Reconstructing the Holocene depositional environments along the northern coast of Sfax (Tunisia): Mineralogical and sedimentological approaches

Science.gov (United States)

Lamourou, Ali; Touir, Jamel; Fagel, Nathalie

2017-05-01

A sedimentological and mineralogical study of sedimentary cores allowed reconstructing the evolution of depositional environments along the Northern coast of Sfax (Tunisia). The aim of this research work is to identify the factors controlling the sedimentation from the Holocene to the Present time. Three 30-m sediment cores collected by drilling at 30 m water depth were analyzed for their color, magnetic susceptibility signal, grain size by laser diffraction, organic matter content by loss of ignition, carbonate content by calcimetry and mineralogy by X-ray diffraction on bulk powder and clay <2 μm. They broadly present the same sedimentological and mineralogical features. Microscopical observations of petrographic slides allowed identifying six main sedimentary facies. Bulk mineralogical assemblages comprised clay minerals, quartz, calcite, gypsum and K-feldspars were examined. Considerable change was observed in the carbonate content that mimicked the bioclaste abundance and diluted the detrital minerals (clay minerals, quartz and feldspars). The gypsum mainly occurred in the lower sedimentary columns (SC12 and SC9) and in the upper/middle of core SC6. The clay fraction was made of a mixture of kaolinite, illite, smectite and palygorskite with no clear variation through core depth. Both grain-size parameters and magnetic susceptibility profile showed a sharp transition in the upper 2-5 m of the sedimentological columns. Coarse, sandy to gravely sediments characterized by a low magnetic susceptibility signal were replaced by fine bioclastic-rich clayey sediments. The analysis of vertical succession of depositional facies revealed a fluvial depositional environment (coastal plain) basically marked by fluvial channels and inundation plains at the bottom of all cores. However, core-top sediments recorded a littoral marine environment with sand depositions rich in gastropods, lamellibranches and algæ. Depositional facies, sedimentological and mineralogical

Geomorphology of the Namoi alluvial plain, northwestern New South Wales

International Nuclear Information System (INIS)

Young, R.W.; Young, A.R.M.; Price, D.M.; Wray, R.A.L.

2002-01-01

The Quaternary history of the extensive alluvial plains of the northern part of the Darling River Basin has received little attention, and has generally been assumed to be an analogue of the very detailed history compiled for the Riverine Plain of southeastern Australia. Our study of the Namoi valley, which is a tributary to the upper Darling, shows that this assumption is unfounded. Thermoluminescence dating demonstrates that the oldest palaeochannels of the Namoi River correspond only to the youngest palaeochannels on the Riverine Plain. The thermoluminescence analyses were carried out on the 90-125 μm quartz fraction thermally stimulated by ionizing radiation using the combined additive/regenerative technique. This technique utilises a second glow normalisation procedure that involves re-irradiating each of the quartz sample aliquots and measuring the thermoluminescence induced in the grains. It has ben demonstrated that unlike the streams on the Riverine Plain, the Namoi River has moved progressively away from its buried Tertiary palaeovalley, probably due to declining sediment input from its southern tributaries. In contrast to the streams of the Riverine Plain, the dimensions of the Namoi palaeochannels are indicative of substantially greater discharges until the mid-Holocene. There is also evidence of significant aeolian input throughout the Late Quaternary. The study indicates that the water resources of this increasingly important irrigated region seem to be considerably constrained by the Quaternary heritage of the Namoi valley. Copyright (2002) Geological Society of Australia

Role of neotectonics and climate in development of the Holocene geomorphology and soils of the Gangetic Plains between the Ramganga and Rapti rivers

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Srivastava, Pankaj; Parkash, B.; Sehgal, J. L.; Kumar, Sudhir

1994-12-01

Fifteen soil-geomorphic units have been delineated from the Gangetic Plains between the Ramganga and Rapti rivers. They were identified by remote sensing and field checks. On the basis of degree of profile development, their soils are grouped into five members (QGH1 to QGH5, QGH5 being the oldest) of a soil chrono-association. Tentative ages assigned to QGH1 to QGH5 are 500, > 2500, 8000 and 13,5000 yr B.P., respectively. From the early Holocene to about 6500 yr. B.P. a cold, arid to semi-arid climate prevailed and pedogenic calcrete developed over large areas in the Gangetic Plains. Later, a warm and humid climate and improved drainage resulted in complete removal of calcrete from soil profiles in some areas or its dissolution and re-precipitation in lower horizons in other areas. Neotectonics seems to have played a significant role in the evolution of the geomorphology and soils of the area. It determined areas of active sedimentation, pedogenesis and erosion (in upland regions). It led to tilting and sagging of large blocks resulting in shifting and increase in sinuosity of the rivers. Tectonic slopes/faults determined the courses of large rivers.

