scholarly journals Control of glacial and fluvial environments in the Ny-Alesund region, Arctic

MAUSAM ◽  
2021 ◽  
Vol 62 (4) ◽  
pp. 641-646
Author(s):  
DHRUV SENSINGH ◽  
RASIK RAVINDRA
Keyword(s):  
Coarse Sand ◽  
Cold Climate ◽  
Tectonic Activity ◽  
Direct Control ◽  
Sedimentary Environments ◽  
Geomorphic Features ◽  
The Matrix ◽  
Wrinkled Surface ◽  
Basic Characteristics ◽  
Fluvial Environments

Ny-Alesund, located in Svalbard, Arctic exhibits complex topography and geomorphic features evolved by various sedimentary environments under direct control of climate and tectonics. The controls of glacial and fluvial environments were analyzed on the basis of field documentation of geomorphic features evolved by small valley glaciers (Vestre brogger and Midre loven) and streams originating from it. These terrestrial valley glaciers are characterized by convex wrinkled surface, crevasses, bergchrunds, supraglacial streams, longitudinal debris strips, lateral moraines, recessional moraines, hummocky moraines, thrust moraines, convex longitudinal profile with breaks in slope, fractures and joints. The glacial deposits are made up of very poorly sorted clast to matrix supported boulders with varying sizes of clast, matrix and gravels. The matrix supported facies underlain by clast supported facies indicate the increasing energy of the glacier and so the cold climate. The bi-modal palaeocurrent pattern of moraines suggests two prominent directions for the movement of glaciers in the past under direct control of tectonic activity. The granulometric analysis of the streams indicate moderately sorted medium to coarse sand. The mean grain size decreases from origin to the middle reaches of the river and increases towards its mouth. The percentage of the finer sediments decreases and coarser fragments increases in the downstream direction. The results of the granulometric parameters which are contrary to the normal fluvial system are due to the control of tectonic activity. The present study provides the basic characteristics and activity of the glacial and fluvial environments the interpretation of, which explains the control of tectonic activity in this region.

Hillslope Form and Process: History 1960− 2000+

2021 ◽  
pp. M58-2021-8
Author(s):  
Mike Kirkby
Keyword(s):  
Land Surface ◽  
Drainage Density ◽  
Cold Climate ◽  
Lower Atmosphere ◽  
Tectonic Activity ◽  
Significant Advance ◽  
Mass Movements ◽  
Solution Processes ◽  
Process Understanding ◽  
Rapid Mass

AbstractThe study of hillslopes has been dominated by the expansion of studies into process rates and mechanisms. Perhaps the greatest volume of work has been on the ‘wash’ processes of soil erosion, but there has also been significant work on the diffusive mass movements of linear and non-linear ‘creep’ that shape the convexity of hilltops, on more rapid mass movements and on solution processes. There has also been fresh work on distinctive processes in coastal, arid and cold-climate environments.Accompanying and integrated with process understanding, and made possible by ubiquitous computational power, modelling has developed from soluble mathematical simplifications to complex simulations that incorporate much of our understanding of process and climate.Particular topics that have seen significant advance include a more complete understanding of drainage density and texture, and a broadening of interest to encompass the ‘critical zone’ that constructively unifies the land surface with the lower atmosphere, the biosphere and the regolith. There has also been a change of focus towards steeplands, dominated by mass movements, supply limited removal and tectonic activity.Most recently, and now incorporated into the concept of the ‘Anthropocene’, human impact is now receiving increasing attention as we acknowledge its accelerating role in changing landscapes and their relationships.

Late Quaternary aggradation and incision in the headwaters of the Yangtze River, eastern Tibetan Plateau, China

2021 ◽  
Author(s):  
Yang Yu ◽  
Xianyan Wang ◽  
Shuangwen Yi ◽  
Xiaodong Miao ◽  
Jef Vandenberghe ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Yangtze River ◽  
Late Quaternary ◽  
Cold Climate ◽  
Luminescence Dating ◽  
Tectonic Activity ◽  
The Yangtze River ◽  
Eastern Tibetan Plateau ◽  
Sedimentary Process ◽  
Fluvial Terraces

