Research Areas and Recent Projects
German version
The late growth history of the terrestrial planets, from the last giant collisions with planetary embryos to the subsequent late bombardment with smaller objects, is of critical importance for understanding the early chemical differentiation processes and the evolution of the terrestrial planets. The goal of this research program is to improve our current understanding of the late-accretion history of the Earth, its Moon, and other terrestrial planets from 4.5 to 3.8 billion years ago. A ...
The element concentrations and isotopic composition of solutes in continental surface water and in suspended particles provide constraints on the fractionation processes and kinetics of chemical weathering. Isotopic fractionation of Li and Mg in these materials, in combination with other light element isotopes, has been used to constrain chemical weathering processes. Light stable isotopes of O, H, C, S in surface water and in shells was also applied to constrain the sources and transport ...
The latet Neoproterozoic to Cambrian time marks the appearance of the animals and major changes in the oxygen content of the atmosphere-ocean system. In the context of the DFG research group “The Precambrian-Cambrian Biosphere (R)evolution: Insights from Chinese Microcontinents” (FOR 736), we have obtained geochronological constraints on black shale deposition using the Re-Os system. We also study the response of Neoproterozoic marine carbonates to diagenetic alteration and fluid flow in ...
A major research focus lies on the processes that formed the early continental crust with tonalitic-trondhjemitic-granodioritic (TTG) composition. This includes the identification of Earth’s early geodynamic processes, characterization of the mafic rocks that melted to produce TTGs and the investigation of the pressure/temperature conditions of partial melting. In addition, we study mantle-derived basalts, komatiites and Archean peridotites to place constraints on crust-mantle recycling ...
Important questions regarding the origin of the terrestrial planets and their building blocks are still open. Are primitive meteorites in our collections really the building blocks of Earth and other terrestrial planets? What processes are responsible for the depletion of volatile elements in the inner solar system? What is the origin and budget of volatile elements in the terrestrial planets? How much of the original volatile budget is lost during planetary growth? What can the Moon tell us ...
Because we use lithophile (silicate-loving) siderophile (iron metal-loving) and chalcophile (sulfide-loving) element abundances in planetary materials to constrain planetary-scale processes in the early solar system (core formation, late accretion), it is necessary to understand the processes that can change abundances of these elements in magmatic and in surface processes. The formation of continental crust and recycling of oceanic crust and sediments via subduction have had substantial ...
Several previous projects have focused on method development for microgeochronology for sampling of rocks and minerals on the sub-mm scale, in particular from ductile shear zones and the determination of cooling and uplift rates. Other projects have used Nd model ages and U-Pb dating of zircon. Contact: Dr . Elis Hoffmann Projects: - A Rb-Sr perspective on the timing of peak burial for the HP-UHP Akezayi metamorphic complex (Tianshan, NW China) L. Bayet, T. John, H. Becker, E. ...
The ultra-slow spreading South West Indian Ridge (SWIR) near Marion Rise comprises segments of thin crust and abundant abyssal peridotites exposed near the ridge axis. As part of the “MARION” project we use highly siderophile elements and radiogenic isotopic ratios (187 Os/ 188 Os) to understand the melting/enrichment history of the mantle beneath SWIR. Thereby we test the hypothesis of buoyant depleted mantle beneath the SWIR that may represent Proterozoic melting residues recycled from ...