Places like NWA produce many, many separately numbered meteorites that are undoubtedly paired. The same thing happens in Antarctica. See Marilyn Lindstrom's analysis of this at:
http://www-curator.jsc.nasa.gov/curator/antmet/ppr/ppr.htm
By number, only 1% of Antarctic meteorite finds are irons. When corrected for extensive pairing among stony meteorites, this percentage rises to near the 5% value observed among new meteorite falls.
I have also read (I forget who made this claim) that in areas like the Sahara, iron meteorites are likely to have been picked up and used as tools by nonindustrial or preindustrial cultures, whereas stony meteorites were ignored. Maybe one of you can come up with a reference. This further lowers the percentage of irons among collections of meteorite finds. It did not, obviously, affect the Antarctic meteorite population.
The other two effects, differential weathering and the ease with which finders have recognized irons compared to stones, probably aren't that important in northwest Africa, Libya, and Oman. Weathering rates are low, and people know what to look for. Other places have been greatly affected by these factors, e.g., the southeast US, where almost all meteorite finds are irons.
jeff
At 05:34 PM 1/16/2003, ROCKS ON FIRE wrote:
Hello, List,
does anyone know about how many new irons have been found recently compared to stony meteorites?
It occurs to me that the market gets flooded with new chondrites every day but hardly any new iron, nut to mention stony irons. There are more than a thousand L's and H's just from NWA, I guess.
It seems to me that apart from Campo and Nantan (yes, Sikhote and Brahin too) that stuff is getting rare. And it shows such nice etching pattern!
--
Best regards from DOWN-UNDER,
Norbert & Heike Kammel
ROCKS ON FIRE
IMCA #3420
www.rocksonfire.com
US Geological Survey fax: (703) 648-6383
954 National Center
Reston, VA 20192, USA