River aggradation or incision at different spatial-temporal scales are governed by tectonics, climate change, and surface processes which all adjust the ratio of sediment load to transport capacity of a channel. But how the river responds to differential tectonic and extreme climate events in a catchment is still poorly understood. Here, we address this issue by reconstructing the distribution, ages, and sedimentary process of fluvial terraces in a tectonically active area and monsoonal environment in the headwaters of the Yangtze River in the eastern Tibetan Plateau, China. Field observations, topographic analyses, and optically stimulated luminescence dating reveal a remarkable fluvial aggradation, followed by terrace formations at elevations of 55−62 m (T7), 42−46 m (T6), 38 m (T5), 22−36 m (T4), 18 m (T3), 12−16 m (T2), and 2−6 m (T1) above the present floodplain. Gravelly fluvial accumulation more than 62 m thick has been dated prior to 24−19 ka. It is regarded as a response to cold climate during the last glacial maximum. Subsequently, the strong monsoon precipitation contributed to cycles of rapid incision and lateral erosion, expressed as cut-in-fill terraces. The correlation of terraces suggests that specific tectonic activity controls the spatial scale and geomorphic characteristics of the terraces, while climate fluctuations determine the valley filling, river incision and terrace formation. Debris and colluvial sediments are frequently interbedded in fluvial sediment sequences, illustrating the episodic, short-timescale blocking of the channel ca. 20 ka. This indicates the potential impact of extreme events on geomorphic evolution in rugged terrain.

Depositional Environments of Plant Bearing Sediments

1988 ◽  
Vol 3 ◽  
pp. 1-13 ◽  
Author(s):  
Scott L. Wing
Keyword(s):  
Mass Flow ◽  
Depositional Environments ◽  
Fluvial Systems ◽  
Volcanic Origin ◽  
Sedimentary Environments ◽  
Plant Remains ◽  
Mass Flow Deposits ◽  
Fluvial Environments

Plants can become incorporated into the sediments of virtually any environment, from the oozes of abyssal plains to the silts and sands of delta fronts to brecciated mudflows of volcanic origin. However there is a much narrower range of sedimentary environments in which identifiable plant remains are found in abundance. Generally speaking these are the very shallow or subaerial portions of deltas and estuaries, the channels and floodplains of fluvial systems, lakes of all sizes, ash-falls, and mass-flow deposits such as mudflows. For the purposes of this paper peat swamps are considered as unusual subtypes of deltaic and fluvial environments in which clastic input is low relative to organic accumulation.

The UK marine sand and gravel dredging industry: an application of Quaternary geology

1998 ◽  
Vol 13 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Andrew G. Bellamy
Keyword(s):  
Resource Assessment ◽  
Cold Climate ◽  
Aggregate Consumption ◽  
Marine Sand ◽  
Sea Bed ◽  
History Of ◽  
The Uk ◽  
Sand And Gravel ◽  
Fluvial Environments ◽  
Marine Aggregate

AbstractMarine sands and gravels currently contribute 24% (over 20 million tonnes/year) of the total sand and gravel aggregate consumption of Great Britain. To maintain or increase this contribution into the future, the identification, assessment and licensing of additional sand and gravel resource areas is of fundamental importance. Research into the Quaternary history of the continental shelf surrounding the UK assists in the prediction of sand and gravel resource locations. Similarly, resource assessment is significantly improved through an understanding of the origin and formation of these Quaternary deposits.Geological considerations also feature strongly in the management of existing dredging licence areas and in the acquisition of future licences from the Crown Estate. Precise resource assessment, coupled with accurate dredger positioning and track recording systems, minimizes the extent of dredged sea bed, thereby limiting environmental impact and improving the consistency of dredged cargoes. Also important is the need to overcome marine aggregate prejudice which arises from the perception by some customers that marine dredged sands and gravels differ markedly from those obtained onshore. Central to this issue is the argument that some of the most substantial marine deposits originated in subaerial environments at similar times and by the same processes as their present-day terrestrial equivalents, having been deposited in Quaternary cold climate fluvial environments.

Production of Zirconium Aluminides by Self-Propagating High-Temperature Synthesis

2018 ◽  
Vol 769 ◽  
pp. 66-71 ◽  
Author(s):  
Oleg Yu. Dolmatov ◽  
Daniil K. Kolyadko ◽  
Nikita O. Pimenov ◽  
Stanislav S. Chursin
Keyword(s):  
Matrix Material ◽  
Chemical Processes ◽  
Optimal Parameters ◽  
Synthesis Conditions ◽  
High Temperature Synthesis ◽  
The Matrix ◽  
Basic Characteristics ◽  
Physical And Chemical ◽  
The Impact ◽  
Shs Method

This work presents the possibility of carrying out the SH-synthesis of materials based on intermetallic zirconium-aluminium compounds. This material can be used as the matrix material of dispersion nuclear fuel. As the result of experiments on the synthesis of zirconium aluminide by the SHS-method, the technological features and basic characteristics of physical and chemical processes have been identified. During the synthesis, the temperature distributions along the volume of samples and the impact of synthesis conditions on the phase composition of finished product were analyzed. Also, the optimal parameters for the production of specific phases of zirconium aluminides have been stated. In this paper, a material with a content of intermetallic Al2Zr and Al3Zr of more than 90 percent was obtained.

scholarly journals Basic Characteristics and Evolution of Geological Structures in the Eastern Margin of the Qinghai-Tibet Plateau

2019 ◽  
Vol 23 (4) ◽  
pp. 283-291
Author(s):  
Dejie Deng ◽  
Changliu Wang ◽  
Peihao Peng
Keyword(s):  
Three Dimensional ◽  
Dynamic Environment ◽  
Geological Structure ◽  
Tibet Plateau ◽  
Tectonic Activity ◽  
Late Cenozoic ◽  
Eastern Margin ◽  
Lateral Dislocation ◽  
Basic Characteristics ◽  
Qinghai Tibet Plateau

Based on field geological survey and stratigraphic profile survey in the eastern margin of the Qinghai-Tibet Plateau, the basic characteristics and evolution of geological structure in the eastern margin of the Qinghai-Tibet Plateau are studied. The Dongyuan area of the Qinghai-Tibet Plateau is divided into the late Cenozoic period and the current period. During the Late Cenozoic, the Pliocene Xigeda lacustrine deposits develops from 4.2 MaBP to 2.6 MaBP, with 9 cold-warm climate change stages. There are 4.3 MaBP old glacial period in this area, and 5 extreme paleoclimate events in Quaternary. At present, the horizontal movement intensity and mode of different tectonic zones are determined by the northward extrusion, eastward extrusion and rotation around the eastern tectonic junction in the study area, and the stages of the movement state changing with time are related to the gestation and occurrence of extra-large earthquakes. At present, the three-dimensional crustal movement shows that the tectonic activity differentiation of mountain and basin, which is related to tectonic dynamic environment and deep material activity, is related to the compression, shortening and uplift of plateau mountain and the extension and subsidence of basin, reflecting the inheritance of neotectonic activity. Through practical analysis, it is found that the eastern margin of the Qinghai-Tibet Plateau is composed of Minshan fault block and Longmenshan structural belt. The left-lateral dislocation of Minjiang fault is roughly the same as the vertical dislocation. In Longmenshan tectonic belt, the right-lateral dislocation of Maowen-Wenchuan fault, Beichuan-Yingxiu fault and other main faults is the same as the vertical dislocation.

Study on Depositional Environment of Soil Based on Multi-Fractal Theory

2011 ◽  
Vol 255-260 ◽  
pp. 3530-3534 ◽  
Author(s):  
Jiang Dong Cai ◽  
Ding Ceng Yu ◽  
Ya Dong Chen ◽  
Qing You
Keyword(s):  
Earth Science ◽  
Fractal Theory ◽  
Modern Science ◽  
Local Area ◽  
Human Beings ◽  
Sedimentary Environments ◽  
Living Space ◽  
Fractal Properties ◽  
Geomorphic Features ◽  
The Difference

Fluvial action is the most universal erosion process in geological history. Rivers in the surface of the Earth had molded different kinds of geomorphic features and varied landforms; also they had great effect on the human beings. Evaluating the fluvial landforms correctly and objectively will help people to exploit the living space adequately and utilize natural environment reasonably. Moreover studying on the spatial distribution of the rivers in a local area will help people to understand the situation of the river at present and forecast the development of the river in the future. Fractal and multi- fractal theory is a new and developing subject in modern science; it is widely used in many fields of earth science. Static Cone Penetrate Test is an exploration technology which can obtain the physical indices of soil. A study had found that specific penetration resistances varied with the buried depth of the strata and the curves of test values have characteristics of fractal. In this paper, with the assistance of fractal and multi-fractal theory, we analyzed the simple dimension and multi-fractal properties of these curves. Results suggested that simple dimension as well as the multi-fractal spectrum can tell the difference between the soils deposited in distinct sedimentary environments.

scholarly journals Aportaciones didácticas al origen de la pirita en el Barranco de las Cañadas (Paraje del Pizcalejo, Caravaca-Murcia). Estudio en un laboratorio de Educación Secundaria

2019 ◽  
pp. 47-58
Author(s):  
José Pedro López Pérez ◽  
Raquel Boronat Gil
Keyword(s):  
Hydrogen Sulfide ◽  
Secondary Education ◽  
The Other ◽  
Bacterial Metabolism ◽  
Biological Production ◽  
Basic Study ◽  
Practical Activity ◽  
Sedimentary Environments ◽  
Production Of Hydrogen ◽  
The Matrix

Resumen Este trabajo describe una actividad en un laboratorio de educación secundaria que, por un lado pone de manifiesto la producción biológica de ácido sulfhídrico mediante la reducción de sulfitos a microescala, introduciendo para ello el estudio básico del metabolismo bacteriano responsable y, por otro, lo relaciona con la génesis incipiente de las piritas sedimentarias. Esta actividad práctica, destinada a alumnos de segundo ciclo de ESO y Bachillerato, también ayuda a recrear multitud de manifestaciones geológicas halladas en el área del Barranco de las Cañadas (Paraje del Pizcalejo, Caravaca-Murcia), así como postular lo que podría hallarse en la matriz de rocas procedentes de ambientes sedimentarios semejantes. Abstract This paper present a activity in the compulsory secondary education laboratory that, on one hand, reproduces biological production of hydrogen sulfide by reducing sulfites at microscale, introducing the basic study of the responsible bacterial metabolism and, on the other hand, its relationship with the incipient genesis of sedimentary pyrites. This practical activity, destined to students in the second cycle of ESO and A-level (Bachillerato), also helps to recreate a multitude of geological manifestations found in the Barranco de las Cañadas area (Paraje del Pizcalejo, Caravaca-Murcia), and postulate what could be found in the matrix of rocks from similar sedimentary environments.

A comparative analysis of indices of social and economic development using the characteristics of regional differentiation

2020 ◽  
Vol 19 (7) ◽  
pp. 1336-1359
Author(s):  
M.Yu. Afanas'ev ◽  
A.V. Kudrov ◽  
A.A. Gusev
Keyword(s):  
Economic Development ◽  
Comparative Analysis ◽  
Correlation Analysis ◽  
Regional Differentiation ◽  
Scientific Methods ◽  
Third Stage ◽  
Social And Economic Development ◽  
The Matrix ◽  
Level Of Economic Development ◽  
Basic Characteristics

Subject. The article considers indices of socio-economic development of regions. Objectives. We perform a comparative analysis of indices that characterize the level of economic development of the subjects of the Russian Federation and identify the indices that do not have significant differences. Methods. The study draws on general scientific methods of analysis. Results. The correlation analysis at the first stage helped reduce the number of indices to be analyzed at the next stages. At the second stage, we built regressions of each index for the basic characteristics of differentiation. Based on the analysis of beta coefficients, we identified differentiation characteristics, which have a significant impact on the indices in question. At the third stage, we built the matrix of values of the cosines of angles between each pair of indices under consideration. Conclusions. The analysis of the cosines of angles between indices calculated using the regression coefficients of these indices for differentiation characteristics enabled to confirm the results of correlation analysis and identify a subset of indices that are not distinguishable in solving management tasks parameterized with the use of differentiation characteristics.

MARINE TERRACES ALONG THE MYANMAR COAST AND THEIR ACTIVE TECTONIC SIGNIFICANCE

2008 ◽  
Vol 02 (04) ◽  
pp. 267-277 ◽  
Author(s):  
WIN SWE ◽  
SOE THURA TUN
Keyword(s):  
Sea Level ◽  
Tectonic Setting ◽  
Strike Slip ◽  
Tectonic Activity ◽  
Megathrust Earthquakes ◽  
Marine Terraces ◽  
Active Tectonic ◽  
Tectonic Significance ◽  
Geomorphic Features ◽  
The Last Glacial

Wave-cut platforms, uplifted marine terraces, and areas of subsidence are among the most striking geomorphic features along some parts of the Myanmar coast. Depending on the local tectonic setting, processes of development of terraces of the Myanmar coast can be classified into at least three categories viz. (i) uplifting of wave-cut platforms or intertidal deposits by megathrust earthquakes, (ii) growth of prodelta sandbars where tectonic signatures, should they ever form, are overwhelmed by rapid sedimentation, and (iii) uplifting of wave-cut platforms or intertidal deposits developed in strike-slip related sigmoidal basins on the coast by strike-slip tectonic activity. Some of the higher flat areas behind those on or close to the shore could probably belong to the fourth category that is lowering of the sea level during the last glacial ages in Pleistocene time. Many of these terraces are still not yet properly studied, hence should be carried out.

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