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 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.

Lithostratigraphy of the Kookfontein Formation (Ecca Group, Karoo Supergroup), South Africa

2017 ◽  
Vol 120 (3) ◽  
pp. 447-458
Author(s):  
H. de V. Wickens ◽  
D.I. Cole
Keyword(s):  
South Africa ◽  
Depositional Environment ◽  
Delta Front ◽  
Southwestern Part ◽  
Fine Grained ◽  
Karoo Basin ◽  
Deformation Features ◽  
Stratigraphic Position ◽  
Shelf Margin ◽  
Upper Slope

Abstract The Permian Kookfontein Formation forms part of the upper Ecca Group in the southwestern part of the main Karoo Basin of South Africa. It occupies a stratigraphic position between the underlying Skoorsteenberg Formation and the overlying Waterford Formation, with its regional extent limited to the cut-off boundaries of the Skoorsteenberg Formation. The Kookfontein Formation has an average thickness of 200 m, coarsens upwards, and predominantly comprises dark grey shale, siltstone and thin- to thick-bedded, fine- to very fine-grained, feldspathic litharenite. Characteristic upward-coarsening and thickening successions and syn-sedimentary deformation features reflect rapid deposition and progradation of a predominantly fluvially-dominated prodelta and delta front slope environment. The upward increase in the abundance of wave–ripple marks further indicates a gradual shallowing of the depositional environment through time. The upper contact with the Waterford Formation is gradational, which indicates a transition from deposition in an unstable upper slope/shelf margin environment to a more stable shelf setting.

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

2019 ◽  
Vol 156 (10) ◽  
pp. 1715-1741 ◽  
Author(s):  
Jake Breckenridge ◽  
Angelos G. Maravelis ◽  
Octavian Catuneanu ◽  
Kevin Ruming ◽  
Erin Holmes ◽  
...  
Keyword(s):  
Source Region ◽  
Depositional Environments ◽  
Sediment Supply ◽  
Upper Permian ◽  
Delta Front ◽  
Sediment Grain Size ◽  
Sequence Stratigraphic ◽  
Delta Plain ◽  
Facies Associations ◽  
The Impact

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.

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
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.

scholarly journals New observations of marine trace fossils in delta plain sequences, southern Nûgssuaq, West Greenland

1989 ◽  
Vol 145 ◽  
pp. 37-42
Author(s):  
G.K Pedersen ◽  
B.F Rasmussen
Keyword(s):  
Natural Science ◽  
Upper Cretaceous ◽  
Research Council ◽  
Science Research ◽  
Field Work ◽  
Delta Plain ◽  
Natural Science Research Council ◽  
Field Season ◽  
Marine Influence ◽  
Science Research Council

During the 1988 field season new observations were made on the sediments of the Upper Cretaceous Atane Formation in southern Nûgssuaq. These observations indicate that the degree of bioturbation may be taken as an indicator of the degree of marine influence within the interdistributary delta plain environments. The field work was carried out during six days in July 1988 as part of a sedimentological research project supported by GGU and the Danish Natural Science Research Council.

Architecture of a river-dominated, wave- and tide-influenced, pre-vegetation braid delta: Cambrian middle member of the Wood Canyon Formation, southern Marble Mountains, California, U.S.A.

2020 ◽  
Vol 90 (9) ◽  
pp. 1011-1036
Author(s):  
Jason G. Muhlbauer ◽  
Christopher M. Fedo
Keyword(s):  
Mojave Desert ◽  
Fluid Mud ◽  
Delta Front ◽  
Sand Waves ◽  
Motion Models ◽  
Facies Associations ◽  
Surface Measurements ◽  
Marine Influence ◽  
Middle Member ◽  
Stratigraphic Height

ABSTRACT Across the Mojave Desert of southeastern California, outcrops of the Cambrian middle member of the Wood Canyon Formation preserve the deposits of pre-vegetation braided-fluvial and braid-delta environments. One 78-meter-thick section in the southern Marble Mountains, documented here through detailed stratigraphic logging, facies analysis, architectural panels based on “Structure-from-Motion” models, and a suite of paleocurrent and accretion-surface measurements, provides insight into the development of a river-dominated, wave- and tide-influenced braid delta at the distal end of a continent-scale braidplain. In contrast to other pre-Devonian braid-delta strata, in which mudrock is largely absent, the greater part of the middle member system contains over 5% mudstone. Four facies associations, FA4–7, constitute the middle member section and represent (in order of stratigraphic height) a braidplain-to-delta transition (FA4), proximal braid delta (FA5), distal braid delta (FA6), and upper braid-delta front (FA7). The 20 meters of braidplain-to-delta transition strata are largely similar to those of fluvial middle member sections, containing approximately 2% mudstone, unimodal north-northwest paleoflow, and vertical, downstream, and downstream-lateral accretion elements representing compound barforms and channel fills. Above, each braid-delta facies association (FA5–7) preserves high-sinuosity paleocurrent indicators, 6–12% mudstone, and symmetrical, wave-formed sand waves. Decimeter-thick fluid-mud deposits found chiefly in FA6 and less commonly in FA7 indicate the presence of a turbidity-maximum zone that records brackish-water conditions in the distal braid delta. Trace fossils concentrated in FA7 suggest that metazoans were confined to the upper braid-delta front and could not tolerate the variable salinity of the braid delta. Increased marine influence with stratigraphic height requires gradual transgression during deposition of the middle member of the Wood Canyon Formation, possibly as part of a lowstand systems tract.

scholarly journals Fluvial-Tidal to Fluvial-Lacustrine Sedimentation of the Middle Miocene to Pleistocene Mapia Formation, Dogiyai, Papua (Indonesia)

2021 ◽  
Vol 50 (7) ◽  
pp. 1885-1899
Author(s):  
Rakhmat Fakhruddin
Keyword(s):  
Depositional Environment ◽  
Middle Miocene ◽  
Sedimentary Rocks ◽  
Tidal Channel ◽  
Delta Front ◽  
Late Pliocene ◽  
Clastic Sediments ◽  
Piggyback Basin ◽  
Facies Associations ◽  
Age Range

A sedimentological and palynological investigation was carried out on outcropping sedimentary rocks at Dogiyai, Papua, proposed to be named as the Mapia Formation. The age range is from Middle Miocene to Pleistocene. The lower Mapia Formation was deposited at Metroxylon type to Nothofagus emarcida Zone, Middle Miocene to Early Pliocene. It is comprised of three facies associations: tidal channel, tidal point bar, and tidal flat deposits. A tidally dominated fluvially influenced depositional environment is suggested for the deposition of sediments of this unit. The upper Mapia Formation was deposited at Malvacipollis diversus Zone, Garcinia cuspidata type Zone, and Proteacidites sp. Zone, Late Pliocene to Pleistocene. It is comprised of five facies associations: delta front, slump, debrite, turbidite, and lacustrine mud deposits. A non-channelized deep-lacustrine slump and debris-flow dominated depositional environment is suggested for the deposition of sediments of this unit. The lower Mapia Formation was deposited as synorogenic clastic sediments at the beginning of Central Range orogeny event while the upper Mapia Formation was deposited in the piggyback basin at the major uplift event.

Neogene shallow-marine and fluvial sediment dispersal, burial, and exhumation in the ancestral Brahmaputra delta: Indo-Burman Ranges, India

2020 ◽  
Vol 90 (9) ◽  
pp. 1244-1263
Author(s):  
Ryan Sincavage ◽  
Paul M. Betka ◽  
Stuart N. Thomson ◽  
Leonardo Seeber ◽  
Michael Steckler ◽  
...  
Keyword(s):  
Thermal Modeling ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Depositional Environments ◽  
Accumulation Rates ◽  
Shallow Marine ◽  
Sediment Dispersal ◽  
Delta Plain ◽  
Stratigraphic Record ◽  
Surma Group

