Giovedì 26 febbraio alle ore 14, in aula C, Yves Marrocchi e Isabella Pignatelli (Centre de Recherches Pétrographiques et Géochimiques di Nancy, Francia) terranno i seguenti seminari:

Ore 14 - 14:45
Yves Marrocchi - Testing the permeability of the barrier separating the inner and outer circumsolar disk

Meteorites provide key insights on the evolution of the solar system. The recent discovery of a fundamental isotopic dichotomy between non-carbonaceous (NC) and carbonaceous (C) meteorites attests that the solar system was divided by a physical barrier into two distinct reservoirs. However, the nature and permeability of this barrier remain unclear. These uncertainties impact our understanding of how terrestrial planets formed in the inner solar system. Deciphering the permeability of the NC/C barrier can be approached by studying chondrules –submillimeter spheroids representing the most abundant high-temperature material in NC and carbonaceous chondrites (CC). Although this makes chondrules a unique tracer of disk processes, no dedicated study has yet investigated the potential inward migration of CC-like chondrules into the terrestrial planet-forming zone. In this context, Yves Marrocchi will present combined O-Ti-Cr-Fe isotopic data on NC chondrules and discuss the implications of these results on the isotopic evolution of the NC reservoir and its implications for the permeability and nature of the NC/C barrier.

Ore 14:45 - 15
Isabella Pignatelli - Water-rock interaction in the Martian crust - The record of Fe-rich phyllosilicates in the Nakhla meteorite

The Nakhla Martian meteorite is known to contain secondary minerals, in particular phyllosilicates. A section of this meteorite was analyzed by transmission electron microscopy to characterize the phyllosilicates in veins and mesostasis. What was simply considered as iddingsite in previous works reveals surprising mineralogical associations (e.g. hisingerite and ferripyrophyllite). In addition, for the first time, wadsleyite was observed within the vein margins in olivine, providing evidences of shock metamorphism. The identification of Fe-rich secondary phyllosilicates helped to reconstruct the aqueous alteration of this meteorites and has also implications on possible past life on Mars.

I seminari potranno essere seguiti anche da remoto tramite il seguente link: https://teams.microsoft.com/meet/38377631095497?p=yyfO9Mu87SJjsJcflN
Meeting ID: 383 776 310 954 97 Passcode: AK7DT7cM

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