Chris Herd, PhD, BSc

Area of Study / Keywords

Geology Meteorites Mars Petrology Sample Return and Curation

About

I am a geologist who studies the planets and moons of the Solar System as understood through meteorites and complemented by other sources of information. I am an internationally-recognized expert in the geology of Mars from studies of Martian meteorites, and a member of the NASA Mars 2020 Perseverance Rover mission, as a participating scientist and expert in Returned Sample Science. My NSERC- and CSA-funded research involves carrying out detailed studies of various meteorite types to gain insights into their conditions of formation, as well as the best methods of curation and handling of pristine planetary materials, including those from sample return missions. I led the consortium of Canadian institutions that acquired the pristine specimens of the unique Tagish Lake (B.C.) meteorite, and established the University’s Meteorite Curation Lab, home to the largest university-based collection in Canada, and the world’s first cold meteorite curation facility. The recipient of the 2013 Faculty of Science Research Award, and elected fellow of the Meteoritical Society in 2016, I am currently the Principal Director of the Institute for Space Science, Exploration and Technology (ISSET), a multidisciplinary virtual institute at the University of Alberta.

Research

Research areas and interests

Organic Molecules and Water in Primitive Meteorites

On January 18, 2000 a unique, carbon-rich meteorite fell on the frozen surface of Tagish Lake in northern B.C. The first specimens were picked up without direct hand contact a few days later, and kept frozen. Acquisition of these pristine Tagish Lake meteorite specimens in 2006 enabled a systematic study of the degree of variation in the mineralogy, petrology, geochemistry and organic chemistry. Several specimens were selected based on variations in macroscopic characteristics, with the prediction that these variations would reflect lithological variations and thus differences in the geologic conditions on the asteroid parent body. We demonstrated that the degree of parent body aqueous alteration corresponds to the degree of modification of organic matter (Herd et al. 2011; Glavin et al. 2012), a result that has had a significant impact on current science in the field. Hydrogen isotopic compositions of organic matter and clays in Tagish Lake have also contributed to understanding the sources of volatiles in the terrestrial planets (Alexander et al. 2012).

Meteorites from Mars

The work that I initiated during my Ph.D. demonstrated that oxygen fugacity, which is a measure of the redox potential, varies significantly in Martian meteorites and that the correlation between oxygen fugacity and radiogenic isotopic composition is best explained by the characteristics of the mantle of Mars that were established during planetary formation and differentiation by 4.5 Ga, yet are nevertheless recorded in young (200-600 Ma) basalts (Herd, 2003). I have contributed oxygen fugacity estimates to studies of many different martian meteorites, and have gained insights into the impact shock effects recorded in these meteorites (collaborations with E. Walton, MacEwan University), and alteration processes. I co-authored the first paper on the Tissint meteorite (martian meteorite which fell July 18, 2011; Aoudjehane et al. (2012)), and led a consortium study of the Northwest Africa 8159 meteorite, a unique sample of Mars (Herd et al., 2017). I have also contributed to the geochronology of martian meteorites through application of ion probe methods to the U-Pb dating of baddeleyite (Zhou et al. 2013), and to a recent review paper on Mars as an Earth-like world (Ehlmann et al. 2017).

Meteorites and Small Impact Craters

In part due to my role as curator of the University of Alberta Meteorite Collection, my research program includes meteorites of many different types. As curator, I receive dozens of inquiries from members of the public every year regarding potential meteorites; one such inquiry in 2007 resulted in the discovery of the < 1100 year old Whitecourt Meteorite Impact Crater, the youngest impact crater in Canada and one of only 15 worldwide with associated meteorites. This crater formed the basis of novel research into small craters (Herd et al. 2008; Kofman et al. 2010; Newman and Herd 2015), and the addition of many 10s of kg in the form of hundreds of meteorites to the Collection. Expansion of the Meteorite Collection has also taken place through classification of new meteorites from Canada and elsewhere: the collection has expanded by 60% since 2006. This work recently resulted in the discovery of three new minerals in the El Ali meteorite from Somalia.  The Meteorite Collection represents countless potential research projects for students.

The Importance of Sample Return

My Canadian Space Agency-supported research investigates the types of advanced methods that are required to process, handle and curate samples returned from missions - especially those from solar system bodies where organics and/or ices may be present. For a recent view on this - and the significance of the samples returned from asteroid Ryugu by the JAXA Hayabusa2 mission - please read this article in Science.

Teaching

EAS 467/567 Planetary Geology - Planetary Systems

EAS 206 Geology of the Solar System

I am looking for a student to develop methods for curation and analysis of returned samples from asteroids.

The postdoctoral researcher in Advanced Curation of Planetary Materials position has now been filled.

EAS 205 - Violent Earth: The Geology of Catastrophic Events

Processes and geological evidence of natural catastrophes, such as volcanoes, earthquakes, slope failures, tsunamis, floods, extraterrestrial impacts, and other rapid environmental changes. Natural hazard risk in the context of geological time. Prerequisite: Any 100-level Science course. [Faculty of Science]

EAS 206 - Geology of the Solar System

Origin of the elements and the solar system, origin and evolution of the planets. Geologic and atmospheric properties of the planets, the nature of meteorites and comets. Results of recent space exploration. Prerequisite: Any 100-level or higher Science course. [Faculty of Science]

EAS 331 - Igneous Petrology

A survey of igneous rocks from the ocean basins and the continents; their field settings, classification, petrography, mineralogy and chemistry; magmatic processes and petrogenesis; problem solving and laboratory work on major rock suites. Prerequisites: CHEM 102 or SCI 100 and EAS 232 and prerequisite or corequisite EAS 320. [Faculty of Science]

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