Outcrop analysis and facies model of an Upper Permian tidally influenced fluvio-deltaic system: Northern Sydney Basin, SE Australia

AbstractAn integrated study of sedimentological, sequence-stratigraphic and palaeodispersal analysis was applied to the Upper-Permian clastic sedimentary succession in the Northern Sydney Basin, Australia. The succession is subdivided into fifteen facies and three facies associations. The facies associations are further subdivided into eight sub-facies associations. The sedimentary evolution involves progradation from delta-front to delta-plain to fluvial depositional environments, with a significant increase in sediment grain size across the unconformable contact that separates the deltaic from the overlying fluvial system. In contrast to the delta front that is wave/storm- and/or river-influenced, the delta plain is significantly affected by tides, with the impact of tidal currents decreasing up-sequence in the delta plain. The general lack of wave-influenced sedimentary structures suggests low wave energy in the delta plain. The abrupt termination of the tidal impact in the fluvial realm relates to the steep topographic gradients and high sediment supply, which accompanied the uplift of the New England Orogen. The sequence-stratigraphic framework includes highstand (deltaic forest and topset) and lowstand (fluvial topset) systems tracts, separated by a subaerial unconformity. In contrast to most of the mud-rich modern counterparts, this is an example of a sand-rich tidally influenced deltaic system, developed adjacent to the source region. This investigation presents a depositional model for tidal successions in regions of tectonic uplift and confinement.

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Sedimentology and Stratigraphy of an Upper Permian Sedimentary Succession: Northern Sydney Basin, Southeastern Australia

Geosciences ◽

10.3390/geosciences11070273 ◽

2021 ◽

Vol 11 (7) ◽

pp. 273

Author(s):

Sean Melehan ◽

Chrysanthos Botziolis ◽

Angelos G. Maravelis ◽

Octavian Catuneanu ◽

Kevin Ruming ◽

...

Keyword(s):

New England ◽

Depositional Environments ◽

Upper Permian ◽

Delta Front ◽

Sequence Stratigraphic ◽

Delta Plain ◽

Southeastern Australia ◽

Normal Regression ◽

Facies Associations ◽

The Impact

This study integrates sedimentological and stratigraphic insights into the Upper Permian sedimentary rocks of the Wittingham, Tomago and Newcastle Coal Measures in the Northern Sydney Basin, Australia. Facies analysis documented fifteen facies that belong to seven facies associations. These facies associations correspond to different depositional environments and sub-environments including prodelta, delta-front, upper, lower delta-plain and fluvial. The stratigraphic development points to a shallowing upward trend and is reflected with fluvial deposits sitting on top of the deltaic deposits. The fluvio-deltaic contact is represented by an unconformity and displays an upward increase in sediment caliber. The delta front is mainly controlled by wave, storms- and/or river currents, even though the contribution of tides also occurs in the form of sedimentary structures that suggest tidal influence. In contrast, prodelta and delta-plain are significantly modulated by tidal currents. The impact of tides in the delta plain is fading away upward and therefore, the upper delta plain is much less impacted compared to the lower delta plain. The low abundance of wave ripples suggests that the wave action was not very important in the delta plain. Steep topographic gradients and increased sediment input are suggested, based on the limited or absent evidence of tides in the fluvial realm, related to the growing New England Orogen. In sequence stratigraphic terms, the deltaic system accumulated during highstand normal regression, while the deposition of the overlying fluvial system occurred during lowstand normal regression. The two systems are separated by a subaerial unconformity developed during an intervening forced regression. Short periods of transgression are inferred from the presence of higher frequency cycles in the delta-front.

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Depositional model and sequential evolution of the upper Quintuco Formation in its type area: implications for paleogeographic reconstructions for the southern Neuquén Basin during the Valanginian

Andean geology ◽

10.5027/andgeov43n2-a04 ◽

2016 ◽

Vol 43 (2) ◽

pp. 215 ◽

Cited By ~ 2

Author(s):

Mariana S. Olivo ◽

Ernesto Schwarz ◽

Gonzalo D. Veiga

Keyword(s):

