Low Temperature Sulfides in Ci Chondrites & Stardust

Content Provider	Semantic Scholar
Author	Berger, Edmond Louis Keller, Lindsay P. Joswiak, David J. Lauretta, Dante S.
Copyright Year	2009
Abstract	Introduction: The strongest evidence from Comet Wild 2 for preservation of grains that experienced aqueous alteration at some point in their history may be low-temperature sulfide minerals similar to those in the CI chondrites such as cubanite, pentlandite, and pyrrhotite [1, 2]. Unraveling the mechanisms and conditions of sulfide formation – through detailed characterization of cometary and meteoritic samples, thermodynamic modeling, and experimentation – has implications about large-scale mixing of low-temperature assemblages in the early Solar System. Here we present preliminary results of our investigation of such sulfides from Stardust tracks and compare them to analogous phases in CI chondrites. Cubanite: Prior to the Stardust Mission, extraterrestrial CuFe2S3 had only been found in CI chondrites [3]. It is believed to be a hydrothermal alteration product [2]. The discovery of this mineral in the Stardust population has implications for the low-temperature history of Comet Wild 2. CI chondrites: We have characterized cubanite grains from Alais and Orgueil on the Cameca SX50 electron microprobe at LPL. The composition of the cubanite is near stoichiometric CuFe2S3 with trace amounts of Ni. It occurs in association with pyrrhotite and as isolated grains. In two cases cubanite grains appear to have overgrown pyrrhotite (Figure 1).
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1892.pdf
Alternate Webpage(s)	https://www.lpi.usra.edu/meetings/lpsc2009/pdf/1892.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article