scholarly journals Meandering river deposits in sediment cores, the Middle Jurassic Alma Field, Southern Danish Central Graben

2018 ◽  
Vol 66 ◽  
pp. 189-209
Author(s):  
Aslaug C. Glad ◽  
Lars Ole Boldreel ◽  
Lars B. Clemmensen ◽  
Mads E. Willumsen
Keyword(s):  
Middle Jurassic ◽  
Facies Analysis ◽  
River System ◽  
Point Bar ◽  
Meandering River ◽  
Channel Belt ◽  
River Deposits ◽  
Floodplain Deposits ◽  
Channel Deposits ◽  
Mixed Load

Fluvial deposits are amongst the most important terrestrial hydrocarbon reservoirs, but the complex nature of these deposits is challenging in subsurface reservoir characterisation. This study is the first detailed facies analysis of the meandering river deposits of the Middle Jurassic Alma Field situated in the southern Danish North Sea. The fluvial sandstones and their associated deposits are described and interpreted based on studies from two core sites (Alma-1X and Alma-2X). The facies analysis of the cores demonstrates the presence of three meandering river facies associations: Channel deposits, channel margin deposits and floodplain deposits. The channel deposits comprise channel thalweg and point bar sediments, the channel margin deposits include crevasse channel and crevasse splay sediments, while the floodplain deposits comprise overbank and backswamp sediments. The point bar deposits are composed of fine- to medium-grained sandstones but can contain intervals of finer grained sediments, particularly in their upper parts where they can grade into muddy sandstones or true heterolithic deposits. Preserved sand body thicknesses (channel thalweg and point bar deposits) in both Alma cores have a mean value of 2.6 m and a maximum value of 4.35 m (Alma-1X) and 6.55 m (Alma-2X). Using maximum values of channel deposit thicknesses, and assuming the preservation conditions are met, the width of the largest ancient channel belt in Alma-1X would be between 90 m and 200 m or around 900 m, depending on whether the fluvial system is mud-rich or sand-rich. The same method applied to Alma-2X gives a width of the largest channel belt between 130 m and 330 m or around 1300 m. Fluvial sediments of the Middle Jurassic Scalby Formation (north-east England) were deposited in a sandy meandering river with sedimentary characteristics corresponding to those observed in the Alma cores. Outcrop analogue investigations of this formation were carried out to examine the architecture of the fluvial facies in a two-dimensional section with emphasis on channel thalweg and point bar deposits. Combined evidence from core analysis and outcrop analogue studies suggests that the fluvial deposits in the Alma Field represent a mixed-load meandering river system with sandy point bars. The meandering river system developed on a coastal plain with overbank fines and organic-rich backswamp deposits. The mud-rich or heterolithic deposits in the upper part of the point bar facies intervals are noteworthy and could indicate markedly fluctuating discharge in a mixed-load river.

scholarly journals Lithology distribution model of point-bar dominated meandering river deposits for uncertainty quantification

2013 ◽  
Vol 119 (8) ◽  
pp. IX-X
Author(s):  
Takashi Tsuji ◽  
Osamu Takano ◽  
Satoko Watanabe ◽  
Kinya Okada ◽  
Koji Kashihara ◽  
...  
Keyword(s):  
Uncertainty Quantification ◽  
Distribution Model ◽  
Point Bar ◽  
Meandering River ◽  
River Deposits

scholarly journals The effect of fluvial environments on sediment bleaching and Holocene luminescence ages — A case study from the German Alpine Foreland

2013 ◽  
Vol 40 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Patrick Schielein ◽  
Johanna Lomax
Keyword(s):  
Statistical Modelling ◽  
Moderate Degree ◽  
Point Bar ◽  
Fine Grained ◽  
Sedimentary Environments ◽  
Fine Grain ◽  
Floodplain Deposits ◽  
Crevasse Splay ◽  
Channel Deposits ◽  
Floodplain Sediments

Abstract This study investigates the potential of luminescence to date deposits from different fluvial sedimentary environments; namely point bar deposits, sandy and silty channel fills and floodplain sediments. Samples were taken from Holocene (<5 ka) terraces of the Lech and Danube rivers, for which independent age constraint is available through 14C ages, archaeological data and historical maps. OSL-ages were obtained using small aliquots of coarse grain quartz for the majority of samples. Two further samples were dated by the IRSL-signals of polymineral fine grain extracts, as no sufficient number of coarse grains could be extracted from these sediments. In order to detect and ac-count for incomplete bleaching, we used the decision process suggested by Bailey and Arnold [Statistical modelling of single grain quartz De distributions and an assessment of procedures for estimating burial dose. Quaternary Science Reviews 25, 2475–2502, 2006]. Although their model was designed for single grains of quartz, our study shows that it is also applicable to multiple grains of quartz, pro-vided that a low number of luminescent grains is present on one aliquot. Luminescence ages of point bar deposits and a sandy channel fill correspond most closely to the independent age control. In the floodplain, sand-striped floodplain channel deposits were incompletely bleached to a moderate degree, yielding ages with acceptable overestimations, while fine-grained floodplain deposits were worst bleached. One crevasse splay deposit was so severely incompletely bleached that none of the age models was able to yield accurate ages.

scholarly journals Interpretasi Lingkungan Pengendapan Formasi Batuan Menggunakan Analisis Elektrofasies di Lokasi Tapak Puspiptek Serpong

EKSPLORIUM ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 29
Author(s):  
Heri Syaeful ◽  
Adi Gunawan Muhammad
Keyword(s):  
Depositional Environment ◽  
Gamma Ray ◽  
River System ◽  
Shape Variation ◽  
Point Bar ◽  
Meandering River ◽  
The North ◽  
Rock Formations ◽  
Subsurface Material ◽  
Crevasse Splay

ABSTRAKKegiatan karakterisasi material bawah permukaan penyusun pondasi tapak merupakan bagian dari studi tapak instalasi nuklir. Karakterisasi dilakukan dengan berbagai metode, diantaranya pemahaman tentang sistem pengendapan formasi batuan. Sebagai bagian dari metode interpretasi lingkungan pengendapan, analisis pemodelan fasies berdasarkan elektrofasies memberikan informasi yang cepat mengenai sistem pengendapan suatu formasi batuan. Metodologi yang digunakan adalah dengan interpretrasi log sinar gamma (log GR) menggunakan korelasi relatif antara variasi bentuk log dan fasies sedimentasi. Berdasarkan analisis diketahui Formasi Bojongmanik terbentuk pada lingkungan marine-lagoonal dengan pengaruh gelombang sangat rendah. Log GR yang menunjukan bentuk funnel, bergerigi dan simetris, mengindikasikan fasies shoreface, lagoon, dan tidal point bar. Arah sedimentasi, cekungan, dan suplai pada pengendapan sedimen Formasi Bojongmanik diinterpretasikan relatif ke utara. Formasi Serpong diendapkan pada sistem sungai bermeander dan tersusun atas endapan point bar, crevasse splay dan floodplain. Hasil analisis ini diharapkan dapat menjadi panduan dalam analisis lanjutan terkait karakterisasi material pondasi. ABSTRACTThe activity of subsurface material composing site foundation characterization is part of nuclear installation siting study. Characterization conducted by several methods, such as understanding the depositional environment of rock formations. As a segment of depositional environment interpretation method, facies model analysis based on electrofacies provides quicker information on depositional system of rock formation. Methodology applied is gamma ray log (log GR) interpretation using relative correlation between log shape variation and sedimentation facies. Based on the analysis, Bojongmanik Formation was deposited on marine-lagoonal environment with very low wave influence. Log GR that shows shape of funnel, serrated, and symmetry, indicate shoreface, lagoon, and tidal point bar facies. The direction of sedimentation, basin, and supply of Bojongmanik Formation interpreted relatively to the north. Serpong Formation deposited on meandering river system, and composed of point bar deposit, crevasse splay, and floodplain deposit. The result of analysis is expected to be guidance in further analysis related to the characterization of foundation materials.

scholarly journals River response to climate and sea level changes during the Late Saalian/Early Eemian in northern Poland – a case study of meandering river deposits in the Chłapowo cliff section

Geologos ◽  
2016 ◽  
Vol 22 (1) ◽  
pp. 1-14
Author(s):  
Damian Moskalewicz ◽  
Robert J. Sokołowski ◽  
Stanisław Fedorowicz
Keyword(s):  
Sea Level ◽  
River Sediments ◽  
Luminescence Dating ◽  
Heavy Minerals ◽  
Sea Level Changes ◽  
Point Bar ◽  
Meandering River ◽  
Base Level ◽  
River Deposits ◽  
And Sea Level