[Aboveground biomass of Tamarix on piedmont plain of Tianshan Mountains south slope].

Science.gov (United States)

Zhao, Zhenyong; Wang, Ranghui; Zhang, Huizhi; Wang, Lei

2006-09-01

Based on the geo-morphological and hydro-geological characteristics, the piedmont plain of Tianshan Mountains south slope was classified into 4 geo-morphological belts, i.e., flood erosion belt, groundwater spill belt, delta belt, and the joining belt of piedmont plain and Tarim floodplain. A field investigation on the Tamarix shrub in this region showed that there was a significant difference in its aboveground biomass among the four belts, ranged from 1428.53 kg x hm(-2) at groundwater spill belt to 111.18 kg x hm(-2) at the joining belt of piedmont plain and Tarim floodplain. The main reason for such a big difference might be the different density of Tamarix shrub on different belts. Both the Tamarix aboveground biomass and the topsoil's salinity were decreased with increasing groundwater level. Groundwater level was the main factor limiting Tamarix growth, while soil salinity was not.

Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

Energy Technology Data Exchange (ETDEWEB)

Keene, Joshua L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-04-01

The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating to the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.

Palaeoenvironmental assessment of Westphalian fluvio-lacustrine deposits of Lorraine (France) using a combination of organic geochemistry and sedimentology

International Nuclear Information System (INIS)

Fleck, Stephanie; Michels, Raymond; Izart, Alain; Elie, Marcel; Landais, Patrick

2001-01-01

The quality and the quantity of organic carbon preserved in modern and ancient terrestrial sediments is the result of a complex interactions of sedimentological factors, such as in-situ productivity, allochtonous supply of organic matter, oxidation processes, biodegradation and sediment accumulation rates. The study aims at utilizing multidisciplinary information in order to characterize the palaeoenvironment in Westphalian fluvio-lacustrine deposits of the Lorraine Coal Basin (NE France). In this basin, the lack of outcrops is the major difficulty. To compensate for this problem, sedimentology, and molecular geochemistry are combined in order to significantly improve the palaeoenvironmental assessment of the area. Geochemical analyses and sedimentology have been carried out on several core samples of the Saulcy drill hole to evaluate local palaeoenvironmental variability. The lithofacies associations in the Upper Carboniferous of the Lorraine basin suggest an alluvial plain environment without marine incursions. Sedimentological interpretations of the core, as well as comparison with sedimentological models, suggests the recognition of different depositional environments from braided and/or meandering rivers to swamp and lakes. The organic geochemistry is focussed on the recognition of aliphatic hydrocarbons and especially on molecular biomarkers, which provide valuable information about the original organic matter and the transformations that took place during sedimentation and diagenesis. In the Lorraine basin, the botanical variability is high and clearly related to the position of the vegetation communities in the fluvial system. The biomarkers (e.g., diterpanes, steranes) show variations, which can be related to the diversity of this ecosystem. In this study, a reinterpretation of the environmental zonation in the sterane ternary diagram adapted to a fluvio-lacustrine sedimentology is proposed. The correlation between sedimentological and geochemical

Pannonian plain as a morphostructural unit of Serbia

Directory of Open Access Journals (Sweden)

