Dr. Melanie Sieber
Funktion und Aufgaben:
My current research focuses on the long term carbon (C) cycle, operating between the Earth’s crust and mantle. Large amounts of C are subducted into the Earth’s mantle and some C is released to shallower reservoirs through arc volcanism, but some C is subducted deeper. Within the subducting slab, carbonates (e.g. CaCO3, CaMg(CO3)2, MgCO3) are the main carrier of C and thus the stability of carbonates are of particular interest to the long term C cycle. For instance, melting of carbonates may release C from the mantle to shallower reservoirs and thus the melting relations of carbonates are relevant for understanding the possible storage of C in the mantle as well as the genesis of carbonate-bearing magma.
As part of this work, I perform quenched multi anvil experiments at 6 and 9 GPa to (1) gain a deeper insight into the phase relations and melting behavior of the anhydrous and hydrous CaCO3 – MgCO3 system and (2) to investigate the distribution of trace elements between carbonate and carbonate melt. Further, the pressure dependence of the melting curve of magnesite is examined in situ by X-ray diffraction measurements for the anhydrous system and by monitoring the change of the electrical conductivity for the hydrous system.
This study is conducted as part of the CarboPaT research unit investigating the structure, properties and reactions of carbonates under high pressures and temperatures. More information can be found here.
- Experimental Petrology
- Cycle of volatiles (CO2 and H2O) in the mantle
- Trace element partitioning (between carbonates/fluids and carbonates/melts)
Werdegang / Ausbildung:
Since 11/2019: Researcher at the University of Potsdam
Since 02/2019: Representative of the Geo.X. Early Career Scientists Section
Since 11/2018: PostDoc at the GFZ
2014-2018: PhD Student at Research School of Earth Science, Australian National University, Australia
2012-2014: Master of Science in Geosciences/Mineralogy, Goethe-University, Frankfurt, Germany
2009-2012: Bachelor of Science in Geosciences, Goethe-University, Frankfurt, Germany