Sedimentary characteristics and internal architecture of a river-dominated delta controlled by autogenic process: implications from a flume tank experiment

Abstract

Autogenic processes are widely found in various sedimentary systems and they play an important role in the depositional evolution and corresponding sedimentary architecture. However, autogenic processes are often affected by changing allogenic factors and are difficult to be identified and analyzed from modern and ancient records. Through the flume tank experiment under constant boundary conditions, the depositional process, evolution principles, and the sedimentary architecture of a river-dominated delta was presented, and a corresponding sedimentary architecture model was constructed. The evolution of river-dominated delta controlled only by autogenic process is obviously periodic, and each autogenic cycle can be divided into an initial progradational stage, a middle retrogratational stage, and a late aggradational–progradational stage. In the initial progradational stage, one feeder channel incised into the delta plain, mouth bar(s) was formed in front of the channel mouth, and small-scale crevasse splays were formed on the delta plain. In the middle retrogradational stage, the feeder channel was blocked by the mouth bar(s) which grew out of water at the end of the initial stage, and a set of large-scale distributary splay complexes were formed on the delta plain. These distributary splay complexes were retrogradationally overlapped due to the continuous migration of the bifurcation point of the feeder channel. In the late aggradational–progradational stage, the feeder channel branched into several radial distributary channels, overlapped distributary channels were formed on the delta plain, and terminal lobe complexes were formed at the end of distributary channels. The three sedimentary layers formed in the three stages constituted an autogenic succession. The experimental delta consisted of six autogenic depositional successions. Dynamic allocation of accommodation space and the following adaptive sediments filling were the two main driving factors of the autogenic evolution of deltas.

Modeling the Dynamic Response of River Deltas to Sea‐Level Rise Acceleration

“…In this work, we provide evidence that an allogenic sea level forcing influences both surface processes and subsurface form. This finding is consistent with prior studies on the subject, which showed that steady SLR (e.g., Feng et al., 2019; Finotello et al., 2019; Guerit et al., 2021; Liang, Van Dyk, & Passalacqua, 2016; Martin, Sheets, et al., 2009) and base level cycles (e.g., Hajek et al., 2014; Kim et al., 2006; Koss et al., 1994; van Heijst & Postmal, 2001) impact both surface processes and the resulting stratigraphy. Uniquely, here, we focus on SLR acceleration by testing the impact that different future sea level trajectories may have on deltaic landscapes.…”

Integrated uplift, subsidence, erosion and deposition in a tightly coupled source‐to‐sink system, Pagliara basin, northeastern Sicily, Italy

“…However, unsteady production of sediment in the source (Bull, 1991; Schumer et al., 2011; Sharman et al., 2019; Smith, 1994; Tucker & Slingerland, 1997), the climatic modulation of base level in the sink (Vail et al., 1977), and variable coupling between tectonics and surface processes that exhibit a range of autogenic behaviours (Beaumont et al., 1992; Hoffman & Grotzinger, 1993; Koons, 1989; Zeitler et al., 2001) obscure the record of tectonic forcing in sediments and sedimentary rocks (Romans et al., 2015; Straub et al., 2009). For example, surface autogenic processes (Feng et al., 2019; Foreman & Straub, 2017), effective diffusivity (Paola et al., 1993), characteristic time scales (Jerolmack & Sadler, 2007) and response times of the system ( τ ) (Whipple & Tucker, 1999) introduce significant uncertainty in how tectonic processes drive unsteady sediment yield (Jerolmack & Paola, 2010), how they can be interpreted from the architecture of sedimentary basin fill (Allen, 2008), or how they are used to infer the time preserved by sedimentary facies (Paola et al., 2018). Understanding how all of these factors operating on an erosional landscape, ultimately becoming the sedimentary facies in sedimentary basins, is crucial to inversion of the stratigraphic record (Sharman et al., 2019).…”

An accurate and practical analysis for Neogene-marls in Central regions of Iran

“…The marl is impermeable and the accumulation of rainwater and groundwater causes it to loosen. In this case, its upper layers become unstable and are driven by gravity or seismic force (12,13) .…”

“…To test, a sample of soil paste is placed in the cup and made by a groove in the middle of the groove dough. The groove on the bottom of the cup (13 cm long) is noted and then the amount of moisture in the soil is determined (12) , (13) ; To determine the amount of dough, the test soil is mixed with some distilled water and made into a paste. Then a portion of the sample (approximately 2.5 grams) is woven with fingers on a polished plate to a diameter of 6 mm and then tried to reduce its diameter to 3 mm.…”