Three-Dimensional Numerical Modeling of Deltaic Depositional Sequences 1: Influence of the Rate and Magnitude of Sea-Level Change

Ritchie, Bryan D.; Gawthorpe, Rob L.; Hardy, Stuart

doi:10.1306/091303740203

Cited by 38 publications

(38 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During normal regression (i.e., ascending clinoform trajectories), in contrast, continental-margin and shelf-edge deltas are normally associated with aggradational wave-dominated clinoforms that are near-linear in planview, lack focused sediment dispersal and, in the absence of gullied shelf-edges, are characterised by slopes that are either mudstone-prone or host only minor tempestite sheet sandstones, and by negligible or muddy submarine fan development (Kolla et al, 2000;Steel and Olsen, 2002;Steel, 2002, 2006;Deibert et al, 2003;Ritchie et al, 2004aRitchie et al, , 2004bBullimore et al, 2005;Johannessen and Steel, 2005;Porębski and Steel, 2006;Uroza and Steel, 2008;Gong et al, 2015;Gong et al, 2015;c.f. also the c2 clinothem of the upper Pleistocene Po-Adriatic succession, as detailed in Pellegrini et al, 2018).…”

Section: Shelf-edge Delta and Continental-margin Delta Hybrid Clinoformsmentioning

confidence: 99%

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

Patruno

Helland‐Hansen

2018

Earth-Science Reviews

200

166

View full text Add to dashboard Cite

A B S T R A C TClinoforms are inclined and normally basinward-dipping horizons developed over a range of spatial and temporal scales in both siliciclastic and carbonatic systems. The study of clinoform successions underpins sequence stratigraphy and all efforts to reconstruct the relative partitioning of reservoir, seal and source rocks along shoreline to basin-floor profiles.Here, we review clinoform research and propose a more systematic description and classification of clinoforms. This is a crucial step to improve predictions of facies and lithology distribution within shoreline to continental shelf and abyssal plain successions, together with the genesis, drivers and dynamics of their constituent sedimentary units.Four basic clinoform types are here distinguished in delta/shorelines, lacustrines and marine environments, on the basis of their overall spatial and temporal scale, morphology, outbuilding dynamic and geodynamic and depositional setting: (1, 2) delta-scale clinoforms, which in turns are sub-divided into shoreline and delta-scale subaqueous clinoforms; (3) shelf-edge clinoforms; and (4) continental-margin clinoforms. Delta-scale clinoform sets are tens of metres high and typically represent 1-10 3 kyr, with progradation rates ranging from 1,000-100,000 m/kyr for shorelines and "subaerial deltas" to 100-20,000 m/kyr for subaqueous deltas; shelfedge clinoform sets are hundreds of metres high and are nucleated and accreted in 0.1-20 Myr (usual progradation rates of 1-100 m/kyr) by successive cross-shelf transits of delta-scale clinoforms; continental-margin clinoform sets are thousands of metres high, hallmark key geodynamic/crustal boundaries (e.g., continent/ocean transition) and slowly prograde basinwards in ca. 5-100 Myr, with typical rates of 0.1-10 m/kyr. As a consequence of the very different progradation rates and of the difficulty of large-scale clinothems to backstep during transgressions, shorelines are the most dynamic clinoforms with regards to position, continental margins the least, and shelf-edges are intermediate. Shortly after a transgression, therefore, the four clinoform types may prograde synchronously along shoreline-to-abyssal plain transects, forming "compound clinoform" systems. During the subsequent regressive cycle, however, due to the dissimilarity in progradation rates, different clinoform types will normally merge progressively with each other, giving rise to "hybrid clinoforms" (e.g., shelf-edge deltas), and fewer depositional breaks-in-slope are distinguished along a single shoreline-toabyssal plain transect. Overall, all clinoform systems are the result of the dynamic evolution of compound and hybrid clinoforms along a temporal and spatial continuum, regulated by the cyclical backstepping of the smallerscale system within natural progradational-retrogradational cycles of larger-scale clinothem outbuilding.All clinothem types may show either an accretionary/active or draping/passive style, depending on the proximity to the sediment source. Draping clinothems are nearly...

