Quench temperatures of Moore County and other eucrites: residence time on eucrite parent body

Mathematics – Probability

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5

Scientific paper

We report an electron probe investigation of the eucrite Moore County. Moore County consists predominantly of four pyroxene phases and plagioclase, with minor tridymite, ilmenite, chromite, troilite, iron metal and possibly apatite. Temperatures have been computed for Moore County and other eucrites using three independent techniques for coexisting pairs of pyroxenes. These computed temperatures are all subsolidus and approach those calculated for slowly cooled terrestrial igneous and metamorphic rocks. These temperatures conflict with the conclusions of earlier workers that Moore County was catastrophically removed from its cumulate environment at high temperatures. The eucrites cooled to temperatures substantially below the solidus on their parent body. Our results are consistent with the conclusion that Moore County resided for an extended period of time on the eucrite parent body, perhaps from the time of its crystallization from a basaltic melt (~-4.5AE) until a few tens of millions of years ago. This extended residence time is consistent with the conclusion that the eucrite parent body is still intact, but raises dynamical objections to the tentative identification of the eucrite parent body as asteroid 4 Vesta. An alternative scenario involves ejection from the eucrite parent body, at times significantly older than those indicated by cosmic ray exposure ages, of meteoroids of sufficient size that their interiors were shielded from cosmic rays. These meteoroids were removed by low-probability mechanisms into Earth-crossing orbits where they were disrupted and ultimately sampled by the Earth. This proposal appears to remove the dynamical objections to the tentative identification of the eucrite parent body as Vesta.

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

Quench temperatures of Moore County and other eucrites: residence time on eucrite parent body 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 Quench temperatures of Moore County and other eucrites: residence time on eucrite parent body, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quench temperatures of Moore County and other eucrites: residence time on eucrite parent body will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1296768

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