Channel Architecture Influenced by Precursor Channelized Submarine Landslide Topography in the Taranaki Basin

Join Zoom Meeting
Join this presentation In-Person: BEG Building 130, VR Room 1.116C Or Via Zoom
This meeting will not be recorded

Meeting ID: 932 0137 7630
Passcode: 013011

Presenter

Dallas B. Dunlap, Ph. D
Research Scientist Associate IV
Bureau of Economic Geology
Jackson School of Geosciences
The University of Texas at Austin

Description

Availability of high-resolution, laterally extensive 3D seismic reflection data in the Taranaki Basin reveals deep-water submarine channels with unusually high-angle meander bends developed above channelized Miocene-age debris-flow deposits. We interpret this system as a vertically stacked channel complex in which an upper channel system, composed of at least eleven channel elements, overtops and diverts around large rafted blocks embedded within a heterogeneous submarine mass-transport deposit (MTD). These block–flow interactions redirect turbidity currents toward channel margins, driving lateral migration, localized erosion, and channel expansion. In contrast, where channels traverse the MTD without exposed blocks, they remain comparatively linear and laterally confined, with limited migration or avulsion. Block size, relief, and orientation relative to flow direction appear to exert a first-order control on depositional architecture: larger or obliquely oriented blocks strongly deflect flow, producing asymmetric erosion and thicker margin deposits, whereas smaller or more flow-parallel blocks generate subtler perturbations with less diversion and wider splaying channel deposits.