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Submarine channels act as the main conduits for the transport of sediment to deep‐water basins by sediment gravity flows. The interplay between fault‐related deformation and the initiation and development of the channels is poorly known. Here, we present the identification, formation and evolution of the Miocene slope‐parallel channel by employing 3D seismic reflection, wireline‐log and core data in the eastern slope of Yinggehai Basin, South China Sea. Based on the lengths and plan‐view shapes, a total of three different types of fault‐associated slope‐parallel depressions have been identified. The depressions were formed in the fault zone and controlled by the reactivation of the underlying older faults. Among them, Type‐1 depressions are short (<20 km) oval or circle shaped possessing only one depocenter. Type‐2 depressions are elongated (25–70 km), and usually have multiple depocenters. Type‐3 depressions, which are usually connected by slope‐perpendicular channels in the head and middle, are longer (more than 190 km) and connect shallow and deep‐water basins. The analysis of morphology, erosivity and material transport shows that Type‐3 depressions are fully fledged channels. Type‐1 and Type‐2 depressions are channel precursors representing the initial stage of channel evolution. With this motive, a model for the initiation and evolution of slope‐parallel submarine channels controlled by strike‐slip‐extensional faults is presented. Unlike the previous investigations which suggest that erosion takes place at the inception of submarine channel formation, the fault‐controlled slope‐parallel channel is mainly controlled by faulting and has no initial erosive base and does not develop levees. The depressions are extended and elongated by the continuous fault activity. It was not until the slope‐parallel depression connected with large‐scale slope‐perpendicular channels transporting materials into the depression via erosive turbidity currents that it evolved into a channel‐levee system. This study is of global importance for understanding submarine channel generation and evolution since the fault‐controlled slope‐parallel channels have been found in tectonic active basins worldwide. [ABSTRACT FROM AUTHOR]

The c. 1.5–1.3 Ga Wilton package, the upper succession of the greater McArthur Basin, preserves detailed tectono-sedimentary evidence for the Mesoproterozoic evolution of the North Australian Craton (NAC). In addition, it is a valuable global sedimentary repository for the poorly explored Mesoproterozoic. New detrital zircon U–Pb age and Lu–Hf isotope data, collected from multiple, geographically separated, basins that make up the Wilton package, are compiled with previously published data to illuminate the basin evolution. The spatial and temporal variation in sedimentary provenance illustrates two major geographic changes that correspond to continent-scale tectonic convulsions of the NAC during the Mesoproterozoic. The first is shown by the influx of sediment sourced from east and southeast terranes. This is linked to rifting between Proterozoic Australia and Laurentia at c. 1.45 Ga, resulting in the uplift of the eastern margin of the NAC–SAC (South Australian Craton). The second basin geographic change is illustrated by a flux of southerly-sourced detritus that is interpreted to be tectonically driven by the uplift of the southern NAC, during the subduction/closure of the Mirning Ocean at c. 1.32 Ga. Spatially, sediment in the Wilton package is separated into two depositional systems: sedimentary rocks within the Birrindudu Basin, the western component of the Wilton package, have different detrital signatures relative to other Wilton package successions found east of the Daly Waters Fault Zone, in the Beetaloo Sub-basin, the McArthur Basin and the South Nicholson Basin. The Daly Waters Fault Zone is interpreted as an ancient bathymetric high, blocking sediment transport. Although they differ in sources, rocks in both the Birrindudu Basin and the eastern Wilton package record coeval shifts of basin provenance to southern sources. The coherent evolution of basin provenance indicates a consistent tectono-sedimentation history, and links the Birrindudu Basin and the other Wilton successions in a tectonic framework. [ABSTRACT FROM AUTHOR]

