D.T. HALFORD
Postdoctoral Scholar · Caltech GPS

Daniel T. Halford

Geochemist decoding helium, hydrogen and CO₂ in the subsurface. From noble-gas mass spectrometry to probabilistic exploration models.

View publications Experience
Pasadena, CA dhalford@caltech.edu +1 626 395 6730 US citizen
1HHydrogen
1.008 · natural H₂
2HeHelium
4.0026 · ³He/⁴He
6CCarbon
12.011 · CO₂ carrier

Three gases · one subsurface fluid system

11Years of field, lab & modelling
12Publications · 6 first-author
$121kResearch funding secured
8Conference talks · 1 best-presentation award

01 · Profile

Gas, fluid and rock data, turned into exploration models

I am a geochemist specialising in subsurface hydrogen (H₂), helium (He) and carbon dioxide (CO₂) systems, with experience across academic research at Caltech and Oxford and applied resource assessment at the Bureau of Indian Affairs.

I combine field mapping, laboratory analysis (noble gas and isotope-ratio mass spectrometry, gas chromatography) and quantitative modelling in MATLAB, Python, Petra and ArcGIS to turn raw gas, fluid and rock data into exploration models and resource assessments.

First-author publications in Geochimica et Cosmochimica Acta and Chemical Geology; experienced in securing funding, leading field teams and training colleagues.

Sample → decision pipeline

01
FieldGas & water sampling, structural mapping, core & chip logging
02
LaboratoryNoble gas MS (ARGUS, HELIX SFT, MiniRUEDI), IRMS, GC, H₂ crush & fusion
03
ModelSolubility, mass balance, heat flow, gas–water partitioning, probabilistic targeting
04
DecisionExploration targets and resource assessments for industry, surveys and tribal nations

02 · Expertise

Instruments, code and the ground truth

Systems

Geologic heliumNatural hydrogenCO₂ as carrier gasNoble gas geochemistryHe sourcing & migrationPetroleum systemsCritical mineralsAquifer fluid mixing

Laboratory

ARGUS · HELIX SFT · MiniRUEDIIsotope-ratio MSGas chromatographyHigh-vacuum magnetic-sector MSH₂ crush & fusion releaseClumped isotopes (collab.)

Modelling & software

MATLABPythonPetraArcGISSolubility & mass balanceHeat-flow modellingGas–water partitioningProbabilistic targetingWell-log & seismic interpretation

Field & leadership

Gas & water sampling campaignsPit & core loggingStructural & isopach mappingGrant writing · $121k securedProject & budget managementTribal resource consultingMSHA · OSHA · DOT

03 · Experience

Eleven years across research and applied geology

2024 — PresentPasadena, CA

Postdoctoral Scholar Research Associate in Geochemistry

California Institute of Technology · P.I. Ken Farley

  • Quantify CO₂–water interactions in aquifers (dissolution, precipitation, gas–water partitioning, fluid migration) to determine how CO₂ acts as a carrier gas for helium.
  • Build solubility, mass-balance and heat-flow models that constrain aquifer scale, gas–groundwater exchange and fluid mixing.
  • Integrate noble gas isotopic and bulk gas data with geologic and geophysical datasets to evaluate geologic H₂ and He accumulations, funded by the Saskatchewan Geological Survey (CAD $40,000).
  • Developed reproducible lab methods to measure H₂ released from rocks (crushing and fusion), and wrote MATLAB and Python workflows for gas fingerprinting, mass balance, fluid–gas partitioning and accumulation modelling.
  • Operate GC, IRMS and high-vacuum-line magnetic-sector mass spectrometry to generate composition and isotopic datasets.
Applied Geochemistry · in prepEPSL · in prepGCA · in prepPresidential Fellow
2015 — 2024Lakewood, CO

Mining and Petroleum Geologist

Division of Energy and Mineral Development, Bureau of Indian Affairs · via Insight Global, Lockheed Martin, Leidos, Flatwater Group

