Abstract The San Juan volcanic field comprises 25,000 km 2 of intermediate composition mid-Tertiary volcanic rocks and dacitic to rhyolitic calderas including the San Juan-Uncompahgre and La Garita caldera-forming super-volcanoes. The region is famous for the geological, ecological, hydrological, archeological, and climatological diversity. These characteristics supported ancestral Puebloan populations. The area is also important for its mineral wealth that once fueled local economic vitality. Today, mitigating and/or investigating the impacts of mining and establishing the region as a climate base station are the focuses of ongoing research. Studies include advanced water treatment, the acid neutralizing capacity (ANC) of propylitic bedrock for use in mine-lands cleanup, and the use of soil amendments including biochar from beetle-kill pines. Biochar aids soil productivity and revegetation by incorporation into soils to improve moisture retention, reduce erosion, and support the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO 2 emissions. This field trip will examine the volcano-tectonic and cultural history of the San Juan volcanic field as well as its geologic structures, economic mineral deposits and impacts, recent mitigation measures, and associated climate research. Field trip stops will include a visit to (1) the Summitville Superfund site to explore quartz alunite-Au mineralization, and associated alteration and new water-quality mitigation strategies; (2) the historic Creede epithermal-polymetallic-vein district with remarkably preserved resurgent calderas, keystone-graben, and moat sediments; (3) the historic mining town of Silverton located in the nested San Juan-Silverton caldera complex that exhibits base-metal Au-Ag mineralization; and (4) the site of ANC and NTS studies. En route back to Denver, we will traverse Grand Mesa, a high NTS area with Neogene basalt-derived soils and will enjoy a soak in the geothermal waters of the Aspen anomaly at Glenwood Springs.

Since 2003, the standard igneous and metamorphic petrology class at Fort Lewis College has been taught as a field-based, inquiry-driven course focused on topics in three different field areas (Ship Rock, Western Needle Mountains, San Juan volcanic field). This format allows undergraduate students to investigate advanced topics in petrology through field research while developing skills for continuing education and scientific careers. These courses serve the needs of the students by promoting critical analysis and inquiry, and building on content taught in previous courses to solve actual geologic problems. Many of the students also find enthusiasm for continued research and make further contributions to the geologic community. A research-focused field course at the undergraduate level allows students to engage in all facets of research in the context of natural geologic complexity. In addition, these students can collaborate with professional geoscientists to network and find opportunities that are not readily available to their peers outside the course. Engaging undergraduate geoscience students in authentic research projects is a benefit to their education and career development.