scholarly journals Evolution of Depositional Environments in Response to the Holocene Sea-Level Change in the Lower Delta Plain of Nakdong River Delta, Korea

2021 ◽  
Vol 12 (1) ◽  
pp. 177
Author(s):  
Eun Je Jeong ◽  
Daekyo Cheong ◽  
Jin Cheul Kim ◽  
Hyoun Soo Lim ◽  
Seungwon Shin
Keyword(s):  
Grain Size ◽  
Sea Level ◽  
Depositional Environments ◽  
River Delta ◽  
Present Level ◽  
Nakdong River ◽  
Delta Front ◽  
Shallow Marine ◽  
Delta Plain ◽  
Drilling Site

The Nakdong River delta, located in southeastern Korea, preserves thick and wide sediments, which are suitable for the high-resolution study of the evolution of depositional environments in the lower delta plain area. This study traces the Holocene evolution of the Nakdong River delta using deep drill core (ND-3; 46.60 m thick) sediments from the present delta plain. Sedimentary units of the sediments were classified based on grain size compositions and sedimentary structures: (A) alluvial zone, (B) estuarine zone, (C) shallow marine, (D) prodelta, (E) delta front, and (F) delta plain. The weathered sediment, paleosol, was observed at 43.16 m below the surface. There is an unconformity (43.10 m) to separate a Pleistocene sediment layer in the lowermost part differentiating from a Holocene sediment layer in the upper part of the core. The shallow marine sedimentary unit (32.20~23.50 m), in which grain size decreases upward is overlain by the prodelta unit (23.50~15.10 m), which consists of fine-grained sediments and relatively homogeneous sedimentary facies. The boundary between the delta front unit (15.10~8.00 m) and the delta plain unit (8.00~0.00 m) appears to lie at 8.0 m, and the variation in grain size is different; coarsening upward in the delta front unit and fining upward in the delta front unit, respectively. These sediments are characterized by a lot of sand–mud couplets and mica flakes aligned along with cross-stratification, which may be deposited in relatively high-energy environments. Until 13 cal ka BP, the sea level was 70 m below the present level and the drilling site might be located onshore. At 10 cal ka BP, the sea level was located 50 m below the present level and the drilling site might be moved to an estuarine environment. From 8 to 6 cal ka BP, a transgression phase occurred as a result of coastline invasion by the rapid rise of the sea level. Thus, the drilling site was drowned in a shallow marine environment. After 6 cal ka BP, the sea level reached the present level, and, since then, progradation might begin to form, primarily by more sediment input. After this period, the progradation phase continues as the sediments have advanced and the delta grows.

Evolution and stratigraphy of the Nakdong River valley deposits in response to late Quaternary sea-level change

2020 ◽  
Author(s):  
Dong-Geun Yoo ◽  
Seok-Hwi Hong ◽  
Gwang-Soo Lee ◽  
Jin-Cheul Kim ◽  
Gil-Young Kim ◽  
...  
Keyword(s):  
Sea Level ◽  
River Mouth ◽  
River Valley ◽  
Coarse Grained ◽  
Nakdong River ◽  
Delta Front ◽  
Delta Plain ◽  
Depositional System ◽  
Depositional Systems ◽  
The Nakdong River

<p>Sequence analysis using borehole samples and high-resolution seismic data in the Nakdong River valley reveals that the Nakdong River valley deposits, approximately 60 - 70 m thick, consist of a set of lowstand, transgressive, and highstand systems tracts that corresponds to a fifth-order (20 ka) sea-level cycle. Four main depositional systems, including ten sedimentary facies, constitute these systems tracts: fluvial, estuary, coastal/shoreface, and delta. The lowstand systems tract (LST), consisting of gravelly sand, forms a fluvial depositional system (Unit I) which fills the thalweg of river valley mainly developed approximately before 12 ka. The transgressive systems tract (TST) can be divided into two depositional systems (Unit II and III). The river-derived sediments were trapped within the paleo-estuary, forming an estuarine depositional system (Unit II) developed between 12 and 6 ka. As the transgression continued, the coarse sediments were deposited and redistributed by coastal processes, resulting in coastal/shoreface depositional system (Unit III). It is characterized by an isolated sand body and thin sand veneer. The HST is composed of deltaic depositional system including delta plain, delta front, and prodelta (Unit IV). During the delta progradation, most coarse-grained sands derived from the river were deposited in the lower delta plain and delta front, forming sand bars and shoals less than 15 m deep. The remaining fine-grained sediments were transported further offshore in a suspension mode and deposited in the inner shelf off the present river mouth, forming a subaqueous prodelta. Radiocarbon and optica<strong>lly stimulated luminescence (OSL</strong>) dating suggest that the recent deltaic system was initiated by aggradational and progradational stacking patterns at approximately 8 ka during the last stage of decelerated sea-level rise, and was then followed by a prograding clinoform after the highest sea level at approximately 6 ka.</p>

scholarly journals Deciphering tectonic, eustatic and surface controls on the 20 Ma-old Burdigalian transgression recorded in the Upper Marine Molasse in Switzerland

2019 ◽  
Author(s):  
Philippos Garefalakis ◽  
Fritz Schlunegger
Keyword(s):  
Sea Level ◽  
Depositional Environments ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Crustal Material ◽  
Molasse Basin ◽  
Shallow Marine ◽  
Depositional Settings ◽  
Stratigraphic Architecture ◽  
Aar Massif

Abstract. The stratigraphic architecture of the Swiss Molasse basin reveals crucial information about the basin’s geometry, its evolution and the processes leading to the deposition of the clastic material. Nevertheless, the formation of the Upper Marine Molasse (OMM) and the controls on the related Burdigalian transgression are not fully understood yet. During these times, from c. 20 to 17 Ma, the Swiss Molasse basin was partly flooded by a peripheral shallow marine sea, striking SW – NE. We proceeded through detailed sedimentological and stratigraphic examinations of several sites across the entire Swiss Molasse basin in order to deconvolve the stratigraphic signals related surface and tectonic controls. Surface-related signals include stratigraphic responses to changes in eustatic sea level and sediment fluxes, while the focus on crustal-scale processes lies on the uplift of the Aar-massif at c. 20 Ma. Field examinations show, that the evolution of the Burdigalian seaway was characterized by (i) shifts in the depositional settings, (ii) changes in discharge directions, a deepening and widening of the basin, and (iv) phases of erosion and non-deposition. We relate these changes in the stratigraphic records to a combination of surface and tectonic controls at various scales. In particular, roll-back subduction of the European mantle lithosphere, delamination of crustal material and the associated rise of the Aar-massif most likely explain the widening of the basin particular at distal sites. In addition, the uplift of the Aar-massif was likely to have shifted the patterns of surface loads. These mechanisms could have caused a flexural adjustment of the foreland plate underneath the Molasse basin, which we use as mechanism to explain the establishment of distinct depositional environments and particularly the formation of subtidal-shoals where a lateral bulge is expected. In the Alpine hinterland, these processes occurred simultaneously with a period of fast tectonic exhumation accomplished through slip along the Simplon detachment fault, with the consequence that sediment flux to the basin decreased. It is possible that this reduction in sediment supply contributed to the establishment of marine conditions in the Swiss Molasse basin and thus amplified the effect related to the tectonically controlled widening of the basin. Because of the formation of shallow marine conditions, subtle changes in the eustatic sea level contributed to the occurrence several hiatus that chronicle periods of erosion and non-sedimentation. While these mechanisms are capable of explaining the establishment of the Burdigalian seaway and the formation of distinct sedimentological niches in the Swiss Molasse basin, the drainage reversal during OMM-times possibly requires a change in the tectonic processes at the slab scale. We conclude that sedimentological records can be used to decipher surface controls and lithospheric-scale processes in orogens from the stratigraphic record, provided that a detailed sedimentological and chronological database is available.

Sediment properties of lithologic units and their correlation within the lower delta plain of the Nakdong River Delta, southeast Korea

2019 ◽  
Vol 519 ◽  
pp. 170-182
Author(s):  
Boo-Keun Khim ◽  
Seungwon Shin ◽  
Jin Cheul Kim ◽  
Hiroyuki Takata ◽  
Sangmin Hyun ◽  
...  
Keyword(s):  
River Delta ◽  
Nakdong River ◽  
Sediment Properties ◽  
Delta Plain ◽  
The Nakdong River

scholarly journals Changing depositional environments in the Colombian Fúquene Basin at submillennial time-scales during 284-27 ka from unmixed grain-size distributions and aquatic pollen

2012 ◽  
Vol 91 (1-2) ◽  
pp. 199-214 ◽  
Author(s):  
M. Vriend ◽  
M.H.M. Groot ◽  
H. Hooghiemstra ◽  
R.G. Bogotá-Angel ◽  
J.C. Berrio
Keyword(s):  
Grain Size ◽  
Lacustrine Sediments ◽  
Depositional Environments ◽  
Organic Carbon Content ◽  
Size Distributions ◽  
Glacial Cycles ◽  
Available Energy ◽  
Grain Size Distributions ◽  
Drilling Site ◽  
Mis 5E

