Wu, N, Jackson, CA-L, Johnson, HD et al. (4 more authors) (2021) The formation and implications of giant blocks and fluid escape structures in submarine lateral spreads. Basin Research, 33 (3). pp. 1711-1730. ISSN 0950-091X
Abstract
Lateral spread and submarine creep are processes that occur near the headwalls of both terrestrial landslides and submarine mass‐transport complexes (MTCs). Both submarine creep and spread deposits may contain giant (km‐scale) coherent blocks, but their transport processes remain poorly constrained. Here we use seismic reflection data to determine the geometry, scale, and origin of a Late Miocene mass‐transport complex (MTC) located in the Kangaroo Syncline, offshore NW Australia. We show that this large remobilised mass of carbonate ooze is ca. 170–300 m thick and covers an area of at least 1,050 km2. The deposit is defined internally by two distinct seismic facies: (a) large, upward‐tapering blocks (210–300 m thick, 170–210 m wide and 800–1,200 m long) with negligible internal deformation, which decrease in height and spacing along the transport direction (identical, but in situ, seismic facies forms undeformed slope material immediately updip of the deposit headwall); and (b) troughs (160–260 m thick, 190–230 m wide and 800–1,200 m long) comprising moderately deformed strata, which contain ‘v’‐shaped, pipe‐like structures that extend upwards from the inferred basal shear surface to the top surface. The lack of deformation within the blocks, and their correlation to adjacent in situ deposits, suggests they underwent limited transport (ca. 50 m–70 m). The relatively high degree of deformation within the intervening troughs is attributed to the vertical expulsion of fluids and sediment during hydraulic failure of the sediment mass. We present a hydraulic failure model that invokes evacuation of the lower slope by a precursor MTC and which formed the space to trigger the lateral spread. Our study also provides new insights into the genesis and rheology of subaqueous lateral spreads. The genetic links identified between mass wasting and spatially focused fluid flow, as well as disturbing the deep seafloor, indicate that submarine landslides may also create important deep‐sea biodiversity hotspots.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Authors. Basin Research published by International Association of Sedimentologists and European Association of Geoscientists and Engineers and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/) |
Keywords: | Australia; Exmouth Plateau; geohazard; mass‐transport complex (MTC); NW Shelf; slope failure; spread; submarine landslide |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 18 Nov 2020 14:09 |
Last Modified: | 25 Jun 2023 22:30 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1111/bre.12532 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:168100 |