Abstract Fluvial sediments in the Chłapowo cliff section were studied in order to reconstruct their palaeoflow conditions and stratigraphical position. Lithofacies, textural and palaeohydraulic analyses as well as luminescence dating were performed so as to achieve the aim of study. Sedimentary successions were identified as a record of point bar cycles. The fluvial environment probably functioned during the latest Saalian, shortly after the retreat of the Scandinavian Ice Sheet. Discharge outflow was directed to the northwest. The river used the older fluvioglacial valley and probably was directly connected to the Eem Sea. Good preservation and strong aggradation of point-bar cycles were related to a rapid relative base level rise. The meandering river sediments recognised showed responses to climate and sea level changes as illustrated by stratigraphical, morphological and sedimentological features of the strata described. The present study also revealed several insights into proper interpretation of meandering fluvial successions, in which the most important were: specific lithofacies assemblage of GSt (St, Sp) → Sl → SFrc → Fm (SFr) and related architectural elements: channel/sandy bedforms CH/SB → lateral accretion deposits LA → floodplain fines with crevasse splays FF (CS); upward-fining grain size and decreasing content of denser heavy minerals; estimated low-energy flow regime with a mean depth of 1.6–3.3 m, a Froude number of 0.2–0.4 and a sinuosity of 1.5.

scholarly journals Uniqueness Deposit of Sediment on Floodplain Resulting From Lateral Accretion on Tropical Area

2017 ◽  
Vol 2 (1) ◽  
pp. 14 ◽  
Author(s):  
Yuniarti Yuskar ◽  
Tiggi Choanji
Keyword(s):  
Low Energy ◽  
Lateral Migration ◽  
Point Bar ◽  
Fine Grained ◽  
Tropical Area ◽  
Almost All ◽  
Fluvial Environments ◽  
Channel Deposits ◽  
Floodplain Sediments ◽  
Mixed Load

Kampar rivers has a length of 413 km with average depth of 7.7 m and width of 143 m. Sixty percent of  this rivers are meandering fluvial system which transport and deposit a mixture of suspended and bed-load (mixed load) along low energy. River channel that moving sideways by erosion is undergoing lateral migration and the top of the point bar becomes the edge of the floodplain and the fining-upward succession of the point bar will be capped by overbank deposits of Kampar River. Along the Kampar Rivers, there are more than 60% of floodplain sediments and almost all of the floodplain formed by bend migration on the suspended-load channels of Kampar watershed. This formation consist of succession of fine to medium sand and silt/mud, with root traces, that form as drapes on the prograding bank. These beds dip mostly channel wards and quickly wedge out as they grade up and onto the floodplain. The depositional model is presented showing how lateral accretion can make a significant contribution to the preservation of fine-grained within channel deposits in contemporary floodplains. The examples presented here demonstrate that analogues to ancient point-bar deposits containing alternating sandstone and shale sequences are common in the low-energy fluvial environments of Riau rivers especially Kampar rivers.

scholarly journals Environment Of Deposition Of The Jurassic-Cretaceous Continental Deposit In Central Pahang (Peninsular Malaysia) By Sedimentary Facies Analysis

2020 ◽  
Vol 70 (1) ◽  
pp. 153-162
Author(s):  
Azyan Syahira Azmi ◽  
◽  
Mohd Suhaili Ismail ◽  
Jasmi Ab Talib ◽  
Nur Marina Samsudin ◽  
...  
Keyword(s):  
Facies Analysis ◽  
Sedimentary Facies ◽  
High Energy ◽  
Peninsular Malaysia ◽  
Point Bar ◽  
Meandering River ◽  
Fine Grained ◽  
Facies Associations ◽  
Crevasse Splay ◽  
Channel Bar