Ćalić Jelena

2012-01-01

Full Text Available Differentiation between the terms “Pannonian Basin” and “Pannonian Plain” is not clear enough in geographical literature. The paper discusses the usage of the term “plain” in geomorphology, as well as the usage of a quantitative method for plain delineation, through calculation of relief roughness coefficient (using a digital elevation model. Qualitative analysis, which includes the definition of dominant geomorphological processes and the distribution of Quaternary sediments, is an addition to the quantitative analysis. In the Republic of Serbia, the area of the Pannonian plain defined in this way is 24,448 km2, which is 27.5% of the total territory of the country. The paper gives the overview of the geotectonic structure and evolution of the Pannonian Basin System, with special stress on the territory of Serbia, as well as the chronology of the Pannonian sedimentation area in Serbia from the Lower Miocene till present. In order to explain the status of the Pannonian plain as one of the morphostructural units of Serbia, the theoretical basics of morphostructures are discussed, as well as the principles of their spatial definition and the relation to the notion of a geological structure. [Projekat Ministarstva nauke Republike Srbije, br. 47007

Geomorphology, active tectonics, and landscape evolution in the Mid-Atlantic region: Chapter

Science.gov (United States)

Pazzaglia, Frank J.; Carter, Mark W.; Berti, Claudio; Counts, Ronald C.; Hancock, Gregory S.; Harbor, David; Harrison, Richard W.; Heller, Matthew J.; Mahan, Shannon; Malenda, Helen; McKeon, Ryan; Nelson, Michelle S.; Prince, Phillip; Rittenour, Tammy M.; Spotilla, James; Whittecar, G. Richard

2015-01-01

In 2014, the geomorphology community marked the 125th birthday of one of its most influential papers, “The Rivers and Valleys of Pennsylvania” by William Morris Davis. Inspired by Davis’s work, the Appalachian landscape rapidly became fertile ground for the development and testing of several grand landscape evolution paradigms, culminating with John Hack’s dynamic equilibrium in 1960. As part of the 2015 GSA Annual Meeting, the Geomorphology, Active Tectonics, and Landscape Evolution field trip offers an excellent venue for exploring Appalachian geomorphology through the lens of the Appalachian landscape, leveraging exciting research by a new generation of process-oriented geomorphologists and geologic field mapping. Important geomorphologic scholarship has recently used the Appalachian landscape as the testing ground for ideas on long- and short-term erosion, dynamic topography, glacial-isostatic adjustments, active tectonics in an intraplate setting, river incision, periglacial processes, and soil-saprolite formation. This field trip explores a geologic and geomorphic transect of the mid-Atlantic margin, starting in the Blue Ridge of Virginia and proceeding to the east across the Piedmont to the Coastal Plain. The emphasis here will not only be on the geomorphology, but also the underlying geology that establishes the template and foundation upon which surface processes have etched out the familiar Appalachian landscape. The first day focuses on new and published work that highlights Cenozoic sedimentary deposits, soils, paleosols, and geomorphic markers (terraces and knickpoints) that are being used to reconstruct a late Cenozoic history of erosion, deposition, climate change, and active tectonics. The second day is similarly devoted to new and published work documenting the fluvial geomorphic response to active tectonics in the Central Virginia seismic zone (CVSZ), site of the 2011 M 5.8 Mineral earthquake and the integrated record of Appalachian

A geomorphological approach to sustainable planning and management of the coastal zone of Kuwait

Science.gov (United States)

Al Bakri, Dhia

1996-10-01

The coastal zone in Kuwait has been under a considerable pressure from conflicting land uses since the early 1960s, as well as from the destruction and oil pollution caused by the Gulf War. To avoid further damage and to protect the coastal heritage it is essential to adopt an environmentally sustainable management process. This paper shows how the study of coastal geomorphology can provide a sound basis for sustainable planning and management. Based on coastal landforms, sediments and processes, the coastline of Kuwait was divided into nine geomorphic zones. These zones were grouped into two main geomorphic provinces. The northern province is marked by extensive muddy intertidal flats and dominated by a depositional and low-energy environment. The southern geomorphic province is characterised by relatively steep beach profiles, rocky/sandy tidal flats and a moderate to high-energy environment. The study has demonstrated that pollution, benthic ecology and other environmental conditions of the coast are a function of coastline geomorphology, sedimentology and related processes. The geomorphological information was used to determine the coastal vulnerability and to assess the environmental impacts of development projects and other human activities. Several strategies were outlined to integrate the geomorphic approach into the management of the coastal resources.

Geomorphic and sedimentary responses of the Bull Creek Valley (Southern High Plains, USA) to Pleistocene and Holocene environmental change

Science.gov (United States)

Arauza, Hanna M.; Simms, Alexander R.; Bement, Leland C.; Carter, Brian J.; Conley, Travis; Woldergauy, Ammanuel; Johnson, William C.; Jaiswal, Priyank

2016-01-01

Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.

Quaternary base-level drops and trigger mechanisms in a closed basin: Geomorphic and sedimentological studies of the Gastre Basin, Argentina

Science.gov (United States)

Bilmes, Andrés; Veiga, Gonzalo D.; Ariztegui, Daniel; Castelltort, Sébastien; D'Elia, Leandro; Franzese, Juan R.

2017-04-01

Evaluating the role of tectonics and climate as possible triggering mechanisms of landscape reconfigurations is essential for paleoenvironmental and paleoclimatic reconstructions. In this study an exceptional receptive closed Quaternary system of Patagonia (the Gastre Basin) is described, and examined in order to analyze factors triggering base-level drops. Based on a geomorphological approach, which includes new tectonic geomorphology investigations combined with sedimentological and stratigraphic analysis, three large-scale geomorphological systems were identified, described and linked to two major lake-level highstands preserved in the basin. The results indicate magnitudes of base-level drops that are several orders of magnitude greater than present-day water-level fluctuations, suggesting a triggering mechanism not observed in recent times. Direct observations indicating the occurrence of Quaternary faults were not recorded in the region. In addition, morphometric analyses that included mountain front sinuosity, valley width-height ratio, and fan apex position dismiss tectonic fault activity in the Gastre Basin during the middle Pleistocene-Holocene. Therefore, we suggest here that upper Pleistocene climate changes may have been the main triggering mechanism of base-level falls in the Gastre Basin as it is observed in other closed basins of central Patagonia (i.e., Carri Laufquen Basin).

Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska

Directory of Open Access Journals (Sweden)

Carlos Córdova

2009-06-01

Full Text Available The study of glacial landforms and deposits is important, as it isdifficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during Pleistocene times. This study investigates the genesis of little ice age glacial landforms present in Portage Glacier, South-Central Alaska. The present day moraine morphology and sedimentology in Portage Glacier valley reveals the presence of two types of till and moraines. The clast-rich sandy diamicton present on the 1852 moraine is interpreted to be a basal till indicating this feature is a pushmoraine representing an advance or a standstill position of Portage Glacier in 1852. The moderately sorted gray sandy boulder gravel present on the 1900 and 1922 moraines is interpreted to be an ice-marginal deposit (ablation till with a mixture of supraglacial and glaciofluvial sediments deposited by slumping and stream sortingprocesses. All of these features are interpreted to be ablation moraines representing glacier retreat and moraine building in 1900 and1922.

Geomorphological Fieldwork

Science.gov (United States)

Thornbush, Mary J; Allen, Casey D; Fitzpatrick, Faith A.

2014-01-01

Geomorphological Fieldwork addresses a topic that always remains popular within the geosciences and environmental science. More specifically, the volume conveys a growing legacy of field-based learning for young geomorphologists that can be used as a student book for field-based university courses and postgraduate research requiring fieldwork or field schools. The editors have much experience of field-based learning within geomorphology and extend this to physical geography. The topics covered are relevant to basic geomorphology as well as applied approaches in environmental and cultural geomorphology. The book integrates a physical-human approach to geography, but focuses on physical geography and geomorphology from an integrated field-based geoscience perspective.

Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks.

Science.gov (United States)

Rudi, Gabrielle; Bailly, Jean-Stéphane; Vinatier, Fabrice

2018-01-01

To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute

Some holocene geomorphological and sedimentological observations from Oman and their palaeogeological implications

Energy Technology Data Exchange (ETDEWEB)

