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!
News and Highlights
From a single rock, we recovered a nearly complete record of Himalaya-type continental collision
Deeply subducted seafloor sediments of the Indus Fan melted, ascended as magmas, and erupted in southern Afghanistan.
See my paper in Nature Geoscience about the discovery of the first subduction zone carbonatite volcano. Seafloor sediments that are carbon-rich can subduct into Earth's mantle and then return to the surface to form volcanoes formed primarily of carbonate minerals. See Nature Reviews Earth & Environment for a research highlight.
Carbonatites are rare igneous rocks composed primarily of carbonate minerals. Our recent paper about a carbonatite volcano in Afghanistan highlights the important role of fluids during carbonatite volcanism...
See our recent publication in Geochemistry, Geophysics, Geosystems.
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.