  • Assessed mineral (critical elements, precious stones, aggregate) and fluid (He, H₂, CO₂, oil and gas) resources, giving tribal nations a geologic basis for development decisions.
  • Analysed and interpreted field and core samples that provided the primary data behind resource assessments.
  • Produced structural and isopach maps, cross-section correlations, well-log analyses (top and fault picks) and reservoir and production calculations in Petra and ArcGIS.
  • Evaluated resource supply chains and midstream–downstream economics to test commercial viability.
  • Led projects end to end: built teams, managed and trained staff, secured funding, ran budgets and timelines.
Navajo NationJicarilla Apache NationAssiniboine & Sioux Tribes
2014Bagdad, AZ

Mining Geology Intern

Freeport-McMoRan Copper and Gold

  • Mapped pit bench faces and exploration areas for ore control and mine planning.
  • Logged blast-hole chips and drill core, assessed alteration and collected geotechnical samples for ore delineation and pit stability.
  • Coordinated daily with drillers, geologists and mining engineers in an active mine; MSHA, OSHA, DOT and hazard-recognition trained.

04 · Education

Oxford · Colorado School of Mines · Stanford

2024 · OXFORD, UK Ph.D. Earth Sciences University of Oxford · P.I. Chris Ballentine

Thesis on helium sourcing and migration, yielding first-author papers in GCA, Chemical Geology, G-Cubed and Frontiers. Built statistical and probabilistic models combining noble gas and stable isotopes, structural geology, heat flow and geophysics to identify helium-rich targets. Led field campaigns; trained on ARGUS, HELIX SFT and MiniRUEDI.

2018 · GOLDEN, CO M.S. Geology Colorado School of Mines · P.I. Steve Sonnenberg

Helium systems and petroleum geology. Secured US $80,925 for noble gas isotopic analysis of helium wells in the Four Corners area (Navajo Nation), published first-author in Chemical Geology (2022). Coursework in resource economics, seismic interpretation, sequence stratigraphy and energy geology.

2014 · STANFORD, CA B.S. Geological & Environmental Science Stanford University

Structural geology, tectonics, earthquake geology, seismology, geochemistry, mineralogy, volcanology, field geology, economic geology, geophysics, GIS, sedimentology, sequence stratigraphy, paleobiology and astrobiology.

05 · Publications

Twelve papers, theses and reports

First-author work highlighted in orange · DOIs link to the publisher

prep

Understanding the source, migration, and fate of CO₂ as a carrier gas for He

Halford, D. T., Gilfillan, S. M. V., Cathey, B., Cathey, M., Whyte, C. J., Darrah, T. H.

Applied Geochemistryin prep
review

Helium in a deep drill core reveals helium dynamics in crystalline basement

Farley, K. A., Treffkorn, J. S., Halford, D. T.

PNASin review
2025

Examining the effect of heat from Yellowstone on the release of helium gases from the crust

Halford, D. T., Karolytė, R., Barry, P. H., Tyne, R. L., Hillegonds, D. J., Adeniyi, E., Bekaert, D. V., Broadley, M. W., Hudak, M., Lloyd, K. L., Marty, B., Ramirez, C. J., Seltzer, A. M., Ballentine, C. J.

Geochimica et Cosmochimica Acta10.1016/j.gca.2025.06.015
2024

Applications in utilizing soil gas geochemistry along with geological and geophysical data to construct helium exploration statistical models

Halford, D. T., Karolytė, R., Dellenbach, J. T., Cathey, B., Cathey, M., Balentine, D., Andreason, M. W., Rice, G. K.

Frontiers in Earth Science10.3389/feart.2024.1434785
2024

Probabilistic determination of the role of faults and intrusions in helium-rich gas fields

Halford, D. T., Karolytė, R., Andreason, M. W., Cathey, B., Cathey, M., Dellenbach, J. T., Cuzella, J. J., Sonnenberg, S. A., Cheng, A., McCaffrey, K. J. W., Gluyas, J. G., Ballentine, C. J.

Geochemistry, Geophysics, Geosystems 25, e2024GC01152210.1029/2024GC011522
2023

Geologic processes that control sourcing and migration of subsurface helium

Halford, D. T.

PhD thesis · University of Oxford10.5287/ora-00zdnvm4m
2022

High helium reservoirs in the Four Corners area of the Colorado Plateau, US

Halford, D. T., Karolytė, R., Barry, P. H., Whyte, C. J., Darrah, T. H., Cuzella, J. J., Sonnenberg, S. A., Ballentine, C. J.

