Lateral variability in strain along the toewall of a mass transport deposit: a case study from the Makassar Strait, offshore Indonesia

Abstract

Contractional features characterize the toe domain of mass transport deposits. Their frontal geometry is typically classified as frontally confined or frontally emergent. However, it remains unclear how the style of frontal emplacement and contractional strain within a mass transport deposit vary along-strike. We use bathymetry and 3D seismic reflection data to investigate the lateral variability of frontal emplacement and strain within the toe domain of the Haya Slide in the Makassar Strait, offshore Indonesia. The slide originated from an anticline flank collapse and the toe domain is characterized by a radial fold–thrust belt that reflects southwestwards emplacement. The frontal geometry of the slide changes laterally. It is frontally confined in the south and is associated with a deep, c. 200 m b.s.f. planar basal shear surface. The frontal geometry gradually changes to frontally emergent in the west, associated with a shallow, c. 120 m b.s.f., c. 3° NE-dipping basal shear surface. Strain analysis shows c. 8–14% shortening, with the cumulative throw of the thrusts increasing along-strike westwards from c. 20–40 to c. 40–80 m. We show that even minor horizontal translation of mass transport deposits (c. 1 km) can result in marked lateral variability in the frontal geometry and strain within the failed body, which may influence their seal potential in petroleum systems.

Relating seafloor geomorphology to subsurface architecture: How mass‐transport deposits and knickpoint‐zones build the stratigraphy of the deep‐water Hikurangi Channel

“…Where MTDs are confined to the channelform they fill, they may have been sourced from the collapse of a confining terrace or levée where the source has been fully ‘evacuated’ (Kremer et al ., 2018; Nugraha et al ., 2020) or transported from more proximal locations (Bernhardt et al ., 2012; Masalimova et al ., 2015). Due to the presence of small, fully evacuated scars on the modern channel‐wall (Fig.…”

The erosionally confined to emergent transition in a slope‐derived blocky mass‐transport deposit interacting with a turbidite substrate, Ventimiglia Flysch Formation (Grès d’Annot System, north‐west Italy)

“…14B and C). A similar process for formation of megaclast‐bearing MTD has been proposed by several authors (Kvalstad et al ., 2005; Gee et al ., 2006; Callot et al ., 2008; Alves & Lourenço, 2010; Jackson, 2011; Martín‐Merino et al ., 2014; Alves, 2015; de Lima Rodrigues et al ., 2020; Nugraha, et al ., 2020).…”

“…The erosionally‐confined deposit shows an along‐strike textural and compositional variability, with the marlstone megabreccia becoming finer‐grained and more intensely mixed with substrate material (see Hybrid megabreccia section) at the southern, more marginal sector of the MTD (Figs 11 and 12). An increase in mixing with substrate sediments and clast disaggregation at MTD margins has been reported from several case studies (Frey‐Martínez et al ., 2006; Alves & Cartwright, 2009; Alves, 2010; Joanne et al ., 2013; Ortiz‐Karpf et al ., 2017; Nugraha, et al ., 2020) and interpreted to reflect along‐strike strain partitioning resulting from increased shear at flow margins. In agreement with this model, it is believed that the hybrid megabreccia was formed in the outer region of the advancing slide (including its base and leading edge; Fig.…”

Criteria to discriminate between different models of thrust ramping in gravity-driven fold and thrust systems

“…Mass transport deposits (MTDs) are associated with slope failure in both marine and lacustrine settings and are increasingly recognised across a range of scales from both seismic analysis (e.g. Armandita et al, 2015;Scarselli et al, 2016;Steventon et al, 2019;Nugraha et al, 2020;Sammartini et al, 2021) and outcrop-based studies (e.g. Morley et al, 2011;Sharman et al, 2015;Sobiesiak et al, 2016Sobiesiak et al, , 2017Sobiesiak et al, , 2018Jablonska et al, 2018;Cardona et al, 2020;Alsop and Weinberger, 2020).…”

“…The raising of hangingwall blocks during overthrusting may simply be accommodated close to the Earth's surface by areas of surficial uplift creating ridges and bathymetric expression in subaqueous FATS (e.g. Nugraha et al, 2020). However, the consequences of underthrusting and movement of footwalls into deeper levels requires further consideration.…”