RINCON - A NEW L6 CHONDRITE FIND FROM ARGENTINA

A meteorite find from the Puna Desert in northwestern Argentina was st udied using optical, SEM, and electron microprobe techniques. Rincon i s a moderately weathered (W2/W3) L6 ordinary chondrite with shock stag e S4, and shock veins containing ringwoodite. Evolved gas analysis of the meteorite as well as the ignimbrite, on which the meteorite was fo und, proved the transfer of carbonate from the environment to the mete orite. Based on-measured cosmogenic nuclides and model calculations th e preatmospheric radius of the meteoroid could be estimated to 50-85 c m. Rincon entered the Earth atmosphere 22,600 year ago after a single stage exposure history lasting about 5.5 Ma.