The Alexander-Taku terrane boundary in southeast Alaska represents one of the major tectonic accretionary sutures in the North American Cordillera. Prior work has shown that the boundary consists of a major west-vergent thrust belt which formed in middle Cretaceous time in conjunction with the juxta position of the two terranes and the onset of regional plutonism of the Coast Plutonic Complex. This renewal project will complete a detailed analysis of the structure of the thrust belt and its relations with plutonism, and characterization of the stratigraphic units and depositional relations along the terrane boundary. Laboratory analysis will include Pb/U zircon and Nd/Sm-Rb/Sr geochronology, isotopic studies, bulk rock petrochemical studies and shear zone kinematic analyses. Completion of this research will provide a detailed structural and stratigraphic analysis of the Alexander- Taku terrane boundary, which will be a fundamental basis for considering the petrogenesis and structure of the Coast Plutonic Complex.
