^1,2Pierre-Marie Zanetta,²Pierre Rochette,¹Anne-Magali Seydoux-Guillaume,²Valérie Andrieu,¹Colette Guilbaud
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.70116]
¹CNRS, LGL-TPE, UMR5276, Universite Jean Monnet, Saint-Etienne, France
²CNRS, IRD, INRAE, CEREGE, UMR 7330, Aix-Marseille Universite, Aix-en-Provence, France
Published by arrangement with John Wiley & Sons

Australasian tektites (AAT) contain grains from the impact surface that survivedthe tektite formation process. Muong Nong-type (MN) tektites, in particular, preservenumerous inclusions that provide insights into the thermal history of the material duringejection and deposition. Here, we present the first analysis of organic matter residues inMN-AAT, found adjacent to a mineral exhibiting Fe reduction within its crystallinestructure. We propose that this organic matter represents the residue of target biomass thatwas trapped in the impact glass during melting and was preserved due to its compositionand the rapid quenching of the melt, which prevented complete decomposition. Thepresence and composition of this organic matter may be linked to the ecosystem that oncecovered the impacted area and allow us to discuss the nature of this potential biomassreservoir. Moreover, carbon derived from this material appears to have influenced ironspeciation, as evidenced by the nearby dendritic oxide showing a gradient in Fe oxidationstate. These observations suggest that organic matter from soil and biomass may havecontributed to the geochemical evolution of tektites.

^1,2David A. Kring,³Charles S. Cockell
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70126]
¹Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA
²Radcliffe Institute for Advanced Study, Harvard University, Cambridge, Massachusetts, USA
³UK Centre for Astrobiology, University of Edinburgh, Edinburgh, UK
Published by arrangement with John Wiley & Sons

Postimpact recovery and evolution in response to climate changes produced amodern ecosystem at Meteor Crater dominated by a grassland and woodland of pi~non andjuniper, which has been used to evaluate floral and megafaunal consequences of impactcratering during the Phanerozoic Eon of complex life. Here, we describe a postimpactendolithic community that illustrates a potential habitat for micro-ecosystems aroundimpact craters in both Proterozoic and Phanerozoic times. Phototrophs withinimpact-ejected carbonate are dominated by eukaryotic green algae that affiliate withTrebouxiophycaea (Trebouxia and Stichococcus spp.). Eukaryotic fungi are dominated byAscomycota, including Hydropisphaera, Trichoderma, Acremonium, and Stanjemonium spp.,and representatives of Basidiomycota including Agaricomycetes and Clitopilus spp. Theprokaryotic community is dominated by Actinobacteria and Proteobacteria, the latterdominated by Alphaproteobacteria. At a genus level, the bacterial community containstypical representatives of soil and rock environments, including Promicromonospora,Lentzea, Streptomyces, Kribella, Rubrobacter, Deinococcus, Sphingomonas, Belnapia, andMethylobacterium spp. These data show that impact crater rocks host taxonomically diversecommunities potentially involved in carbon cycling in the early stages of colonization.