Our Researchers

IsoTropics Project Management, Infrastructure & General Operations

Lecturer/Researcher (College of Science & Engineering); Lab Supervisor – IsoTropics Lab, Geochemistry Lab

BSc Indiana State University (ISU, USA), MSc Washington University in St. Louis (WUSTL, USA); PhD Institut de Physique du Globe de Paris (IPGP, France).

Dr Brandon Mahan. I have a background in traditional geology (field mapping, structure), experimental rock deformation, experimental petrology, trace element and isotope geochemistry. My research background and interests cover just about anything I can get my hands on, including planetary formation, astro-/cosmochemistry, source/process tracing, ore exploration, biogeochemistry and medical applications of isotope geochemistry (Isotope Metallomics). The unifying threads that runs through all my research are finding parallels between seemingly disparate fields, and developing efficient and efficacious methodologies

I oversee the general operation, maintenance and strategic growth of the lab and affiliated instrumentation, and closely coordinate with associated facilities and entities at JCU, including the EGRU and the Advanced Analytical Centre (AAC).

We actively seek academic and commercial research collaborations, and provide research services (e.g. exploration hydrogeochemistry, contaminant source tracing, metal isotope analyses). Please feel free to reach out to us through our Enquiries page!

JCU Research  Profile

IsoTropics, Data Acquisition & Quality Control

MSc (Geology) Victoria University of Wellington (VUW, New Zealand); PhD (Geochemistry) Australian National University (ANU, Australia).

My research focuses on using a wide range of geochemical tools to understand the evolution of the Earth and it’s major geochemical reservoirs. I have background in traditional geology and petrology but have become increasingly focused on applying geochemistry and in particular isotopes to solve an array of geological problems and have previously held research positions at Durham University (UK) and Monash University (Australia).  I have expert knowledge of a wide range of radiogenic (Sr-Nd-Hf-Pb-Os) and novel stable (Fe, Zn, Mo, and Nd) isotope systems, as well as advanced techniques such as isotope dilution and double spiking methodologies.

Within the IsoTropics Geochemistry Laboratory I oversee the acquisition of geochemical datasets including the isotope analyte separation, mass spectrometer analyses, and quality control procedures of all generated datasets. We actively seek academic and commercial research collaborations, and provide research services (e.g. exploration hydrogeochemistry, contaminant source tracing, radiogenic and metal isotope analyses). Please feel free to reach out to us through our Enquiries page!

JCU Research Profile

Hilary Lewis

Lab Research Officer

Bachelor of Marine Science (Earth Science Major)

I am a Research Assistant for the IsoTropics Geochemistry Laboratory. Within this role, I assist the general operation and functioning of the lab.  My role as research assistant has given me a solid foundation of clean lab protocol in sample preparation, chemistry and analysis. In addition to this, I am a current student of Marine Science at JCU aimed at completing my bachelor’s degree mid 2022. From here, I will commence my honours project in determining Sr isotope compositions in Earth Sciences.

Project: My Honours project is aimed at developing rapid techniques for the determination of Sr isotope compositions across an array of applications in the Earth Sciences. Subject to the project evolution, this will involve developing both solution-based and in situ (laser-ablation) techniques for Sr isotope analyses in aqueous and organic media. For the former, the main focus will be Sr isotope ratio determination in natural water samples, and for the latter the main focus will be the development of in situ Sr isotope ratio determination in hard media of marine organisms (e.g. shark vertebrae and fish otoliths).

Samantha  Russo

Honours Student

BGeol at James Cook University (JCU, Australia)

I have recently completed my Bachelor of Geology (minoring in Chemistry) and am now focusing on my Honours project, where I will be looking at trace rare earth elements and Nd isotopes in banded iron formations. I have always been very passionate about both Chemistry and Geology so being able to bring those things together is really great.

I am interested in looking at rare earth element behaviour as I understand this is a hot topic of discussion right now. I also really enjoy looking at early Earth formation. Thus, my Honours project gives me the perfect blend of these interests and hope to do other projects like this in the future.

Project: Tracing rare earth element mobility during hypogene upgrading and supergene weathering of the Weld Range BIF and its implications for isotopic studies.

