Full Title: Subduction, underplating, and exhumation in a hot subduction zone
Endorsed by: GSA’s Structural Geology and Tectonics, Mineralogy, Geochemistry, Petrology, and Volcanology Divisions
Led by: John P. Platt, Frances Cooper, Justine Grabiec
Date: Wed–Sat. 15–18 Oct. 2025
Time: 8:45 a.m. (first day) – 8:45 a.m. (last day)
Location: Santa Catalina Island, California, USA
Departure Location: Catalina Express San Pedro Terminal, San Pedro, California
CEUs: 2.4
The trip will explore the structure and petrology of the Catalina Schist terrane on Santa Catalina Island, California. The island exposes rocks of oceanic origin metamorphosed under various grades from lawsonite-blueschist to upper amphibolite/eclogite, in a series of tectonic slices, separated in part by ultramafic melange carrying high-grade blocks. The trip will consider the implications of the inverted metamorphic sequence and the significance of the tectonic contacts in terms of the thermal and mechanical evolution of the subduction complex during subduction, underplating, and exhumation. Cost includes transportation to the island (boat) and on the island (vans), bunk space at the Wrigley Center, and meals.
The field trip starts and ends at the Catalina Express Ferry Terminal in San Pedro California. Note that there are other ferry terminals, which do not have ferries to our destination (Two Harbors). The crossing takes 75 minutes, and the San Pedro Channel can be rough: take medication 1 hour before departure if you are susceptible to motion sickness. Transportation on the island will be by van provided by the Wrigley Marine Science Center. Distances are small, but if there is rain, some of the roads may not be passable, and the itinerary may have to be modified. Meals (including packed lunch everyday including the first and last days) will be provided by the Wrigley Center, as well as dormitory style accommodation. Please bring a canteen; drinking water and bathrooms are available at some of the field stops.
By purchasing this item, you are buying a seat on an in-person geological field trip.
Please review these Field Safety Documents. You will be contacted to provide your consent to these forms after purchasing a field trip.
Learn more about this and other GSA Connects 2025 events.
For additional information, please contact Rebecca Taormina, rtaormina@geosociety.org, GSA Field Trip and Short Program Coordinator.
Product Code: FT25CN418
Product Category: FTRIP