SEDIMENTATION and TECTONIC EVOLUTION of CENOZOIC SEQUENCES from BENGAL and ASSAM FORELAND BASINS, EASTERN HIMALAYAS Except Wher
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Sediment Transport in the San Francisco Bay Coastal System: an Overview
Marine Geology 345 (2013) 3–17 Contents lists available at ScienceDirect Marine Geology journal homepage: www.elsevier.com/locate/margeo Sediment transport in the San Francisco Bay Coastal System: An overview Patrick L. Barnard a,⁎, David H. Schoellhamer b,c, Bruce E. Jaffe a, Lester J. McKee d a U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, USA b U.S. Geological Survey, California Water Science Center, Sacramento, CA, USA c University of California, Davis, USA d San Francisco Estuary Institute, Richmond, CA, USA article info abstract Article history: The papers in this special issue feature state-of-the-art approaches to understanding the physical processes Received 29 March 2012 related to sediment transport and geomorphology of complex coastal–estuarine systems. Here we focus on Received in revised form 9 April 2013 the San Francisco Bay Coastal System, extending from the lower San Joaquin–Sacramento Delta, through the Accepted 13 April 2013 Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by Available online 20 April 2013 numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic Keywords: sediment transport species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet 9 3 estuaries connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~8 × 10 m /day, in addition circulation to the transport of mud, sand, biogenic material, nutrients, and pollutants. -
Sedimentation and Clarification Sedimentation Is the Next Step in Conventional Filtration Plants
Sedimentation and Clarification Sedimentation is the next step in conventional filtration plants. (Direct filtration plants omit this step.) The purpose of sedimentation is to enhance the filtration process by removing particulates. Sedimentation is the process by which suspended particles are removed from the water by means of gravity or separation. In the sedimentation process, the water passes through a relatively quiet and still basin. In these conditions, the floc particles settle to the bottom of the basin, while “clear” water passes out of the basin over an effluent baffle or weir. Figure 7-5 illustrates a typical rectangular sedimentation basin. The solids collect on the basin bottom and are removed by a mechanical “sludge collection” device. As shown in Figure 7-6, the sludge collection device scrapes the solids (sludge) to a collection point within the basin from which it is pumped to disposal or to a sludge treatment process. Sedimentation involves one or more basins, called “clarifiers.” Clarifiers are relatively large open tanks that are either circular or rectangular in shape. In properly designed clarifiers, the velocity of the water is reduced so that gravity is the predominant force acting on the water/solids suspension. The key factor in this process is speed. The rate at which a floc particle drops out of the water has to be faster than the rate at which the water flows from the tank’s inlet or slow mix end to its outlet or filtration end. The difference in specific gravity between the water and the particles causes the particles to settle to the bottom of the basin. -
Estuarine and Coastal Sedimentation Problems1
ESTUARINE AND COASTAL SEDIMENTATION PROBLEMS1 Leo C. van Rijn Delft Hydraulics and University of Utrecht, The Netherlands. E•mail: [email protected] Abstract: This Keynote Lecture addresses engineering sedimentation problems in estuarine and coastal environments and practical solutions of these problems based on the results of field measurements, laboratory scale models and numerical models. The three most basic design rules are: (1) try to understand the physical system based on available field data; perform new field measurements if the existing field data set is not sufficient (do not reduce on the budget for field measurements); (2) try to estimate the morphological effects of engineering works based on simple methods (rules of thumb, simplified models, analogy models, i.e. comparison with similar cases elsewhere); and (3) use detailed models for fine•tuning and determination of uncertainties (sensitivity study trying to find the most influencial parameters). Engineering works should be designed in a such way that side effects (sand trapping, sand starvation, downdrift