Mathematics – Logic
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufm.p51b1437h&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #P51B-1437
Mathematics
Logic
[1060] Geochemistry / Planetary Geochemistry, [3672] Mineralogy And Petrology / Planetary Mineralogy And Petrology, [5464] Planetary Sciences: Solid Surface Planets / Remote Sensing, [6225] Planetary Sciences: Solar System Objects / Mars
Scientific paper
Koeppen and Hamilton [2008, JGR-Planets] produced global mineral maps of Mars from Thermal Emission Spectrometer (TES) data using a library of mineral and amorphous phase spectra and a linear least squares fitting algorithm. Here we will use known or estimated bulk chemistries of the phases in the Koeppen and Hamilton [2008] spectral library, along with each phase's modeled abundance in the TES data from that work, to calculate effective bulk chemistry for Martian dark regions at a spatial resolution of ~3x6 km. By doing this, we are able to analyze global bulk chemical variation as well as enable direct comparisons between TES data and chemical/elemental abundance maps (e.g., wt.% SiO2) produced using data collected by the Gamma Ray Spectrometer. A second chemical analysis also makes use of the Koeppen and Hamilton [2008] global mineral maps and focuses on the spatial variations in solid solution chemistry among feldspars, pyroxenes, high silica phases (e.g., silica, phyllosilicates, zeolites), and sulfates. Koeppen and Hamilton [2008] demonstrated that there is a range of Mg-Fe olivine compositions on Mars and that there are distinct geographic distributions of those phases, pointing to spatial variations in geologic processes. We use the same methodology to search for correlations between geography (e.g., geologic unit, latitude), elevation, and chemical (solid solution) composition. Preliminary analyses of pyroxene chemical variation reveal that globally, low-Ca pyroxenes are dominated by the clinopyroxene pigeonite and that among orthopyroxenes, Mg-rich phases (enstatite) are virtually never identified and phases with greater proportions of Fe (bronzite and hypersthene) are identified in distinct geographic and/or geologic terrains. Only the distribution of hypersthene (the composition of pyroxene in the Martian meteorite ALH 84001) correlates with the OMEGA-mapped distribution of low-Ca pyroxene suggesting that OMEGA-based maps of high-Ca pyroxene may include pigeonite. Many of the chemical-spatial variations observed among solid solution phases in TES data correspond to both relative surface age and the distribution of lithologic units identified by Rogers and Christensen [2007, JGR-Planets], where the lithologic units were identified using a different analytical approach, giving us confidence in the variations observed in our mineral maps. These results point to variations in and/or the evolution of igneous compositions over time. Any observable variations in other phase groups (e.g., sulfates, phyllosilicates) may indicate variations in the timing and extent of aqueous or alteration processes over time.
Hamilton Victoria E.
Rogers David
No associations
LandOfFree
Martian Surface Composition From Multiple Datasets, Part II: Chemical Analysis of Global Mineral Distributions from MGS-TES does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Martian Surface Composition From Multiple Datasets, Part II: Chemical Analysis of Global Mineral Distributions from MGS-TES, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Martian Surface Composition From Multiple Datasets, Part II: Chemical Analysis of Global Mineral Distributions from MGS-TES will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1497730