Chemical fractionations in meteorites--VI. Accretion temperatures of H-, LL- and E-chondrites, from abundance of volatile trace elements

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

18

Scientific paper

Extending our earlier work on 11 L-chondrites, we have measured 9 volatile elements (Ag, Bi, Cs, In, Rb, Tl, Se, Cd, Zn) by neutron activation analysis in 11 LL- and 10 E-chondrites; the first 6 elements also in 22 H-chondrites. The observed fractionation patterns are consistent with theoretical condensation curves and hence were apparently established during condensation from the solar nebula. Ordinary chondrites seem to have accreted between 420 and 500°K at P 10 -5 atm; enstatite chondrites, at 460 to 520°K and P 5 10 -4 atm. The values for ordinary chondrites agree with O 18 -based temperatures by . et al. (1972) and with other characteristics such as Fe 2+ content, presence of FeS and absence of Fe 3 O 4 . A few detailed trends were noted. Seven of the 54 meteorites seem to contain small amounts of a material enriched in Ag, Bi and especially T1; possibly a late condensate from a region depleted in metal. Silver shows considerable scatter, which suggests inhomogeneous distribution in the meteorites. Xenon correlates with In approximately as expected for equilibrium solubility, with some differences (petrologic type 3; E-chondrites) attributable to mineralogical factors. Meteorites of higher petrologic types are slightly deficient in Xe, probably due to gas losses during metamorphism. Cesium also appears to have been redistributed during metamorphism. Various features of the two-component model are critically examined in the light of the latest evidence. Apparently this model still is an adequate approximation of reality.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Chemical fractionations in meteorites--VI. Accretion temperatures of H-, LL- and E-chondrites, from abundance of volatile trace elements 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 Chemical fractionations in meteorites--VI. Accretion temperatures of H-, LL- and E-chondrites, from abundance of volatile trace elements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical fractionations in meteorites--VI. Accretion temperatures of H-, LL- and E-chondrites, from abundance of volatile trace elements will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1444886

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.