31 CRITICAL MINERAL DEPOSITS AND ORE SYSTEMS OF THE NORTHEAST (Poster)

This session will showcase new findings pertaining to critical mineral resources and hydrothermal-magmatic ore systems across the northeast. We welcome submissions involving fieldwork, geochemical, petrologic, geochronologic, and other approaches from micro- to macroscopic scales.

Monday, 23 March 2026
1:30 PM - 5:30 PM
CCC, Ballroom C

Copper Partitioning between Fluid and Melt at High Pressure-Temperature Conditions

Paper number: 31-2
Program: Technical Sessions
Time: 1:30 PM – 1:30 PM

Authors

Abstract

Copper production is becoming increasingly important with the electrification of society, as it is used extensively in modern technology. Copper deposits are often associated with granitic composition rocks and fluids exsolved from granitic melts. Both the melt and fluid can host, transport, and deposit copper. Previous studies analyzing copper partitioning between fluid and melt have focused on upper crustal Pressure-Temperature (P-T) conditions, mimicking copper’s depositional environment. However, these melts likely originate at much greater depths before being transported up through the crust. This project studies copper partitioning between aqueous fluid and granitic melt at high P-T conditions, equivalent to lower continental crust depths. Experiments were synthesized in piston-cylinder devices with a natural granitic starting material and spiked with either copper chloride or copper oxide. This allows us to also explore the effect that the addition of chlorine has on copper partitioning. Fractured quartz was used to trap fluid inclusions to study the fluid chemistry, and the experiments were quenched so the melt formed a glass. The copper concentration in the glass was measured using Electron Probe Microanalysis (EPMA), and the fluid inclusions were studied using microthermometry. Initial estimates of copper partition coefficients were calculated using mass balance principles, and future work will use Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICPMS) to directly measure the copper concentration in the fluid inclusions.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411433

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