The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates

Details The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates

Mar 1996

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996lpi....27..477h&link_type=abstract

Lunar and Planetary Science, volume 27, page 477

Physics

Cooling Rates, Meteorites: Iif, Meteorites: Iron

Scientific paper

With only five members, group IIF is one of the smallest groups of iron meteorites. Their high Ni concentrations give them an ataxitic texture which inhibits determination of their metallographic cooling rates using traditional techniques. Cooling rates based on alpha-bandwidths show a wide range suggesting that these irons did not cool in a common core. We find that the previously determined alpha-bandwidth cooling rates are in error due to the presence of massive schreibersite blebs in the alpha-spindles on which the cooling rates are based. We have therefore redetermined the metallographic cooling rates of the five group IIF iron meteorites based on alpha-bandwidths of alpha-lamellae devoid of schreibersite. We have determined metallographic cooling rates based on three sets of observations: (1) Ni profiles in the taenite rims surrounding alpha-lamellae, (2) Ni profiles in the outer edge of alpha-lamellae, and (3) bandwidths of alpha-lamellae. We find cooling rates of approximately 10 K/My for all five members of group IIF. Low overall Ni concentrations observed in the alpha-lamellae may, however, indicate a lower cooling rate at low temperatures. The metallographic cooling rates suggest that the IIF iron meteorites cooled slowly in a central core.

Affiliated with

Also associated with

No associations

Rating

The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates 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 The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Origin of Group IIF Iron Meteorites-Clues from Metallographic Cooling Rates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1612139