Collaborative Research: Is the Ingalls Complex (N. Cascades, WA) a Polygenetic Ophiolite? A Multidisciplinary Study

San Jose State University Foundation, San Jose CA

Investigators

Abstract

0003444 Harper 0087829 Miller Accretionary and subduction complexes are commonly difficult to reconstruct due to subsequent structural complexity and lack of distinctive lithologies, fossils or stratigraphic sequences. Ophiolites, either of ocean floor or back-arc origins, provide unusually robust data that can guide structural and stratigraphic correlations and tectonic reconstructions in areas of controversial histories. This collaborative project will examine the Ingalls ophiolite complex of the north Cascades in order to help discriminate between several regionally important assembly possibilities. The work involves geochemical characterization, age dating and provenance analysis of the Ingalls complex and comparison of the results to other ophiolites that extend for 1000 km along the western United States margin. These data will help determine whether the Ingalls complex was formed near its present position, was transported long distances laterally as part of Baja-BC, or is exotic with respect to stable North America.