Richard Carlson became the Director of the Department of Terrestrial Magnetism in 2014. In 2019, he oversaw the joining of the historic Department of Terrestrial Magnetism and Geophysical Laboratory to form the Earth and Planets Laboratory. Under his guidance, the division has hired its first three staff scientists, as well as two cohorts of incoming postdocs. Carlson’s steady and capable leadership has been further amplified throughout the COVID-19 pandemic, enabling the division to carry out a robust portfolio of on-site research while maintaining a high level of safety across campus.
Carlson's nucleosynthesis studies focus on precise isotopic measurements of Cr, Sr, Ba, Nd, Sm and Hf (e.g. Carlson et al., 2007; Qin et al., 2011) to detect the isotopic anomalies, correlate them with the responsible nucleosynthetic processes, and then map their distribution in different types of meteorites and the terrestrial planets.
The work contributes to our understanding of the stellar nucleosynthetic processes that created the elements in our Solar system, to the question of how well mixed the Solar nebula was before the start of planet formation, and how compositional heterogeneities in the nebula may have influenced the composition of the terrestrial planets.
This work also revealed that the accessible Earth may have a composition different from primitive meteorites (Boyet and Carlson, 2005) with implications for the mechanism of formation and early differentiation history of our home planet (Carlson and Boyet, 2008; Carlson et al., 2015).
Several studies are ongoing concerning the nature and mechanism of formation of Earth’s first crust (Carlson et al., 2019). These include studies of what may be 4.3 Gyr mafic meta-volcanic rocks in the Nuvvuagittuq terrane of northern Quebec (O’Neil et al., 2012) with former DTM postdoc Jonathan O’Neil (now at U. Ottawa), 3 to 4 Gyr old rocks of the Slave Craton (Reimink et al., 2019) with former postdoc Jesse Reimink (now at Penn State), and 3.7-3.9 Gyr rocks in a newly discovered terrane in China with former postdoc Da Wang (now at Chengdu U).
These studies have identified two types of ancient crust, one derived from the reworking of even older, Hadean, crust and the other by melting of the mantle left behind following the extraction of this first crust on Earth.
Work with EPL colleague Steve Shirey and postdocs Richard Walker and Graham Pearson applied the Re-Os isotope system to dating the time when sections of the subcontinental mantle developed its distinctive compositional characteristics that give it buoyancy and strength that likely is responsible for the survival of old sections of continent at Earth’s surface (Walker et al., 1989; Pearson et al., 1995; Carlson et al., 2005). Recent work has characterized the composition of the mantle beneath Mongolia (Carlson and Ionov, 2019) that is remarkably similar in composition to the mantle that supplies volcanism along the global ocean ridge system.
Beginning with his graduate studies, Carlson explored the timing of formation and initial differentiation of the Moon. Early work focused on the time of formation of the lunar chemical component known as KREEP (Carlson and Lugmair, 1979) and the age of the Moon’s oldest crustal rocks (Carlson and Lugmair, 1988).
This work has been refined recently with the addition of high-precision studies of Nd isotopic composition (Borg et al., 2011; Carlson et al., 2014), leading to documentation of the repeated occurrence of ages near 4.36 Gyr, suggesting either an unexpectedly prolonged magma ocean episode or more likely a late formation of the Moon by giant impact into the Earth (Borg and Carlson, 2022).
One type of volcanism on Earth that does not easily fit into plate tectonic theory is the occasional eruption of millions of cubic kilometers of basaltic magma over less than a million years. These flood basalt events have been linked with extinction events, most obviously at the Permian-Triassic boundary. Carlson’s work on this subject began with investigations of the chemical characteristics of the Columbia River Basalts in the Pacific Northwest (Carlson, 1984) and most recently on the Karoo Flood Basalts of southern Africa and Antarctica (Heinonin et al., 2014).
Carlson also led a multidisciplinary investigation of the causes of large volume volcanism east of the Cascades that discovered an interesting interplay between mantle motions induced by the subducted oceanic plate with those that may be related to the uprise of the Yellowstone mantle plume (James et al., 2011; Long et al., 2012; Carlson et al., 2018).
