Sedimentology and ichnology of the fluvial reach to inner estuary of the Ogeechee River estuary, Georgia, USA

Shchepetkina, Alina; Gingras, Murray K.; Pemberton, S. George

doi:10.1016/j.sedgeo.2016.07.005

Cited by 20 publications

(9 citation statements)

References 27 publications

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“…4). The periodic high discharge, water turbidity and sedimentation rates, combined with low salinity levels in fluvially influenced channels are conditions unfavourable for infauna colonization (Pearson & Gingras, 2006; MacEachern & Gingras, 2007; Sisulak & Dashtgard, 2012; Johnson & Dashtgard, 2014; La Croix & Dashtgard, 2015; Shchepetkina et al ., 2016). In contrast, strictly tidal conditions are more conducive for burrowing organisms due higher and less varying saline conditions (Sisulak & Dashtgard, 2012; Johnson & Dashtgard, 2014; Brivio et al ., 2016; Ghinassi et al ., 2019; Bellizia et al ., 2021).…”

Section: Discussionmentioning

confidence: 99%

“…Sexton & Hayes (1996) observed clean, fine to medium‐grained sand with occasional rip‐up clasts overlying flaser bedding in the upper part of an ebb‐dominated portion of a tidal point bar, and Shchepetkina et al . (2016) illustrated a coarse‐granular interval ( ca 35 cm) on the top of coarse‐grained cross‐bedded sands in their schematic representation of point bars and channel bars in the FMT. In addition to the description of coarsening‐upward sequences, the following authors also suggest mechanisms responsible for their formation.…”

Section: Discussionmentioning

confidence: 99%

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Hydrodynamic controls on sedimentary facies of tidal point bars: A case study in the Georgia coastal plain, USA

et al. 2022

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Tidal point bars are commonly developed in coastal plain meandering channels. They form by the same basic processes as fluvial point bars but are further modified by tidal action. This study analyses the sedimentary facies of six active tidal point bars and their relationships. The bars are situated along the Georgia coastal plain, USA, in the lower and upper reaches of the fluvial marine transition and in tidal channels without upstream river input. Based on millimetric logging of 31 cores, nine sedimentary facies were identified, which are proposed to be used for the characterization of tidal point bars in other depositional settings. These bars share common sedimentary facies; however, the internal organization of these facies and their associations differ appreciably in response to complex local tidal processes and fluvial-tidal interactions. The increase in tidal influence results in prominent heterogeneous architectures, with greater concentration of heterolithic stratification (mostly inclined), bioturbation and evidence of flow reversals. In contrast, when freshwater river discharge overcomes tidal stages in the fluvial marine transition bars, structureless coarse-grained facies with attendant erosional surfaces and decreased bioturbation are predominantly developed. In the lower reach of the fluvial marine transition, along the estuarine turbidity maximum, alternations of fluvial and tidal sedimentation are evidenced by a bimodal facies association, where alternations of gravel lag and muddy facies (massive to heterolithic) dominate. Moreover, despite differences in local hydrodynamics, coarsening-upward sequences, mostly composed of structureless coarser facies, are consistently distributed along the upper parts of the bars, which may indicate overprinting of regional events such as storm surge-related floodings in the sedimentological record. This study provides a basis for better identifying the hydrodynamic processes that shape coastal systems, such as estuarine and backbarrier environments. Additionally, those deposits are analogues for certain hydrocarbon reservoirs, thereby increasing knowledge of their facies distribution and aiding production optimization.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Hydrodynamic controls on sedimentary facies of tidal point bars: A case study in the Georgia coastal plain, USA

et al. 2022

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“…Examples of successions representative of fluvial to shallow-marine sub-environments (including those of the FMTZ) include the Triassic Mungaroo Formation, NW Shelf, Australia (Heldreich et al, 2017), the Jurassic Brent Group, North Sea, UK (Livera and Caline, 1990), the Cretaceous McMurray Formation, Alberta, Canada (Hubbard et al, 2011;Hein, 2015;Jablonski and Dalrymple, 2015), and the Cretaceous Burgan Formation, Kuwait (Al-Eidan et al, 2001). In these settings, sand-body accumulations can be laterally extensive over kilometers where they represent large-scale depositional elements (Wightman and Pemberton, 1997;Shchepetkina et al, 2016;Reynolds, 2017). However, although sand-prone overall, these types of successions tend to be internally lithologically heterogeneous at a variety of smaller scales, for example as exemplified by sandstone beds partitioned by thin but numerous mudstone interbeds (e.g., Reineck and Wunderlich, 1968;Reineck and Singh, 1980;Thomas et al, 1987;Nio and Yang, 1991).…”

Section: Introductionmentioning

confidence: 99%

Sedimentology and stratigraphic architecture of a fluvial to shallow-marine succession: The Jurassic Dhruma Formation, Saudi Arabia

