14 Lost Oceans, Shifting Continents: Interdisciplinary Records of Paleo-Pacific Plate Histories in the American Cordilleras

This session integrates tectonics, petrology, geochronology, stratigraphy, and paleontology to illuminate how Paleo-Pacific plates drove subduction dynamics, crustal evolution, and paleogeographic reconstructions across the complex geological architecture of the American Cordilleras.

Wednesday, 22 April 2026
1:30 PM - 4:00 PM
LMH, Meeting Room

Participants

• Chair María Sandoval
• Chair Vanessa Colás
• Chair Elisa Fitz-Diaz
• Chair Kennet Flores

Presentations

• 1:30 PM
  Asymmetric spreading formed a Shatsky-Ojin-Hess conjugate (SOHCO) oceanic plateaux that subducted under North America
  Jonny Wu, University of Arizona, Tucson, AZ and Edward Clennett, Birkbeck, University of London, London
  410832 (Technical Sessions)
• 1:50 PM
  Initiation of Subduction Recorded in the Franciscan Complex: Plate Tectonic Models and Context in the Cordillera of Alta California
  John Wakabayashi, California State University, Fresno, Castro Valley, CA
  410797 (Technical Sessions)
• 2:10 PM
  Detrital zircon U-Pb CA-ID-TIMS constraints on deposition of the Cerro Rajon Formation (Sonora, Mexico) and identification of a potential local source of volcanism
  Ada Encinas-Symonds, Universidad de Sonora, Hermosillo, Sonora and William Matthews, University of Calgary, Calgary, Alberta and James Crowley, Boise State University, Boise, ID and James Hagadorn, Denver Museum of Nature & Science, Denver, CO
  411063 (Technical Sessions)
• 2:30 PM
  Reappraisal of plagiogranites and mafic rocks of a Late Triassic upper plate ophiolite, Vizcaíno Peninsula, Baja California Sur, Mexico
  Manuel Contreras-López, Instituto de Geología, Universidad Nacional Autónoma de México, Mexico City, 04510 and Vanessa Colás, Universidad Zaragoza, Zaragoza, 50009 and Elisa Fitz-Díaz, Instituto de Geología, Universidad Nacional Autónoma de México, Mexico City, 04510 and Luis Gutiérrez-Trejo, Universidad Nacional Autónoma de México, Mexico City, 04510 and Megan Mueller, University of Arizona, Arizona, 85721 and Bodo Weber, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, 22860 and James, The University of Texas, El Paso, 79902 and Timothy Lawton, University of Texas, Austin, 78712
  410782 (Technical Sessions)
• 2:50 PM
  Review of gabbroic and ultramafic rocks in the northern segment of the Colombian Andes: dismembered ophiolites versus subduction complexes
  Agustin Cardona, Universidad Nacional de Colombia, Medellin and Sebastian Zapata, Universidad del Rosario, Bogota and Juan Jaramillo, Pontificia Universidad Catolica del Peru, Lima and Paulina Munoz, Universidad Nacional de Colombia, Medellín and Victor Valencia, Washington State University, Pullman, Washington and Alejandra Bedoya, Universidad del Rosario, Bogotá and Juan Pablo Zapata, Universidad del Rosario, Medellín and Luna Amaya, Universidad del Rosario, Bogota and Edward Mora, Universidad Nacional de Colombia, Medellín and Julian Parra, Universidad Nacional de Colombia, Medellín and David Patino, Universidad Nacional de Colombia, Medellín and Sara Villa, Universidad Nacional de Colombia, Medellín and Maria Banquez, Universidad del Rosario
  411045 (Technical Sessions)
• 3:10 PM
  Calcareous nannofossils as proxies for paleoclimatic conditions across the paleocene–eocene boundary in the Tepetate Formation, arroyo El Conejo, Baja California Sur, Mexico
  Michelle Santiago Armenta, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur and Mara Cortés Martínez, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur and Tobias Schwennicke, Universidad Autonoma de B.C.S., Depto. de Ciencias de la Tierra, La Paz, BCS and José Pérez Venzor, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur
  411046 (Technical Sessions)
• 3:30 PM
  A new occurrence of Oncorhynchus rastrosus (the spike-toothed salmon) in coastal Oregon
  Win McLaughlin, Southwestern Oregon Community College, Coos Bay, OR and Nicholas Weldon, Southwestern Oregon Community College, Coos Bay, Oregon and Derek Morrelli, Southwestern Oregon Community College, Coos Bay, Oregon and Amy Burgess, Southwestern Oregon Community College, Coos Bay, Oregon and Elisabeth Tonn, University of Oregon, Eugene, Oregon
  411029 (Technical Sessions)