ABSTRACT The stratigraphic record of Cenozoic uplift and denudation of the Himalayas is distributed across its peripheral foreland basins, as well as in the sediments of the Ganges–Brahmaputra Delta (GBD) and the Bengal–Nicobar Fan (BNF). Recent interrogation of Miocene–Quaternary sediments of the GBD and BNF advance our knowledge of Himalayan sediment dispersal and its relationship to regional tectonics and climate, but these studies are limited to IODP boreholes from the BNF (IODP 354 and 362, 2015-16) and Quaternary sediment cores from the GBD (NSF-PIRE: Life on a tectonically active delta, 2010-18). We examine a complementary yet understudied stratigraphic record of the Miocene–Pliocene ancestral Brahmaputra Delta in outcrops of the Indo-Burman Ranges fold–thrust belt (IBR) of eastern India. We present detailed lithofacies assemblages of Neogene delta plain (Tipam Group) and intertidal to upper-shelf (Surma Group) deposits of the IBR based on two ∼ 500 m stratigraphic sections. New detrital-apatite fission-track (dAFT) and (U-Th)/He (dAHe) dates from the Surma Group in the IBR help to constrain maximum depositional ages (MDA), thermal histories, and sediment accumulation rates. Three fluvial facies (F1–F3) and four shallow marine to intertidal facies (M1–M4) are delineated based on analog depositional environments of the Holocene–modern GBD. Unreset dAFT and dAHe ages constrain MDA to ∼ 9–11 Ma for the Surma Group, which is bracketed by intensification of turbidite deposition on the eastern BNF (∼ 13.5–6.8 Ma). Two dAHe samples yielded younger (∼ 3 Ma) reset ages that we interpret to record cooling from denudation following burial resetting due to a thicker (∼ 2.2–3.2 km) accumulation of sediments near the depocenter. Thermal modeling of the dAFT and dAHe results using QTQt and HeFTy suggest that late Miocene marginal marine sediment accumulation rates may have ranged from ∼ 0.9 to 1.1 mm/yr near the center of the paleodelta. Thermal modeling results imply postdepositional cooling beginning at ∼ 8–6.5 Ma, interpreted to record onset of exhumation associated with the advancing IBR fold belt. The timing of post-burial exhumation of the IBR strata is consistent with previously published constraints for the avulsion of the paleo-Brahmaputra to the west and a westward shift of turbidite deposition on the BNF that started at ∼ 6.8 Ma. Our results contextualize tectonic controls on basin history, creating a pathway for future investigations into autogenic and climatic drivers of behavior of fluvial systems that can be extracted from the stratigraphic record.

Unravelling the depositional environment of the Archaean Rajkharsawan conglomerate (Jharkhand, eastern India)

2012 ◽  
Vol 91 (1-2) ◽  
pp. 129-135 ◽  
Author(s):  
A.J. van Loon ◽  
R. Mazumder ◽  
S. De
Keyword(s):  
Depositional Environment ◽  
Sediment Accumulation ◽  
Horizontal Distribution ◽  
Eastern India ◽  
Singhbhum Craton ◽  
Fine Grained ◽  
Stratigraphic Position ◽  
Vertical And Horizontal Distribution

AbstractLarge conglomerate lenses occur in a fine-grained siliciclastic succession of the Singhbhum craton, eastern India. They overlie an Archaean orthogneiss, from which they are separated by a palaeosol. Neither the conglomerates nor the directly overlying rocks have been dated, but the conglomerate unit is assumed to have also an Archaean age. The conglomerate lenses occur within a succession of pelitic and mafic schists, and the depositional environment of this conglomerate/schist unit had not been clarified thus far. On the basis of a combination of the vertical and horizontal distribution of the conglomerates, their stratigraphic position and analysis of their sedimentological characteristics and the sedimentological context, it is concluded that the succession must have developed in a fluvial lowland environment where volcanic input contributed significantly to the sediment accumulation.

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

Geosciences ◽  
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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