Tom Marchitto

Tom Marchitto

Fellow of INSTAAR

  • Associate Professor, Dept. of Geological Sciences
  • Affiliate Faculty, Dept. of Atmospheric and Oceanic Sciences
  • Associate Editor, Geochimica et Cosmochimica Acta



  • PhD: Marine Geology and Geophysics, MIT-Woods Hole Oceanographic Institution Joint Program, 1999
  • BS: Geology and Geophysics, Yale University, 1994

Contact Information

(Office) 303 492-7739


Paleoceanography and paleoclimatology
ICP-MS Trace Element Lab

Research Interests

Past abrupt climate change, ocean circulation, ocean biogeochemistry, marine carbon cycle, trace and minor elements in biogenic calcium carbonates, biomineralization

Marchitto on Google Scholar


Graduate students assist with retrieval of a gravity core aboard the R/V Knorr in the Florida Straits. This coring device is useful for obtaining records of relatively recent climate, typically spanning some tens of thousand of years. Photo credit: Tom Marchitto.

As human activities continue to alter Earth’s climate, it becomes increasingly important to look to the past to better understand the future. I am a paleoceanographer, studying large-scale changes in ocean circulation and biogeochemistry that occur over timescales ranging from a few years to tens of millennia. Most of my work has focused on the last full glacial-interglacial cycle, spanning roughly the past 150,000 years. Major variations in ocean circulation, from the surface to abyssal depths, have influenced climate via the transport and storage of heat. The oceans also exert control over atmospheric levels of carbon dioxide, an important greenhouse gas. Such changes are reflected in the physical and chemical properties of seawater, including temperature, salinity, carbonate system parameters, radiocarbon content, and the concentrations of various nutrients. I mainly use the chemistry of the shells of marine protozoa (foraminifera) as recorders of these properties. By analyzing and dating sediment cores that contain foraminifera, we can reconstruct ocean chemistry and inferred circulation patterns during the past.


  • College Scholar Award, University of Colorado Boulder, 2017
  • Kavli Frontiers of Science Fellow, National Academy of Sciences, 2013
  • Provost's Faculty Achievement Award, University of Colorado Boulder, 2008


Research Statement

Paleoceanographers deploy a multicorer aboard the R/V Knorr in the Florida Straits. This coring device is designed to capture multiple undisturbed samples of the sediment-water interface. Photo credit: Tom Marchitto.

Recent and ongoing research has revolved around these NSF-funded projects:

Development of individual foraminiferal Mg/Ca to reconstruct past ENSO variability
PI: Tom Marchitto (2016-2018)

A visual system for autonomous foraminifera identification
Collaborative PIs: Edgar Lobaton, Tom Marchitto (2016-2018)

Automating reasoning in interpreting climate records of the past
PI: Liz Bradley; co-PIs: Ken Anderson, Tom Marchitto, Jim White (2012-15)

Investigation of a dynamical response of the tropical Pacific to orbital and solar forcing during the Holocene
PI: Tom Marchitto (2011-14)

Active Research

Research Programs

Research Labs and Groups



Whitney Doss,Tom Marchitto,Eagle, R.,Rashid, H.,Tripati, A, 2018: Deconvolving the saturation state and temperature controls on benthic foraminiferal Li/Ca, based on downcore paired B/Ca measurements and coretop compilation. Geochimica et Cosmochimica Acta, 236(SI): 297-314. DOI: 10.1016/j.gca.2018.02.029

Tom Marchitto,Bryan, S. P.,Whitney Doss,McCulloch, M. T.,Montagna, P, 2018: A simple biomineralization model to explain Li, Mg, and Sr incorporation into aragonitic foraminifera and corals. Earth and Planetary Science Letters, 481: 20-29. DOI: 10.1016/j.epsl.2017.10.022

Valley, S.,Lynch-Stieglitz, J.,Tom Marchitto{/exp:playa:children, 2017: Timing of deglacial AMOC variability from a high-resolution seawater cadmium reconstruction. Paleoceanography, 32(11): 1195-1203. DOI: 10.1002/2017PA003099

Ge, Q.,Zhong, B.,Kanakiya, B.,Mitra, R.,{playaEHL0BUAv:title},Lobaton, E, 2017: Coarse-to-fine Foraminifera image segmentation through 3D and deep features. 2017 IEEE Symposium Series on Computational Intelligence (SSCI), Honolulu, HI, pp. 1-8. DOI: 10.1109/SSCI.2017.8280982

Zhong, B.,Ge, Q.,Kanakiya, B.,Mitra, R.,Tom Marchitto,Lobaton, E, 2017: A comparative study of image classification algorithms for Foraminifera identification. 2017 IEEE Symposium Series on Computational Intelligence (SSCI), Honolulu, HI, pp. 1-8. DOI: 10.1109/SSCI.2017.8285164

Hasenfratz, A. P.,Schiebel, R.,Thornalley, D. J. R.,Schönfelde, J.,Jaccard, S. L.,Martínez-García, A.,Holbourn, A.,Anne Jennings,Kuhnt, W.,Lear, C. H.,Tom Marchitto,Ursula Quillmann,Rosenthal, Y.,Hauga, G. H, 2017: Mg/Ca-temperature calibration for the benthic foraminifera Melonis barleeanum and Melonis pompilioides. Geochimica et Cosmochimica Acta, 217: 365-383. DOI: 10.1016/j.gca.2017.08.038

Gill, E. C.,Rajagopalan, B.,Molnar, P. H.,Kushnir, Y.,Tom Marchitto{/exp:playa:children, 2017: Reconstruction of Indian summer monsoon winds and precipitation over the past 10,000 years using equatorial pacific SST proxy records. Paleoceanography, 32(2): 195-216. DOI: 10.1002/2016PA002971

{playaEoekMtXK:title},Tom Marchitto,Herguera, J. C, 2017: Understanding the effects of dissolution on the Mg/Ca paleothermometer in planktic foraminifera: Evidence from a novel individual foraminifera method. Paleoceanography, 32(12): 1386-1402. DOI: 10.1002/2017PA003179

All publications by Tom Marchitto >



Current Courses

  • GEOL 5430: Paleoceanography and Paleoclimatology (alternate Falls)
    Examines scientific tools, data, and theories related to the dramatically varied past climate of the Earth. Focus will be on marine records of climate change and ocean circulation, but ice core and other continental archives will also be discussed. Course will cover the Cretaceous Period to the present, with particular emphasis on the past 150,000 years (the last ice age cycle). Prereq., intro geology or equivalent. Recommended prereq., intro oceanography or atmospheric science.

Past Courses

Postdocs & Students






American Journal of Science
Annual Review of E&PS
Chemical Geology
Climate Dynamics
Climate of the Past
Climatic Change
Deep Sea Research I
Deep Sea Research II
Earth and Planetary Science Letters
Geochimica et Cosmochimica Acta
Geophysical Research Letters
Global Biogeochemical Cycles
The Holocene
Journal of Climate
JGR Atmospheres
JGR Oceans
Journal of Physical Oceanography
Journal of Quaternary Science
Marine Chemistry
Marine Geology
Marine Micropaleontology
Nature Geoscience
Progress in Oceanography
Quaternary Research
Quaternary Science Reviews

Chinook Catalog
Interlibrary Loan
Web of Science