Geology & Environmental Science Colloquium: Dr. Cari Corrigan | Smithsonian Institution’s National Museum of Natural History

Evidence of Impact Melting in Iron Meteorites

Presented by Dr. Cari Corrigan | Research Geologist and Curator of Meteorites, Smithsonian Institution’s National Museum of Natural History

Talk Abstract:

Of the ~1250 recognized iron meteorites, ~10% are compositionally distinct, and thus termed “ungrouped”. Among these, iron meteorite impact melts are exceptionally rare, despite the fact that iron meteorite parent bodies, exposed cores of larger differentiated protoasteroids, must have experienced a violent impact history. While a few iron meteorites may exhibit impact melt features, others, including an anomalously high number of Antarctic iron meteorites, also contain anomalously low volatile siderophile element concentrations attributed to impact devolatilization. Here, we present results of a three-dimensional (3D) μXCT study of sulfide (troilite, FeS) inclusions in ungrouped irons that are suggestive of formation by diapiric rise of troilite through (partially?) molten metal after impact melting.

Biography:

Cari Corrigan is a Research Geologist and Curator of Meteorites at the Smithsonian Institution’s National Museum of Natural History in Washington DC. Standing on the shoulders of Pitt Professor Bill Cassidy and former Ph.D. student Ralph Harvey, she curates the US Antarctic Meteorite Collection and has classified over 7000 meteorites during her time at the Smithsonian. Her scientific interest is in the petrology and geochemistry of chondrites, differentiated materials (including iron meteorites), and impact melted materials from a variety of meteorite types. She has participated in planetary missions including the Mars Exploration Rovers (Pancam Team) and most recently OSIRIS-REx (Mineralogy and Petrology Working Group). She served on the Meteoritical Society Council from 2016 to 2020, as the Editor to Elements Magazine from 2011-2025 and is the current society Treasurer. Asteroid 9924 Corrigan was named for her in 2017 and she became a fellow of the Meteoritical Society in 2022.