Beydoun, Z R

1980-04-01

Observed exhumed Pleistocene river channel conglomerates now standing as ridges, and inland sabkha sedimentological structural phenomena from Oman, are discussed. Their significance as tools in the interpretation of similar palaeogeological environments is considered. Correlation with similar channel fills elsewhere in Arabia and Iran indicates aggradation as having occurred between 35,000 to 7000 y BP and suggests that this was principally by sustained flow during pluvial phases accompanying the last global glaciation, (at least in this part of the Middle East). Elevations of the now inverted channels above their deflated desert surroundings are used for calculating deflation rates, and reservoir porosity-permeability characteristics of similar ancient deposits are considered. Additional and new data on halite crust structures from the Umm-as-Samim inland sabkha are presented mainly in photographs backed by factural data which are commented upon; sabkha formation probably commenced about 4500 y BP. The preservation of similar origin halite deposits in the stratigraphic record is briefly discussed. This note is intended to augment data on desert environments that appear to have either had passing mention, or simply recording without assessment of their significance as tools or indicators in the interpretation of similar palaeogeological environments. It is the hope that the observations recorded here will stimulate further work on these and other Holocene phenomena in the region concerned and also elsewhere, together with dissemination of results, so that their implications to various aspects of applied geology can be better evaluated and understood. 9 figures.

Principles of lake sedimentology

International Nuclear Information System (INIS)

Janasson, L.

1983-01-01

This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

Yangon River Geomorphology Identification and its Enviromental Imapacts Analsysi by Optical and Radar Sensing Techniques

Science.gov (United States)

Lwin, A.; Khaing, M. M.

2012-07-01

The Yangon river, also known as the Rangoon river, is about 40 km long (25miles), and flows from southern Myanmar as an outlet of the Irrawaddy (Ayeyarwady) river into the Ayeyarwady delta. The Yangon river drains the Pegu Mountains; both the Yangon and the Pathein rivers enter the Ayeyarwady at the delta. Fluvial geomorphology is based primarily on rivers of manageable dimensions. The emphasis is on geomorphology, sedimentology of Yangon river and techniques for their identification and management. Present techniques such as remote sensing have made it easier to investigate and interpret in details analysis of river geomorphology. In this paper, attempt has been made the complicated issues of geomorphology, sedimentation patterns and management of river system and evolution studied. The analysis was carried out for the impact of land use/ land cover (LULC) changes on stream flow patterns. The hydrologic response to intense, flood producing rainfall events bears the signatures of the geomorphic structure of the channel network and of the characteristic slope lengths defining the drainage density of the basin. The interpretation of the hydrologic response as the travel time distribution of a water particle randomly injected in a distributed manner across the landscape inspired many geomorphic insights. In 2008, Cyclone Nargis was seriously damaged to mangrove area and its biodiversity system in and around of Yangon river terraces. A combination of digital image processing techniques was employed for enhancement and classification process. It is observed from the study that middle infra red band (0.77mm - 0.86mm) is highly suitable for mapping mangroves. Two major classes of mangroves, dense and open mangroves were delineated from the digital data.

Geomorphology of Afekan Crater, Titan: Terrain Relationships in Titan’s Blandlands

Science.gov (United States)

Malaska, Michael; Shoenfeld, Ashley M.; Lopes, Rosaly M.; Hayes, Alex G.; Le Gall, Alice; Birch, Sam; Solomonidou, Anezina; Neish, Catherine D.; Soderblom, Jason M.; Farr, Thomas G.

2014-11-01

The enigmatic mid-latitude undifferentiated plains of Saturn’s moon Titan cover an estimated 29% of the surface of that world, making them one of the most important terrain units. Nicknamed “blandlands”, they appear nearly featureless to the Cassini spacecraft’s Visual and Infrared Mapping Spectrometer (VIMS), Imaging Science Subsystems (ISS) and Synthetic Aperture Radar (SAR) imaging. The possible origins and identity of the vast undifferentiated plains have ranged from thick organic photochemical deposits to cryovolcanic flood deposits of aqueous materials. To help constrain these possibilities, we selected the region around Afekan Crater for detailed geomorphological mapping. We defined and determined terrain units in ArcGIS primarily using SAR images and used the resulting contact and embayment relationships to determine a preliminary stratigraphy between the previously known units and the undifferentiated plains.We find that although the plains are relatively featureless, they are not flat - some topographic variation is observed. Our work suggests Titan’s dunes embay the undifferentiated plains. This is consistent with dunes actively invading and depositing in the topographically low regions of the undifferentiated plains. Correlation of our defined undifferentiated plains regions with radiometric data is not consistent with large exposures of putative water-based cryovolcanic outflows, but is consistent with dune materials. The infrared reflectance obtained by Cassini VIMS and ISS show distinctive albedo differences between the dunes and undifferentiated plains materials. Combined, these results provide support that the undifferentiated plains are composed of organic materials, but that they are distinct from unmodified dune materials. Undifferentiated plains are found partially filling the interior of Afekan Crater, as well as in the presumed wind shadow of Afekan Crater, implying that plains material deposition happened after Afekan Crater was

