Paleogeographic and litho-facial conditions of meso-cenozoic sediment formation of the Anadyr depression

Background. The Anadyr depression has a marginal structure. It comprises four sub-regional elements. Disjunctive dislocations are widely developed within the area.Aim. To reconstruct the paleogeographic and litho-facies conditions of the formation of the Meso-Cenozoic sediments of the Anadyr depression. The reconstruction was performed by evaluating the initial data and developing paleogeographic and litho-facies maps. Data on the conditions of sediment formation in the study area, rich in hydrocarbon and mineral deposits, is essential from a practical standpoint.Materials and methods. Paleogeographic reconstructions of the Anadyr depression were performed based on an analysis of the sediment thickness and litho-facies composition of the relevant age. To build litho-facies maps, we used the data on the material composition of the Bering Sea sedimentary cover and adjacent areas, including well-drilling data, outcropping descriptions, thickness gradient analysis, seismic study results, etc.Results. In the course of the work, sedimentary environment maps were created. Litho-facies maps were developed for all four main sedimentary complexes of the Anadyr depression. Based on the generalised geological data and paleoreconstructions, we constructed forecasting schemes of the distribution of barrier formations in the study area.Conclusions. It was found that the formation of the sedimentary cover of the Anadyr depression took place mainly in shallow-water sedimentary environments. In addition, the depths of paleobasins did not overpass the internal relatively shallow marine shelf. Based on the analysis, two most probable reservoirs were selected. Regional fluid and potential seals were characterised.

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Postglacial Diatom Stratigraphy in Relation to the Recession of Glacial Lake Agassiz

Quaternary Research ◽

10.1016/0033-5894(75)90014-9 ◽

1975 ◽

Vol 5 (4) ◽

pp. 529-540 ◽

Cited By ~ 10

Author(s):

J.C. Ritchie ◽

L.K. Koivo

Keyword(s):

Sandy Beach ◽

Sedimentary Environment ◽

Glacial Lake ◽

Lake Agassiz ◽

Organic Detritus ◽

Sedimentary Environments ◽

Grand Rapids ◽

Glacial Lake Agassiz ◽

Diatom Stratigraphy ◽

Beach Sands

The sediment and diatom stratigraphy of a small pond on The Pas moraine, near Grand Rapids, Manitoba, reveals a change in sedimentary environment related directly to the last stages of Glacial Lake Agassiz. Beach sands were replaced by clay 7300 14C y. a., then by organic silt and, at 4000 14C y. a. by coarse organic detritus; the corresponding diatom assemblages were (I) a predominantly planktonic spectrum in beach sands, (II) a rich assemblage of nonplanktonic forms, and (III) a distinctly nonplanktonic acidophilous spectrum. These results confirm Elson's (1967) reconstruction of the extent and chronology of the final (Pipun) stage of Glacial Lake Agassiz. The sedimentary environments change from a sandy beach of a large lake at 7300 BP to a small, shallow eutrophic pond with clay and silt deposition from 7000 to 4000 BP. From 4000 BP to the present, organic detritus was deposited in a shallow pond that tended toward dystrophy.

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Geochemical Features of Redox-Sensitive Trace Metals in Sediments under Oxygen-Depleted Marine Environments

Minerals ◽

10.3390/min10111021 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1021

Author(s):

Moei Yano ◽

Kazutaka Yasukawa ◽

Kentaro Nakamura ◽

Minoru Ikehara ◽

Yasuhiro Kato

Keyword(s):

Sedimentary Environment ◽

Organic Matter Content ◽

Oxygen Depletion ◽

Major And Trace Elements ◽

Matter Content ◽

Open Ocean ◽

Chemical Compositions ◽

Marine Environments ◽

High Productivity ◽

Sedimentary Environments

Organic- and sulfide-rich sediments have formed in oxygen-depleted environments throughout Earth’s history. The fact that they are generally enriched in redox-sensitive elements reflects the sedimentary environment at the time of deposition. Although the modern ocean is well oxidized, oxygen depletion occurs in certain areas such as restricted basins and high-productivity zones. We measured bulk chemical compositions (major and trace elements, total organic carbon, and total sulfur) of organic- and sulfide-rich sediments collected from eight areas having oxygen-depleted water to discuss relationships between geochemical features and sedimentary environments. Major elemental compositions generally show mixtures of terrigenous detritus and biogenic carbonate. Some redox-sensitive elements might be controlled by organic matter content, whereas others could be contained in sulfide minerals in sediments. In particular, Mo and U show a characteristic trend; areas with higher Mo and U—at least partially owing to a depositional process called the “particulate shuttle”—generally correspond to regions influenced by the open ocean. In contrast, areas with lower Mo and U are more restricted marine environments. This suggests that the degree of Mo and U enrichment reflects the geography in terms of proximity to the open ocean, or the degree of the supply of these elements from the open ocean.

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Sedimentary environment prediction of grain-size data based on machine learning approach

Interpretation ◽

10.1190/int-2019-0153.1 ◽

2020 ◽

Vol 8 (3) ◽

pp. SL71-SL78

Author(s):

Qiao Su ◽

Yanhui Zhu ◽

Fang Hu ◽

Xingyong Xu

Keyword(s):

Machine Learning ◽

Grain Size ◽

Prediction Model ◽

Sedimentary Environment ◽

Machine Learning Algorithms ◽

Grain Size Analysis ◽

Size Analysis ◽

Data Set ◽

Sedimentary Environments ◽

Size Data

Grain size is one of the most important records for sedimentary environment, and researchers have made remarkable progress in the interpretation of sedimentary environments by grain size analysis in the past few decades. However, these advances often depend on the personal experience of the scholars and combination with other methods used together. Here, we constructed a prediction model using the K-nearest neighbors algorithm, one of the machine learning methods, which can predict the sedimentary environments of one core through a known core. Compared to the results of other studies based on the comprehensive data set of grain size and four other indicators, this model achieved a high precision value only using the grain size data. We have also compared our prediction model with other mainstream machine learning algorithms, and the experimental results of six evaluation metrics shed light on that this prediction model can achieve the higher precision. The main errors of the model reflect the length of the conversation area of sedimentary environment, which is controlled by the sedimentary dynamics. This model can provide a quick comparison method of the cores in a similar environment; thus, it may point out the preliminary guidance for further study.

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Ground Penetrating Radar investigation of depositional architecture: the São Sebastião and Marizal formations in the Cretaceous Tucano Basin (Northeastern Brazil)

Brazilian Journal of Geology ◽

10.1590/2317-4889201620150031 ◽

2016 ◽

Vol 46 (1) ◽

pp. 15-27 ◽

Cited By ~ 3

Author(s):

Larissa Natsumi Tamura ◽

Renato Paes de Almeida ◽

Fabio Taioli ◽

André Marconato ◽

Liliane Janikian

Keyword(s):

Ground Penetrating Radar ◽

Sedimentary Environment ◽

Geophysical Methods ◽

Radar Data ◽

Northeastern Brazil ◽

Sedimentary Environments ◽

Hydrocarbon Reservoir ◽

Depositional Architecture ◽

Ground Penetrating ◽

Radar Facies

ABSTRACT: One key factor for the advance in the study of fluvial deposits is the application of geophysical methods, being the Ground Penetrating Radar one of special value. Although applied to active rivers, the method is not extensively tested on the rock record, bearing interest for hydrocarbon reservoir analogue models. The São Sebastião and Marizal formations were the subject of previous studies, which made possible the comparison of Ground Penetrating Radar survey to previous stratigraphic studies in order to identify the best combination of resolution, penetration and antenna frequency for the studied subject. Eight radar facies were identified, being six of them related to fluvial sedimentary environments, one related to eolian sedimentary environment and one radar facies interpreted as coastal sedimentary environment. The Ground Penetrating Radar data showed compatibility to sedimentary structures in the outcrops, like planar and trough cross-stratified beds. It is noted that the obtained resolution was efficient in the identification of structures up to 0.3 m using a 100 MHz antenna. In this way, the Ground Penetrating Radar survey in outcrops bears great potential for further works on fluvial depositional architecture.

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Impacts of bottom trawling on benthic trophic status and meiofauna in a deep-sea sedimentary environment (Gulf of Castellammare, southwestern Mediterranean Sea)

10.5194/egusphere-egu2020-9804 ◽

2020 ◽

Author(s):

Antonio Pusceddu ◽

Sarah Paradis ◽

Davide Moccia ◽

Pere Puig ◽

Pere Masque ◽

...

Keyword(s):

Community Composition ◽

Deep Sea ◽

Biochemical Composition ◽

Benthic Communities ◽

Sedimentary Environment ◽

Sediment Cores ◽

Organic Detritus ◽

Bottom Trawling ◽

Sedimentary Environments ◽

The Impact

The impacts of bottom trawling on the structure of benthic communities can be relatively non-selective, hitting biodiversity as a whole. This holds true also in the deep sea, where the impacts of trawling can be more severe and long-lasting than in shallow-waters, due to the reduced capacity for recovery and greater vulnerability of deep-sea organisms. For years, our knowledge of the impact of trawling on deep-water ecosystems has remained limited and has focused mainly on fish stocks and hard bottom systems. More recently, a number of studies have addressed the impacts of bottom trawling in the deep-sea sedimentary environments, and very few of them have focused on the impacts on meiofauna, though it is a key faunal component of deep-sea ecosystems.We investigated the impact of bottom trawling on the quantity, biochemical composition and nutritional value of sedimentary organic matter and meiofauna along the Sicilian Margin (Gulf of Castellammare, southwestern Mediterranean) at ca. 550 m depth, during the summer of 2016. Amount, biochemical composition and freshness of sedimentary OM, as well as the abundance and community composition of meiofauna were determined in sediment cores taken at both trawled and untrawled grounds. The continuous erosive processes in the trawled site have led, generally, to the depletion of OM contents (20-60% lower than those in the untrawled site), as well as to statistically significant differences from the untrawled site in its biochemical composition. Nevertheless, the upper 2 cm of the trawled site consisted of recently accumulated sediments, enriched in phytopigments, and bulk OM contents similar to those in the untrawled one, interpreted as a very recent input of fresh OM from the upper water column. The abundance of meiofauna in trawled grounds was significantly higher than that in untrawled ones, whereas no differences were observed between trawled and untrawled grounds deeper in the sediment. Differences in the meiofaunal community composition among sediment layers in each site were larger than those among sites.As previously reported, deep bottom trawling in the Gulf of Castellammare erodes large volumes of sediment, exposing old compacted sediment that is depleted in OM. This erosive action generally prevents the accumulation of fresh sediment. However, the episodic short-lived deposition of fresh organic detritus between hauls can lead to a temporary accumulation of fresh and bioavailable OM which, in turn, can induce a positive response in meiofauna abundance.These results pinpoint the need of considering the impacts of bottom trawling on the benthic communities of deep-sea sedimentary environments at temporal scales shorter than previously done.

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Turning waves and crustal reflection profiling

Geophysics ◽

10.1190/1.1444135 ◽

1997 ◽

Vol 62 (1) ◽

pp. 335-341 ◽

Cited By ~ 3

Author(s):

Ralf Stadtlander ◽

Larry Brown

Keyword(s):

Sedimentary Cover ◽

Indirect Evidence ◽

Sedimentary Environments ◽

The Past ◽

Velocity Gradients ◽

Basement Structures ◽

Wave Migration ◽

Seismic Reflection Profiles ◽

Imaging Algorithms ◽

Crustal Reflection

In the past, steeply dipping features were often recognized on seismic reflection profiles only from indirect evidence such as vertical offsets of cross‐cutting structures. New imaging algorithms, as for example, turning wave migration have had dramatic success in delineating steep, even‐overturned reflectors in sedimentary environments. Evaluation of the applicability of this technology to deep seismic recordings indicates that steep‐dip and turning wave migration will have limited practicality, generally, in the imaging of basement features because of the weak velocity gradients involved and the corollary requirement for large recording offsets. A potential exception arises when the basement structures to be imaged lie beneath a significant thickness of relatively young (i.e., steep velocity gradient) sedimentary cover.

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Sedimentary environment, lithostratigraphy and dating of sediment sequences from Arctic lakes Revvatnet and Svartvatnet in Hornsund, Svalbard

Polish Polar Research ◽

10.1515/popore-2016-0005 ◽

2016 ◽

Vol 37 (1) ◽

pp. 23-48 ◽

Cited By ~ 9

Author(s):

Antti E.K. Ojala ◽

Laura Arppe ◽

Tomi P. Luoto ◽

Lukas Wacker ◽

Eija Kurki ◽

...

Keyword(s):

Little Ice Age ◽

Sedimentary Environment ◽

Arctic Lakes ◽

Ice Age ◽

Sedimentary Environments ◽

Northern Basin ◽

Climate And Environmental Change ◽

Dating Methods ◽

Valley Glacier ◽

Paleomagnetic Dating

Abstract The sedimentary environment, sediment characteristics and age-depth models of sediment sequences from Arctic lakes Revvatnet and Svartvatnet, located near the Polish Polar Station in Hornsund, southern Svalbard (77°N), were studied with a view to establishing a basis for paleolimnological climate and environmental reconstructions. The results indicate that catchment-to-lake hydroclimatic processes probably affect the transportation, distribution and accumulation of sediments in different parts of lakes Revvatnet and Svartvatnet. Locations with continuous and essentially stable sedimentary environments were found in both lakes between water depths of 9 and 26 m. We used several different dating techniques, including 137Cs, 210Pb, AMS 14C, and paleomagnetic dating, to provide accurate and secured sediment chronologies. Arecovered sequence from the northern basin of Revvatnet spans more than one thousand years long with laminated stratigraphy in the upper part of the sediment. Based on AMS 14C dates, it is possible to suppose that Revvatnet basin was not occupied by a valley glacier during the Little Ice Age. The dates were supported by 137Cs chronologies, but not confirmed with other independent dating methods that extent beyond the last 50 years. A sedimentary sequence from the northern basin of Svartvatnet provides a potential archive for the study of climate and environmental change for the last ca. 5000 years. Based on the stratigraphy and a Bayesian age-depth model of AMS14C and paleosecular variation (PSV) dates, the recovered sediment sections represent a continuous and stable sedimentation for the latter half of the Holocene.

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The Relationship Analysis of Surrounding Rock Stability and Continental Sedimentary Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.1580 ◽

2011 ◽

Vol 217-218 ◽

pp. 1580-1583

Author(s):

Cui Liang ◽

Chao Zhang ◽

Nian Jie Ma ◽

Ming Ming Wen ◽

Chong Li

Keyword(s):

Rock Strength ◽

Sedimentary Environment ◽

Flood Plain ◽

Surrounding Rock ◽

Sedimentary Environments ◽

Delta Plain ◽

Relationship Analysis ◽

Rock Stability ◽

The Relationship ◽

Internal Relationship

The continental coal-bearing strata are mainly formed in the flood plain, delta plain and lake shore subfacies. Through the study on the sedimentary cause of differences of rock strength and sedimentary location, the paper analyzes the internal relationship between sedimentary environment and surrounding rock stability based on different coal-forming models. To take an example of Shendong Coal Mine Area, the differences of surrounding rock stability in various sedimentary environments are quantitative analyzed. The paper’s research promotes the combination between surrounding rock stability and sedimentology.

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The Kaolinite Crystallinity and Influence Factors of Coal-Measure Kaolinite Rock from Datong Coalﬁeld, China

Minerals ◽

10.3390/min12010054 ◽

2021 ◽

Vol 12 (1) ◽

pp. 54

Author(s):

Dongna Liu ◽

Yun Zhang ◽

Anchao Zhou ◽

Emmanuel Nnachi ◽

Shuting Huo ◽

...

Keyword(s):

Sedimentary Environment ◽

Influence Factors ◽

Coal Measure ◽

Molar Ratio ◽

Petrographic Analysis ◽

X Ray ◽

Chemical Index ◽

Study Results ◽

Chemical Index Of Alteration ◽

Permian Coal

In order to ascertain the kaolinite crystallinity of Carboniferous Permian coal-measure kaolinite rocks, seven groups of fresh samples were collected from below the ground in the Xiaoyu mine, Datong coalfield. Microscopy, X-ray diffraction (XRD), differential thermal analysis (DTA), infrared (IR) spectroscopy and X-ray fluorescence (XRF) spectrometry methods were applied to the samples. The petrographic analysis results show that the kaolinite rocks are characterized as compact, phaneritic, clastic, sand-bearing, sandy and silty types; the kaolinite content in the Shanxi formation and upper Taiyuan formations was more than 95%, while it was 60–90% in the middle and lower Taiyuan formations. Based on the Hinckley index and the features of XRD, DTA and IR of kaolinites, crystallinity was classified as having three grades: ordered, slightly disordered and disordered. The kaolinites’ SiO2 /Al2O3 molar ratio was about 1.9–5.7, with a chemical index of alteration (CIA) of about 95.4–99.5. This research suggests that the kaolinite crystallinity correlates positively to its clay mineral content, purity and particle size, which are also related to the SiO2/Al2O3 molar ratio and CIA. The original sedimentary environment and weathering have a direct influence on kaolinite crystallinity, and the existence of organic matter is conducive to the stable existence of kaolinite. The study results have significance for the extraction and utilization of coal-measure kaolinite and the development of kaolinite crystallography and mineralogy.

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Thenardite after mirabilite deposits as a cool climate indicator in the geological record: lower Miocene of Central Spain

Climate of the Past Discussions ◽

10.5194/cpd-10-3223-2014 ◽

2014 ◽

Vol 10 (4) ◽

pp. 3223-3253

Author(s):

M. J. Herrero ◽

J. I. Escavy ◽

B. C. Schreiber

Keyword(s):

Sedimentary Environment ◽

Lower Miocene ◽

Sedimentary Environments ◽

Diagenetic Alteration ◽

Time Period ◽

Industrial Mineral ◽

Climate Indicator ◽

Mammal Assemblages ◽

Cool Climate

Abstract. Evaporites are commonly used as indicators of different paleoclimates and sedimentary environments, as well as being geological resources of great economic interest. Ordinarily the presence of evaporites is related to warm and arid environmental conditions, but there are evaporitic minerals, like mirabilite, that form by cooling and a concentration mechanism based on cooling and/or freezing. The diagenetic transformation of mirabilite into thenardite in the upper part of the lower Miocene unit of the Tajo basin (Spain) resulted in the largest reserves of this important industrial mineral in Europe. This unit was formed in a time period (~ 18.4 Ma) that, in other basins of the Iberian Peninsula, is characterized by the existence of particular mammal assemblages appropriate to a relatively cool and arid climate. Determining the origin of the thenardite deposits as related to the diagenetic alteration of a pre-existing mirabilite permits the establishment and characterization of the sedimentary environment where it was formed and also suggests use as a possible analogue with comparable deposits from extreme conditions such as Antarctica or Mars.

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