The Primary data for Shidian meteorites

Published: 13 September 2021| Version 1 | DOI: 10.17632/wpdkxnh8cf.1
Contributor:
Yan Fan

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The Primary data for Shidian meteorites include mineral composition, bulk chemistry, whole rock oxygen and Cr isotopic compositions, reflectance spectrum, and density and porosity data.

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Mineral compositions The mineral composition of forsterite was determined with JXA 8230 electron microprobe analysis (EMPA) operated at an accelerating voltage of 15 kV, an electron beam current of 20 nA and 1-5 μm diameter. TCIs are too fine-grained to allow individual minerals to be analyzed, therefore, 10 μm probe diameter was applied for the determination of TCIs, representing bulk compositions (Rubin et al., 2007). Whole rock major and trace elements An aliquot of a 50 mg whole rock sample of Shidian was digested with a double distilled concentrated HNO3-HF (1:4) mixture in a Teflon bomb for elemental concentration measurement. a Thermal X series 2 inductively coupled plasma mass spectrometer (ICP-MS) equipped with a Cetac ASX-510 Autosampler was applied for measuring the elemental concentration. Whole rock oxygen isotopic composition Whole rock oxygen isotopic composition of Shidian was determined at the University of New Mexico. Fresh fragments of interior materials weighing between 1-3 mg were selected under a stereomicroscope to avoid any possible contamination from fusion crust. Oxygen isotope analyses were performed using a CO2 laser + BrF5 fluorination system following modified procedures of Sharp (1990). Whole rock chromium isotopic composition Whole rock chromium isotopic composition of Shidian was measured by a Thermo Triton Plus thermal ionization mass spectrometer at the University of California Davis. Reflectance spectrum The visible and near-IR reflectance spectra (wavelength from 0.35 μm to 2.5 μm) of Shidian were measured at the Reflectance Spectroscopy Laboratory of Shandong University, Weihai Campus by ASD FieldSpec 4 Hi-Res Spectrometer equipped with a silicon array detector and two indium gallium arsenide detectors (InGaAs). The reflectance spectra of Shidian, Murchison and Allende (wavelength from 2 to 16 μm) were measured at Shanghai Institute of Technical Physics, Chinese Academy of Sciences, by a model 102F FTIR spectrometer. Measurements of Grain Density, Bulk Density and Porosity The grain density, bulk density, and porosity of Shidian, Murchison, and Allende were determined by the Micro-Ultrapyc 5000 ideal gas pycnometer following the method described by Li et al. (2012; 2019), which is briefly as follows. First, the mass of samples (m) was measured by a balance. Second, the grain volume of samples (Vg) was measured directly by the pycnometer, and the grain density (ρg) was calculated as ρg = m/Vg. Third, samples were loaded in the thin-wall balloon which was subsequently evacuated, and the total volume (Vt) was determined by the pycnometer. Finally, the thin-balloon was stripped from the sample, and the related volume (Vb) of obtained by the pycnometer. Therefore, the bulk volume of sample could be expressed as Vt-Vb, and the bulk density of which could be calculated as ρb = m/(Vt-Vb) and the porosity as P = (Vt‐Vg)/Vt×100%.