elements, in combination with spectral observations that constrain FeO in silicates ( |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect