scholarly journals Channel, dune and sand sheet architectures of strait-adjacent deltas

2021 ◽  
Author(s):  
Daan Beelen ◽  
Lesli Wood ◽  
Mohamed Zaghloul ◽  
Michiel Arts ◽  
Sebastian Cardona
Keyword(s):  
Tidal Currents ◽  
Delta Front ◽  
Delta Plain ◽  
Complex Architectures ◽  
Tidal Deposits ◽  
Sand Sheet ◽  
Seismic Scale ◽  
Sand Sheets ◽  
Delta Model

Sea strait geographies amplify tidal currents, which can result in the formation of tidal strait deposits with a symmetrical facies arrangement. It can be problematic to distinguish such confined tidal strait deposits from strait systems that developed in less constricted settings. To push a more robust differentiation between the confined tidal strait model and a model for less constricted tidal deposits, this study presents an example of a strait-adjacent delta and compares it to the existing model of confined tidal straits. The strait-adjacent delta interpretations are based on an exposed succession in Northern Morocco, that formed in the Miocene Rifian Corridor. The multi-km, seismic-scale exposures at the Ben Allou locality, formed in a region with a largely unconstrained coastline. Clayey and silty portions dominate the distal offshore and prodelta facies, while the proximal delta front and delta plain are comprised of carbonate-rich sandstones. These sandstones exhibit complex architectures of stacked channels and dunes in the delta front, and mud drape-bearing sand sheets on the delta plain. It is shown that the strait-adjacent delta model that is presented herein, is different from a confined tidal strait deposit as it has an asymmetric facies arrangement, and a basinward reduction in depositional energy.

Pliocene–Pleistocene fluvial/wave-dominated deltaic sedimentation: the Pamisos delta, southwest Peloponnesus, Greece

1994 ◽  
Vol 131 (5) ◽  
pp. 653-668 ◽  
Author(s):  
Abraham Zelilidis ◽  
Nikolaos Kontopoulos
Keyword(s):  
Active Faults ◽  
Early Pleistocene ◽  
Total Organic Matter ◽  
Delta Front ◽  
Wave Type ◽  
Late Pliocene ◽  
Delta Plain ◽  
Deltaic Sedimentation ◽  
Grain Size Parameters ◽  
Delta Model

AbstractA fluvial /wave-dominated delta was formed during late Pliocene times in southwestPeloponnesus, influenced by NNW—SSE and ENE—WSW trending faults. The depositional patternremained unchanged through early Pleistocene times, when the pre-existing active faults with WNW—ESE extension were combined with an eastward asymmetrical subsidence of the graben. Inthe deltaic environment, marshes, lakes and lagoons were created in the western parts, whereas largequantities of sediments were deposited in the central and eastern parts adjacent to basin marginsof steeper relief.This study combines grain size parameters, total organic matter, carbonate and clay mineralogyand structural analysis to: (a) determine the pattern of sedimentation in sub-environments and (b)create a fluvial/wave-type deltaic depositional model, and distinguish between delta-plain, delta-front and pro-delta environments. The Pliocene-Pleistocene, fluvial/wave-dominated delta model inthis study can be used to predict deltaic sedimentation in analogous basins.

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

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.

Tsunami Deposits Beneath Tidal Marshes on Northwestern Vancouver Island, British Columbia

1997 ◽  
Vol 48 (2) ◽  
pp. 192-204 ◽  
Author(s):  
Boyd E. Benson ◽  
Kurt A. Grimm ◽  
John J. Clague
Keyword(s):  
British Columbia ◽  
Plate Boundary ◽  
Vancouver Island ◽  
Tidal Marshes ◽  
Tsunami Source ◽  
Cascadia Subduction Zone ◽  
Tsunami Deposits ◽  
The North ◽  
Sand Sheet ◽  
Sand Sheets

AbstractTwo sand sheets underlying tidal marshes at Fair Harbour, Neroutsos Inlet, and Koprino Harbour on the northwestern coast of Vancouver Island, British Columbia, were probably deposited by tsunamis. The sand sheets become thinner and finer-grained landward, drape former land surfaces, contain marine microfossils, are locally graded or internally stratified, and can be correlated with earthquakes that generated tsunamis in the region. 137Cs dating and historical accounts indicate that the upper sand sheet was deposited by the tsunami from the great Alaska earthquake in 1964. Radiocarbon ages on plant fossils within and on top of the lower sand sheet show that it was deposited sometime after about A.D. 1660. We attribute the lower sand sheet to a tsunami from the most recent plate-boundary earthquake on the Cascadia subduction zone about 300 yr ago, extending the documented effects of this earthquake north of the Nootka fault zone. The 1964 tsunami deposits differ little in thickness and continuity among the three marshes. In contrast, the lower sand sheet becomes thinner and less continuous to the north, implying a tsunami source south of the study area.

Lithofacies and fluvial–lacustrine environments of the Palaeogene Sevkhuul and Ergil members (Ergiliin Zoo Formation, South Gobi, Mongolia)

2006 ◽  
Vol 143 (2) ◽  
pp. 165-179 ◽  
Author(s):  
H. G. DILL ◽  
S. KHISHIGSUREN ◽  
J. BULGAMAA ◽  
KH. BOLORMA ◽  
F. MELCHER
Keyword(s):  
Source Area ◽  
Field Work ◽  
Late Eocene ◽  
Climatic Conditions ◽  
Heavy Minerals ◽  
Gobi Desert ◽  
Carbonate Minerals ◽  
Delta Front ◽  
Delta Plain ◽  
Sheet Silicates

The clastic sequence of the Ergiliin Zoo Formation stretches along the Mongolian–Chinese border in the southern Gobi Desert, Mongolia. Its members (Sevkhuul, Ergil) exposed in the Erdene Sum region are well known for their vertebrate remains of Late Eocene and Oligocene age. Based upon field work, the continental red beds were subdivided into four units described as (I) prodelta/mud-sand flat, (II) delta front, (III) delta plain and (IV) calcretes. All sub-environments are in a fluvial–lacustrine setting. Electronmicroprobe analysis, in addition to conventional thin-section examination, was applied to shed some light on the complex mineral association made up of light minerals (quartz, plagioclase, ternary feldspar, orthoclase, smectite, illite, rare palygorskite), heavy minerals (almandine–pyrope solid solution series, zoisite–epidote s.s.s.) and abundant goethite and carbonate minerals (calcite, dolomite). Igneous rocks being exposed in the source area have contributed to the formation of carbonate minerals and Mg-bearing sheet silicates during diagenesis. Higher up on the delta plain transitional between distal alluvial and deltaic deposits, fluids emerged from the distal alluvial–fluvial deposits and formed calcareous duricrusts. Drawing conclusions from the rock colour, the mineral assemblage and the palaeoecological data, the climatic conditions may be described as alternating wet and dry seasons, closely resembling those conditions of a modern savannah.

scholarly journals A continuous record of Holocene eolian activity in West Greenland

2003 ◽  
Vol 59 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Nico W. Willemse ◽  
Eduard A. Koster ◽  
Babette Hoogakker ◽  
Frank G.M. van Tatenhove
Keyword(s):  
Greenland Ice Sheet ◽  
Sedimentary Facies ◽  
Two Phase ◽  
Air Masses ◽  
West Greenland ◽  
History Of ◽  
Floodplain Development ◽  
Sand Sheet ◽  
Maritime Air ◽  
Sand Sheets

AbstractEolian landforms are widespread alongside proglacial valley-sandurs in West Greenland and comprise low-relief sand sheets, climbing dunes, and upland loess. Sedimentary facies mainly reflect distance to outwash-source zones and the influence of vegetation cover. The sediments show stratification types typical for poorly to moderately vegetated sand-sheets, alternately laminated silt/peat sequences, and unstratified loess. Twenty-five accelerator mass spectrometry 14C dates provide the basis for the chronostratigraphy of the inland eolian deposits. 14C dates from interstratified sand-sheets suggest that the bulk of eolian sands were deposited prior to 3400 cal yr B.P. and after 550 cal yr B.P. This two-phase formation for the inland dunes most likely reflects local changes in proglacial floodplain development and meltwater rerouting associated with a significant recession of the Greenland ice sheet during the mid Holocene climate optimum. Subsequent floodplain regeneration and renewed sand-sheet formation after 550 cal yr B.P. followed when the ice margin readvanced to its present position. In contrast, atmospheric deposition of regionally derived silt in upland peat mires has been continuous since at least 4750 cal yr B.P. Silt influx data demonstrate a strongly episodic history of the intensity of eolian activity over the past five millennia, which tentatively reflects alternating periods of (winter) aridity associated with the variable incursion of maritime air masses over the interior ice-free areas of West Greenland.

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

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.

scholarly journals The Serbian Lake Pannon formations - their significance and interregional correlation

2021 ◽  
pp. 7-7
Author(s):  
Filip Andjelkovic ◽  
Dejan Radivojevic
Keyword(s):  
Geothermal Energy ◽  
Pannonian Basin ◽  
Construction Materials ◽  
Seismic Survey ◽  
Petroleum Geology ◽  
Delta Front ◽  
Lake Pannon ◽  
Delta Plain ◽  
Lithostratigraphic Correlation ◽  
Basin System

The problem of correlating Lake Pannon sediments across its basin has been the occupation of many geologists. At first, it was hampered by the prevalence of biostratigraphic, rather than lithostratigraphic correlation. The task became accomplishable when, thanks to seismic survey data, the strongly progradational character of Lake Pannon sedimentation had been understood. Thus, this paper aims to describe the formations from all parts of Lake Pannon and compare them to the ones described in Serbia. Material used includes published and unpublished data from all countries w ith Pannonian Basin System upper Miocene and lower Pliocene deposits, in the form of seismic, borehole and outcrop data. Even though the system is strongly asymmetric, both spatially and temporally, the formation synthesis framework should help better understanding among geologists operating w ithin the basin. For the first t ime the informal formations are proposed for all Lake Pannon sediments in Serbia. The formations are linked to a progradational deltaic system w ithin the following succession: basinal plain-turbidite-slope-delta front-delta plain-lacustrine and alluvial environments. The lithostratigraphic correlation has a huge potential in the context of industry. The main potential surely lies in petroleum geology, but it could be also very useful for exploration of geothermal energy, hydrogeology and construction materials.

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

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.

A Research for Division and Correlation of Fuyu Oil Layer in Northern Honggang Area

2014 ◽  
Vol 962-965 ◽  
pp. 622-625
Author(s):  
Xi Cheng Cao ◽  
Ming Ming Tang
Keyword(s):  
Songliao Basin ◽  
Western Slope ◽  
Delta Front ◽  
The West ◽  
Delta Plain ◽  
The North ◽  
Facies Types

Northern Honggang Area is situated in the north of Daan-Honggang terraces, southern Songliao Basin, bounded on the west of the western slope, on the northeast by Cologne sag, and on the southeast by Changling sag. The facies types of Northern Honggang District are mainly delta. The upper part of Fuyu oil layer is dominated by delta-front facies, the lower part is dominated by delta-plain facies.

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