Activity of aqueous fluids in the early solar system - characterization and formation timescales of the earliest water-bearing phases in chondritic samples

• Applicants: Professor Dr. Addi Bischoff; Dr. Christian Vollmer
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 211767861

This project aims to unravel the origins and formation timescales of one of the least understood components in primitive solar system samples: hydrous minerals like tochilinite and cronstedtite that have reacted with a nebular and/or parent body water reservoir and related phases like carbonates. Since decades a fundamental controversy in meteorite research is heavily discussed: Does all aqueous alteration observed in chondrites is the result of a reaction with liquid water (in-situ) on the meteorite parent body after final accretion or has at least an important fraction of these minerals reacted with water before incorporation into the final parent body (pre-accretionary alteration)? It will therefore be essential to distinguish a pre-accretionary from an asteroidal-only formation environment by means of structural and isotopic analyses. The fundamental importance of this project is to study different isotope systems (O- and D/H-isotopes including Mn-Cr-isotopes for carbonates) and mineralogical details on the same grains in order to distinguish between different reservoirs of aqueous activity and to define different formation timescales of hydrous phases and carbonates. The techniques in this proposal are exclusively in-situ and will combine the isotopic analysis of individual phases by secondary ion mass spectrometry (SIMS) with structure determinations by high resolution transmission electron microscopy (TEM).

• DFG Programme: Priority Programmes
• Subproject of: SPP 1385: The first 10 Million Years of the Solar System - A Planetary Materials Approach
• Participating Person: Professor Dr. Andrew Putnis