show abstract

Section: Shelf-edge Delta and Continental-margin Delta Hybrid Clinoformsmentioning

confidence: 99%

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

Patruno

Helland‐Hansen

2018

Earth-Science Reviews

200

166

View full text Add to dashboard Cite

show abstract

“…During transgression, the high rates of lake-level rise, which are common in glacial lake basins (Oviatt et al 1992;Winsemann et al 2011), will cause a rapid landward shift of delta-front lobes (Posamentier & Morris 2000;Catuneanu et al 2011) and the formation of a stair-stepped delta morphology (Muto & Steel 2001;Ritchie et al 2004b;Villiers et al 2013). Alluvialplain aggradation and delta-front progradation commonly accompany normal regression, whereas fluvial incision and sediment bypass occur during forced regression (Posamentier & Morris 2000; Ritchie et al 2004a, b;Strong & Paola 2008;Catuneanu et al 2011), leading to a rapid basinward stepping of delta lobes (Fig. Alluvialplain aggradation and delta-front progradation commonly accompany normal regression, whereas fluvial incision and sediment bypass occur during forced regression (Posamentier & Morris 2000; Ritchie et al 2004a, b;Strong & Paola 2008;Catuneanu et al 2011), leading to a rapid basinward stepping of delta lobes (Fig.…”

Section: Delta Styles and Depositional Processesmentioning

confidence: 99%

Ice‐marginal forced regressive deltas in glacial lake basins: geomorphology, facies variability and large‐scale depositional architecture

Winsemann

Lang

Polom

et al. 2018

Boreas

130

View full text Add to dashboard Cite

Brandes, C. 2018 (October): Ice-marginal forced regressive deltas in glacial lake basins: geomorphology, facies variability and large-scale depositional architecture.This study presents a synthesis of the geomorphology, facies variability and depositional architecture of ice-marginal deltas affected by rapid lake-level change. The integration of digital elevation models, outcrop, borehole, groundpenetrating radar and high-resolution shear-wave seismic data allows for a comprehensive analysis of these delta systems and provides information about the distinct types of deltaic facies and geometries generated under different lake-level trends. The exposed delta sediments record mainly the phase of maximum lake level and subsequent lake drainage. The stair-stepped profiles of the delta systems reflect the progressive basinward lobe deposition during forced regression when the lakes successively drained. Depending on the rate and magnitude of lake-level fall, fanshaped, lobate or more digitate tongue-like delta morphologies developed. Deposits of the stair-stepped transgressive delta bodies are buried, downlapped and onlapped by the younger forced regressive deposits. The delta styles comprise both Gilbert-type deltas and shoal-water deltas. The sedimentary facies of the steep Gilberttype delta foresets include a wide range of gravity-flow deposits. Delta deposits of the forced-regressive phase are commonly dominated by coarse-grained debrisflow deposits, indicating strong upslope erosion and cannibalization of older delta deposits. Deposits of supercritical turbidity currents are particularly common in sand-rich Gilbert-type deltas that formed during slow rises in lake level and during highstands. Foreset beds consist typically of laterally and vertically stacked deposits of antidunes and cyclic steps. The trigger mechanisms for these supercritical turbidity currents were both hyperpycnal meltwater flows and slope-failure events. Shoal-water deltas formed at low water depths during both low rates of lake-level rise and forced regression. Deposition occurred from tractional flows. Transgressive mouthbars form laterally extensive sand-rich delta bodies with a digitate, multi-tongue morphology. In contrast, forced regressive gravelly shoal-water deltas show a high dispersion of flow directions and form laterally overlapping delta lobes. Deformation structures in the forced-regressive ice-marginal deltas are mainly extensional features, including normal faults, small graben or half-graben structures and shear-deformation bands, which are related to gravitational delta tectonics, postglacial faulting during glacial-isostatic adjustment, and crestal collapse above salt domes. A neotectonic component cannot be ruled out in some cases. facies and the larger-scale depositional architecture. The results are compared with other marine and lacustrine delta examples from the literature, and provide information about the distinct types

