Institut für Planetologie
Wilhelm-Klemm-Str. 10, D-48149 Münster
2018 - Wiley Award of the Meteoritical Society
2018 - American Geophysical Union Outstanding Student Presentation Award
Recent project work
Tellurium stable isotope fractionation in meteorites and terrestrial samples – Implications on the nature and origin of late accretion
The budget of the siderophile volatile element Te in the Earth’s mantle is thought to predominantly derive from late accretion of broadly chondritic material. To better constrain the nature and origin of the late-accreted material, we obtained mass-dependent Te isotopic data for terrestrial samples and a comprehensive set of chondrites. Tellurium stable isotope variations may arise as a result of nebular processes, leading to distinct isotopic compositions among chondrites, which allow to distinguish between different chondrite groups as potential sources of the late veneer. To this end, we developed a 123Te-125Te double spike method for the precise measurements of Te isotope variations by multi-collector ICP-MS. The Te stable isotopic composition of the bulk silicate Earth was precisely defined by analyses of several peridotites. Samples from the major chondrite classes display a range in Te isotopic compositions, and combined with their Se/Te ratios only some carbonaceous chondrite group overlap with the composition determined for the Earth's mantle.
J.L. Hellmann, T. Hopp, C. Burkhardt and T. Kleine (2019) Te stable isotopic constraints on the nature of late accretion. Goldschmidt Geochemistry Conference 2019, Barcelona, Spain.
J.L. Hellmann, T. Hopp, C. Burkhardt and T. Kleine (2018) Tellurium stable isotope variations among chondrites and terrestrial samples. American Geophysical Union Conference 2018, Washington D.C., USA.
J.L. Hellmann, M. Fischer-Gödde and T. Kleine (2018) Tellurium stable isotope measurements by double spike MC-ICPMS. Panerth Kolloquium 2017. Nördlingen, Germany.
Archer G J, Walker R J, Tino J, Blackburn T, Kruijer T S, Hellmann J L. 2019. ‘Siderophile Element Constraints on the Thermal History of the H Chondrite Parent body.’ Geochimica et Cosmochimica Acta 245: 556-576. doi: 10.1016/j.gca.2018.11.012.
Kleine T, Budde G, Hellmann J L, Kruijer T S, Burkhardt C. 2018. ‘Tungsten Isotopes and the Origin of Chondrules and Chondrites.’ In Chondrules: Records of Protoplanetary Disk Processes, edited by Russell S S, Connolly Jr. H C, Krot A N, 276-299. Cambridge University Press. doi: 10.1017/9781108284073.010.