An experimental investigation of Fe-sulfides as an indicator of heating conditions in CM and CI carbonaceous chondrites

The data are SEM-EDS point analyses (acquired using a ZEISS EVO 15LS scanning electron microscope equipped with an Oxford Instruments 80 mm2 X-Max silicon-drift detector (SDD) EDS at the Natural History Museum, London) and average phase compositions within individual Fe-sulfide grains in the unheated CI chondrite Ivuna, unheated CM chondrite Murchison, naturally heated CM chondrite Jbilet Winselwan, and experimentally heated samples of Ivuna, Murchison, and Jbilet Winselwan. Also included are SEM EDS-point analyses of the fugacity controls used in the heating experiments.