Identification of calcite grains in the Vaca Muerta mesosiderite by Raman spectroscopy

Abstract

Within the framework of a detailed micro-Raman study of Vaca Muerta mesosiderite, the Raman spectra of calcite globules inside the meteorite are reported for the first time. These spectra were compared with spectra of terrestrial calcite of sedimentary, hydrothermal and magmatic origin under the same experimental conditions. Some differences are found in the relative intensities and bandwidths between Vaca Muerta and terrestrial calcite spectra, which cannot be assigned to micro-crystal orientations effects. The origin of these calcite globules is discussed. Although a secondary mineral process due to terrestrial weathering after the fall can not be completely discarded, two hypotheses are proposed. The first addresses the possibility of the formation of calcite with small structural changes due to shocks at various times in the complex history of the meteorite. The second is related to the very recent discovery of carbonates (calcite and dolomite), not formed by aqueous alteration, in the dust shells of evolved stars.

Laboratory Analysis of Returned Samples from the AMADEE-18 Mars Analog Mission

“…Identification of mineral species is achieved by using the RRUFF Database within the Crystal Sleuth software (Laetsch and Downs, 2006;Downs et al, 2015). The following references for each mineral were considered alongside the spectral analyses: oxides (Balachandran and Eror, 1982;Wang et al, 2004;Markovski et al, 2017), carbonates (Rull-Perez and Martinez-Frias, 2003;Buzgar and Apopei, 2009), pyroxenes (Huang et al, 2000;Wang et al, 2001), feldspar (Freeman et al, 2008;Lalla et al, 2015Lalla et al, , 2019, clays (Apopei and Buzgar, 2010;Lalla et al, 2016;Black and Hynek, 2018), and organics (Ferrari, 2007). The organics present in the main Raman bands in the range of 2800 to 3000 cm -1 correspond to C-H bonding, and the other less intense bands *1300 cm -1 correspond to C-C vibrations (Beegle et al, 2015).…”

Estudio espectroscópico y DRX de afloramientos terrestres volcánicos en la isla de Tenerife como posibles análogos de la geología marciana

“…En el caso de la calcita (CaCO 3 ), considerando las vibraciones principales a 1086, 712 y 280 cm −1 y realizando una comparativa entre distancias relativas de bandas e intensidades relativas, se confirma el origen volcánico de los mismos (Rull & Martínez-Frías, 2003 (Kloprogge et al, 2002).…”

Revealing the biotic origin of silicified Precambrian carbonaceous microstructures using Raman spectroscopic mapping, a potential method for the detection of microfossils on Mars

“…This ability combined with its relatively small size and energy requirements makes it also particularly suited for space exploration. Thus, a Raman spectrometer called RLS (Raman Laser Spectrometer) will be part of the future ExoMars 2018 ESA/Roscosmos . A Raman system called SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) is also planned for the Mars 2020 NASA mission…”

“…Thus, a Raman spectrometer called RLS (Raman Laser Spectrometer) will be part of the future ExoMars 2018 ESA/Roscosmos. [8][9][10][11] A Raman system called SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) is also planned for the Mars 2020 NASA mission. [12] Raman spectroscopy is often used for the study of fossilized carbonaceous remains of microorganisms because of its high sensitivity to the presence of carbonaceous matter as graphite or disordered sp 2 carbon.…”