I study how Earth's crust and mantle evolve over time using a variety of quantitative geochemical and geochronologic techniques. My research interests include ancient mantle domains, radiogenic heating in the crust, continental collision zones, and geobiological feedbacks.

Contact me if you are interested in research opportunities or collaboration. I am enthusiastic about working with scientists at all levels!

Exploring Earth with high-temperature isotope geochemistry.

News and Highlights

We set a new high 3He/4He terrestrial record!

Recent crushing experiments released isotopically lighter helium than has been measured in any other terrestrial igneous rocks. Our preliminary results indicate that the 3He/4He ratio in one Baffin Island sample exceeds 57 Ra (where Ra is the atmospheric ratio of 1.39 x 10^-6).

See our paper about helium in olivine

"Helium distributions in ocean island basalt olivines revealed by X-ray computed tomography and single-grain crushing experiments" - Horton, Farley, and Jackson

We discovered that helium and CO2 are hosted in fluid inclusions inside olivine crystals. Carbon escapes as grains decrepitate (crack due to a buildup of overpressure in the inclusions) as they ascend in hotspot lavas. Helium probably diffuses through the olivine lattice.


Successful 2018 field season on Baffin Island!

Paul Asimow, Joe Biasi, and I had an adventurous field season in the Arctic Circle in August, 2018. We explored the high 3He/4He lavas that erupted as Greenland and Canada rifted apart. These rocks potentially hold clues about the deepest, oldest domains in Earth's mantle.


Click here to learn more about this research.

New laser ablation system

Our ICP-MS lab is now equipped with a state-of-the-art ASI RESOlution excimer (193nm) laser. This instrument can ablate geologic samples with a beam as small as 2 microns (less than 1/10th the thickness of a human hair) and send that material to a multi-collector ICP-MS (Neptune Plus), single-collector ICP-MS (Element), and/or quadrupole MS for isotopic analysis.

Click here for more info about WHOI analytical facilities.



Department of Geology & Geophysics

Woods Hole Oceanographic Institution

360 Woods Hole Rd, MS #08
Woods Hole, MA 02543 USA


The Woods Hole Oceanographic Institution is dedicated to advancing knowledge of the ocean and its connection with the Earth system through a sustained commitment to excellence in science, engineering, and education, and to the application of this knowledge to problems facing society.