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Title: Pre-accretional sorting of grains in the outer solar nebula

Despite their micrometer-scale dimensions and nanogram masses, chondritic porous interplanetary dust particles (CP IDPs) are an important class of extraterrestrial material since their properties are consistent with a cometary origin and they show no evidence of significant post-accretional parent body alteration. Consequently, they can provide information about grain accretion in the comet-forming region of the outer solar nebula. We have previously reported our comparative study of the sizes and size distributions of crystalline silicate and sulfide grains in CP IDPs, in which we found these components exhibit a size-density relationship consistent with having been sorted together prior to accretion. Here we extend our data set and include GEMS (glass with embedded metal and sulfide), the most abundant amorphous silicate phase observed in CP IDPs. We find that while the silicate and sulfide sorting trend previously observed is maintained, the GEMS size data do not exhibit any clear relationship to these crystalline components. Therefore, GEMS do not appear to have been sorted with the silicate and sulfide crystals. The disparate sorting trends observed in GEMS and the crystalline grains in CP IDPs present an interesting challenge for modeling early transport and accretion processes. They may indicate that several sorting mechanisms operatedmore » on these CP IDP components, or alternatively, they may simply be a reflection of different source environments.« less
Authors:
 [1] ; ;  [2] ;  [3] ;  [4]
  1. Earth Sciences Department, Mineral and Planetary Science Division, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)
  2. Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)
  3. School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom)
  4. Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)
Publication Date:
OSTI Identifier:
22348441
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; COMETS; CRYSTALS; DENSITY; DISTRIBUTION; DUSTS; GLASS; INTERPLANETARY SPACE; MASS; METALS; POROUS MATERIALS; PROTOPLANETS; REFLECTION; SIMULATION; SOLAR NEBULA