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How to take a closer look at unmelted micrometeorites


Flore van Maldeghem
AMGC, Vrije Universiteit Brussel

ABSTRACT: Every year, 40,000 tons of extraterrestrial material reaches the Earth, mostly under the form of micrometeorites. A large collection of micrometeorites is recovered from sedimentary traps near mountain summits in the Sør Rondane Mountains, Antarctica. The deposits recovered from the sediment traps are among the most proficient deposits in the world, as large unmelted particles are more frequently observed than in other collections from deep-sea sediments, ice and snow, lakes and continental sands. Unmelted micrometeorites represent unique extraterrestrial materials that largely preserved the original petrographic, mineralogical and geochemical properties of their precursor parent bodies or phases.
In order to understand the origin and characteristics of the rare unmelted micrometeorites, two main approaches are used. Imaging techniques non-destructively characterize the mineralogical, textural, structural and chemical variations in these particles, providing a set of tools also applicable for future asteroid sample-return missions. In a later stage, destructive and semi-destructive techniques are used to identify the original parent body of the unmelted micrometeorites.
In this presentation, I will give an outline of the different methods used to analyze unmelted micrometeorites, what features unmelted micrometeorites can preserve from the primary parent body and what the implications of this are towards the future.

BIO:  Flore Van Maldeghem is a doctoral researcher based at the Vrije Universteit Brussel (VUB). As a member of the Analytical, Environmental and Geochemistry research group (AMGC), she focusses on spinel group minerals as a tracer for the extraterrestrial flux on Earth by analyzing these minerals in a variety of extraterrestrial materials, such as micrometeorites, impact spherules and meteorites using state-of-the-art analytical techniques (synchrotron radiation based XRF, CT and XRD, SIMS, LA-ICP-TOF).