Source Area ◽

Evolutionary Stage ◽

Delta Front ◽

Sequence Stratigraphic ◽

Architectural Analysis ◽

Delta Plain ◽

Stratigraphic Analysis ◽

Facies Associations ◽

Neuquen Basin ◽

Neuquén Basin

The Quintuco Formation (Berriasian-early Valanginian) in central Neuquén province comprise marine, transitional and continental deposits. These deposits were included in several regional stratigraphic studies since the 80’s but receiving little attention in terms of detailed facies analysis, palaeoenvironmental reconstructions and evolution. Understanding the evolutionary stage corresponding to cusp section of the Quintuco Formation and its relation with basal deposits of the Mulichinco Formation, is key to estimate the magnitude of associated change to the event of basin reconfiguration occurred in the early later Valanginian. In order to reconstruct the final stages of the evolution of the Quintuco Formation in its type locality (Sierra de la Vaca Muerta), a facial, architectural and sequence-stratigraphic analysis of the uppermost interval is presented. The study comprise the sedimentological description and interpretation of facies, combined with architectural analysis of key intervals. This allowed the identification of 7 facies associations, which represent the accumulation in prodelta (FA 1), delta front (FA 2 and FA 3), distal delta plain (FA 4 y FA 5) and proximal delta plain (FA 6 and FA 7). Subsequently, the spatial distribution of the different facies associations were analyzed and key surfaces related to significant changes in the depositional settings were identified across the investigated region. In this context, sequence-stratigraphic analysis of the studied interval was addressed and stacking patterns of the successions and vertical evolution of the interval are discussed. The upper interval of the Quintuco Formation represents the development of a deltaic system, where fluvial processes were dominant, but waves affected the off-axis parts of the system. The proximal areas were located towards the southwest with prodelta settings located toward the east. The delta system was built by successive shallowing-upward successions (15-40 m), bounded by regional transgressive surfaces, and with a long-term progradational staking. The reconstructed paleogeography for the last evolutionary stage of the Quintuco Formation suggest a well-established source area from the west-southwest, that would represent a new insight for paleogeographic settings for the southern Neuquén Basin during the Valanginian.

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Facies analysis of Sunakothi Formation, Kathmandu basin, Nepal and its significance

Journal of Nepal Geological Society ◽

10.3126/jngs.v47i1.23105 ◽

2014 ◽

Vol 47 (1) ◽

pp. 57-64

Author(s):

Mukunda Raj Paudel

Keyword(s):

Lake Level ◽

Facies Analysis ◽

Flood Plain ◽

Delta Front ◽

Gravel Beds ◽

Delta Plain ◽

Facies Associations ◽

Ripple Sand ◽

Lacustrine Delta ◽

Lacustrine Facies

This study decipher facies characteristic of Sunakothi Formation at southern part of Kathmandu Basin. Thick sandy and muddy sequence is found on an open lacustrine facies of the Kalimati Formation. Five facies associations have been recognized within the sandy and muddy facies. These are: (a) muddy rhythmites and silt and laminated to ripple sand bed of the prodeltaic origin (pd), (b) association of cross-stratification, rippledrift and parallel lamination in the lacustrine delta front origin (df), (c) muddy flood-plain and alteration of the fine and coarse sediments of delta-plain origin (dp), (d) sandy to silty rhythmites of the marginal shallow lacustrine origin above the delta-plain (ml), and (e) association of fluvial origin (fl ). Former three associations are interbeded by the thick gravel deposits, which is gravelly braided river origin. Transition from lacustrine to alluvial system is characterized by fluvial and deltaic system in the south. Sedimentology of the Sunakothi Formation indicates deposition during rapid lake level rise and also the thick channelized fluvial gravel beds within the sandy and muddy sequence indicate lake level fall. The cause could be climatic as well as activity of the basin margin tectonics. Sunakothi Formation is the southern counterpart of the Thimi-Gokarna Formations distributed in the northern part of the basin.

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The occurrence of marine fossils in the Upper Cretaceous deltaic sediments at Pautut, central West Greenland

Bulletin of the Geological Society of Denmark ◽

10.37570/bgsd-1991-39-03 ◽

1991 ◽

Vol 39 ◽

pp. 111-122

Author(s):

Torben Olsen ◽

Gunver Krarup Pedersen

Keyword(s):

