Mechanisms of weathering of meteorites recovered from hot and cold deserts and the formation of phyllosilicates

Suspected Presence of Hibbingite in Olivine Pyroxenite Adjacent to the Ug2 Chromitite, Bushveld Complex, South Africa

“…On the basis of its high Cl and Fe contents, and very low concentrations of all other elements, and its optical properties, we tentatively suggest that this phase is hibbingite, and refer to it henceforth as such. Although our analysis was not quantitative, it indicated far higher concentrations of Cl than found in akaganéite (Lee & Bland 2004). These authors also referred to the possible existence of an unidentified mineral with a higher Cl content than hibbingite, but we note that the optical properties of the Bushveld sample agree with the descriptions of hibbingite (Dahlberg & Saini-Eidukat 1991).…”

Atmospheric halogen and acid rains during the main phase of Deccan eruptions: Magnetic and mineral evidence

“…Akaganeite also precipitates naturally as a pure mineral phase with an average Fe/Cl molar ratio of 6.7 from oxidation of iron sulfi de minerals during occasional drying of sulfi de sediments from Australian wetlands (Bibi et al, 2011). Naturally occurring akaganeite is also observed in weathered meteorites, especially from cold environments such as the Antarctic continent (Bland et al, 1997;Lee and Bland, 2004). Akaganeite from meteorites often contains a small amount of Ni.…”

Weathering of meteorites from Oman: Correlation of chemical and mineralogical weathering proxies with14C terrestrial ages and the influence of soil chemistry

“…The reference soil samples are strongly enriched in Cr, Sc, Ni, Ca, S, Ti, Mg, Sr, and depleted in Ta, P, Rb, Ga, Na, Cs, K, Fe, Sc, and Al. porosity, demonstrated by Lee and Bland (2004). Based on a typical chondrite porosity of 10 vol% (Consolmagno et al 1988), L chondrites with low porosity and most H chondrites will experience a significant bulk volume increase.…”

“…As the degree of weathering of meteorites increases with their terrestrial age, old surfaces are likely to yield more highly-weathered meteorites than younger surfaces. Due to meteorite accumulation over long periods of time, hot or cold desert environments are most suitable for weathering studies (Bischoff and Geiger 1995;Bland et al 1996;Stelzner et al 1999;Welten 1999;Lee and Bland 2004).…”