erosion) are minimum. Furthermore, engineering works should be designed and constructed or built in harmony rather than in conflict with nature. This ‘building with nature’ approach requires a profound understanding of the sediment transport processes in morphological systems. Keywords: Sedimentation, sediment transport, morphological modelling 1. INTRODUCTION This lecture addresses sedimentation and erosion engineering problems in estuaries and coastal seas and practical solutions of these problems based on the results of field measurements, laboratory scale models and numerical models. Often, the sedimentation problem is a critical element in the economic feasibility of a project, particularly when each year relatively large quantities of sediment material have to be dredged and disposed at far•field locations. -
Changing Wage Structure in India in the Post-Reform Era: 1993–2011 Hanan G
A Service of Leibniz-Informationszentrum econstor Wirtschaft Leibniz Information Centre Make Your Publications Visible. zbw for Economics Jacoby, Hanan G.; Dasgupta, Basab Article Changing wage structure in India in the post-reform era: 1993-2011 IZA Journal of Development and Migration Provided in Cooperation with: IZA – Institute of Labor Economics Suggested Citation: Jacoby, Hanan G.; Dasgupta, Basab (2018) : Changing wage structure in India in the post-reform era: 1993-2011, IZA Journal of Development and Migration, ISSN 2520-1786, Springer, Heidelberg, Vol. 8, Iss. 8, pp. 1-26, http://dx.doi.org/10.1186/s40176-017-0115-1 This Version is available at: http://hdl.handle.net/10419/197467 Standard-Nutzungsbedingungen: Terms of use: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Documents in EconStor may be saved and copied for your Zwecken und zum Privatgebrauch gespeichert und kopiert werden. personal and scholarly purposes. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle You are not to copy documents for public or commercial Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich purposes, to exhibit the documents publicly, to make them machen, vertreiben oder anderweitig nutzen. publicly available on the internet, or to distribute or otherwise use the documents in public. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, If the documents have been made available under an Open gelten abweichend von diesen Nutzungsbedingungen die in der dort Content Licence (especially Creative Commons Licences), you genannten Lizenz gewährten Nutzungsrechte. may exercise further usage rights as specified in the indicated licence. https://creativecommons.org/licenses/by/4.0/ www.econstor.eu Jacoby and Dasgupta IZA Journal of Development and Migration (2018) 8:8 IZA Journal of Development DOI 10.1186/s40176-017-0115-1 and Migration ORIGINAL ARTICLE Open Access Changing wage structure in India in the post-reform era: 1993–2011 Hanan G. -
Coastal and Shelf Sediment Transport: an Introduction
Downloaded from http://sp.lyellcollection.org/ by guest on September 28, 2021 Coastal and shelf sediment transport: an introduction MICHAEL B. COLLINS 1'3 & PETER S. BALSON 2 1School of Ocean & Earth Science, University of Southampton, Southampton Oceanography Centre, European Way, Southampton S014 3ZH, UK (e-mail." mbc@noc, soton, ac. uk) 2Marine Research Division, AZTI Tecnalia, Herrera Kaia, Portu aldea z/g, Pasaia 20110, Gipuzkoa, Spain 3British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG, UK. Interest in sediment dynamics is generated by the (a) no single method for the determination of need to understand and predict: (i) morphody- sediment transport pathways provides the namic and morphological changes, e.g. beach complete picture; erosion, shifts in navigation channels, changes (b) observational evidence needs to be gathered associated with resource development; (ii) the in a particular study area, in which contem- fate of contaminants in estuarine, coastal and porary and historical data, supported by shelf environment (sediments may act as sources broad-based measurements, is interpreted and sinks for toxic contaminants, depending by an experienced practitioner (Soulsby upon the surrounding physico-chemical condi- 1997); tions); (iii) interactions with biota; and (iv) of (c) the form and internal structure of sedimen- particular relevance to the present Volume, inter- tary sinks can reveal long-term trends in pretations of the stratigraphic record. Within this transport directions, rates and magnitude; context of the latter interest, coastal and shelf (d) complementary short-term measurements sediment may be regarded as a non-renewable and modelling are required, to (b) (above) -- resource; as such, their dynamics are of extreme any model of regional sediment transport importance. -
Soil Erosion, Runoff, and Sedimentation Construction Site Fact Sheet No
Soil Erosion, Runoff, and Sedimentation Construction Site Fact Sheet No. 1 What Is Soil Erosion? What Problems Happen On Construction Soil erosion is the detachment and movement of soil Sites? particles by water, wind, ice, or gravity. Safety and Nuisance Issues – Sediment on roadways and in the air can cause safety hazards. Flooding– Excessive sediment accumulation in drainage systems can create blockages that promote flooding. Sediment Build‐Up – Sediment that accumulates in streams, lakes, and bays can only be remediated by costly dredging. Increased Costs – Uncontrolled erosion and sedimentation requires costly maintenance and What Is Sedimentation? repair. It is cheaper and easier to PREVENT Sediment is the result of erosion. Sedimentation is erosion than to fix sedimentation problems. the build‐ up of eroded soil particles that are transported in runoff from their site of origin and Negative Public Perception ‐Observing muddy deposited in drainage systems, on other ground water flowing from construction sites negatively surfaces, or in bodies of water or wetlands. effects public perception. Why Should I Care? It’s the Law– Federal, State and local regulations require construction sites to be compliant with the Clean Water Act. Water Quality‐Erosion from construction projects can be a non‐point source pollutant that deteriorates the health of our lakes, streams and Narragansett Bay. Soil Loss ‐ Much of the total sediment loss that occurs each year is generated by highway construction and land development projects. Quality of Life‐ If you enjoy fishing, eating local Sediment‐filled runoff from a RIDOT construction site shellfish or swimming at one of Rhode Island’s beautiful beaches, this pollution can threaten your quality of life. -
Dr. Sabyasachi Dasgupta Present Employment / Teaching Experience
CURRICULUM VITAE Dr. Sabyasachi Dasgupta Address for Communication Permanent Address Associate Professor C/O Aparajita Dasgupta Department of Forestry & Biodiversity A.K. Road [Opp. Western Club] Tripura University (A Central University) Ramnagar, Agartala Suryamaninagar, PIN-799022 Tripura- 799002 Tripura, INDIA Tel: +91 9410127024 (m) Email: [email protected] [email protected] Date of Birth : 9th December, 1974 Sex : Male Nationality : Indian I am working in the field of conservation ecology which always includes humans as a component. I work well as a team leader and I am known as active team member whenever given some assignment, I am very reliable and organized. Present Employment / Teaching Experience 13th November 2017 onwards Associate Professor in Department of Forestry and Biodiversity, Tripura University. Job responsibility: Teaching, Research, Consultancy and administration. 6th March 2007 to 10th November 2017 Assistant Professor in Department of Forestry, HNB Garhwal Central University. Teaching experience includes taking classes of Graduates and Post-Graduates of Forestry, Guiding Masters & Ph.D students. Administrative responsibilities include- Coordinating foreign collaboration, Resident tutor of Forestry Hostel, Member of IQAC task group for Research and Consultancy, Member of Departmental Purchase committee. Apart from these as a Coordinator, I am also looking after the consultancy related to Environmental Impact Assessment and Biodiversity management planning. 28th September, 2006 –28th February 2007 Assistant Professor, Agroforestry, in the College of Horticulture & Forestry, Central Agricultural University, Arunachal Pradesh, Govt. of India 13th August, 2005 – 20th September 20th 2006 Lecturer in Department of Forestry, HNB Garhwal University. 1 of 13 Qualifications May, 2007 Ph.D. in Ecology & Environment, Wildlife Institute of India, FRI University, Dehradun, Uttarkhand. -
Sedimentary Rock Formation Models
Sedimentary Rock Formation Models 5.7 A Explore the processes that led to the formation of sedimentary rock and fossil fuels. The Formation Process Explained • Formation of these rocks is one of the important parts of the rock cycle. For millions of years, the process of deposition and formation of these rocks has been operational in changing the geological structure of earth and enriching it. Let us now see how sedimentary rocks are formed. Weathering The formation process begins with weathering of existent rock exposed to the elements of nature. Wind and water are the chisels and hammers that carve and sculpt the face of the Earth through the process of weathering. The igneous and metamorphic rocks are subjected to constant weathering by wind and water. These two elements of nature wear out rocks over a period of millions of years creating sediments and soil from weathered rocks. Other than this, sedimentation material is generated from the remnants of dying organisms. Transport of Sediments and Deposition These sediments generated through weathering are transported by the wind, rivers, glaciers and seas (in suspended form) to other places in the course of flow. They are finally deposited, layer over layer by these elements in some other place. Gravity, topographical structure and fluid forces decide the resting place of these sediments. Many layers of mineral, organics and chemical deposits accumulate together for years. Layers of different deposits called bedding features are created from them. Crystal formation may also occur in these conditions. Lithification (Compaction and Cementation) Over a period of time, as more and more layers are deposited, the process of lithification begins. -
Sedimentary Rocks
Sedimentary Rocks • a rock resulting from the consolidation of loose sediment that has been derived from previously existing rocks • a rock formed by the precipitation of minerals from solution Sedimentary Stages of the Rock Cycle Weathering Erosion Transportation Deposition (sedimentation) Burial Diagenesis Fig. 5.1 1 Table 5.1 Sorting Fig 5.2 Transport will effect the sediment in several ways Sorting:Sorting a measure of the variation in the range of grain sizes in a rock or sediment • Well-sorted sediments have been subjected to prolonged water or wind action. • Poorly-sorted sediments are either not far- removed from their source or deposited by glaciers. 2 Fig. 5.3 Sedimentary Environments Fig. Story 5.5 Table 5.2 3 Sedimentary Structures Stratification = Bedding = Layering This layering that produces sedimentary structures is due to: • Particle size • Types (s) of particles Sedimentary Layering Other Examples of Sedimentary Structures • Cross-beds • Ripple marks • Mudcracks • Raindrop impressions • Fossils 4 Cross-bedded sandstone Fig. 5.6 Fig. 5.7 Ripples on a beach Fig. 5.8 5 Ripples Preserved in Sandstone Fig. 5.9 Fig. 5.9 6 Fig. 5.10 Turbidity Currents Suspension of water sand, and mud that moves downslope (often very rapidly) due to its greater density that the surrounding water (often triggered by earthquakes). The speed of turbidity currents was first appreciated in 1920 when a current broke lines in the Atlantic. This event also demonstrated just how far a single deposit could travel. From Sediment to Sedimentary Sock (lithification) • Compaction:Compaction reduces pore space. clays and muds are up to 60 % water; 10% after compaction • Cementation:Cementation chemical precipitation of mineral material between grains (SiO2, CaCO3, Fe2O3) binds sediment into hard rock. -
Erosion and Sediment Control for Agriculture
Chapter 4C: Erosion and Sediment Control 4C: Erosion and Sediment Control Management Measure for Erosion and Sediment Apply the erosion component of a Resource Management System (RMS) as defined in the Field Office Technical Guide of the U.S. Department of Agriculture–Natural Resources Conservation Service (see Appendix B) to minimize the delivery of sediment from agricultural lands to surface waters, or Design and install a combination of management and physical practices to settle the settleable solids and associated pollutants in runoff delivered from the contributing area for storms of up to and including a 10-year, 24-hour frequency. Management Measure for Erosion and Sediment: Description Application of this management measure will preserve soil and reduce the mass of sediment reaching a water body, protecting both agricultural land and water quality. This management measure can be implemented by using one of two general strategies, or a combination of both. The first, and most desirable, strategy is to implement practices on the field to minimize soil detachment, erosion, and transport of sediment from the field. Effective practices include those that maintain crop residue or vegetative cover on the soil; improve soil properties; Sedimentation reduce slope length, steepness, or unsheltered distance; and reduce effective causes widespread water and/or wind velocities. The second strategy is to route field runoff through damage to our practices that filter, trap, or settle soil particles. Examples of effective manage- waterways. Water ment strategies include vegetated filter strips, field borders, sediment retention supplies and wildlife ponds, and terraces. Site conditions will dictate the appropriate combination of resources can be practices for any given situation. -
Description of a Contourite Depositional System on the Demerara Plateau: Results from Geophysical Data and Sediment Cores
1 Marine Geology Achimer August 2016, Volume 378, Pages 56-73 http://dx.doi.org/10.1016/j.margeo.2016.01.003 http://archimer.ifremer.fr http://archimer.ifremer.fr/doc/00308/41957/ © 2016 Elsevier B.V. All rights reserved Description of a contourite depositional system on the Demerara Plateau: Results from geophysical data and sediment cores Tallobre Cédric 1, 2, *, Loncke Lies 1, 2, Bassetti Maria-Angela 1, 2, Giresse Pierre 1, 2, Bayon Germain 3, Buscail Roselyne 1, 2, Durrieu De Madron Xavier 1, 2, Bourrin François 1, 2, Vanhaesebroucke Marc 1, 2, Sotin Christine 1, 2, Iguanes Scientific Party 1 Univ. Perpignan Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens (CEFREM), UMR 5110, 52 Avenue Paul Alduy, 66860 Perpignan, France 2 CNRS, Centre de Formation et de Recherche sur les Environnements Méditerranéens (CEFREM), UMR 5110, 52 Avenue Paul Alduy, 66860 Perpignan, France 3 IFREMER, Unité de Recherche Géosciences Marines, 29280 Plouzané, France * Corresponding author : Cédric Tallobre, email address : [email protected] Abstract : The Demerara Plateau, belonging to the passive transform margin of French Guiana, was investigated during the IGUANES cruise in 2013. The objectives of the cruise were to explore the poorly-known surficial sedimentary column overlying thick mass transport deposits as well as to understand the factors controlling recent sedimentation. The presence of numerous bedforms at the seafloor was observed thanks to newly acquired IGUANES bathymetric, high resolution seismic and chirp data, while sediment cores allowed the characterization of the deposits covering the mass transport deposits. Modern oceanographic conditions were determined in situ, using mooring monitoring over a 10-month period. -
Curriculum Vitae
Curriculum Vitae Name: Dr. SANKAR BOSE Mailing address (Office): Department of Geology Presidency University 86/1 College Street Kolkata 700 073 Tel: -91-33-22192636 Email: [email protected] [email protected] Web: http://www.presiuniv.ac.in/web/staff.php?staffid=104 Residence: Flat No. Q/6 Lake Gardens R.H.E. 48/4 Sultan Alam Road Kolkata 700 033 Telephone: +91-9874171661 (mobile) Date of Birth: June 07, 1968 Nationality: Indian Area of specialization: Metamorphic Petrology and Mineralogy Additional research interest Geochemistry and geochronology Current Status: Professor of Geology Educational qualification: Ph.D. in Science from Jadavpur University, Kolkata, India in 2003. M.Sc. in Applied Geology from Jadavpur University, Kolkata in 1993 with 1st class (75% marks). B.Sc. with Geological Sciences (Hons.) from Jadavpur University, Kolkata in 1991 with 1st class (73% marks). Higher Secondary Examination (12th standard, WB Board) in 1987 with 1st division (75% marks). Secondary Examination (10th standard, WB Board) in 1985 with 1st division (79% marks). Academic Awards: o Awarded National Scholarship for the result of Secondary and B.Sc. Examination in 1985 and 1991 respectively. o Awarded Junior Research Fellowship by University Grants Commission, Government of India in 1993. o Awarded Post-Doctoral Fellowship from the Japan Society for the Promotion of Science (JSPS) in 2006. o Awarded National Geoscience Award 2012 in the field of Basic Geoscience. o Awarded DST-JSPS Bilateral Research Fellowship for 2014-2016. 1 o Awarded JSPS Bridge Fellowship for the year 2016. Teaching experience: Worked as Lecturer in Geology in Durgapur Government College, Durgapur, India during the period July 1998 - January 2003 (UG and PG teaching) Worked as Lecturer in Geology in Presidency College, Kolkata, India during the January 2003 - December 2003 (UG and PG teaching) Worked as Senior Lecturer in Geology in Presidency College, Kolkata, India during the period December 2003 - December 2008 (UG and PG teaching).