Alshammari

Mountney

Colombera

et al. 2021

Journal of Sedimentary Research

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The interaction of fluvial, tidal, and wave processes in coastal and paralic environments gives rise to sedimentary successions with highly varied styles of facies architecture; these are determined by the morphology and evolutionary behavior of the range of coastal sub-environments, which may be difficult to diagnose in subsurface sedimentary successions with limited well control. This study presents depositional models to account for stratigraphic complexity in a subsurface fluvial to shallow-marine succession, the Middle Jurassic Dhruma Formation, Saudi Arabia. The study achieves the following: i) it examines and demonstrates sedimentary relationships between various fluvial, nearshore, and shallow-marine deposits, ii) it develops depositional models to account for the stratigraphic complexity inherent in fluvial to shallow-marine successions, and iii) it documents the sedimentology and the stratigraphic evolutionary patterns of the lower Dhruma Formation in the studied area of Saudi Arabia. The dataset comprises facies descriptions of 570 m of core from 14 wells, 77 representative core thin sections, 14 gamma-ray logs, and FMI image logs from 4 wells. These data are integrated with quantitative information from > 50 analogous systems from a wide range of modern and ancient settings, stored in a relational database. Stratigraphic correlations reveal the internal anatomy of the succession. Facies associations are representative of fluvial channels, intertidal flats, pedogenically modified supratidal flats or floodplains, river-influenced tidal bars, weakly storm-affected shoreface and offshore-transition zones, storm-dominated delta-front and prodelta settings, and an open-marine carbonate-dominated shelf. These sub-environments interacted in a complex way through space and time. The vertical succession of the studied interval records an overall transition from coastal-plain deposits at the base to marine deposits at the top. As such, the succession records a long-term transgressive, deepening-upward trend. However, this general trend is punctuated by repeated progradational events whereby coastal sand bodies of fluvial, wave, and tidal origin prograded basinward during stillstands to fill bays along a coastline. The nature of juxtaposition of neighboring sub-environments has resulted in a sedimentary record that is highly complex compared to that generated by morphologically simple shoreface systems that accumulate more regularly ordered stratal packages.

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“…In addition, IHS can form with elements of downstream accretion and counter point‐bars (Smith et al ., ). Based on the examination of both modern (de Mowbray, ; Smith, ; Allen, ; Choi et al ., ; Choi, ; Sisulak & Dashtgard, ; La Croix & Dashtgard, ; Shchepetkina et al ., 2016a) and ancient settings (Rahmani, ; Ranger & Pemberton, ; Räsänen et al ., ; Eberth, ; Falcon‐Lang, ; Gingras et al ., ; Rebata et al ., ; Shchepetkina et al ., 2016b), the majority of reported IHS has been attributed to the deposition of tidally influenced point bars. The development of IHS is most prominent in meandering channels of estuaries (Thomas et al ., ) where deposition is influenced by fluvial and tidal processes in varying proportions and the overall hydraulic energy is at a minimum (Dalrymple et al ., ).…”

Section: Introductionmentioning

confidence: 99%

“…The development of IHS is most prominent in meandering channels of estuaries (Thomas et al ., ) where deposition is influenced by fluvial and tidal processes in varying proportions and the overall hydraulic energy is at a minimum (Dalrymple et al ., ). The IHS deposits of the McMurray Formation have been variably ascribed to deltas (Carrigy, ; Nelson & Glaister, ), fluvially dominated point bars (Mossop, ; Mossop & Flach, ; Flach & Mossop, ; Smith et al .,; Hubbard et al ., ; Labrecque et al ., ; Durkin et al ., ) and tidally influenced (estuarine) point bars (Stewart & MacCallum, ; Pemberton et al ., ; Wightman et al ., ; Smith, ; Smith, ; Beynon et al ., ; Keith et al ., ; Ranger & Pemberton, 1988; Ranger & Pemberton, ; Wightman & Pemberton, ; Langenberg et al ., ; Crerar & Arnott, ; Musial et al ., ; Gingras et al ., ; Shchepetkina et al ., ,b).…”

Section: Introductionmentioning

confidence: 99%

Using ichnological relationships to interpret heterolithic fabrics in fluvio‐tidal settings

Melnyk¹,

Gingras

2019

Sedimentology

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In fluvio-tidal settings, the sediment is dominantly derived from the river systems. However, the importance of landward tidal transport of sediment in tidally influenced sedimentary environments is difficult to assess, particularly in the rock record. This problem is addressed using two intervals within the Lower Cretaceous McMurray Formation, each representing a distinct inclined heterolithic stratification motif. The ichnological variation between the heterolithic intervals is analyzed to determine which lithosomes are associated with brackish-water (tidally influenced) colonization windows. From this, the relative fluvial influence responsible for the deposition of the fine and coarse members can be determined. Both of the inclined heterolithic stratification fabrics studied record the deposition of fluvio-tidal point bars wherein the heterolithic bedding represents variations in river discharge. The first fabric comprises inclined heterolithic stratification in which bioturbation only occurs in mudstone beds. This fabric indicates that deposition occurred in more proximal positions within a fluvio-tidal system (i.e. the outermost inner to middle estuary or distributary channels). In this example sand deposition is interpreted to represent high-energy, freshwater dune migration within a fluvial-dominated setting, whereas mud beds reflect brackish-water suspension deposition during times of low river discharge. The second fabric, which is interpreted to have developed in more distal depositional positions (i.e. the middle estuary or seaward of the turbidity maximum in deltas), consists of inclined heterolithic stratification with laminated mudstone and bioturbated sandstone. In these inclined heterolithic stratification successions the mudstone beds were deposited under the influence of freshwater and heightened sedimentation rates, whereas bioturbated sandstone was colonized under brackish-water conditions and in the presence of tidally facilitated sediment transport. In both examples, the bioturbated lithosomes are related to colonization windows that indicate the predominance at that time of marine or tidally influenced processes over fluvial processes.

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Sedimentology and ichnology of the fluvial reach to inner estuary of the Ogeechee River estuary, Georgia, USA

Cited by 20 publications

References 27 publications

Hydrodynamic controls on sedimentary facies of tidal point bars: A case study in the Georgia coastal plain, USA

Hydrodynamic controls on sedimentary facies of tidal point bars: A case study in the Georgia coastal plain, USA

Sedimentology and stratigraphic architecture of a fluvial to shallow-marine succession: The Jurassic Dhruma Formation, Saudi Arabia

Using ichnological relationships to interpret heterolithic fabrics in fluvio‐tidal settings

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