Chemical Geology 596, 12079010.1016/j.chemgeo.2022.120790
2018

Isotopic analyses of helium from wells located in the Four Corners area, southwestern US

Halford, D. T.

Master's thesis · Colorado School of Mines
2014

Multi-method measurement of offset from the 1857 Fort Tejon earthquake along the San Andreas fault in the Carrizo Plain at channel Seih31

Akciz, S. O., Grant Ludwig, L., Halford, D. T., Marliyani, G. I., Salisbury, J. B., Kleber, E. J., Arrowsmith, J. R., Rhodes, E., Capaldi, T.

Seismological Research Letters 85(2), 518
2014

3D investigation of channel morphology across the San Andreas fault zone using structure from motion and terrestrial laser scanning

Kleber, E. J., Arrowsmith, J. R., Akciz, S. O., Salisbury, J. B., Grant Ludwig, L., Halford, D. T., DeLong, S. B., Marliyani, G. I., Henderson, W. M.

Seismological Research Letters 85(2)
2013

Polyextremophiles and the constraints for terrestrial habitability

Capece, M., Clark, E., Saleh, J. K., Halford, D. T., Henl, N., Hoskins, S., Rothschild, L.

Polyextremophiles (Springer), pp. 3–5910.1007/978-94-007-6488-0_1
2013

Refining the south-central San Andreas Fault slip rate at the 6 ka timescale: Phelan Creeks

Salisbury, J. B., Kleber, E. J., Akciz, S., Arrowsmith, J. R., Marliyani, G. I., Grant Ludwig, L., Halford, D. T.

Southern California Earthquake Center · Project #13146technical report

06 · Presentations

Conference and seminar talks

  • 2026Goldschmidt Conference · Montreal, Canada
  • 2025Caltech Economic Geology Seminar · Pasadena, USA
  • 2024GeoConvention · Calgary, CanadaBest student presentation
  • 2023Energy Geoscience Conference · Aberdeen, Scotland
  • 2023Rocky Mountain Association of Geologists Helium Conference · Denver, USA
  • 2022Geological Society of America · Denver, USA
  • 2019Society of Independent Professional Earth Scientists · Denver, USA
  • 2019Geological Society of America · Manhattan, USA

07 · Funding & awards

Grants secured, fellowships held

Grants as lead

  • 2025–26CAD $40,000
    Saskatchewan Geological Survey · He and H₂ exploration
  • 2017–18USD $80,925
    Isotopic analysis of helium wells on the Navajo Nation

Fellowships & scholarships

  • 2024–26Caltech Presidential Fellowship
  • 2019–23University College Oxford–Radcliffe Graduate Scholarship
  • 2018–19Society of Independent Professional Earth Scientists Scholarship
  • 2018–19Four Corners Geological Society Master's Thesis Fund
  • 2017–18Achievement Rewards for College Scientists Scholarship
  • 2017–18Knight Foundation & Chevron Fellowship · Kent, Barlow and Haun Fund
  • 2017AAPG John & Erika Lockridge Fund
  • 2016–17DEMD Indian Resource Fund

08 · Network

Collaboration, teaching and service

Founded an H₂ research group at Caltech integrating clumped isotopes with noble gas geochemistry, and advise tribal nations on helium exploration.

Industry

KolomaHyTerraExxonMobilHestia EnergyMax Power

Academic

StanfordUT AustinCU BoulderOxfordDurham

Government & tribal

Manitoba Geological SurveySaskatchewan Geological SurveyNavajo NationJicarilla Apache NationAssiniboine & Sioux Tribes

Peer review

G-CubedApplied GeochemistryMarine & Petroleum GeologyGeoscience FrontiersEarth-Science ReviewsGeology

Teaching & mentoring

Economic Geology seminar · Caltech, 2026Co-lead of a quarter-long graduate seminar.
Mathematical problem solving for Earth sciences · Oxford, 2019–22Numerical problem solving in MATLAB, programming fundamentals, data visualisation, statistics and probability on geoscience data.
Teaching development · Caltech CTLO, 2025Completed Transforming your research into teaching for postdocs.
MentoringUndergraduate and graduate students at Caltech, the University of Oxford and Durham University.
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