show abstract

“…1B). Decreasing accommodation tends to stabilize distributary channels through enhanced incision (Suter 1999;Posamentier and Morris 2000) and create distinct, widely separated delta lobes (Ritchie et al 2004). It also results in laterally (frontally) stacked mouth bars separated by minor downlap unconformities that mostly reflect minor discrete pulses in base-level fall rather than an autocyclic switch (Tesson et al 2000).…”

Section: Mid-shelf Deltasmentioning

confidence: 99%

Deltas and Sea-Level Change

Porębski

Steel

2006

Journal of Sedimentary Research

187

107

View full text Add to dashboard Cite

Sea-level shift from the innermost shelf out to the shelf edge produces bayhead, inner-shelf, mid-shelf, and shelfmargin deltas. We suggest that these delta types are distinguishable in the ancient record and that such distinction has advantages as compared to the conventional, entirely process-based classification. Bayhead and inner-shelf deltas tend to form thin clinoforms (a few meters to tens of meters amplitude, respectively), and as they aggrade with rising relative sea level they generate a ''tail'' of thick paralic deposits. Mid-shelf deltas produce clinoforms as high as the mid-shelf water depth, tend to follow a subhorizontal trajectory, generate little or no paralic tail, and are commonly thinned by transgressive ravinement. Shelf-edge deltas in a stable-to-falling relative sea level usually have no paralic tail, create by far the highest clinoforms, and can have a thick succession of sandy turbidites on the delta fronts. If sea level falls below the shelf margin, the shelf-edge delta becomes incised by its own channels and large volumes of sand can be delivered onto the slope and the basin floor.Many deltas require a strong fluvial drive to attain a shelf transit, though as they approach the outer shelf they commonly become wave dominated. Tidal influence can increase on the outermost shelf if relative sea level is falling, if the shelf-break is poorly developed, and if basinal water depth is shallow. During transgression, the system tends to be tidally and/or wave influenced.Deltas that transit back and forth on the shelf on short time scales (tens of kiloyears to 100 ky) and that are driven largely by sea-level fluctuations are referred to here as accommodation-driven deltas. Deltas that can reach the shelf edge without sealevel fall are termed supply-driven deltas. These highstand deltas deposit thick, sandy, stacked parasequences during their shelf transit, and they tend to have an extensive muddy delta front on reaching the shelf-edge area. Such deltas would not normally be incised at the shelf edge, and they would produce a progradational, shelf-edge attached, sandy slope apron (Exxonian shelfmargin systems tract) rather than basin-floor fans, except in cases of extremely high supply.Sequence boundaries are best developed on accommodation-driven deltas, and are likely to be represented on a variety of time scales (third, fourth, and fifth order). Sequence boundaries in supply-dominated deltas may be identifiable only at lowerorder time scales, or they may be non-existent. STEADY-STATE VERSUS EVOLUTIONARY DELTA CLASSIFICATIONDeltas have traditionally been classified in terms of process-product reaction, where delta type is defined by the relative contribution of fluvial-, wave-, or tidal-energy flux that was dominant during deposition at the seaward edge of the delta (Galloway 1975). In this actualistic (based on present highstand of sea level) and uniformitarian (steady-state) approach, the delta system is seen as the outcome of intrabasinal processes, whereas external controls are held constant...

show abstract

Three-Dimensional Numerical Modeling of Deltaic Depositional Sequences 1: Influence of the Rate and Magnitude of Sea-Level Change

Cited by 38 publications

References 31 publications

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

Ice‐marginal forced regressive deltas in glacial lake basins: geomorphology, facies variability and large‐scale depositional architecture

Deltas and Sea-Level Change

Contact Info

Product

Resources

About