GSA Connects 2022 meeting in Denver, Colorado

Paper No. 10-9
Presentation Time: 10:40 AM

3D MODEL OF THE SOUTHERN ALISITOS ARC CRUSTAL SECTION, BAJA CALIFORNIA


MORRIS, Rebecca, School of Earth & Ocean Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, CANADA, BUSBY, Cathy, Earth and Planetary Sciences, University of California Davis, One Shields Ave, Davis, CA 95616, DEBARI, Susan M., Western Washington University, 516 High St, Bellingham, WA 98225 and MEDYNSKI, Sarah, Centre Scientifique et Technique du Bâtiment, Champs-sur-Marne, 77447, France

We present the Cretaceous Alisitos Oceanic Arc 3D Model, which is a publicly accessible and interactive 3D model of juvenile arc crust from surface to approximately 7 km depth, with geologic map overlays on Google Earth. The model provides a virtual field trip through exceptional exposures of the upper- to middle-crust transition in the exhumed Cretaceous southern Alisitos Arc, Baja California, Mexico (‘Rosario Segment’). Within this region, exposures of heterogeneous upper volcanic crust and underlying plutonic rock display details of the transition between them.

The model presents profiles of three paleo-volcanic centers, which include (from north to south): a northern fault-bounded basin, a central subaerial edifice, and a southern volcano-bounded basin. Each volcanic center is underpinned by a separate pluton, which include (also from north to south): the Los Martires pluton, the La Burra pluton, and the San Fernando pluton. The interactive model is available for download (Morris et al., 2022: https://doi.org/10.25710/hw4d-7335) and provides GPS-located outcrop information from >200 sample/site locations by linking unique outcrop details, which include field images, +/- petrography, +/- geochemistry, and +/- geochronology.

This model supports a paper of Busby et al. (submitted and in revision) that summarizes decades of field mapping completed by Busby and colleagues and the associated petrogenetic story of Morris et al. (2019; JPet, v.60(6), pp.1195-1228). The model will provide an interactive web-based tool that can be used by scientists as a reference model for active arc systems. The model can also be used as a database for curriculum and instruction in undergraduate and graduate classes.