Organic residues from biomass in a Muong Nong Australasian tektite
Pierre-Marie Zanetta, Pierre Rochette, Anne-Magali Seydoux-Guillaume, Valérie Andrieu, Colette Guilbaud
MAPS, Version of Record online: 10 March 2026
“Australasian tektites (AAT) contain grains from the impact surface that survived the tektite formation process. Muong Nong-type (MN) tektites, in particular, preserve numerous inclusions that provide insights into the thermal history of the material during ejection and deposition. Here, we present the first analysis of organic matter residues in MN-AAT, found adjacent to a mineral exhibiting Fe reduction within its crystalline structure. We propose that this organic matter represents the residue of target biomass that was trapped in the impact glass during melting and was preserved due to its composition and the rapid quenching of the melt, which prevented complete decomposition. The presence and composition of this organic matter may be linked to the ecosystem that once covered the impacted area and allow us to discuss the nature of this potential biomass reservoir. Moreover, carbon derived from this material appears to have influenced iron speciation, as evidenced by the nearby dendritic oxide showing a gradient in Fe oxidation state. These observations suggest that organic matter from soil and biomass may have contributed to the geochemical evolution of tektites.”
