An unidentified reservoir of cometary chondrules

Table DS1. SEM-EDS data of olivine and pyroxene standards as compared with those determined by EPMA; Table DS2. SEM-EDS data of the running standard Johnstown hypersthene as compared with those determined by EPMA; Table DS3. SEM-EDS data of silicate fragments from T2227; Table DS4. The instrumental bias relative to SC-OL in olivine and pyroxene reference materials (RMs) among the three sessions of this study; Table DS5. Data reduction for oxygen three-isotope ratios in silicate fragments from T227.