[meteorite-list] Self Proclaimed Pairings Issues (SPPI)

David Weir dgweir at earthlink.net
Fri May 5 16:57:54 EDT 2006


Hello Rob,

I don't believe that a new find can ever be considered absolutely and 
without a doubt to be paired with another meteorite or group of 
meteorites that have already been analyzed and classified under a 
specific name. The best that can be said is that it is "likely" paired. 
You would have to submit the new material and go through the 
classification process again, which takes lots of money and may take 
years, even 5 years as Greg Hupe's anomalous chondrite did. This outlay 
of resources is the reason for the defensive post by Adam, which I 
understand. But he is also the one who benefited with the ~$1000/g 
sales, now reduced to only $15/g. What's not fair?

See the following info on pairing:

Meteorite Pairing (P. Benoit et al., 2000)
PAIRING CRITERIA:

Parent body history
     Bulk elemental and isotopic concentrations
     Mineral abundance and compositions
     Petrography (shock, metamorphic, and igneous textures)
     Stable isotope abundance and formation ages
Meteoroid space history
     Cosmogenic noble gas ratios (cosmic-ray exposure age, shielding, 
solar gases, thermal history)
     Natural TL (reheating)
Meteorite terrestrial history
     Geographic proximity
     Shape and size
     Number of specimens
     Terrestrial age
     Weathering grade
     Natural TL levels

Applying data from these criteria to the formula below, a pairing score 
and its associated pairing likelihood is obtained.

Prel = Prel* × Pss × Pbrec × Pcre × Psolar × P3He × Ptage × Pweath × PNatTL
where...
Prel* = relative abundance by classification
Pss = relative abundance by shock stage
Pbrec = relative abundance by brecciation
Pcre = relative abundance by cosmic-ray exposure age
Psolar = relative abundance by solar-gas-bearing meteorites
P3He = relative abundance by light noble gas depleted meteorites
Ptage = relative abundance by terrestrial age
Pweath = relative abundance by weathering factor
PNatTL = relative abundance by natural TL levels
Pairing score (%) / Pairing likelihood

 >90_______Likely
80-90_____Probable
70-80_____Possible
50-70_____Potential
<50_______Candidate or Unlikely

David



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