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

1988 ◽  
Vol 125 (3) ◽  
pp. 241-255 ◽  
Author(s):  
C. R. Fielding ◽  
M. Al-Rubaii ◽  
E. K. Walton

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.

2014 ◽  
Vol 47 (1) ◽  
pp. 57-64
Author(s):  
Mukunda Raj Paudel

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.


1991 ◽  
Vol 39 ◽  
pp. 111-122
Author(s):  
Torben Olsen ◽  
Gunver Krarup Pedersen

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.


2020 ◽  
Author(s):  
Yueyue Bai ◽  
Qingtian Lv ◽  
Zhaojun Liu ◽  
Pingchang Sun ◽  
Rong Liu ◽  
...  

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.


2019 ◽  
Vol 156 (10) ◽  
pp. 1715-1741 ◽  
Author(s):  
Jake Breckenridge ◽  
Angelos G. Maravelis ◽  
Octavian Catuneanu ◽  
Kevin Ruming ◽  
Erin Holmes ◽  
...  

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.


Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 273
Author(s):  
Sean Melehan ◽  
Chrysanthos Botziolis ◽  
Angelos G. Maravelis ◽  
Octavian Catuneanu ◽  
Kevin Ruming ◽  
...  

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.


1994 ◽  
Vol 131 (5) ◽  
pp. 653-668 ◽  
Author(s):  
Abraham Zelilidis ◽  
Nikolaos Kontopoulos

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.


2016 ◽  
Vol 43 (2) ◽  
pp. 215 ◽  
Author(s):  
Mariana S. Olivo ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga

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.


2017 ◽  
Vol 11 (3) ◽  
pp. 1265-1282 ◽  
Author(s):  
Graham L. Gilbert ◽  
Stefanie Cable ◽  
Christine Thiel ◽  
Hanne H. Christiansen ◽  
Bo Elberling

Abstract. The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.


2015 ◽  
Vol 45 (suppl 1) ◽  
pp. 13-27 ◽  
Author(s):  
Roberto Cesar de Mendonça Barbosa ◽  
Afonso César Rodrigues Nogueira ◽  
Fábio Henrique Garcia Domingos

ABSTRACTGlaciotectonic features studied in the siliciclastic deposits of Cabeças Formation, Upper Devonian, represent the first evidence of Famennian glaciation in Southeastern Parnaíba Basin, Brazil. Outcrop-based stratigraphic and facies analyses combined with geometric-structural studies of these deposits allowed defining three facies association (FA). They represent the advance-retreat cycle of a glacier. There are: delta front facies association (FA1) composed of massive mudstone, sigmoidal, medium-grained sandstone with cross-bedding and massive conglomerate organized in coarsening- and thickening-upward cycles; subglacial facies association (FA2) with massive, pebbly diamictite (sandstone, mudstone and volcanic pebbles) and deformational features, such as intraformational breccia, clastic dikes and sills of diamictite, folds, thrust and normal faults, sandstone pods and detachment surface; and melt-out delta front facies associations (FA3), which include massive or bedded (sigmoidal cross-bedding or parallel bedding) sandstones. Three depositional phases can be indicated to Cabeças Formation: installation of a delta system (FA1) supplied by uplifted areas in the Southeastern border of the basin; coastal glacier advance causing tangential substrate shearing and erosion (FA1) in the subglacial zone (FA2), thus developing detachment surface, disruption and rotation of sand beds or pods immersed in a diamicton; and retreat of glaciers accompanied by relative sea level-rise, installation of a high-energy melt-out delta (FA3) and unloading due to ice retreat that generates normal faults, mass landslide, folding and injection dykes and sills. The continuous sea-level rise led to the deposition of fine-grained strata of Longá Formation in the offshore/shoreface transition in the Early Carboniferous.


The North Sea sedimentary basin has developed on the northwestern margin of the European tectonic plate and contains an almost continuous record of epeirogenic marine and deltaic sedimentation from Carboniferous to Recent times. The subsidence required to accommodate the pile of sediment deposited, which in places exceeds 12 km, has been brought about at various times and in various places by differing geodynamical processes. As a result the types of sedimentary rocks deposited vary widely both in time and space, but the nature of the mechanism is reflected in the sedimentary type deposited. The following broad generalizations can be made. The late Carboniferous was a period of deltaic sedimentation during which eustatic changes in sea level or local variations in subsidence rates are reflected in the typical Coal Measures swamp deposits. Late Carboniferous - early Permian times saw the silting up of this basin, and in an arid climate aeolian sands were deposited grading laterally to sabkha shales and evaporites. The Permian culminated in a series of widespread marine incursions during which repetitive evaporites were deposited. Triassic times were marked by a period of major rifting and the deposition of thick sequences of continental elastics in the north, while widespread marine sedimentation persisted in southern areas. Jurassic times saw the re-establishment of marine to deltaic deposition in a series of basins possibly controlled in their distribution by the Triassic fault systems. Late Jurassic deposits were laid down in a sea whose bathymetry reflected the structure of the underlying horsts and grabens inherited from Triassic times, and towards the close of the Jurassic the bottom waters at least of this sea become increasingly stagnant. Sands deposited during the late Jurassic were deposited as near-shore marine bars, beach sands, and proximal and distal submarine fans. Triassic to early Cretaceous deposition was concentrated in the areas now occupied by the main grabens of the North Sea, i.e. the Viking, Central and Moray - Witch Ground grabens. Subsequent deposition in late Cretaceous to Tertiary times took place in a more widely subsiding area, resulting in progressive onlap onto the surrounding basin margins. Deposition within this broadly subsiding and relatively unfaulted basin is characterized by chalky limestones in southern areas, giving way laterally to shales and minor sands to the north. During early Tertiary times a large delta was formed in the area beneath the present Moray Firth, and from this delta a supply of sand was fed into submarine fans to the northeast and southeast of the delta front. Late Tertiary deposition is largely represented by a monotonous sequence of marine shales.


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