6-4 Porphyry Copper Genesis Using REE Modeling in the Magma Chamber Simulator: A teaching perspective

Session: Geoscience Education in the Western U.S and México. Practices, Pathways, and Partnerships. (Posters)

Poster Booth No.: 4

Presenting Author:

Tomás Grijalva-Rodríguez

Authors:

Grijalva-Rodríguez, Tomás Israel¹, Santillana-Villa , Cecilia², Valencia-Moreno, Martín³, Hernández, David⁴

(1) Departamento Académico de Ciencias de la Tierra, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur, Mexico, (2) Universidad Nacional Autónoma de México, Hermosillo, Sonora, Mexico, (3) Universidad Nacional Autónoma de México, Hermosillo, Sonora, Mexico, (4) Department of Earth and Environmental Sciences,, University of Illinois, Chicago, Illinois, USA,

Abstract:

Assessing magmatic differentiation and ore-forming processes remains challenging because many of the key mechanisms operate at depth and under conditions that are difficult to estimate. To address this challenge, this poster presents an inquiry-based educational case study that uses rare earth element (REE) systematics from the Buenavista del Cobre porphyry copper deposit (Sonora, Mexico) as a unifying framework for process-oriented learning in upper-level undergraduate and graduate geoscience courses. Within this framework, differences in chondrite-normalized REE patterns between a precursor pluton and a productive intrusive stock—most notably lower overall REE abundances and a shift from slightly negative to positive Eu anomalies—serve as the starting point for student-driven exploration. These geochemical observations are examined using the Magma Chamber Simulator (MCS), which enables students to move beyond qualitative descriptions and quantitatively investigate fractional crystallization, crustal assimilation, redox conditions, and mineral stability during magma evolution.

Building on these simulations, the instructional sequence is organized around a two-stage magmatic scenario. First, students model the assimilation and fractional crystallization of a calc-alkaline basaltic melt at lower-crustal depths, developing an understanding of how deep-crustal processes influence melting composition. The focus then shifts to fractional crystallization within a mid-crustal magma chamber, followed by late-stage, fluid-rich magmatic ascent, which is relevant to porphyry copper mineralization. MCS modeling experiments assess the importance of amphibole fractionation under oxidizing conditions in shifting the polarity of the Eu anomaly and promoting a concave-up heavy REE pattern once a substantial portion of the magma has crystallized.

From a geoscience education perspective, this integrated approach emphasizes quantitative reasoning, systems thinking, and hypothesis testing through numerical simulation. Students gain experience interpreting trace-element proxies, comparing competing petrogenetic models, and linking mineralogical processes to ore-forming efficiency. The case study is adaptable to courses in igneous petrology, geochemistry, economic geology, and computational geoscience, and it demonstrates how research-grade modeling tools and industry-relevant geological problems can be effectively incorporated into geoscience curricula to enhance conceptual understanding and modeling literacy.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

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