General Research Interests

Ore Deposits: My research interests are focused on the application of experimental geology to the formation of ore deposits. I perform experiments in cold-seal pressure vessels, hydrothermal reactors, a piston-cylinder apparatus, and evacuated silica tubes to characterize the behavior of metals in magmatic systems. The metals I am interested in are commonly referred to as “critical materials”. Critical materials have been defined as elements that are necessary to the production of technology used in modern life, but are difficult to obtain. These metals commonly include, but are not limited to, the rare earth elements, scandium, yttrium, indium, and tellurium. To date my research has taken an in-depth look at indium (the subject of my MS) and scandium (the subject of my PhD), as well as large suites of both critical and non-critical metals (Post-doc research). More information on metals resources can be found at the Critical Materials Institute and the United States Geological Survey.

Experimental Geology: I have a general interest in magmatic-hydrothermal experimentation, which includes experiments conducted in cold-seal pressure vessels, evacuated silica tubes, gas-mixing furnaces, piston-cylinder apparatus, and internally heated pressure vessels. In addition, I am also interested in the various techniques used to control experimental conditions (pressure, temperature, oxygen fugacity, pH, etc.). On a broad level I am interested in the application of these experiments to fields other than economic geology, such as volcanology, petrology, and mineralogy.

Previous Research Projects

Metal Partitioning Between Vapor and Melt in Magmatic Hydrothermal Systems

The goal of this research is to characterize the partitioning of metals between fluids exsolved from a melt and the coexisting melt. Experiments are being performed in internally heated pressure vessels at Institut des Sciences de la Terre d’Orléans (ISTO) at a temperature of 800°C and a pressure of 200 MPa.  The magmatic systems that are being investigated range from fluorine-poor to fluorine-rich systems and the coexisting fluid has a variable chlorine content.   This research will elucidate how the chlorine and fluorine content of a fluid affects the partitioning behavior of metals in magmatic systems. Such information can be used to further understand the formation of ore deposits related to rare element granites, as well as rare-element granitic pegmatites. The results of this research are expected to produce several publications on metal partitioning and the exchange of fluorine and chlorine between a vapor and melt.

Partitioning of Indium Between Ferromagnesian Minerals and a Silicate Melt

The focus of this research was to characterize the behavior of indium in felsic magmatic-hydrothermal systems and predict the characteristics that may generate indium-rich ore deposits.  Experiments were performed in cold-seal pressure vessels at temperatures of 750 and 800°C and a pressure of 100 MPa in order to determine the partition coefficients for indium between biotite and melt, amphibole and melt, and vapor and melt.  By understanding the behavior of indium in felsic, magmatic-hydrothermal systems, it is possible to model and predict which types of ore deposits are more likely to contain elevated concentrations of indium.  Such predictions will increase the ability to find indium-rich deposits, where indium can be mined for use in products such as touch screens and solar panels. This research was published in two papers one in “Chemical Geology” and one in “Economic Geology”.

The Behavior of Scandium During Fractional Crystallization and Implications for Ore Formation

The goal of this research is to characterize the behavior of scandium during fractional crystallization in a series of genetically related melts that range in composition from basaltic to rhyolitic.  Experiments in these systems were performed in cold-seal pressure vessels at temperatures of 800° to 965° C, at a pressure of 100 MPa, and oxygen fugacities ranging from fayalite-magnetite-quartz to nickel-nickel oxide +1.3. Partition coefficients for scandium between olivine, pyroxene, biotite, plagioclase, spinel, and apatite and a coexisting silicate melt were determined.  This research has led to a significant increase in the understanding of the behavior of scandium in magmatic systems and how scandium-bearing ores may form.  This knowledge will increase the ability to find scandium-bearing deposits where scandium can be mined for use in the production of high-strength, lightweight alloys.  This research is ongoing and is expected to result in several publications, which will detail the results of these experiments and include trace element modeling for scandium in magmatic-hydrothermal systems.

