Średni ciężar atomowy chondrytu Ensisheim (LL6)

Mean atomic weight Amean of Ensisheim (LL6, fall 1492) ordinary chondrite has been determined using literature data on chemical composition of the meteorite and using relationships: between mean atomic weight and Fe/Si atomic ratio, between Amean and grain density, and between Amean and magnetic susceptibility (Szurgot 2015a–f, 2016a, b, d, e). It was shown that Ensisheim’s Amean = 23.32, and 23.06 for composition without water, and with H2O, respectively. These values are close to the mean atomic weight of LL chondrite falls (Amean = 23.36, and 23.03), and are close to Amean values of LL6 chondrite falls (Amean = 23.30, and 23.06, Szurgot 2016b). Ensisheim’s Fe/Si atomic ratio (0.509) leads to Amean = 23.16±0.12 which is close to the values determined by bulk composition. This means that Ensisheim belongs to LL6 chondrites, as previously classified (Jarosewich i Dodd 1985). Using dependence between mean atomic weight and grain density (Szurgot 2015a–c, 2016d) leads to Amean = 23.70±0.54 (dgr = 3.52±0.04 g/cm3, Macke 2010), and using dependence between Amean and magnetic susceptibility (Szurgot 2016a, d) gives Ameanc = 22.78±0.24 (logc = 4.15±0.09, Macke 2010). Arithmetic mean Amean (dgr) and Amean (logc) gives 23.24±0.65, and arithmetic mean of Amean (dgr), Amean (logc), and Amean(Fe/Si), gives 23.21±0.46 values close each other, and close to Amean(bulk composition) determined using compositional data. Mean atomic number Zmean, and Amean/Zmean ratio of the meteorite have been also determined. Ensisheim’s Zmean = 11.51 for composition without H2O, and 11.40 for composition with H2O. Amean/Zmean ratios are: 2.026 and 2.023, for composition without water, and with H2O, respectively. Ensisheim’s silicates shown values: Amean = 22.19, Zmean = 10.97, Amean/Z mean = 2.022, Fe/Si = 0.355, Amean(Fe/Si) = 22.28, and Fe, Ni metal values: Amean = 57.26, Zmean = 26.96, and Amean/Z mean = 2.124.