Depositional Environment ◽

Upper Cretaceous ◽

Sediment Accumulation ◽

Accumulation Rates ◽

Delta Front ◽

Delta Plain ◽

Facies Associations ◽

Marine Fossils ◽

Stratigraphic Position ◽

Marine Influence

Finds of Upper Cretaceous marine macrofossils from Pautut have been reported since 1874. Subsequent investigations have led to contrasting views concerning the stratigraphic position of the fossils, the general depositional environment, and the amount of marine influence. During a brief visit to Pautut in the summer of 1989, a section of the exposed sediments was described. The sediments can be divided into 4 facies associations reflecting deposition on a prograding delta front, in distributary channels, on a subaerial to limnic delta plain and on an abandoned delta lobe during a marine transgression. The sedimentological model predicts that marine fossils, if present, should occur in the delta front association. The sediments were thoroughly searched for marine macrofossils, which were found in the lower part of the prominent coarsening-upward delta front sequences. The number of fossils is generally low. Bivalves and echinoids constitute the dominant groups of fossils and seem to have been well adapted to a life in muddy marine bays, subject to fluctuations in salinity and rate of deposition and with much suspended sediment. The fossils indicate that the beds at Pautut were deposited during latest Santonian to earliest Campanian times. Sediment accumulation rates were high. The stratigraphy within the Pautfit area is discussed and all the Cretaceous sediments are referred to the Atane Formation.

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Sedimentary system and coal seam distribution in the coal-bearing sequence stratigraphic framework in the Paleogene Meihe Formation (Meihe Basin, NE China)

10.21203/rs.3.rs-22238/v1 ◽

2020 ◽

Author(s):

Yueyue Bai ◽

Qingtian Lv ◽

Zhaojun Liu ◽

Pingchang Sun ◽

Rong Liu ◽

...

Keyword(s):

Coal Seam ◽

Accumulation Rate ◽

Mapping Method ◽

Sediment Supply ◽

Coal Seams ◽

Delta Front ◽

Contour Maps ◽

Delta Plain ◽

Fan Delta ◽

Wide Range

Abstract The Meihe Basin is one of the important Paleogene coal-bearing fault basins of northeastern China in the Dunhua-Mishan Fault Zone. The Lower Coal-bearing Member and the Upper Coal-bearing Member are the primary layers studied. Through field observation, core description and observation under microscope, fan delta facies and lake facies are observed as the main sedimentary facies of the coal-bearing layers, and subfacies of fan delta plain, fan delta front, shallow lake and swamp have also been recognized. Coal seams primarily accumulated in the subfacies of swamp and fan delta plain. The study on sequence stratigraphy is based on outcrop section, well-log analysis, core observation and geochemical analysis. From the Lower Coal-bearing Member to the Upper Coal-bearing Member, three third-order sequences have been recognized; the Lower Coal-bearing Member developed in Sequence I and the Upper Coal-bearing Member developed in Sequence III, both sequences have developed the lowstand systems tract (LST), the transgressive systems tract (TST) and the highstand systems tract (HST). Single-factor analysis and the multifactor comprehensive mapping method have been used to rebuild the lithofacies palaeogeography of each system tract in Sequence I and Sequence III. Through analysis of contour maps of total stratum thickness, sandstone thickness and sand content, as well as contour maps of thicknesses and numbers of layers of coal seams, the results indicate that the sedimentary environments and coal seam distributions are variable in different system tracts. Coal types accumulating in the swamp facies are primarily developed in the transgressive systems tract (TST) and the highstand systems tract (HST) of Sequence I with a wide range of continuous and large thicknesses and may be mined commercially. Both the balanced accommodation growth rate with peat accumulation rate and little or no influence from sediment supply and channel migration promote to form the stable coal accumulating environments.

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Width control on event scale bedload dynamics in bedrock-confined channels

10.5194/egusphere-egu21-2141 ◽

2021 ◽

Author(s):

Kristen Cook ◽

Jens Turowski ◽

Niels Hovius

Keyword(s):