Amphibolite Anatexis and Implications for the Formation of Scandium-rich Pegmatites

 The goal of this research is to understand the petrogenesis of the Evje-Iveland pegmatite field in Norway.  This pegmatite field is renowned for hosting minerals wherein scandium is a primary constituent.  It has been proposed that these pegmatites were formed as the result of partial melting of an amphibolite host rock and the scandium that is now hosted in the pegmatites was also sourced from the amphibolite.  In order to test this hypothesis, piston-cylinder experiments were performed at 500 MPa and between 700 and 950° C to characterize the phase relations and trace element partitioning during partial melting of an amphibolite.  The results of this project are being prepared to be submitted for publication.

Characterization of Biotite and Amphibole Compositions in Granites

 The goal of this research was to characterize the compositions of ferromagnesian minerals (biotite and amphibole) in S-, I-, and A-type granites.  This research was a combination of an extensive literature search and a simple machine-learning model to test if the composition of biotite and amphibole further characterize granitic rocks.  The results of this project have been published in “Contributions to Mineralogy and Petrology”.

A Novel Technique for Generating Diamond Hosted Inclusion

A technique to generate inclusions hosted in diamonds utilizing a catalytic HP-HT diamond growth method in a multi-anvil press is being developed in collaboration with Dr. Yingwei Fei.  Once this technique is fully developed it can be used to study rates of equilibration and unmixing of minerals included in diamonds during exhumation, as well as plastic or brittle deformation of the inclusion and host.  This is an ongoing project that is expected to produce a publication during the 2020 year.

 Additional Collaborations

 Urban Geochemistry: Collaboration with Dr. Sujay Kaushal on student driven review paper on the geochemistry of urban environments. The emphasis of my contribution to the research was to provide an overview of sulfur in sewer systems and the effect of that sulfur on the corrosion of building materials. This research was published in “Applied Geochemistry”.

 Lithium in Garnet: Collaboration with Dr. Sarah Pennistson-Dorland and students to create lithium in garnet standards for SIMS (secondary ion mass spectrometry) analysis, by the melting of a natural garnet sample, as well as creating synthetic glasses with garnet compositions.

Publications in Refereed Journals

1. Gion, A.M., Gaillard, F., Freslon, N., Erdmann, S. and Di Carlo, I. (2022) A method for the direct analysis of quenched, magmatic-hydrothermal fluids recovered from high-pressure, high-temperature experiments. Chemical Geology 609, 121061, doi:10.1016/j.chemgeo.2022.121061.

2. Gion, A.M., Piccoli, P.M. and Candela, P.A. (2022) Characterization of biotite and amphibole compositions in granites. Contributions to Mineralogy and Petrology 177, 43, doi:10.1007/s00410-022-01908-7.

3. Gion, A.M., Piccoli, P.M., Fei, Y., Candela, P.A. and Ash, R.D. (2021) Experimental Constraints on the Formation of Pegmatite-forming Melts by Anatexis of Amphibolite: A Case Study from Evje-Iveland, Norway. Lithos, doi:10.1016/j.lithos.2021.106342.

4. Hoover, W.F., Penniston-Dorland, S.C., Baumgartner, L.P., Bouvier, A.-S., Baker, D., Dragovic, B. and Gion, A. (2021) A Method for SIMS Measurement of Lithium Isotopes in Garnet: The Utility of Glass Reference Materials. Geostandards and Geoanalytical Research, doi:10.1111/ggr.12383.

5. Kaushal, S.S., Wood, K.L., Galella, J.G., Gion, A.M., Haq, S., Goodling, P.J., Haviland, K.A., Reimer, J.E., Morel, C.J., Wessel, B., Nguyen, W., Hollingsworth, J.W., Mei, K., Leal, J., Widmer, J., Sharif, R., Mayer, P.M., Newcomer Johnson, T.A., Newcomb, K.D., Smith, E. and Belt, K.T. (2020) Making ‘chemical cocktails’ – Evolution of urban geochemical processes across the periodic table of elements. Applied Geochemistry 119.

6. Gion, A. M., Piccoli, P. M., and Candela, P. A., 2019, Constraints on the Formation of Granite-Related Indium Deposits: Economic Geology, v. 114, no. 5, p. 993-1003, doi:10.5382/econgeo.4668.

