231-8 Using Experimental Thermodynamics to Decipher Ore Deposit-Related Geological Processes and More

Session: Critical Mineral Resources and Recovery in the Americas: Emerging Methods in Exploration and Sustainable Extraction (Posters)

Presenting Author:

Authors:

Abstract:

Using Experimental Thermodynamics to Decipher Ore Deposit-Related Geological Processes and More

Manuel Scharrer^1,2,3, Godwin Agbanga^1,3, Anne Harrison⁴, Alexandra Navrotsky^1,2,3

¹ Navrotsky Eyring Center for Materials of the Universe and School of Molecular Sciences,

Arizona State University, Tempe, AZ 85287, USA

² School of Molecular Sciences, Arizona State University, Tempe, AZ 85287

⁴ Department of Earth, Environmental, and Planetary Sciences, University of Tennessee, 37916 TN

⁴ Ira A. Fulton School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, USA

Many geological processes occur at conditions that are difficult or impossible to replicate experimentally—either due to kinetic barriers at low temperatures or inaccessible pressures and temperatures. In such cases, thermodynamic modeling offers a powerful tool to bridge the gap between observation and mechanism. However, these models are only as good as the data they rely on—and for many ore-forming minerals, key thermodynamic properties such as enthalpy of formation, entropy, and heat capacity functions are poorly constrained or estimated using outdated approaches.

Here, we present four case studies demonstrating how experimental thermodynamics can inform ore-related questions: (1) calorimetric data reveal strong negative enthalpies of mixing in the Co-Ni-Fe pentlandite system, significantly enhancing phase stability; (2) rare earth carbonate phase relations in the REE-H₂O-CO₂ system help predict REE fractionation behavior; (3) thermodynamic stability trend of Ni-, Co- and Fe- arsenides is reflected in temporal and spatial zoning of five-element veins; and (4) the relative stability of cinnabar and metacinnabar nanoparticles is shown to depend on surface energies and surfactants, with implications for mercury remediation. These examples illustrate how experimental thermodynamics can unlock insights into mineral stability, ore formation, and environmental behavior.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9616

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.