AN: T11B-06TI: Crustal Structure Across the Coast Shear and the Coast Mountains    Batholith from Wide-Angle Seismic DataAU: Igor B. MorozovAF: Department of Geology and Geophysics, University of Wyoming, Laramie    WY 82071-3006EM: morozov@uwyo.eduAU: Jingru ChenAF: Department of Geology and Geophysics, University of Wyoming, Laramie    WY 82071-3006EM: jingru@uwyo.eduAU: Scott B. SmithsonAF: Department of Geology and Geophysics, University of Wyoming, Laramie    WY 82071-3006EM: smithson@uwyo.eduAU: Lincoln S. HollisterAF: Department of Geosciences, Princeton University, Princeton, New Jersey    08544EM: linc@geo.Princeton.EDUAB: We present the crustal structure along the entire 260 km long ACCRETE    profile along the border between SE Alaska and British Columbia.    P-wave velocity structure and reflectivity is imaged using travel-time    tomography, forward ray tracing and mid-point stacking of the    wideangle reflection/refraction seismic dataset. The stacked Moho    reflector correlates well with the ray tracing model and multi-channel    seismic section. Around 70 km SW of the Coast Shear Zone (CSZ), a Moho    offset of about 2 km might indicate a paleo-subduction zone. From 70    km to the CSZ, Moho is about 25 km in depth, with little variation. NE    of the CSZ, the Moho deepens from about 25 km to 32 km within a    lateral distance of 30 km. The Moho shallows slowly between 40 km to    70 km NE of the CSZ, after which it goes deeper gradually with the    maximum depth of about 36 km under the Skeena fold and thrust belt.    Several steeply dipping reflectors dipping at about 30-40 degrees NE    are imaged within the crust west of the CSZ. One of these reflectors    is reliably traced all the way from the near surface to the Moho under    the CSZ. These reflectors probably correspond to the midCretaceous    thrust system. The fact that none of these reflectors crosses the CSZ    may indicate that the CSZ was formed later than the mid-Cretaceous    thrust system. In the upper crust of the Coast Mountains Batholith    (CMB), several reflectors dipping at about 20-25 degrees NE may    correspond to a fabric related to the 50 Ma extension along the    eastern margin of the CMB. The termination of a number of prominent    mid- and lower crustal reflections reveals a discontinuity of the    reflectivity in the vicinity of the CSZ.SC: TDE: 8105DE: 9350DE: 7218MN: 1997 Fall Meeting