Random Sequence ◽

Bedload Transport ◽

Sediment Supply ◽

Sediment Flux ◽

Channel Width ◽

Sediment Grain Size ◽

Event Scale ◽

Narrow Channels ◽

Coarse Sediment ◽

The Impact

<p>In mixed bedrock-alluvial rivers, the response of the system to a flood event can be affected by a number of factors, including coarse sediment availability in the channel, sediment supply from the hillslopes and upstream, flood sequencing, and coarse sediment grain size distribution. However, the impact of along-stream changes in channel width on bedload transport dynamics remains largely unexplored. We combine field data, theory, and numerical modeling to address this gap. Observations from two flood events in the Daan River gorge in western Taiwan suggest that coarse sediment evacuation and re-deposition can cause intra-flood changes of up to several meters in channel bed elevation that are distinct from measured before/after bed changes. We hypothesize that this could be related to the abrupt change in width between the 1 km long bedrock gorge and the river upstream and downstream. An analysis of the theoretical relationships between discharge, channel width, and bedload transport capacity shows that for a given slope, narrow channels transport bedload more efficiently than wide ones at low discharges, while wider channels are more efficient at high discharges. We used the model sedFlow to explore this effect, running a random sequence of floods through a channel with a narrow gorge section bounded upstream and downstream by wider reaches. Channel response to imposed floods is complex, as high and low discharges drive different spatial patterns of erosion and deposition, and the channel may experience both of these regimes during the peak and recession periods of each flood. Our modeling suggests that width differences alone can drive substantial variations in sediment flux and bed response, without the need for variations in sediment supply or mobility. Further, the deposition or erosion that takes place within a flood is often not reflected in the before/after changes to the bed, and this disconnect increases with increasing flood size.</p>

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Late Pleistocene sedimentary history of multiple glacially dammed lake episodes along the Yarlung-Tsangpo river, southeast Tibet

Quaternary Research ◽

10.1016/j.yqres.2014.06.001 ◽

2014 ◽

Vol 82 (2) ◽

pp. 430-440 ◽

Cited By ~ 14

Author(s):

Shao-Yi Huang ◽

Yue-Gau Chen ◽

George S. Burr ◽

Manoj K. Jaiswal ◽

Yunung Nina Lin ◽

...

Keyword(s):

Late Pleistocene ◽

Depositional Environments ◽

Optically Stimulated Luminescence ◽

Delta Front ◽

Delta Plain ◽

History Of ◽

Southeast Tibet ◽

Yarlung Tsangpo ◽

Dammed Lake ◽

Yarlung Tsangpo River

AbstractWe present a reconstructed lithologic column compiled from a series of lacustrine outcrops along a tributary of the Nyang River, a major tributary of the Yarlung-Tsangpo in southeast Tibet. The deposits were preserved between terraces at altitudes of 2950–3100 m asl. The stratigraphic record features at least two sets of coarsening-upward sequences depicting episodic aggradation and progradation of a glacially dammed lake related delta. Recognized facies changes illustrate the evolution cycles of depositional environments from pro-delta, delta front, to delta plain. Radiocarbon and optically stimulated luminescence dates reveal an aging-downward trend in stratigraphic order and provide an approximate timeline for the formation of glacially dammed lakes in late Pleistocene. This result reflects that the Zelunglung Glacier had progressively advanced to block the Yarlung-Tsangpo river and the dam materials had stepwise stacked up to an altitude of 3095 m asl during Marine Oxygen Isotope Stages 4 to 2.

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Framework of Sequence Stratigraphy Sedimentary System and Evolution of Yimin Formation in Yimin Depression

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.71 ◽

2013 ◽

Vol 734-737 ◽

pp. 71-80 ◽

Cited By ~ 1

Author(s):

Bi Ao Guo ◽

Long Yi Shao ◽

Sheng Zhang ◽

Kang Yang Qing ◽

Ming Ming Wang

Keyword(s):

Flood Plain ◽

Structure Evolution ◽

Cumulative Probability ◽

Delta Front ◽

Sequence Stratigraphic ◽

Delta Plain ◽

Stratigraphic Framework ◽

Sedimentary System ◽

Well Data ◽

Object Of Study

Well data, cores, logging, connecting with the characteristic of structure evolution are used to establish the sequence stratigraphic framework of the coal-bearing formation of Yimin Depression in Early Cretaceous. The coal-bearing formation can be divided into two three-order sequences and Yimin Formation, as one of the three-order sequences,is the most important object of study. Through cores description, research of Spontaneous Potential and Resistivity curve shape and analysis of sedimentary Cumulative Probability Size Curve, four facies including fan delta, braid river delta, sublacustrine fan and lake,and some subfacies are identified in Yimin Formation in the sequence stratigraphic framework. Coal-rich belts develop in the southwest delta plain and northwest interdeltaic bay in Yimin Depression. According to the characteristic of the development of coal and sedimentary system, two kinds of coal accumulation models, shallow lake and flood plain in delta front and interdelta, are concluded in Yimin Depression.

