D-rich Water in Interplanetary

Introduction: Hydrogen isotopic compositions in interplanetary dust particles (IDPs), in the form of D enrichments, provide unequivocal evidence for the survival of presolar organic matter (e.g., [1-4]). D/H enrichments of up to 50,000 o / oo have been reported from IDPs and such extreme values are presumably produced by ion-molecule reactions at 10-50 K in molecular clouds [1]. Although the phase(s) carrying the D enrichments remain unclear, it is generally accepted that the D excesses are associated with organic matter [1-5], while the phyllosilicates (the other host of phase for H in IDPs) do not seem to be anomalous in their H isotopic composition [4]. However, D enrichments in phyllosilicates have been reported from the Semarkona and Renazzo meteorites [6]. The primary goal of this work is to investigate H isotopic heterogeneity in IDPs and understand the chemistry and mineralogy of the phases carrying the D excesses. The current work extends the previous work done on characterizing H isotopic variability in IDPs [e.g., 1-5] and here we report the first clear evidence for a D-rich phase in IDPs that is not associated with organic matter.