Lucy Gardner

Bachelor of Science with Earth Science (major.) and Zoology and Ecology (major) (completion: 2022)

I am currently studying a Bachelor of Science with a double major in Earth Science and Zoology and Ecology. I enjoy studying the health of terrestrial and marine ecosystems through various field and laboratory methods, growing my passion for sustainability, research, and the environment. My degree has allowed me to develop my love of science through many exciting and unique opportunities. From sketching landforms in 40-degree heat, to catching geckos in the bush whilst dodging stinging trees, to getting my hands really dirty making soil ribbons in the lab, to designing my own imaginary, hopefully inhabitable, planet. I currently hold the position of Secretary and Treasurer of the AusIMM Student Chapter at JCU and are hoping to gain a larger student body this year. We are looking forward to holding various events including a Student Meets Industry night and monthly BBQs. I also run the Earth Social Club alongside Elora Baird and Dr Brandon Mahan. We hope to engage students and build connections between their colleagues, postgrads and lecturers through fun and casual events centred around the wonders and marvels of our Planet Earth.

Project:  I am really looking forward to advancing my practical skills in the lab this year at the Advanced Analytical Centre (AAC) through my special topic alongside the supervision of Dr Brandon Mahan. This will be focused on the influx of sediment into the offshore coast of Brazil as a result of the Fundao tailings dam failure in 2015. I am excited to expand my knowledge on isotope geochemistry and apply my practical abilities in a laboratory setting.

Mark Nestmeyer

Post-Graduate (PhD)

BSc Friedrich-Alexander-University of Erlangen-Nuremberg (FAU, Germany), MSc Friedrich-Alexander-University of Erlangen-Nuremberg (FAU, Germany)

My research interests are concerned with the application of geochemical methods to assess the mobilisation and fractionation mechanisms of elements in the earth crust and chemical exchange with hydrosphere and atmosphere. This improves our knowledge about processes crucial for our society such as the genesis of ore deposits or environmental changes through earth history. I am especially interested in developing comprehensive models applicable on a global scale. My past research experience let me contribute to our understanding of the oceans’ biogeochemical cycle by examining hydrothermal processes leading to the enrichment and precipitation of eco-toxological elements as well as base metals in the ocean. Furthermore, I like to assist undergraduate courses to help the students to succeed but also to strengthen my knowledge in the principles of Geoscience.

Project:I am investigating the isotope fractionation of Zn and Nd in constituents of banded iron formations such as goethite, siderite or even primary metastable phases. For this purpose, the minerals of interest are synthesised under simulated archean and proterozoic environmental conditions using an anoxic chamber and artificial ancient seawater solutions. Yielded isotope fractionation in precipitates from aqueous solutions are used to correct natural banded iron formations for these values to obtain net shifts in isotope ratios in the ancient environment. This can be used to trace significant chemical changes in the past ocean and atmosphere due to continental emergence and exposure which caused the mobilisation of specific isotopes. Methods I widely use are XRD, ICP-MS and MC-ICP-MS.

Laboratory Specialist, Geosciences 

BSc Nanjing University (China), PhD Chinese Academy of Sciences (China) & Curtin University (Australia).

I am a geochemist and igneous petrologist. My primary research interest focuses on the generation and evolution of felsic melts and their implications for continental crust formation and differentiation. As a specialist at JCU, I supervise the operation of the Petrographic facilities in the Department of Geosciences and lead the method development of U-Pb isotope dating on various accessory minerals (e.g., zircon, titanite, apatite, rutile, monazite, and garnet) and ore minerals (e.g., cassiterite, wolframite, and bastnasite). In collaboration with government bodies and industry partners, I am currently working on a few projects focusing on direct dating of ore minerals to place robust timing constraints on the origin of ore deposits.

Projects: Dating program of Chilean exploration projects (for HCOVGLOBAL and Tesoro Resources), U-Pb dating of cassiterite samples from Mallee Bull ore deposits (GSNSW),  mapping of trace element distribution in magnetite and sulphides (GSNSW).

Advanced  Geochemical & Isotropic Research

Post-Doctoral Researcher

BA (Hons) Leiden University (Netherlands), RMA Leiden University (Netherlands), PhD University of Wollongong (Australia).

Starting from a background in archaeology, with a focus on palaeolithic archaeology and human evolution, I started in isotope geochemistry to understand how ecology – specifically diet – contributed to the evolution of now‑extinct fauna that lived in the same environments as hominin species. During my PhD project, I applied strontium and calcium isotope analyses to fossil teeth of Australian megafauna and island fauna from Flores (Indonesia) to reconstruct Pleistocene food webs. Through this, I discovered the multi-disciplinary use of geochemical techniques and my research interests extended to the application of trace elements and isotope analyses to many different fields, such as modern ecology, environmental conservation, and biomedicine.