Most of the work done by Carlson involves the development and application of novel analytical techniques ranging from early work in the development of the 147Sm-143Nd (Carlson and Lugmair, 1979) and Re-Os (Walker et al., 1989) isotopic systems and more recently with isotope ratio precision improvements in the 146Sm-142Nd system (Boyet and Carlson, 2005; Garcon et al., 2017; Wang and Carlson, 2022) that also enabled the detection of bulk-meteorite scale nucleosynthetic isotope anomalies in Ba, Sm and Nd (Carlson et al., 2007), Cr and Hf (Qin et al,. 2010; 2011) and K (Nie et al., 2022).
Much of this work involves application advances in thermal ionization mass spectrometry (Carlson, 2014), including the development of improved sample ionization (Reimink et al., 2020), but also has included some of the first applications of multicollector ICP-MS to the analysis of Li (Tomascak et al., 1999), Ag (Carlson and Hauri, 2001; Schonbachler et al., 2007), Ra, 230Th (Pietruszka et al., 2002) and Fe (Kehm et al., 2003).
Carlson looks back on 41 years
"As the year ends, the desire to reflect on the past always surfaces. In this letter, I’ll be looking further back than usual as my 41 years of employment as a postdoc, staff scientist, and director at the Department of Terrestrial Magnetism (DTM) and now the Earth and Planets Laboratory (EPL) are coming to a close."Read Rick's Letter
- B.A. Chemistry - Earth Science, University of California, San Diego, 1976
- Ph.D. Earth Science, Scripps Institution of Oceanography, UCSD, 1980
- Fellow, American Association for the Advancement of Science, 2020
- Victor Moritz Goldschmidt Award, Geochemical Society, 2020
- Distinguished Lecturer, Mineralogical Society of America, 2015-16
- Arthur L. Day Medal, Geological Society of America, 2013
- Member, National Academy of Sciences, 2012
- Inclusion in ISIHighlyCited.com, 2010
- Fellow, American Academy of Arts & Sciences, 2009
- Hamilton Visiting Scholar, Southern Methodist University, 2008
- Norman L. Bowen Award, VGP Section, American Geophysical Union, 2008
- Fellow, American Geophysical Union, 2003
- Fellow, Geochemical Society 2003
- Louis Murray Fellowship, University of Cape Town, 1999
- Director: Carnegie Science, Earth and Planets Laboratory, September, 2019 – December, 2021
- Director: Carnegie Science, DTM, November, 2014 – August, 2019
- Acting Director: Carnegie Science, DTM, May-October, 2014
- Staff Scientist: Carnegie Institution of Washington, DTM, 1981 - Present
- Postdoctoral Research Fellow: Carnegie Institution of Washington, DTM, 1980 - 81
- Teaching, Research Assistant: Scripps Institution of Oceanography, 1976-80
- American Association for the Advancement of Science
- American Geophysical Union
- Geochemical Society (Life member)
- Geological Society of America (Life member)
- Geological Society of Washington
- Meteoritical Society
Richard Carlson | The Impact of Early Earth Differentiation on the Modern World
Richard Carlson at GSA 2021
Earth's First Crust | Neighborhood Lecture Series
Rick Carlson on Probing the Early Solar System
The Formation and Evolution of Cratonic Lithospheric Mantle by Richard Carlson
Dr. Richard Carlson - Carnegie Institution of Washington
Oldest Known Rocks Discovered
On December 31, 2021, after a 42-year-long career as a Carnegie scientist, Richard Carlson stepped down as the Director of the Carnegie Institution for Science’s Earth and Planets Laboratory (EPL). From May 18 - 20, 2022, we joined together with friends, colleagues, and the Carnegie community for a 3-day celebration in honor of former Earth and Planets Laboratory Director Richard Carlson to recognize his substantial contributions to science (and our lives!)
RickFest Recorded Sessions | Friday, May 20
RickFest Recorded Sessions | Thursday, May 19
Rick Fest Group Photo
Graham Pearson in front of slide
Rick Fest Dinner