Exploring Carbon-bearing Matter in an Antarctic Micrometeorite

TAM19B-7 is the largest, unmelted fine-grained micrometeorite found to date. It has carbonaceous chondritic origins, but the oxygen isotopic composition does not match any known parent bodies. Additionally, carbon-bearing matter and isotopic composition has been extensively characterized in meteorites, but this work has not been done yet for micrometeorites. Using the NanoSIMS 50 L instrument, the bulk δ13C for TAM19B-7 was found to be 3 + 8‰, and four anomalous spots were identified with δ13C values of 12.9‰, 16.8‰, 32.7‰, and -27.1‰.