Spatial lithofacies and lithofacies association serves as one of the reliable methods in assessing the depositional process of sediments and interpreting its depositional environment. The method of facies analysis is adapted in this study where four newly exposed stratigraphic sections along the Jerantut-Maran road in Jerantut, Central Pahang of Peninsular Malaysia were studied. Previous studies showed that the environment of deposition of these continental deposits is broadly of braided-meandering river. Sedimentological data from the newly exposed stratigraphic sections had given a better understanding on the sedimentation processes involved in these deposits where interpretation on the environment of deposition is construed up to its sub-environment. The main lithofacies recognized include conglomerate, sandstone, and fine-grained facies. The facies associations identified include (i) massive to laminated silt/mudstone, (ii) massive sandstone, (iii) thin to thick ripple to parallel laminated sandstone, (iv) conglomeratic sandstone, (v) graded channelized sandstone, (vi) coarsening upwards medium bedded sandstone and (vii) heterolithic sandstone. The different facies associations are grouped to four (4) facies assemblages showing characteristics of certain environment: (1) floodplain, (2) channel bar complex, (3) point bar and (4) crevasse splay. Floodplain facies assemblage is marked by fine-grained facies, mainly siltstone/mudstone and fine-grained sands with lower flow regime structures. Channel bar complex is identified by high energy deposits of coarse-to-medium grained sandstones often with scoured bottom and lenticular geometry. Point bar is recognized by the lateral accretion surfaces often consisting of normal graded sandstone with sharp top and bottom contact, sometimes capped with thin mudstones. Crevasse splay facies assemblage is characterized by heterolithic sandstone, dominated by flaser-wavy bedding and coarsening upwards medium bedded sandstone that is overlain by fine-grained facies of the floodplain assemblage. The overall facies based on an outcrop scale suggests general features of fluvial facies with fluctuations in flow energy. The environment of deposition is thus interpreted to be of braided river with floodplains and isolated point bar.

scholarly journals Modeling of dense well block point bar architecture based on geological vector information: A case study of the third member of Quantou Formation in Songliao Basin

2021 ◽  
Vol 13 (1) ◽  
pp. 39-48
Author(s):  
Chao Luo ◽  
Ailin Jia ◽  
Jianlin Guo ◽  
Wei Liu ◽  
Nanxin Yin ◽  
...  
Keyword(s):  
River Sediments ◽  
Three Dimensional ◽  
Songliao Basin ◽  
Point Bar ◽  
Meandering River ◽  
Architecture Model ◽  
The Third ◽  
Continuous Convergence ◽  
Vector Information ◽  
Architecture Modeling

Abstract Although stochastic modeling methods can achieve multiple implementations of sedimentary microfacies model in dense well blocks, it is difficult to realize continuous convergence of well spacing. Taking the small high-sinuosity meandering river sediments of the third member of Quantou Formation in Songliao Basin as an example, a deterministic modeling method based on geological vector information was explored in this article. Quantitative geological characteristics of point bar sediments were analyzed by field outcrops, modern sediments, and dense well block anatomy. The lateral extension distance, length, and spacing parameters of the point bar were used to quantitatively characterize the thickness, dip angle, and frequency of the lateral layer. In addition, the three-dimensional architecture modeling of the point bar was carried out in the study. The established three-dimensional architecture model of well X24-1 had continuous convergence near all wells, which conformed to the geological knowledge of small high-sinuosity meandering river, and verified the reliability of this method in the process of geological modeling in dense well blocks.

James C. Knox (1977) Human impacts on Wisconsin stream channels. Annals of the Association of American Geographers 67: 224–244.

2013 ◽  
Vol 37 (3) ◽  
pp. 422-431 ◽  
Author(s):  
William L. Graf
Keyword(s):  
Mississippi River ◽  
Human Impacts ◽  
Professional Community ◽  
River System ◽  
Stream Channels ◽  
Early 19Th Century ◽  
Driftless Area ◽  
University Of Wisconsin ◽  
History Of ◽  
Floodplain Deposits

James C. Knox’s 1977 paper “Human Impacts on Wisconsin Stream Channels,” published in the Annals of the Association of American Geographers, was a key component of a suite of three papers by him defining the response of rivers to the introduction and management of agriculture and to climate change. In this paper he used the Driftless Area of southwest Wisconsin as a laboratory where he could define fluvial responses by their sedimentary signatures in floodplain deposits. Land-use records dating back to the early 19th century along with shorter climate records provided his understanding of the drivers of change. He found that floods increased as an outcome of land-cover change. Upstream tributaries became wider and shallower as coarse deposits limited their adjustments, while main stem channels became narrower and deeper. His paper reflected the influence of his graduate advisor and especially of prominent faculty colleagues at the University of Wisconsin from fields ranging from soils and climatology to geomorphology and history. The paper was the subject of considerable debate in the professional community, but it remains a much-cited example of Knox’s work in unraveling the Quaternary and Holocene history of rivers of the Driftless Area and by extension the upper Mississippi River system.

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