Inlet Geomorphology Evolution

Science.gov (United States)

2015-04-01

APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Inlet Geomorphology Evolution 5a. CONTRACT NUMBER 5b...Std Z39-18 Coastal Inlets Research Program Inlet Geomorphology Evolution The Inlet Geomorphology Evolution work unit of the CIRP evaluates

Sedimentology and geomorphology analysis of coastal area along pantai penarik, terengganu before and during northeast monsoon season

Science.gov (United States)

Yusoff, Tengku Ahmad Imran Ku; Shaufi Sokiman, Mohamad

2017-10-01

This research is conducted to understand the sedimentology and morphological change before and during the northeast monsoon at the east coast of peninsular Malaysia. The increase in wind speed, wave energy and rainfall during the northeast monsoon are believed to causes the coastal erosion to increase during the season. Rapid development along the east coast area might disrupt the sediments distribution which can increase the coastal erosion rate every year. The understanding on the sediments distribution, erosion and deposition as well as the morphological change can help to figure out if the coastal erosion can affect the infrastructure in the future. The result of the study can show the necessity to perform mitigation or any required action toward the problem that might happen

Tectonic Geomorphology.

Science.gov (United States)

Bull, William B.

1984-01-01

Summarizes representative quantitative tectonic-geomorphology studies made during the last century, focusing on fault-bounded mountain-front escarpments, marine terraces, and alluvial geomorphic surfaces (considering stream terraces, piedmont fault scarps, and soils chronosequences). Also suggests where tectonic-geomorphology courses may best fit…

Coastal plain soils and geomorphology: a key to understanding forest hydrology

Science.gov (United States)

Thomas M. Williams; Devendra M. Amatya

2016-01-01

In the 1950s, Coile published a simple classification of southeastern coastal soils using three characteristics: drainage class, sub-soil depth, and sub-soil texture. These ideas were used by Warren Stuck and Bill Smith to produce a matrix of soils with drainage class as one ordinate and subsoil texture as the second for the South Carolina coastal plain. Soils...

New achievements in sedimentology and lithofacies-paleogeography at present. Sidelights on the fourth national sedimentology and lithofacies-paleogeography academic conference

International Nuclear Information System (INIS)

Chen Daisheng

1996-01-01

This paper summarizes the current new trends and new achievements in sedimentology and lithofacies-paleogeography. They include such aspects as sequence stratigraphy, quantitative lithofacies-paleogeography, sedimentary petrology, lithofacies-paleogeography, resource prognosis, research methods and testing approaches, recent sediment investigation and modern sedimentology frontiers

Geomorphology and habitat diversity in the Pantanal.

Science.gov (United States)

Mercante, M A; Rodrigues, S C; Ross, J L S

2011-04-01

The present study deals with the inter-relations in the relief which forms the Bacia do Alto Rio Paraguay (BAP) in mid-west Brazil. The overall aim is to discuss the relationship between relief forms and the biodiversity of the Pantanal. The BAP is a natural environmental system with contrasts in two of the compartments on which it is formed: the plateau, the most elevated compartment, highly transformed by human activities, and the plain which forms the Pantanal, which is more preserved and less transformed in relation to productive activities. The analysis was performed based on publications with a geomorphologic focus, examining the different relief units of the BAP and the dynamics of the revealing processes of landscape change which the Pantanal has undergone since the end of the Pleistocene.

