Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database

Clegg, S. M.; Wiens, R. C.; Anderson, R. B.; Forni, O.; Frydenvang, J.; Lasue, J.; Cousin, A.; Payré, V.; Boucher, Tommy; Dyar, M. D.; McLennan, Scott M.; Morris, R. V.; Graff, T. G.; Mertzman, Stanley A.; Ehlmann, B. L.; Belgacem, Inès; Newsom, H. E.; Clark, B.; Melikechi, Noureddine; Mezzacappa, A.; McInroy, R. E.; Martinez, Ronald; Gasda, P. J.; Gasnault, O.; Maurice, S.

doi:10.1016/j.sab.2016.12.003

Cited by 162 publications

(206 citation statements)

References 55 publications

Supporting

Mentioning

203

Contrasting

Order By: Relevance

“…Another difference between the Bagnold dunes and the previously observed soils concerns the sum of oxides. The ChemCam quantification method [ Clegg et al ., ] does not force the total of major‐element abundances to be equal to 100 wt %, allowing the indirect measurement of a “missing” chemical component, which is the sum of oxides/elements that are not individually quantified. Mission experience has shown that a low sum of oxides is usually associated with targets enriched in volatile and moderately volatile elements such as H, S, Cl, and P (e.g., the purest Ca‐sulfate veins sampled by ChemCam have sum of oxides as low as ~40 wt %, in agreement with the calcium oxide mass fraction of calcium sulfates) [ Nachon et al ., ].…”

Section: Resultsmentioning

confidence: 97%

Geochemistry of the Bagnold dune field as observed by ChemCam and comparison with other aeolian deposits at Gale Crater

et al. 2017

Self Cite

View full text Add to dashboard Cite

The Curiosity rover conducted the first field investigation of an active extraterrestrial dune. This study of the Bagnold dunes focuses on the ChemCam chemical results and also presents findings on the grain size distributions based on the ChemCam Remote Micro‐Imager and Mars Hand Lens Imager images. These active dunes are composed of grains that are mostly <250 μm. Their composition is overall similar to that of the aeolian deposits analyzed all along the traverse (“Aeolis Palus soils”). Nevertheless, the dunes contain less volatiles (Cl, H, and S) than the Aeolis Palus soils, which appear to be due to a lower content of volatile‐rich fine‐grained particles (<100 μm) or a lower content of volatile‐rich amorphous component, possibly as a result of (1) a lower level of chemical alteration, (2) the removal of an alteration rind at the surface of the grains during transport, (3) a lower degree of interaction with volcanic gases/aerosols, or (4) physical sorting that removed the smallest and most altered grains. Analyses of the >150 μm grain‐size dump piles have shown that coarser grains (150–250 μm) are enriched in the mafic elements Fe and Mn, suggesting a larger content in olivine compared to smaller grains (<150 μm) of the Bagnold dunes. Moreover, the chemistry of soils analyzed in the vicinity of the dunes indicates that they are similar to the dune material. All these observations suggest that the olivine content determined by X‐ray diffraction of the <150 μm grain‐size sample should be considered as a lower limit for the Bagnold dunes.

show abstract

Section: Resultsmentioning

confidence: 97%

Geochemistry of the Bagnold dune field as observed by ChemCam and comparison with other aeolian deposits at Gale Crater

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…SuperCam LIBS data were simulated by data collected using the ChemCam testbed instrument at the Los Alamos National Laboratory (Clegg et al, ), and data reduction was completed using a simple model in an open‐source, multivariate data reduction program termed PySAT (Anderson et al, ). Green Raman was simulated using a green Raman instrument at Caltech, a Renishaw M‐1000 microRaman spectrometer.…”

Section: Methodsmentioning

confidence: 99%

Studies of a Lacustrine‐Volcanic Mars Analog Field Site With Mars‐2020‐Like Instruments

