Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite

Details Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite

Apr 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994icar..108..309w&link_type=abstract

Icarus, Volume 108, Issue 2, p. 309-324.

Computer Science

8

Scientific paper

A few unusual chondrules in the Mezö-Madaras L3 chondrite contain the peralkaline mineral merrihueite, (K,Na)2( Fe,Mg)5 Si12O30, formed by reaction of free silica in the chondrules with K,Na,Fe-rich nebular gas. Vapor fractionation was required to create chondrules poor in Al and rich in Si, and the fractionated condensate produced had to aggregate into protochondrules very promptly (on the order of hours or less) to prevent it from mixing with dust of more generalized composition in the nebula. The traditional paradigm for chondrule formation, involving a series of unrelated events (chemical fractionation of precursor dust; clumping of the dust; melting of the dust-clumps), is inadequate for making these chondrules. A rapid process, all stages of which are related, is required. We propose that this occurred during the cooling and contraction of the volume of hot gas created by a small transient high-energy event in the nebula, of unspecified nature. Microdroplets of silicate melt created by condensation from the cooling, contracting gas had velocity vectors directed toward the center of the volume. Coalescence occurred in the crowded central zone where the microdroplets converged. The Mezö-Madaras merrihueite-bearing chondrules may have been formed by an a typically low-energy nebular event, which achieved the needed chemical fractionations by only partially vaporizing precursor dust. More common place chondrule types may have been created by the same basic process, but involving higher-energy events in which precursor dust was completely vaporized and recondensed.

Affiliated with

Also associated with

No associations

Rating

Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraints Placed on the Chondrule-Forming Process by Merrihueite in the Mezö-Madaras Chondrite will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1257675