Data Set Overview : The Moessbauer spectrometers on the two Mars Exploration rovers identified Fe-bearing phases and quantitatively measured the relative abundance of Fe (as percentage of total Fe) according to oxidation state (e.g., Fe2+ and Fe3+), coordination state (e.g., octahedrally-coordinated), and specific Fe-bearing phases (e.g., percentage of total Fe associated with olivine) at Meridiani Planum (Opportunity) and Gusev Crater(Spirit). For more information on the MER Moessbauer spectrometers please see mer1_mb_inst.cat and mer2_mb_inst.cat. This archive contains Percent Total Fe products for both MER-1 and MER-2 rovers. The archive consists of one table for each rover. Each table has  a detached PDS label that describes the content of the table. Processing : The processing of this archive is described in detail in [MORRISETAL2006A], [MORRISETAL2006B], and [MORRISETAL2008] listed in ref.cat. The archive consists of one table each for MER-1 and MER-2 rovers. Each table contains the percent Moessbauer areas for component subspectra, where subspectral area is the percentage of total Fe associated with specific Fe-bearing phases. Note that subspectral areas do not provide information about the proportion of the iron-bearing phases themselves unless the concentration of Fe in those phases is independently modeled.  Subspectral areas were determined using a variety of commercial and in-house least-squares fitting computer programs in which peak line shape function, peak center, peak width, and area were adjustable parameters. Five double and four sextet subspectra were required to fit the Moessbauer spectra. Note that not all nine subspectra are present in every spectrum. All spectra were fit independently by at least two of the authors of [MORRISETAL2006A], [MORRISETAL2006B], and [MORRISETAL2008], which are listed in ref.cat. Two approaches were used during fitting procedures. In one approach, spectra were fit using individual peaks, and in the other approach spectra were fit using individual subspectra. Values of subspectral areas (percentage of total Fe associated with specific Fe-bearing phases) reported are average values from independent fits by 2-4 co-authors. The reported error is the larger of 2% (absolute) or the deviation from the average value of the independent fits. Fitting constraints included the following: (1) The two peaks in doublet subspectra were constrained to have equal areas and widths. (2) The six peaks in sextet subspectra were often constrained to the ratio 3:2:1:1:2:3 (3) Because of the strong overlap of the innermost two peaks of sextet  subspectra with doublet subspectra and other sextet subspectra, their  positions were often constrained using the positions of the other four peaks and 0.572 for the g-factor ratio of the 14.4 KeV excited state  to the ground state of Fe-57. The areas include a correction factor (the f-factor) to account for  differences in recoil-free fractions according to oxidation state  (f(Fe3+)/f(Fe2+)) : 1.21 independent of mineralogical composition. Phase identification was done using a combination of literature databases of Moessbauer parameters, intercorrelations of subspectral areas, and correlation of subspectral areas with APXS elemental data. Additional processing to improve counting statistics and additional constraints imposed on certain targets or for certain phases where the  combination of reasonable counting statistics and high subspectral area  was not sufficient is described in detail in [MORRISETAL2006A],  [MORRISETAL2006B], and [MORRISETAL2008].  Data : The archive consists of one table each for MER-1 and MER-2 rovers. The table MERA_MB_PCT_TOTAL_FE.CSV contains the percentage of total Fe in Fe-bearing phases from subspectral areas in Spirit (MER-A) Moessbauer Spectra. The table MERB_MB_PCT_TOTAL_FE.CSV contains the percentage of total Fe in Fe-bearing phases from subspectral areas in the Opportunity (MER-B) Moessbauer Spectra. In the field names, D:Doublet Moessbauer spectrum and S:Sextet Moessbauer spectrum, and the phase assignments are OL:Olivine,  PX:Pyroxene, ILM:Ilmenite, CHR:Chromite, MT:Magnetite, NPOX:Nanophase  Ferric Oxide, FE3SULFATE:Fe3+-bearing sulfate, JAR:Jarosite, HM:Hematite, PYR/MAR:Pyrite/Marcasite, GT:Goethite, Tr:Troilite and A-FE:Fe/Ni Metal Alloy (kamacite). Absolute errors are included in the tables in fields named *_ERR. An entry of 0 (zero) denotes that the doublet or sextet was not used in the least squares fitting procedure. Subspectral areas are f-factor corrected.  These comma-separated-value tables are suitable for reading into a  spreadsheet program such as Microsoft Excel. A detached PDS label accompanies each table that describes the content and format of the table. All detached label and document files are in stream format files with a carriage return (ASCII 13) and line feed character (ASCII 10) at the end of each record. This allows files to be read by the MacOS, DOS, Unix, and VMS operating systems. Software : No software is included in this archive. The data products can be viewed in a text editor or in a spreadsheet program such as Microsoft Excel.

Please refer to [MORRISETAL2006A], [MORRISETAL2006B], and  [MORRISETAL2008] listed in ref.cat.