Cosmogenic and radiogenic noble gases in the Sołtmany L6 chondrite

We measured the concentrations and isotopic compositions of He, Ne, Ar, Kr, and Xe in a 60.36 mg sample of the Sołtmany meteorite (L6), which fell in northeastern Poland in 2011. The Kr and Xe data suggest a mixture of atmospheric contamination and Q. Using cosmogenic 21Ne and 38Ar concentrations, Sołtmany’s cosmic-ray exposure (CRE) age was determined to be ~29.2 Ma. The preatmospheric radius for Sołtmany was equal to or less than approximately 15 cm and the sample studied here most likely came from close to the preatmospheric surface of the meteoroid. While the 40Ar gas retention age is about 4137 Ma, the 4He gas retention age is 1610 Ma, suggesting loss of a major 4He fraction likely during an impact and/or degassing event on the Sołtmany parent body prior to the ejection of the Sołtmany meteorite ~29.2 Ma ago.