Our Team
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I am a non-traditional stable isotope geochemist, specialising in nickel. I received my PhD on stable Ni isotopic fractionation in high temperature terrestrial and lunar rocks from Oxford University, UK in January 2019. Immediately following this I moved to New York to work with Alex Halliday setting up the NICER lab.
My research centers on using stable Ni isotopic compositions to investigate planetary scale processes. My research projects largely focus on targeting a range of terrestrial high temperature lithologies to investigate mantle heterogeneity and mantle recycling, but have also included using Ni isotopes to investigate the formation of the Moon.
I am originally from Cumbria in the North of England, and grew up around the magnificent rocks of the Lake District. The Borrowdale volcanics and abundant local hematite started my interest in Geology, and led to an A level in the subject. The A level convinced me that this subject was going to be my passion, and ~10 years on nothing has changed!
My interest in geochemistry specifically began with my Masters project at Oxford University, UK (2013-2014), some of which is published here (https://jgs.lyellcollection.org/content/176/5/830). This work was focused on using geochemistry to investigate a Precambrian meteorite impact deposit in NW Scotland. Specifically, we wanted to discover if the class of meteorite could be determined after >1 billion years since the impact, and see if the geochemistry could give us information about emplacement mechanisms and position crater locality
I work on developing stable isotope systems as tools for geochemical research. My interests cover low and high temperature environments, including topics such as tracing water pollution to the early evolution of the Solar System. Stable isotope compositions can be affected by a number of processes, such as evaporation, changes in redox state etc., therefore, if interpreted correctly, can provide a wealth of information. To develop our knowledge of these stable isotope systems I am combining theoretical calculations with high precision measurements on natural samples.
My current work is on chromium (Cr) and antimony (Sb). Chromium has a variable geochemical behaviour, determined by its oxidation state. This is shown on Earth, where Cr behaved as a slightly siderophile element during core formation and now behaves compatibly during melting. This shows the changing redox conditions during the history of the Earth, with reducing conditions during core formation and oxidised conditions in modern mantle required to explain the current distribution of Cr in the Earth.
Isotope ratios are collected using the Nu Instruments MC-ICPMS and TIMS at LDEO.
Prior to moving to Lamont Doherty in the Autumn of 2019, I completed a DPhil at Oxford University. My thesis was written on high temperature Cr stable isotope variations in the deep Earth and Early solar system.
My background is originally in Geology, but my past and current research is at the interface of geology, molecular biology, life science, and chemistry.
My research focuses on developing fundamental insights on the fluxes of contaminants and nutrients to extend our knowledge of how to remediate contaminated systems, ensure economic sustainability of critical elements (i.e., selenium and tellurium), and ecological sustainability of essential nutrients (i.e., calcium, zinc, copper and iron).
My research interests are:
- Impact of human activity (irrigation, mining) on environmental cycling of redox active metalloids – particularly nutrients (selenium) and emerging contaminants (tellurium, vanadium)
- Effect of microscale microbial and geochemical processes on macroscale ecosystem processes in soil and water
- Trace metal element biogeochemistry assessing deficiency and toxicity risk based on environmental sources and sinks (i.e., zinc, nickel and iron)
- Response of microbial-mediated reactions (i.e., iron, carbon) by variation in process parameters caused by climate change
I was originally trained as a high-temperature geochemist and economic geologist. My research focus switched to cosmochemistry during my Ph.D. at Washington University in St. Louis, and I enjoyed exploring the story behind every meteorite sample.
I am now an isotope geochemist at Lamont-Doherty Earth Observatory. My research interests include the development of analytical methods for non-traditional isotopes (e.g., K and W), the origin and evolution of the early Solar System, and biogeochemical cycling of metal elements.
In general, I am interested in the early evolution of Earth and other bodies in the inner Solar System, including the processes of accretion, core formation, and silicate differentiation. These early events shaped the Earth and planets as we know them today, but many questions remain regarding the timing and nature of each process. The study of the isotopic composition of terrestrial and extra-terrestrial materials is a powerful tool with which to investigate these and other questions, since only specific processes are able to modify isotopic abundances.
My research involves high-precision isotopic analyses of stable and radiogenic isotope systems (e.g., Si, Rb, Zn, Nd, Sr) by MC-ICPMS and TIMS. I analyze terrestrial, lunar, and meteorite samples to search for the isotopic signature of physical and chemical processes to solve current problems in cosmochemistry and geochemistry (e.g. composition and evolution of planetary mantles and cores). I am also involved in the development of novel chemical and analytical techniques for isotope ratio measurements by MC-ICP-MS and TIMS.
Dr. Alex Halliday is the Director of Columbia University’s Earth Institute. He joined the Earth Institute in April 2018, after spending more than a decade at the University of Oxford, during which time he was the dean of science and engineering.
With about 400 published research papers, Halliday has been a pioneer in developing mass spectrometry to measure small isotopic variations in objects as different as meteorites and living organisms, helping to shed light on the birth and early development of our solar system, the interior workings of the Earth, and the processes that affect Earth’s surface environment.
His scientific achievements have been recognized through numerous awards, including the Murchison Medal of the Geological Society, the Bowen Award and Hess Medal of the American Geophysical Union, the Urey Medal of the European Association of Geochemistry, and the Oxburgh Medal of the Institute of Measurement and Control. He is a Fellow of the UK’s Royal Society and Foreign Associate of the US National Academy of Sciences. His contributions to science and innovation have been recognized with the award of a knighthood in the UK.
Halliday has also helped to lead a variety of distinguished scientific societies and advisory panels. He is the former Vice President of the Royal Society and former President of the Geochemical Society. He has served as an external board member for Britain’s Natural Environment Research Council, the Max Planck Society, London’s Natural History Museum, the American Geophysical Union, Carnegie Science and more.
As a professor in Columbia’s Department of Earth and Environmental Sciences, Halliday divides his time between Columbia’s Morningside campus and his geochemistry lab at Lamont-Doherty Earth Observatory.