Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Erosional features as indicators of thrust fault activity (Nankai Trough, Japan)

Alves, Tiago Marcos ORCID: https://orcid.org/0000-0002-2765-3760, Strasser, M. and Moore, G.F. 2014. Erosional features as indicators of thrust fault activity (Nankai Trough, Japan). Marine Geology 356 , pp. 5-18. 10.1016/j.margeo.2013.07.011

[thumbnail of Alves - MGeology 2013.pdf]
Preview
PDF
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (2MB) | Preview

Abstract

A submarine channel system and basal ramps of a Quaternary mass-transport deposit (MTD) are shown to represent thrust fault activity in the Nankai accretionary wedge. Variations in channel bed slope, height and width of submarine channels and gullies indicate uplift and sediment bypass seaward from a margin-dominating out-of-sequence thrust, the megasplay fault (MSF), at < 1.67-1.46 Ma. Between ~ 1.05 and 0.85 Ma, a younger mass-transport deposit (MTD 6) was detached at different depths. Demonstrating the significant deformation observed in the study area, the direction of transport of MTD 6 differs 30o-45o from the strike of scarps and ramps at its base, which are parallel to the structural contours of thrust anticlines underneath. This character contrasts to the geometries frequently documented in frontally-emergent submarine landslides. In parallel, oblique basal ramps form significant boundaries between zones of MTD 6 with distinct acoustic and, suggestively, petrophysical properties. As a result of this study, we postulate that developed channel systems can erode the upper continental slope and lead to bypass of substantial volumes of sediment to distal parts of accretionary wedges. This process bears the potential of generating periods of more intense thrust-wedge deformation, at least locally, than those predicted by mathematical and physical models based on present-day taper geometries. On a regional scale, the observations in this paper are important as they indicate a more diffuse distribution of deformation in the Nankai accretionary wedge than previously assumed for the MSF region.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Environmental Sciences
Subjects: Q Science > QE Geology
Publisher: Elsevier
ISSN: 0025-3227
Date of Acceptance: 17 July 2013
Last Modified: 22 May 2023 05:05
URI: https://orca.cardiff.ac.uk/id/eprint/50509

Citation Data

Cited 28 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics