Pilot study of fossil evidence of onshore-directed storm events in estuarine sediments: Chezzetcook Inlet, Nova ScotiaNatural Resources Canada Climate Change Impacts and Adaptation Program SST 20090027.

2009 ◽  
Vol 46 (3) ◽  
pp. 193-205 ◽  
Author(s):  
Charles T. Schafer ◽  
Franco S. Medioli
Keyword(s):  
Depositional Environment ◽  
Sediment Cores ◽  
Climate Change Impacts ◽  
Estuarine Sediments ◽  
Storm Events ◽  
Southeastern Part ◽  
Planktic Foraminifera ◽  
Sudden Appearance ◽  
Depositional Setting ◽  
Seawater Exchange

Sediment cores collected from the landward side of a baymouth barrier in a lower estuarine environment of Chezzetcook Inlet contain proxy “signals” of onshore-directed storms that are manifested by the sudden appearance of benthic and planktic Foraminifera species. These taxa have been eroded and transported from adjacent inner shelf open-marine environments. One relatively strong onshore-directed storm (hurricane?) event appears to have caused a reduction in seawater exchange in the southeastern part of the inlet that persisted for at least several decades. In this particular barrier-protected lower estuarine depositional environment, foraminiferal storm-indicator species distributions in older sediments seem to be spatially patchy. Consequently, in this Chezzetcook depositional setting, the successful reconstruction of a complete proxy storm record will require replicate coring and high-frequency core subsampling strategies.

Detailed Lithofacies and Architectural Facies Analyses on Mixed Carbonate-Siliciclastic Clastic Shoreline Depositional Environment of the Cibulakan Formation in Cipamingkis River, Jonggol, Bogor, West Java

2021 ◽  
Author(s):  
E. Edwin
Keyword(s):  
Spatial Variation ◽  
Depositional Environment ◽  
Field Observations ◽  
West Java ◽  
Thin Sections ◽  
Fragment Type ◽  
Interesting Study ◽  
Facies Modelling ◽  
Depositional Setting ◽  
Mixed Carbonate

Cibulakan Formation as one of the prolific hydrocarbon-bearing intervals has become an interesting study object for many researchers. The continuous outcrop of the Cibulakan Formation in the Cipamingkis River comprises claystone, sandstone, and subordinate limestone of grainstone, packstone, and wackestone facies. The outcrop should be able to give a clearer vertical and spatial variation of sandstone and limestone geometry compared to the conventional core alone. Field observations followed by measuring the section is conducted to distinguish lithofacies and to create a stratigraphic profile from the chosen interval. Samples and thin sections from sandstone and limestone lithofacies are observed further to determine fragment type variation, matrix, cement, texture, and porosity types qualitatively. Fourteen (14) lithofacies have been recognized from the observation, i.e., Slumped Sandstone (A1), Claystone (A2), Slightly-bioturbated Sandstone (B1), Cross-laminated Sandstone (B2), Parallel-laminated Siltstone (B3), Calcareous Claystone (B4), Moderately-bioturbated Sandstone (C1), Hummocky Cross-stratified Sandstone (C2), Skeletal – Coral clast Wackestone (C3), Skeletal-clast Packstone (C4), Coralline Foraminiferal Boundstone (C5), Low-angle Planar Cross-bedded Sandstone (D1), Intensely-bioturbated Sandstone (D2), and Trough Cross-bedded Sandstone (D3). There are four architectural facies in the research interval and each of them is composed of different and specific lithofacies. An ideal parasequence is composed of all Architectural Facies namely : (A) Offshore-Transition (B) Lower Shoreface (C) Upper Shoreface with the whole thickness range between 15 to 25 m and the parasequence shows thickening upward succession. The detailed information about the lithofacies and architectural facies hopefully will provide a better understanding of the facies modelling of the mixed carbonate-siliciclastic depositional setting, new insights for parasequence recognition in clastic shoreline depositional environment and become a reference for other areas lacking in core data and/or outcrop analogue.

scholarly journals Petrogenesis and depositional environment of paleozoic Sedili and Pengerang Volcaniclastics in East Johor Basin, Peninsular Malaysia

2019 ◽  
Vol 76 ◽  
pp. 04009
Author(s):  
Sugeng Sapto Surjono ◽  
Mohd. Shafeea Leman ◽  
Che Aziz Ali ◽  
Kamal Roslan Mohamed ◽  
Fathan Hanifi Mada M
Keyword(s):  
Depositional Environment ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Peninsular Malaysia ◽  
Calc Alkaline ◽  
Great Abundance ◽  
Volcaniclastic Rocks ◽  
Geochemical Analyses ◽  
Depositional Setting ◽  
Magma Series

Volcaniclastic rocks in East Johor Basin are found in a relatively great abundance comprising Sedili and Pengerang Formations excluding the metamorphics, siliciclastics, and granites. Since the volcaniclastic rocks are found in a different formation, this study aims to find out the characteristics of each rock. Geology, petrography, and geochemical analyses were elaborated to reveal the petrogenesis and depositional environment in the studied area on the basis of fieldwork data and 24 samples collected from outcrops. The Sedili and Pengerang Formations are dominated by acidic rocks of rhyolite, rhyodacite, ignimbrite, and lava classifiied into calc-alkaline magma series which indicates a subduction-related product. Moreover, those acidic rocks are grouped into active continental margin. Eventhough volcanic rocks in Sedili and Pengerang Formations exhibit similar characteristics, they are different in several major contents. Therefore, it is inferred that both Sedili and Pengerang Formations were deposited in different phase. Coincidentally, depositional environment of both formations is also distinct. Sedili Formation were deposited in the subaerial to shallow marine, meanwhile, Pengerang Formation is interpreted to be deposited in deeper depositional setting.

scholarly journals Distribution and partitioning of heavy metals in estuarine sediment cores and implications for the use of sediment quality standards

2002 ◽  
Vol 6 (6) ◽  
pp. 989-998 ◽  
Author(s):  
K. L. Spencer ◽  
C. L. MacLeod
Keyword(s):  
Sequential Extraction ◽  
Surface Sediments ◽  
Sediment Cores ◽  
Sediment Quality ◽  
Contaminated Sediments ◽  
Estuarine Sediments ◽  
Surface Zone ◽  
Metal Concentrations ◽  
Ecotoxicological Risk ◽  
Total Metal

Abstract. Total metal concentrations in surface sediments and historically contaminated sediments were determined in sediment cores collected from three estuaries (Thames, Medway and Blackwater) in south-east England. The partitioning behaviour of metals in these sediments was also determined using a sequential extraction scheme. These data were then compared with sediment quality values (SQVs) to determine the potential ecotoxicological risk to sediment dwelling organisms. When total metal concentrations in surface sediments are examined, no risk to biota in any of the estuaries is indicated. However, when historically contaminated sediments at depth are also considered, risks to biota are apparent and are greatest for the Thames, followed by the Medway and then the Blackwater. This suggests that regulatory authorities should examine vertical metal profiles, particularly in estuaries that are experiencing low sediment accumulation rates where historically contaminated sediments are in the shallow sub-surface zone and where erosion or dredging activities may take place. When metal partitioning characteristics are also considered, the risk to biota is comparable for the Medway and the Blackwater with the potentially bioavailable fraction presenting no ecotoxicological risk. Conversely, over 70% of metals are labile in the Thames Estuary sediments and toxic effects are probable. This suggests that the application of SQVs using total sediment metal concentrations may over- or under-estimate the risk to biota in geochemically dissimilar estuarine sediments. Keywords: sediment quality values, estuarine sediments, metal contamination, partitioning, sequential extraction

scholarly journals Radiocarbon Dating, Chronologic Framework, and Changes in Accumulation Rates of Holocene Estuarine Sediments from Chesapeake Bay

2002 ◽  
Vol 57 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Steven M. Colman ◽  
Pattie C. Baucom ◽  
John F. Bratton ◽  
Thomas M. Cronin ◽  
John P. McGeehin ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Deep Water ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Complex Mixture ◽  
Estuarine Sediments ◽  
Accumulation Rates ◽  
Pollen Stratigraphy ◽  
Mass Accumulation Rates ◽  
Mass Accumulation

AbstractRapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelerator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210Pb and 137Cs data and pollen stratigraphy from the same sites.Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

scholarly journals Geochemistry, mineral chemistry and P-T evaluation of metasediments of Bahram-Gur complex, ES Sanandaj-Sirjan zone, Iran

Mineralogia ◽  
2019 ◽  
Vol 50 (1-4) ◽  
pp. 34-68
Author(s):  
Hadiseh Rahimi Sadegh ◽  
Hesam Moeinzadeh ◽  
Kazu Nakashima
Keyword(s):  
Continental Crust ◽  
Sedimentary Rocks ◽  
Mineral Chemistry ◽  
Amphibolite Facies ◽  
Southeastern Part ◽  
Metasedimentary Rocks ◽  
Magmatic Rocks ◽  
Sanandaj Sirjan Zone ◽  
Metamorphic Zone ◽  
Depositional Setting

AbstractThe Bahram-Gur area in the southeastern part of the Sanandaj – Sirjan metamorphic zone, contains metabasites and metasediments. The metasedimentary rocks are mainly garnet schists and garnet-staurolite schists that were metamorphosed under amphibolite facies conditions. The rocks consist of garnet ± staurolite, biotite, muscovite, chlorite and quartz. The geochemistry of the Bahram-Gur metasediments classifies them as quartziferous sedimentary rocks. The protoliths of the metasedimentary rocks were close to greywackes from an ensialic arc basin depositional setting, with a source comprising mostly mixture of acid and intermediate magmatic rocks in the upper continental crust. The metamorphic conditions of formation of the Bahram-Gur metasedimentary are investigated by geothermobarometric methods. The results show that the metasedimentary rocks formed at temperatures of 600-750°C and pressures of 5-7.5 kbar.

scholarly journals Climate Change Impacts on Coastal Wave Dynamics at Vougot Beach, France

2021 ◽  
Vol 9 (9) ◽  
pp. 1009
Author(s):  
Pushpa Dissanayake ◽  
Marissa L. Yates ◽  
Serge Suanez ◽  
France Floc’h ◽  
Knut Krämer
Keyword(s):  
Climate Change ◽  
Shear Stress ◽  
Sediment Transport ◽  
Climate Change Impacts ◽  
Wave Climate ◽  
Bed Shear Stress ◽  
Storm Events ◽  
Climate Scenarios ◽  
Wave Dynamics ◽  
Waves And Currents

Wave dynamics contribute significantly to coastal hazards and were thus investigated at Vougot Beach by simulating both historical and projected future waves considering climate change impacts. The historical period included a major storm event. This period was projected to the future using three globally averaged sea level rise (SLR) scenarios for 2100, and combined SLR and wave climate scenarios for A1B, A2, and B1 emissions paths of the IPCC. The B1 wave climate predicts an increase in the occurrence of storm events. The simulated waves in all scenarios showed larger relative changes at the beach than in the nearshore area. The maximum increase of wave energy for the combined SLR and wave scenarios was 95%, while only 50% for the SLR-only scenarios. The effective bed shear stress from waves and currents showed different spatial variability than that of the wave height, emphasizing the importance of interactions between nearshore waves and currents. Increases in the effective bed shear stress (combined scenarios: up to 190%, and SLR-only scenarios: 35%) indicate that the changes in waves and currents will likely have significant impacts on the nearshore sediment transport. This work emphasizes that combined SLR and future wave climate scenarios need to be used to evaluate future changes in local hydrodynamics and their impacts. These results provide preliminary insights into potential future wave dynamics at Vougot Beach under different climate change scenarios. Further studies are necessary to generalize the results by investigating the wave dynamics during storm events with different hydrodynamical conditions and to evaluate potential changes in sediment transport and morphological evolution due to climate change.

scholarly journals After Hurricanes Irma and Matthew: Living Shorelines Stabilize Sediments

2019 ◽  
Vol 16 (2) ◽  
pp. 63-72
Author(s):  
Taryn Chaya ◽  
Jessica Veenstra ◽  
Melissa Southwell
Keyword(s):  
Sediment Cores ◽  
High Energy ◽  
Storm Events ◽  
Oyster Reefs ◽  
Living Shorelines ◽  
Before And After ◽  
National Estuarine Research Reserve ◽  
Sediment Profiles ◽  
Oyster Restoration ◽  
Sediment Data

Constructed intertidal oyster reefs, an example of a “living shoreline”, can protect against erosion and loss of habitat, but can they prevent erosion during high-energy storm events such as hurricanes? Oyster reefs were constructed in 2012 within the Guana Tolomato Matanzas National Estuarine Research Reserve in Northeast Florida to stabilize the shoreline sediment and prevent erosion of an archeological site. Sediment cores were collected behind constructed oyster reefs before and after hurricanes Matthew (2016) and Irma (2017) to study changes in sediment particle size due to these high-energy storms. Pre-hurricane data were collected in 2016 from three different constructed reefs, as well as three control sites where no reef was present. Pre-hurricane sediment profiles behind the constructed reefs consisted of finer sediments, ~36% silt and clay, in the surface ~10-12 cm, with decreasing silt and clay and increasing sand content as depth increased. This was different than the sediment from the control sites with ~4% silt and clay in all depths sampled. Like the sediment profiles before the high energy storms, the post-hurricane sediment data showed a clear layer of finer sediment ~10-12 cm over coarser sediment. Although they were high-energy storms, the storms did not appear to significantly affect the sediment behind the constructed oyster reefs. Sediment profiles remained consistent after these storms but may not remain undisturbed during the next storm without some intervention because the oyster reefs have been degrading. KEYWORDS: Oyster Restoration; Living Shorelines; Hurricanes; Coastal Erosion; Sedimentation; Salt Marsh

scholarly journals FORAMINIFERAL STUDY OF NKPORO SHALE EXPOSURES, CALABAR FLANK (SE NIGERIA): AGE AND DEPOSITIONAL ENVIRONMENT

2019 ◽  
Vol 4 (4) ◽  
pp. 369-378
Author(s):  
Asukwo Essien Itam ◽  
Victoria Inyang Emeka ◽  
Chimezie Ndunagum Emeka
Keyword(s):  
Organic Matter ◽  
Benthic Foraminifera ◽  
Depositional Environment ◽  
Hydrodynamic Conditions ◽  
Planktic Foraminifera ◽  
Southeastern Nigeria ◽  
Fine Grained ◽  
Sedimentary Deposits ◽  
Geological Age ◽  
Foraminíferos Bentónicos

Foraminiferal analysis of the sedimentary deposits of Nkporo shale exposed at PAMOL along Calabar/Odukpani Road, in the Calabar Flank, Southeastern Nigeria, was investigated in order to determine its geological age and paleoenvironmental conditions. The lithology is predominantly composed by shale with traces of siltstone and sandstone. Shale is generally light to dark grey, occasionally light brown, sub-fissile to fissile, moderately hard, carbonaceous, and slightly ferruginous. Results of foraminiferal analysis showed that the samples consist predominantly of arenaceous/agglutinated benthic foraminifera. Calcareous planktic foraminifera are absence and calcareous benthic taxa are almost absence of calcareous. The occurrence of the following foraminifera taxa Ammobaculite sp., Haplophragmoides sahariense, Haplophragmoides talokaense, Trochammina sp., Trochammina dustuna, Ammobaculites amabensis and Bolivina sp. suggest that sediments in the study area were deposited during the Maastrichtian age. The paleo-depositional-environment should occur in transitional marine settings, probably a marsh/lagoon. In the study area, calm hydrodynamic conditions prevailed. They favored the accumulation of fine-grained sediment and organic matter which gave rise to oxygen scarcity. The environment would be stressful for benthic foraminifera not only because of oxygen scarcity but also due to the variability of water salinity (hypo to hypersaline). ESTUDO DE FORAMINÍFEROS DOS FOLHELHOS DE NKORHO, CALABAR FLANK (SE DA NIGERIA): IDADE E AMBIENTE DEPOSICIONAL ResumoA análise de foraminíferos dos depósitos sedimentares do folhelho Nkporo expostos em PAMOL ao longo da estrada de Calabar/Odukpani, em Calabar Flank, sudeste da Nigéria, foi estudada tendo em vista determinar sua idade relativa e condições paleoambientais. A litologia é predominantemente composta por folhelho com camadas de siltito e arenito. O folhelho é, em geral, cinza claro a escuro, ocasionalmente marrom claro, sub-físsil a físsil, moderadamente consolidado, carbonáceo e levemente ferruginoso. Os resultados da análise dos foraminíferos mostraram que as amostras estudadas contêm predominantemente foraminíferos bentónicos arenáceos/aglutinantes. Não foram encontrados foraminíferos planctónicos, estando também quase ausentes táxons bentónicos com carapaça constituída por carbonato de cálcio. A ocorrência dos seguintes taxa Ammobaculites sp., Haplophragmoides sahariense, Haplophragmoides talokaense, Trochammina sp., Trochammina dustuna, Ammobaculites amabensis e Bolivina sp. sugerem que os sedimentos na área de estudo foram depositados durante o Maastrichtiano (Cretaceo superior). A sedimentação deverá ter ocorrido em ambiente marinho de transição, provavelmente em pântanos/lagoas. Na área de estudo, prevaleceram condições hidrodinâmicas calmas que favoreceram o acúmulo de sedimentos finos e matéria orgânica, que originou a escassez de oxigênio. O ambiente seria estressante para os foraminíferos bentónicos, não só devido à escassez de oxigênio, mas também devido à variabilidade da salinidade da água (hipo a hipersalina). Palavras-chave: Bioestratigrafia. Foraminíferos Bentônicos. Aglutinantes. Maastrichtiano. Cretáceo. Ambiente marinho de transição.

Independent verification of age tie points and planktic reservoir ages deduced for two marine sediment records at the Chilean continental margin by 14C plateau tuning

2020 ◽  
Author(s):  
Kevin Küssner ◽  
Michael Sarnthein ◽  
Frank Lamy ◽  
Elisabeth Michel ◽  
Gesine Mollenhauer ◽  
...  
Keyword(s):  
Continental Margin ◽  
Marine Sediment ◽  
Sediment Cores ◽  
Ice Cores ◽  
Time Interval ◽  
Stratigraphic Correlation ◽  
Short Term ◽  
Planktic Foraminifera ◽  
Last Glacial ◽  
Tephra Layers

<p>On the basis of <sup>14</sup>C plateau tuning we established a robust centennial-scale age control for last glacial-to-deglacial sediment sections in two marine sediment cores MD07-3088 and PS97-137 from the upper Chilean continental margin to facilitate a precise stratigraphic correlation between short-term changes in South Pacific oceanography and global paleoclimate signals recorded in ice cores from Antarctica and elsewhere (Küssner et al., in prep.). Age tie points and reservoir ages were derived from tuning a suite of planktic <sup>14</sup>C plateaus to a suite of pertinent atmospheric <sup>14</sup>C plateaus defined at Lake Suigetsu (Sarnthein et al., 2015). Off central Chile four tephra layers in Core MD07-3088 provide independent proof both for the age assignment and for short-term changes in planktic reservoir age we deduced by means of <sup>14</sup>C plateau tuning. Reservoir ages derived from <sup>14</sup>C plateau tuning at 11–16.5 cal. ka closely match, one-by-one, four reservoir ages that have been deduced from the difference between the <sup>14</sup>C ages of planktic foraminifera associated with the tephra layers in marine sediments and the atmospheric <sup>14</sup>C ages of plants associated with paired tephras analyzed nearby on land (Siani et al. 2013). – In Core PS97-137, near to the southern tip of Chile, sediments of the Last Glacial Maximum show a section with distinct lamination of 5-7 layers / cm depth, associated with atmospheric <sup>14</sup>C Plateau 6a by plateau tuning. A rough count of the layers in the 160 cm long sediment section of the planktic <sup>14</sup>C Plateau 6a gives a number that comes extremely close to the ~900 year-long time span of the atmospheric <sup>14</sup>C Plateau 6a, thus provides independent proof for both the accuracy of the time interval assigned to correlated atmospheric ‘Plateau 6a’ and the approach of plateau tuning in general.</p><p> </p><p>Küssner et al., Paleoceanography, in prep.,</p><p>Sarnthein et al., Radiocarbon, 2015, 57 (1), 129–151.</p><p>Siani et al., 2013, Nature comm., 4, 2758.</p>

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