Martin

Ehlmann

Thomas

et al. 2020

Earth and Space Science

Self Cite

View full text Add to dashboard Cite

On the upcoming Mars‐2020 rover two remote sensing instruments, Mastcam‐Z and SuperCam, and two microscopic proximity science instruments, Scanning for Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) and Planetary Instrument for X‐ray Lithochemistry (PIXL), will collect compositional (mineralogy, chemistry, and organics) data essential for paleoenvironmental reconstruction. The synergies between and limitations of these instruments were evaluated via study of a Mars analog field site in the Mojave desert, using instruments approximating the data that will be returned by Mars‐2020. A ground truth data set was generated for comparison to validate the results. The site consists of a succession of clay‐rich mudstones of lacustrine origin, interbedded tuffs, a carbonate‐silica travertine deposit, and gypsiferous mudstone strata. The major geological units were mapped successfully using simulated Mars‐2020 data. Simulated Mastcam‐Z data identified unit boundaries and Fe‐bearing weathering products. Simulated SuperCam passive shortwave infrared and green Raman data were essential in identifying major mineralogical composition and changes in lacustrine facies at distance; this was possible even with spectrally downsampled passive IR data. Laser‐induced breakdown spectroscopy and simulated PIXL data discriminated and mapped major element chemistry. Simulated PIXL revealed millimeter‐scale zones enriched in zirconium, of interest for age dating. Scanning for SHERLOC‐like data mapped sulfate and carbonate at submillimeter scale; silicates were identified with increased laser pulses/spot or by averaging of hundreds of spectra. Fluorescence scans detected and mapped varied classes of organics in all samples, characterized further with follow‐on spatially targeted deep‐UV Raman spectra. Development of dedicated organics spectral libraries is needed to aid interpretation. Given these observations, the important units in the outcrop would be sampled and cached for sample return.

show abstract

“…Boxplot of Li, Sr, Rb, and Ba concentration distribution within the laboratory database, described by Clegg et al . []. The median is the dashed red line, the lower edge is the first quartile, and the upper edge is the third quartile.…”

Section: Methodsmentioning

confidence: 99%

“…As a result, Clegg et al . [] expanded and updated this database to ~400 diversified standards with a larger range of concentrations, which was used to better quantify the major elements. Here univariate calibration models are used on these new data to better constrain the quantification of Li, Rb, Sr, and Ba compositions obtained during the first 1000 sols (Martian days).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Alkali trace elements in Gale crater, Mars, with ChemCam: Calibration update and geological implications

et al. 2017

View full text Add to dashboard Cite

The Chemistry Camera (ChemCam) instrument onboard Curiosity can detect minor and trace elements such as lithium, strontium, rubidium, and barium. Their abundances can provide some insights about Mars' magmatic history and sedimentary processes. We focus on developing new quantitative models for these elements by using a new laboratory database (more than 400 samples) that displays diverse compositions that are more relevant for Gale crater than the previous ChemCam database. These models are based on univariate calibration curves. For each element, the best model is selected depending on the results obtained by using the ChemCam calibration targets onboard Curiosity. New quantifications of Li, Sr, Rb, and Ba in Gale samples have been obtained for the first 1000 Martian days. Comparing these data in alkaline and magnesian rocks with the felsic and mafic clasts from the Martian meteorite NWA7533—from approximately the same geologic period—we observe a similar behavior: Sr, Rb, and Ba are more concentrated in soluble‐ and incompatible‐element‐rich mineral phases (Si, Al, and alkali‐rich). Correlations between these trace elements and potassium in materials analyzed by ChemCam reveal a strong affinity with K‐bearing phases such as feldspars, K‐phyllosilicates, and potentially micas in igneous and sedimentary rocks. However, lithium is found in comparable abundances in alkali‐rich and magnesium‐rich Gale rocks. This very soluble element can be associated with both alkali and Mg‐Fe phases such as pyroxene and feldspar. These observations of Li, Sr, Rb, and Ba mineralogical associations highlight their substitution with potassium and their incompatibility in magmatic melts.

show abstract

Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database

Cited by 162 publications

References 55 publications

Geochemistry of the Bagnold dune field as observed by ChemCam and comparison with other aeolian deposits at Gale Crater

Geochemistry of the Bagnold dune field as observed by ChemCam and comparison with other aeolian deposits at Gale Crater

Studies of a Lacustrine‐Volcanic Mars Analog Field Site With Mars‐2020‐Like Instruments

Alkali trace elements in Gale crater, Mars, with ChemCam: Calibration update and geological implications

Contact Info

Product

Resources

About