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Deltaic sedimentation in an unstable tectonic environment – the Lower Limestone Group (Lower Carboniferous) of East Fife, Scotland

Geological Magazine ◽

10.1017/s0016756800010189 ◽

1988 ◽

Vol 125 (3) ◽

pp. 241-255 ◽

Cited By ~ 16

Author(s):

C. R. Fielding ◽

M. Al-Rubaii ◽

E. K. Walton

Keyword(s):

Shallow Water ◽

Organic Soils ◽

Coal Seams ◽

Delta Front ◽

Delta Plain ◽

Tectonic Environment ◽

Facies Associations ◽

Free Drainage ◽

Deltaic Sedimentation ◽

Clastic Sedimentary

AbstractThe Lower Limestone Group, which outcrops extensively on the east coast of Fife, southeast Scotland, consists of interbedded sandstones, siltstones and claystones with occasional coal seams, and limestone beds. Several of the coals have been mined economically in the past.The sequence was deposited in a shallow-water, deltaic setting. Three facies associations have been distinguished; (1) laminated claystones, and marine bioclastic limestones, which were deposited in prodelta and marine shelf environments, (2) crudely coarsening-upward sandstone units, interpreted as delta front deposits of fluvially-dominated though wave-influenced, shallow-water deltas, and (3) interbedded clastic sedimentary rocks and coals, deposited in delta plain environments. The sequence as a whole accumulated by repeated progradation and abandonment of deltaic complexes.Palaeosol profiles of four types are superbly preserved within the delta plain facies association. These are (1) organic soils (peats), now coal seams, (2) gley palaeosols, which formed in persistently waterlogged conditions, (3) freely drained soils which formed on a quartz sand-rich substrate, and (4) similar profiles formed by free drainage through variable substrates and involving B horizon accumulation of concretionary iron oxides. Compound palaeosols are common.Deposition of the Lower Limestone Group was influenced by the tectonic and volcanic instability of the Fife area during Visean times. Frequent seismic events centred on active fault lines caused local uplift of parts of the normally waterlogged delta plain environment, allowing the formation of well-drained soils. Peats (coals) were best developed and least affected by oxidation in an elongate, fault bounded zone of enhanced subsidence.

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Small-amplitude lake-level fluctuations recorded in aggrading deltaic deposits of the Upper Pleistocene Thimi and Gokarna formations, Kathmandu Valley, Nepal

Journal of Nepal Geological Society ◽

10.3126/jngs.v25i0.32049 ◽

2001 ◽

Vol 25 ◽

Author(s):

Tetsuya Sakai ◽

Ananta Prasad Gajurel ◽

Hideo Tabata ◽

Bishal Nath Upreti

Keyword(s):

Small Amplitude ◽

Lake Level ◽

Fine Sediment ◽

Sediment Supply ◽

Kathmandu Valley ◽

Delta Front ◽

Lake Level Fluctuations ◽

Delta Plain ◽

Wet And Dry Cycles ◽

Sand Beds

Small-amplitude lake-level fluctuations have been recognized from the aggrading delta-plain deposits in the lower parts of the Thimi and Gokarna formations, Kathmandu Valley, Nepal. The delta-plain deposits consist or gravelly sand beds of fluvial channel origin (coarse-sediment interval) and alternation of' fine to very line sand and sandy silt beds (line-sediment interval). Wave generated structures occur in the sand beds or the fine sediment intervals. The vertical and lateral facies changes suggest that the deposition or a set of coarse- and fine-sediment intervals associated with prograding delta front deposits was controlled by a lake-level rise and fall sequence superimposed on a long-term lake level rise trend. The aggradation of fluvial sediments occurred during a lake-level rise period with sufficient sediment supply to fill a newly created accommodation space on the delta plain. The observation or wave-generated structures in an overlying fine-sediment interval suggests that the delta plain was subsequently inundated due to further lake-level rise, exceeding the sedimentation rate. Subsequent delta progradation occurred during a lake-level stabilized phase after a lake level fall. The small-amplitude lake-level changes are thought to be attribute able to seasonal wet and dry cycles, as inferred based on the presence of peculiar aggrading delta successions, implying that lake-level fluctuations may have occurred over short time scales, and on the results of a previous palaeopalynological study in which a moist palacoclimate was inferred in the lower part of the Gokarna Formation in particular.

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