Study of Dronino Iron Meteorite Weathering in Clay Sand Using Mössbauer Spectroscopy

Abstract

Weathering products of two fragments of Dronino iron ungrouped meteorite found in the wet and drier clay sand were studied using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution. The products of metal oxidation in the internal and external surface layers were different for both fragments. The weathering products in fragment found in the wet clay sand contain magnetite (Fe3O4), maghemite (-Fe2O3), goethite (-FeOOH) and probably ferrihydrite (5Fe2O3  9H2O) while those in fragment found in drier clay sand contained ferric hydrous oxides (FeOOH) and siderite (FeCO3) mainly. Concretions found near the first fragment contain ferric hydrous oxides (FeOOH) mainly.

New insights on the Dronino iron meteorite by double-pulse micro-Laser-Induced Breakdown Spectroscopy

“…The pres ence of Al, Ca, Mg and Si on the un pol ished sur face of frag ment 1, which was con firmed also by EDSSEM data, was in dica tive of min er als typ i cal of clays and sands. In agree ment with Yakovlev et al [17], these re sults sug gested the oc cur rence of ter res trial con t a m i na tion dur ing weath er ing. Fur ther, the pres ence of Li might be re lated to the Lirich wa ter in the swamp where frag ment 1 was col lected.…”

“…the de scrip tion of the geopedo log i cal set tings where the frag ments were found and col lected. How ever, by com par ing these sam ples with the frag ments of Dronino me te orite stud ied by Yakok lev et al [17] and ac cord ingly with the re sults ob tained in this pre vi ous pa per, frag ment 1 could be re lated to a sandy, per me able, wa terbear ing soil (a wet clay sand), and frag ment 2 to a drier site. Due to the ev i dent weath er ing layer (rusty as pect) cov er ing frag ment 1, a por tion of it was pre vi ously cleaned off the weath ered layer, and both orig i nal and pol ished sam ples were an a lyzed and char ac ter ized com par a tively.…”

“…More re cently, Yakovlev et al [17] stud ied, also by Xray dif frac tion and Möss bauer spec troscopy the weath er ing prod ucts of two Dronino frag ments found the one in a wet and the other in a dry clay sand. Two types of al ter ation con sist ing in an in ter nal and an ex ter nal sur face layer were found in both frag ments.…”

Applications of Mössbauer Spectroscopy in Meteoritical and Planetary Science, Part II: Differentiated Meteorites, Moon, and Mars

“…The magnetic sextets 1 and 3 were assigned to the octahedral [B] and tetrahedral (A) sites in γ-Fe2O3, respectively (δ = 0.397 mm/s, Heff = 501.1 kOe, A = ~4.8% and δ = 0.277 mm/s, Heff = 483.9 kOe, A = ~10.3%), sextets 2, 4, and 5 were related to the (A), [B1], and [B2] sites in Fe3O4, respectively (δ = 0.332 mm/s, Heff = 494.0 kOe, A = ~13.3%; δ = 0.425 mm/s, Heff = 472.8 kOe, A = ~4.2% and δ = 0.578 mm/s, Heff = 449.0 kOe, A = ~8.5%), sextets 6, 7, and 8 were associated with α-FeOOH magnetic particles with different sizes, respectively (δ = 0.380 mm/s, Heff = 326.4 kOe, A = ~8.5%; δ = 0.316 mm/s, Heff = 253.9 kOe, A = ~9.8% and δ = 0.286 mm/s, Heff = 189.6 kOe, A = ~8.2%), and quadrupole doublets 9, 10, and 11 were assigned to the paramagnetic FeOOH particles, respectively (δ = 0.444 mm/s, ΔEQ = 1.033 mm/s, A = ~15.8%; δ = 0.389 mm/s, ΔEQ = 0.782 mm/s, A = ~2.6%, and δ = 0.390 mm/s, ΔEQ = 0.503 mm/s, A = ~14.1%). The fit of these and other spectra measured with a high velocity resolution in [81][82][83][84] revealed more spectral components compared to that in the low velocity resolution spectra measured in [75]. Synchrotron Mössbauer spectroscopy was applied to study the Tazewell IAB-sLH iron meteorite with a spatial resolution of ~10-20 μm in [43,44].…”

“…(a A re-examination of Dronino iron-ung meteorite and its weathering (oxidation) products in clay was carried out using Mössbauer spectroscopy with a high velocity resolution in [82][83][84]. The room temperature 2048-channel Mössbauer spectra of powdered Fe-Ni-Co alloy and extracted internal weathering product are shown in Figure 34.…”