The South China Sea (SCS) coastlines are particularly vulnerable to tsunamis due to rapid urbanization and dense infrastructures. However, whether the SCS has experienced ocean-wide tsunamis is still under debate. Some geological records from the offshore islands inside the SCS imply a regional tsunami event may have occurred approximately 1000-yr-ago. We address these questions for the first time using forward numerical simulations in the SCS: what source could be responsible for such deposits, how the deposits were formed and at what conditions do the deposits could be preserved? Here, we assume the validity of the tsunami deposit hypothesis and use the forward model COMCOT-SED to investigate if these tsunami deposits can be linked to potential seismogenic tsunami sources inside the SCS, including megathrust earthquakes (Mw8.8–9.2) from the Manila subduction zone (MSZ) and the 1918 Mw7.5 Nan'ao earthquake from the Littoral Fault Zone (LFZ) in the northern continental shelf of the SCS. We also utilize a reported tsunami deposit from Qing'ao Embayment, Nan'ao Island, China, to exemplify the deposit formation process in a typical barrier-low coastal plain system. Quantitative analysis suggests large earthquakes from the MSZ may account for the reported geological deposits. The full-rupture earthquake scenario could best explain the depositions if such extreme case is geophysically and geologically plausible. If not, earthquakes (∼ Mw 9.0) covering the northern (16–23.5°N) or southern portion (14–19°N) of the MSZ could also be suitable candidates. Such great earthquakes can generate large tsunami waves (>7 m) that inundate the Qing'ao Embayment, transporting sediments and leaving tsunami deposits in low-lying areas. Conversely, tsunamis triggered by nearshore earthquakes in the LFZ cannot cause deposition in Qing'ao Embayment. The barrier-low coastal plain system is well-suited for preserving tsunami deposits, which remain unaltered by subsequent tsunami waves. Our findings offer a quantitative reference for paleo-tsunami research in the SCS and enhance global understanding of the tsunami deposition process in barrier-low coastal plain systems. • The full-rupture earthquake (Mw 9.0) from the MSZ best explains the reported plausible tsunami deposits in the South China Sea. • Tsunami waves >7 m generated by MSZ earthquakes could inundate the Qing'ao Embayment anddeposit sediments in low-lying areas. • The barrier-low coastal plain system in Qing'ao Embayment forms favorable conditions to preserve overwash tsunami deposits. [ABSTRACT FROM AUTHOR]

Topographic relief and bedrock fractures caused by fault activity can accelerate surface erosion, suggesting that erosion rates increase with decreasing distance to the fault core. To test this hypothesis, we used 10Be cosmogenic nuclides to quantify catchment-wide erosion rates at various distances from a fault in the footwall of the Daqing Shan fault system, a 200-km-long active normal fault in Inner Mongolia, northern China. In addition, in order to examine the influence of topography and bedrock fractures on the surface erosion processes in the fault-weakened zone, their relationships with hillslope erosion, fluvial sediment grain size and transport efficiency, erosion rates, and erosion coefficients were studied. The resulting catchment-wide erosion rates ranged from 0.01 ± 0.00–0.13 ± 0.01 mm yr−1. These erosion rates and coefficients were unaffected by distance from the fault. The analysis of topography, bedrock fractures, and hillslope erosion yielded distinct hillslope erosion processes at different distances from the fault. Rapid mass wasting events, such as landslides, occurred at <15 km from the fault in steep, rocky hillslopes with abundant bedrock fractures. In contrast, at >15 km from the fault, hillslopes gradually become more gentle and soil-mantled. These spatial-slope configuration differences result in a decrease in sediment grain size delivered to river channels with increasing distance from the fault. Once sediments enter river channels, they impact fluvial transport capacity by influencing the initial motion threshold of sediment. Correlation analyses revealed that sediment transport efficiency in channels directly controls the catchment-averaged erosion rate and coefficient. This mechanism explains why the erosion rate remains insensitive to variations in topography and bedrock fractures in fault-weakened zones. • Study of patterns and controls on erosion rate across Daqing Shan fault zone. • Cosmogenic nuclide 10Be used to derive catchment-averaged erosion rate. • Erosion rates do not vary with distance from the fault. • Erosion rate remains insensitive to variations in topography and bedrock fractures. • Sediment transport efficiency in channels controls erosion rate. [ABSTRACT FROM AUTHOR]

