Dr. Lisa Krämer Ruggiu

PROJECT:

FEMINA : Tracing the Flux variations of Extraterrestrial Material : A Novel multiparameter Approach.

Extraterrestrial (ET) material arrives on Earth daily, ranging from large-scale projectile to a constant flux of cosmic dust. The flux of ET material arriving on Earth is dominated by small cosmic particles between 0.01 and 2 mm, called micrometeorites (MM). Unfortunately, most of this material does not survive geological timescales, limiting robust reconstructions of the ET flux through time. Thus, the nature and magnitude of the changes in the intensity and composition of this ET flux remain the source of considerable ongoing scientific debate. The conventional proxies (Os isotope ratios, Ir concentrations, ³He contents and Cr-chromites) used to assess changes in the ET flux have not allowed to reconstruct a robust ET flux on Earth. In addition, with the exception of the Cretaceous-Paleogene boundary event, no unambiguous evidence has been found to link the variations in the ET flux to either cosmic or terrestrial events. The goal of this project is to (i) construct a first ever ET flux baseline using fossil MMs, (ii) determine the origin or source of the flux; (iii) constrain the atmospheric conditions at the time of accretion, and (iv) detect unusual variations and link these to either terrestrial parameters (sedimentary rates, preservation bias) or extraterrestrial parameters (earth eccentricity, large asteroids break up, impact). By combining fossil MMs with conventional proxies, FEMINA represents the first true multiparameter approach to document the ET flux to Earth.

RESEARCH SUMMARY:

My work is focused on the study of the mineralogy and chemistry of meteorites and micrometeorites. My research at AMGC focuses on the study of the extraterrestrial flux over time, by studing fossil micrometeorites, for the FWO funded project FEMINA.

I focus also on parent body linking of meteorites with infrared spectroscopy in order to find new links between meteorites and asteroid parent bodies. I work also on aqueous alteration of meteorites, such as carbonaceous chondrites and Martian meteorites, in order to understand their parent body alteration history at the start of the Solar System to the younger alteration on Mars surface. Finally, I work on the classification of meteorites and the characterization of their alteration state, more specifically on primitive samples. I use a multi-methods approach in order to characterize the samples from a macro to a nanoscale using complementary instruments such as optical and electron microscopy (SEM and TEM), Raman and infrared spectroscopies, microprobe, XRD, and SIMS.

EDUCATION:

PhD – Aqueous alteration of meteorites – CEREGE- Université Aix-Marseille - 2021

Master 2 - Planetology – Université Paris-Saclay - 2018

Master 1 - Mineral Ressources - Université de Lorraine Nancy – France - 2017 

BSc - Geology – Université de Lorraine Nancy – France - 2016

KEYWORDS:

Meteorite, Micrometeorites, Extraterrestrial flux, Mineralogy, Chemistry, Petrography.

COLLABORATORS:

• Steven Goderis