7. Gion, A. M., Piccoli, P. M., and Candela, P. A., 2018, Partitioning of indium between ferromagnesian minerals and a silicate melt: Chemical Geology, v. 500, p. 30-45, doi:10.1016/j.chemgeo.2018.08.020.

8. Gion, A. M., Williams, S. E., and Muller, R. D., 2017, A reconstruction of the Eurekan Orogeny incorporating deformation constraints: Tectonics, v. 36, doi:10.1002/2015TC004094.

Abstracts and Presented Works

1. Gion, A.M., Gaillard, F., Scaillet, B., Freslon, N., Erdmann, S. and Di Carlo, I. (2022) The Exchange of Metals Between Low-Salinity Vapors and Felsic Melts. Goldschmidt, Honolulu, Hawaii, USA.

2. Gion, A.M., Piccoli, P.M., Fei, Y., Candela, P.A. and Ash, R.D. (2021) Experimental Constraints on the Formation of Pegmatite-forming Melts by Anatexis of Amphibolite: A Case Study from Evje-Iveland, Norway. Goldschmidt, Lyon, France.

3. Kaushal, S., Wood, K. L., Galella, J. G., Haq, S., Haviland, K., Wessel, B., Morel, C., Reimer, J., Nguyen, W. D., Hollingsworth, J., Mei, K., Widmer, J. M., Sharif, R., Mayer, P. M., Johnson, T. A. N., Gion, A. M., Newcomb, K. D., and Belt, K., 2019, Watershed ‘Chemical Cocktails’ – Evolving Urban Biogeochemical Processes: American Geophysical Union Fall Meeting, San Francisco, CA.

4. Gion, A. M., Piccoli, P. M. Candela, P. A, 2018, An Experimental Study on the Formation of Scandium-Rich Rocks: American Geophysical Union Fall Meeting, Washington, D.C.

5. Sullivan, G., Gion, A. M., Piccoli, P. M. Candela, P. A., and Ash R. D., 2018, Modeling Indium Enrichment in the Mount Pleasant Ore: American Geophysical Union Fall Meeting, Washington, D.C.

6. Gion, A. M., Candela, P. A., and Piccoli, P. M., 2017, Experimental Geochemistry and Modeling as an Aide to Exploration: An Indium Case Study: Geological Society of America Abstracts with Programs, Seattle, Washington, v. 49, no. 6, doi:10.1130/abs/2017AM-306392

7. Gion, A. M. Williams, S. E., and Muller, R. D., 2017, Modelling and visualizing distributed compressional plate deformation using GPlates2.0: The Arctic Eurekan Orogeny: EGU General Assembly, Vienna, Austria.

8. Gion, A. M., Piccoli, P. M., and Candela, P. A., 2017, From Lab to Lode: Applications of Experimental Geochemistry to Mineral Exploration with Reference to Indium: Student Mineral Colloquium, Prospectors and Developers Association of Canada, Toronto, Canada.

9. Gion, A. M., Piccoli, P. M., Candela, P. A., and Nance, J. R., 2016, Indium In Ferromagnesian Minerals: An Experimental Study: Geological Society of America Abstracts with Programs, v. 48, no. 7, doi:10.1130/abs/2016AM-286546

10. Gion, A. M., Piccoli, P. M., Candela, P. A., and Nance, J. R., 2016, Partitioning of Indium Between Biotite and Felsic Melts: Pan-American Current Research on Fluid Inclusions Conference, Columbia, Missouri.

11. Gion, A. M., Williams, S. E., and Muller, R. D., 2015, The Wegener Fault revisited: Building a deforming plate model for the Eurekan Orogeny: GeoBerlin Dynamic Earth – from Alfred Wegener to today and beyond, Berlin, Germany.

Grants

NSF REU (Research Experience for Undergraduates) awarded to Philip Piccoli and Philip Candela as an extension for NSF EAR 1348010 to study the distribution of indium in the Mount Pleasant ore system. Amount awarded: $6,000.