Taphonomic and sedimentological aspects from PICOS II paleontological site, a quaternary pond deposit of Alagoas, Brazil

Science.gov (United States)

Asakura, Yumi; Silva, Jorge Luiz Lopes da; Silva, Ana Paula Lopes da; Silva, Elaine Pollyanne Alves da; Omena, Érica Cavalcante

2016-11-01

The Picos II Paleontological Site (PIIPS), located in the city of Piranhas, in Alagoas State, is a fossil deposit with a pond-like geomorphological feature, a kind of peculiar deposit for the Quaternary of Northeast Brazil. A detailed taphonomic study is presented about the PIIPS assemblage, from material collection to the laboratory analysis. The conservation state of the collected fossils in PIIPS is different from that found in other tank deposits, showing a high degree of specimen preservation. Two taxa of pleistocenic mammals have been identified: Eremotherium laurillardi and Notiomastodon platensis, and fragments of an avian bone, whose taxonomic identification was not possible. The taphonomic analysis indicates that the deposited material experienced a short transportation in high-energy event, with a short period of subaerial exposure before the final burial, where at least the final disarticulation occurred in situ, which explains the high conservation level of the material. The sedimentological analysis made in each layer of the deposit corroborates the information related to the transport of the material, which were obtained in taphonomic analysis. Regarding these aspects, PIIPS reflects nearly non-biased biocenotic patterns. The well-preserved material found in PIIPS demonstrates the great potential of deposits with pond-like geomorphological features, with sidelines that are less steep than traditional tanks, providing smoother transport and accommodation for skeletal elements, which is a distinguishing factor in preserving fossils of vertebrates.

Inlet Geomorphology Evolution Work Unit

Science.gov (United States)

2015-10-30

Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...morphologic response. Presently, the primary tool of the Inlet Geomorphology Evolution work unit is the Sediment Mobility Tool (SMT), which allows the user

Geomorphology and seismic risk

Science.gov (United States)

Panizza, Mario

1991-07-01

The author analyses the contributions provided by geomorphology in studies suited to the assessment of seismic risk: this is defined as function of the seismic hazard, of the seismic susceptibility, and of the vulnerability. The geomorphological studies applicable to seismic risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce seismic susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition seismic susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.

Current trends in geomorphological mapping

Science.gov (United States)

Seijmonsbergen, A. C.

2012-04-01

Geomorphological mapping is a world currently in motion, driven by technological advances and the availability of new high resolution data. As a consequence, classic (paper) geomorphological maps which were the standard for more than 50 years are rapidly being replaced by digital geomorphological information layers. This is witnessed by the following developments: 1. the conversion of classic paper maps into digital information layers, mainly performed in a digital mapping environment such as a Geographical Information System, 2. updating the location precision and the content of the converted maps, by adding more geomorphological details, taken from high resolution elevation data and/or high resolution image data, 3. (semi) automated extraction and classification of geomorphological features from digital elevation models, broadly separated into unsupervised and supervised classification techniques and 4. New digital visualization / cartographic techniques and reading interfaces. Newly digital geomorphological information layers can be based on manual digitization of polygons using DEMs and/or aerial photographs, or prepared through (semi) automated extraction and delineation of geomorphological features. DEMs are often used as basis to derive Land Surface Parameter information which is used as input for (un) supervised classification techniques. Especially when using high-res data, object-based classification is used as an alternative to traditional pixel-based classifications, to cluster grid cells into homogeneous objects, which can be classified as geomorphological features. Classic map content can also be used as training material for the supervised classification of geomorphological features. In the classification process, rule-based protocols, including expert-knowledge input, are used to map specific geomorphological features or entire landscapes. Current (semi) automated classification techniques are increasingly able to extract morphometric, hydrological

Geomorphological and sedimentary processes of the glacially influenced northwestern Iberian continental margin and abyssal plains

Science.gov (United States)

Llave, Estefanía; Jané, Gloria; Maestro, Adolfo; López-Martínez, Jerónimo; Hernández-Molina, F. Javier; Mink, Sandra

