Analysis of individual matrix particles in the Allende meteorite by high-resolution FIB-TOF-SIMS

The matrix in the "Allende meteorite" was analyzed by high-spatial-resolution focused ion beam time-of-flight secondary ion mass spectrometry (FIB-TOF-SIMS), and consisted of fine grains with sizes of several micrometers. It is difficult to analyze the matrix particles individually. As FIB-TOF-SIMS has a high spatial resolution, it can analyze the matrix individually. In addition, if the sample can be smoothed, no other pretreatment is required. By this method, it was clarified that Al, Cr, etc., which were conventionally detected as trace components in mass spectra, existed as fine particles between the matrix particles, rather than as impurities within them. The Al-rich particles did not match the minerals already found in the Allende meteorite matrix. Although the identity of the aluminum-rich particles has not been clarified, the abundance and localization could be observed correctly. Al-rich particles are likely to be affected by metamorphism and have important information to clarify the metamorphism process.