Combined use of novel and traditional stable isotope systems in identifying source components and processes of moldavite formation

01.01.2013 - 30.12.2016
Grant agency: 
Registration number: 
Internal investigator/coinvestigator: 
Karel Žák
Interní řešitel: 
is coinvestigator
External investigator/coinvestigator: 
Česká geologická služba, Ústav jaderné fyziky AV ČR, v. v. i.

Moldavites are central European tektites genetically related to the Ries crater. However, source materials of moldavites and processes of their chemical fractionation are not properly constrained. Investigation of moldavites indicates that, in parallel to sedimentary rocks, plant biomass could have supplied significant portion of source matter as indicated by enrichments in contents of plant-essential elements, depletion in plant-non-essential elements and C and O isotope composition in moldavite glass. We aim at exploring this hypothesis by C and O isotope analysis in glass and fluid inclusions in moldavites, as well as Si, Ca, Mg and Li in moldavites and sedimentary units of the Ries area by means of isotope mass spectrometry. Selection of samples for detailed isotope analyses will be based on prior geochemical characterization. Further, Re–Os systematics, Cr and platinum group element contents will be studied in order to reveal any extraterrestrial signature in moldavites. These findings should constrain processes of tektite formation, with possible application in astrobiology.