AN: T11B-08TI: Neotectonics of the Northern Queen Charlotte Fault ZoneAU: Scheidhauer, MarenAF: Oregon State UniversityEM: AU: Rohr, KristinAF: Geological Survey of Canada, PO Box 6000, Sidney BC, V8L 5S1,    CanadaEM: rohr@pgc.emr.caAU: Trehu, AnneAF: Oregon State UniversityEM: AB: Multi-channel images of the northern Queen Charlotte Fault (QCF), a    transform plate boundary between the Pacific and North American    plates, reveal a complex structural history since the onset of    transpression at 5 Ma. GLORIA images of the QCF collected by the USGS    show that its active trace lies just seaboard of the continental shelf    break and within a chaotic sequence in the reflection records. Seaward    of the main fault sediments have been faulted and folded into a    terrace 5-30 km wide. The outer edge of the terrace is usually defined    by a sharp topographic slope; behind it sedimentary beds have been    coherently uplifted and back tilted presumably on faults defining the    outer terrace. The faults strike at a small angle to the northern QCF    and the terrace consists of triangular wedges of deformed sediments.    Further south the terrace edge is subparallel to the QCF which strikes    more northwesterly. It seems likely that these faults first formed on    the southern QCF and have since been translated north with the Pacific    plate. When transpression began, oceanic crust was flexed and thrust    upward at the plate boundary to eventually reach a steadystate    configuration of an underthrust plate. Sediments on the oceanic plate    have significant angular unconformities which we believe are the    result of this first underthrusting.SC: TDE: 3025DE: 8015DE: 8109MN: 1997 Fall Meeting