In oblique collision settings, parallel and perpendicular components of the relative plate motion can be partitioned into different structures of deformation and may be localized close to the plate boundary, or distributed on a wider region. In the Southern Alps of New Zealand, it has been proposed that one-third of the regional convergence is distributed in a broad area along the Southern Alps orogenic wedge. To better document and understand the regional dynamics of such systems, reliable markers of the horizontal tectonic motion over geological time scales are needed. River networks are able to record a large amount of distributed strain and they can thus be used to reconstruct the mode and rate of distribution away from major active structures. To explore the controls on river resilience to deformation, we develop an experimental model to investigate river pattern evolution over a doubly-vergent orogenic wedge growing in a context of oblique convergence. We use a rainfall system to activate erosion, sediment transport and river development on the model surface. At the end of the experiment, the drainage network is statistically rotated clockwise, confirming that rivers can record the distribution of motion along the wedge. Image analysis of channel time-space evolution shows how the fault-parallel and fault-perpendicular components of motion decrease toward the fault and impose rotation to the main trunk valleys. However, rivers do not record the whole imposed rotation rate, which suggest that the natural lateral channel dynamics can alter the capacity of rivers to act as passive markers of deformation. [ABSTRACT FROM AUTHOR]

Abstract: Hundred-meter-thick lacustrine sediments are widespread along the Middle Yangtze River. The distribution of these sediments suggests that an event blocked the river, forming a lake stretching 160 km from east to west and 110 km north to south, with a depth of ≥500 m. Using the cosmogenic nuclides 10Be and 26Al we have dated the time of burial of the lacustrine sediments and fluvial gravels beneath the sediments. Our results indicate a deposition age for these sediments between 1.34 and 1.58 Ma. Studies of zircon U–Pb age distributions within lacustrine sediments and fluvial sands related to the paleo-lake formation show diverse provenances from the upper Yangtze River and Yalong River, a major tributary of the Yangtze River. These deposits contain geologic fingerprints that allow identification of the source region of the lacustrine deposits and fluvial sands. Our results support the reversal of the Middle Yangtze River before the paleo-lake formation. We hypothesize that the geologic event that dammed the originally southward flow was the lateral movement of Chenghai fault in the Dali fault system initiated in early Quaternary. Water eventually cut through the spillway and flowed to the east. [Copyright &y& Elsevier]

We have numerically simulated contaminant transport through heterogeneous fault zones that consist of three components: a core, a damaged zone and a protolith, each with a different permeability. The interface between each of the components was assigned a fractal topography. This was done to quantify the scaling of a contaminant plume through a fault, as large-scale faults can dominate regional flow. The numerical method used was a modified lattice gas scheme for flow in porous media, coupled to a finite-difference solution to the advection–dispersion equation. The introduction of heterogeneity leads to complex behaviour of a chemical plume in several faults with the same statistical properties. A range of arrival times is observed along with bimodal break-through curves. This behaviour was a common feature in each heterogeneous fault model. The mean and the variance of the plume were calculated for every simulation and indicated that the transport is anomalous. The mean scaled through time from t1.00 to t0.54 for the different models. Thus, the mean velocity decreased with time in each of the fault models. The minimum and maximum scaling through time of the variance of the plume was from t1.0 to t1.87 indicating anomalous transport. The simulated break-through curves were analysed using the continuous time random walk method that quantifies the scaling of migrating contaminants using a single parameter β. For β>2 the transport is Gaussian and for β<2 the transport is anomalous and the variance scales as t(3−β) for 1<β<2. The average value of β for the different models ranged from 1.65 to 2.00. We have also shown that the scaling of the transport can vary significantly over short distances relative to the size of our models. [Copyright &y& Elsevier]