AbstractIn a ~60 m long record reflecting the period from 284 ka to 27 ka we analysed grain size distributions (GSD), organic carbon content, and aquatic pollen assemblages at 1-cm increments. The 4768-points time series show with ~60 yr resolution the dynamic history of Lake Fúquene (2540 m alt., 4° N lat.) of the northern Andes during two full interglacial-glacial cycles. GSD show proportions of clay, fine silt, coarse silt, and sand evidencing the location of the sediment source (proximal vs distal) in relation to the drilling site, and available energy to transport sediments in the catchment area. Loss-on-ignition (LOI) values reflect estimates of the abundance of organic matter (OM) in the sediments. Aquatic pollen were grouped into assemblages characteristic of deep water, shallow water, swamp, and wet lake shore environments, reflecting a hydrological gradient sensitive for lake level changes.The End-Member Modelling Algorithm (EMMA) showed that 4 end-members (EMs) explain an optimal proportion (70%) of the observed variation. EMMA is able to unmix GSD of lacustrine sediments in a genetically meaningful way allowing EMs to be interpreted in past depositional and environmental settings. Most unexplained variability is located in the fraction of coarse sediment. OM content was estimated on the basis of LOI data and formed a fifth EM that mainly indicates presence of peat. Changes concur with submillennial-scale variability established in other proxies from this record (Groot et al., 2011). Periods with distinct sediment compositions are 284-243 ka (mainly MIS 8), 243-201 ka (mainly MIS 7), 201-179 ka (mainly MIS 7/6 transition), 179-133 ka (mainly MIS 6), 133-111 ka, (mainly MIS 5e) 111-87 ka (mainly MIS 5d-5b), 87-79 ka (mainly MIS 5a), 79-62 ka (mainly MIS 4), and 62-27 ka (MIS 3) showing sedimentological regimes are climate driven.

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

2014 ◽  
Vol 82 (2) ◽  
pp. 430-440 ◽  
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.

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.

scholarly journals Cryostratigraphy, sedimentology and the late Quaternary evolution of the Zackenberg Delta, Northeast Greenland

2017 ◽  
Author(s):  
Graham L. Gilbert ◽  
Stefanie Cable ◽  
Christine Thiel ◽  
Hanne H. Christiansen ◽  
Bo Elberling
Keyword(s):  
Grain Size ◽  
Late Quaternary ◽  
Sediment Cores ◽  
Depositional Environments ◽  
Coastal Processes ◽  
Delta Plain ◽  
Valley Fill ◽  
Subaerial Exposure ◽  
Coastal Cliffs ◽  
The Relationship

Abstract. The Zackenberg Delta is located in Northeast Greenland (74°30'N, 20°30'E) at the outlet of the Zackenberg Valley. The deltaic fill at the mouth of the valley consists of a series of terraces (ca. 2 km2) formed during a fall in relative sea level. The modern Zackenberg River has incised through the paleo-deltaic deposits creating exposures (up to 22 m in height) along the rivers banks. In addition, coastal processes have exposed sediments in 4 m – 20 m high coastal cliffs. In 2012, two 20 m long ice-bonded sediment cores were retrieved from within the deltaic deposits. The combination of river and coastal exposures with the analysis of ground ice in these cores permitted the reconstruction of the valley-fill succession and evaluation of the timing and nature of permafrost aggradation. Permafrost in the palaeo-deltaic deposits is predominantly epigenetic and aggraded following the subaerial exposure of the delta plain (beginning ca. 11 ka). The exposed deposits in the Zackenberg Valley provide a unique opportunity to investigate the relationship between depositional environments and processes, grain-size properties and cryostratigraphy in epigenetic lowland permafrost environments.

scholarly journals Holocene Sedimentary Environment in HP1 Core at Duong Kinh, Haiphong

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Nguyen Thi Thu Cuc ◽  
Nguyen Thuy Duong ◽  
Nguyen Thi Minh Phuong ◽  
Doan Dinh Lam ◽  
Vu Van Loi ◽  
...  
Keyword(s):  
Grain Size ◽  
Coastal Area ◽  
Sedimentary Environment ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Diatom Species ◽  
Delta Front ◽  
Environment Change ◽  
Delta Plain

Holocene environment change in Hai Phong coastal area was reconstructed based on diatom and grain-size analysis in the HP1 core at Duong Kinh, Hai Phong. 52 diatom species were identified and divided in five diatom ecozones by changing of four diatom groups including marine planktonic, brackish planktonic, brackish benthic and freshwater one. The sedimentary environment at the Hai Phong coastal area was estuary- bay condition in the Flandrian trangression (Z1, Z2 and Z3 Unit). Deltaic environment changed from prodelta (Z4), delta front (Z5) to delta plain (Z6 and Z7) corresponding to the Flandrian regression.

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