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Updated: Jun 02, 2016
IGCP Project 559 - Seismic Images
Convergent continental margins
North American Western Margin Transects, Pacific Ocean margin, USA - Canada
Nine transects across the west margin of North America. Common tectonic elements identified along these transects all relate to convergent continental margins and include: 1. actively subducting oceanic crust; 2. accreted oceanic/arc lithosphere of Mesozoic through Cenozoic ages; 3. Cenozoic accretionary prisms; 4. Mesozoic accretionary prisms; 5. backstops to the Mesozoic prisms; 6. undivided lower crust. Four of the transects cross subduction-zones, and five cross a transform-fault (San Andreas fault).
ANCORP '96 Transect, Chile and Bolivia, South America
Transect crosses the Central Andes, an active subduction margin. Transect shows components of the active continental margin, including the forearc, the arc, the Altiplano (region of overthickened crust, plateau uplift and backarc dynamics) and basin formation in the actively deforming upper plate.
Central and southern Andes Transects, Chile, South America (PDF file)
Transect crosses the central and southern Andes and (includes ANCORP'96). Transect shows structure and rheology of the upper plate from seismological investigations.
Central Andes Transect, South America (PDF file)
Transect crosses the central Andes. Transect shows Moho topography from teleseismic receiver functions and its geodynamic implications.
Central Andes Transect, South America (PDF file)
Transect crosses the central Andes. Transect shows dynamics of the central Andes and provides constraints from P-to-S converted seismic waves.
Southern Cordillera Transect, British Columbia, Canada
Transect crosses the Southern Cordillera of western Canada. Transect shows process of accretion of terranes that comprise plate fragments, island arcs, or microcontinents, within the Canadian Cordillera.
Puget Sound Transect, Seattle, northwest USA (I) (PDF file)
Transect crosses the Cascadia subduction zone of northwestern US and southwest Canada. Transect shows a cross section of seismicity across an active subduction zone.
Puget Sound Transect, Seattle, northwest USA (II) (PDF file)
Transect crosses the Cascadia subduction zone of northwestern US and southwest Canada. Transect shows the Seattle uplift, the Seattle fault, the Kingston arch, the transpressional Southern Whidbey Island Fault Zone and the Puget Lowlands area; an area lying on a north-directed thrust sheet.
Central Andes Transect, North Chile, South America
Transect crosses the Central Andes. An excellent example of a cordilleran orogen related to active subduction of an oceanic plate under a continental plate. Transect shows components of the active continental margin, including the trench, arc, coastal Cordillera, Longitudinal Valley, Precordillera, western Cordillera and the Altiplano. Composite sections show that petrological processes driven by active subduction are the probable causes for most of the conspicuous features seen in the section.
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