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Title: Analysis of chondritic interplanetary dust thin-sections

Journal Article · · Geochimica et Cosmochimica Acta; (USA)
 [1]
  1. McCrone Associates, Inc., Westmont, IL (USA)

Chondritic interplanetary dust particles (IDPs) are heterogeneous aggregates of predominantly submicrometer mineral grains and carbonaceous material, whose bulk compositions agree within a factor of two with type CI/CM carbonaceous chondrites. The mineralogy and petrography of 25 such particles were studied by analytical electron microscopic examination of ultramicrotomed thin-sections (500-1,000 {angstrom} thick). Four classes of chondritic IDPs were recognized, referred to as pyroxene, olivine, smectite, and serpentine, and their relative abundances were 9:4:10:2 respectively. Pyroxene and olivine particles are porous assemblages of anhydrous mineral grains, glass, and carbonaceous material. Smectite and serpentine particles are low porosity objects whose matrices contain layer silicates and glassy material. Quantitative thin-film analyses indicate that pyroxene particles most closely resemble material emitted from comet Halley. Smectite particles may have formed from pyroxene particles by aqueous alteration of glass and enstatite crystals. Serpentine particles are the only class that are similar to the matrices of carbonaceous chondrites, but these are the least abundant chondritic IDPs. Collectively, chondritic particles are a mineralogically diverse group of extraterrestrial materials.

OSTI ID:
5181165
Journal Information:
Geochimica et Cosmochimica Acta; (USA), Vol. 52:4; ISSN 0016-7037
Country of Publication:
United States
Language:
English