2018-07-01

The offshore region of northwestern Iberia offers an opportunity to study the impacts of along-slope processes on the morphology of a glacially influenced continental margin, which has traditionally been conceptually characterised by predominant down-slope sedimentary processes. High-resolution multibeam bathymetry, acoustic backscatter and ultrahigh-resolution seismic reflection profile data are integrated and analysed to describe the present-day and recent geomorphological features and to interpret their associated sedimentary processes. Seventeen large-scale seafloor morphologies and sixteen individual echo types, interpreted as structural features (escarpments, marginal platforms and related fluid escape structures) and depositional and erosional bedforms developed either by the influence of bottom currents (moats, abraded surfaces, sediment waves, contourite drifts and ridges) or by gravitational features (gullies, canyons, slides, channel-levee complexes and submarine fans), are identified for the first time in the study area (spanning 90,000 km2 and water depths of 300 m to 5 km). Different types of slope failures and turbidity currents are mainly observed on the upper and lower slopes and along submarine canyons and deep-sea channels. The middle slope morphologies are mostly determined by the actions of bottom currents (North Atlantic Central Water, Mediterranean Outflow Water, Labrador Sea Water and North Atlantic Deep Water), which thereby define the margin morphologies and favour the reworking and deposition of sediments. The abyssal plains (Biscay and Iberian) are characterised by pelagic deposits and channel-lobe systems (the Cantabrian and Charcot), although several contourite features are also observed at the foot of the slope due to the influence of the deepest water masses (i.e., the North Atlantic Deep Water and Lower Deep Water). This work shows that the study area is the result of Mesozoic to present-day tectonics (e.g. the marginal platforms

Hydrology, geomorphology, and vegetation of Coastal Plain rivers in the southeastern United States

Science.gov (United States)

Cliff R. Hupp

2000-01-01

Rivers of the Coastal Plain of the southeastern United States are characteristically low-gradient meandering systems that develop broad floodplains subjected to frequent and prolonged flooding. These floodplains support a relatively unique forested wetland (Bottomland Hardwoods), which have received considerable ecological study, but distinctly less hydrogeomorphic...

Smart "geomorphological" map browsing - a tale about geomorphological maps and the internet

Science.gov (United States)

Geilhausen, M.; Otto, J.-C.

2012-04-01

With the digital production of geomorphological maps, the dissemination of research outputs now extends beyond simple paper products. Internet technologies can contribute to both, the dissemination of geomorphological maps and access to geomorphologic data and help to make geomorphological knowledge available to a greater public. Indeed, many national geological surveys employ end-to-end digital workflows from data capture in the field to final map production and dissemination. This paper deals with the potential of web mapping applications and interactive, portable georeferenced PDF maps for the distribution of geomorphological information. Web mapping applications such as Google Maps have become very popular and widespread and increased the interest and access to mapping. They link the Internet with GIS technology and are a common way of presenting dynamic maps online. The GIS processing is performed online and maps are visualised in interactive web viewers characterised by different capabilities such as zooming, panning or adding further thematic layers, with the map refreshed after each task. Depending on the system architecture and the components used, advanced symbology, map overlays from different applications and sources and their integration into a Desktop GIS are possible. This interoperability is achieved through the use of international open standards that include mechanisms for the integration and visualisation of information from multiple sources. The portable document format (PDF) is commonly used for printing and is a standard format that can be processed by many graphic software and printers without loss of information. A GeoPDF enables the sharing of geospatial maps and data in PDF documents. Multiple, independent map frames with individual spatial reference systems are possible within a GeoPDF, for example, for map overlays or insets. Geospatial functionality of a GeoPDF includes scalable map display, layer visibility control, access to attribute

Lacustrine-fluvial interactions in Australia's Riverine Plains

Science.gov (United States)

Kemp, Justine; Pietsch, Timothy; Gontz, Allen; Olley, Jon

2017-06-01

Climatic forcing of fluvial systems has been a pre-occupation of geomorphological studies in Australia since the 1940s. In the Riverine Plain, southeastern Australia, the stable tectonic setting and absence of glaciation have combined to produce sediment loads that are amongst the lowest in the world. Surficial sediments and landforms exceed 140,000 yr in age, and geomorphological change recorded in the fluvial, fluvio-lacustrine and aeolian features have provided a well-studied record of Quaternary environmental change over the last glacial cycle. The region includes the Willandra Lakes, whose distinctive lunette lakes preserve a history of water-level variations and ecological change that is the cornerstone of Australian Quaternary chronostratigraphy. The lunette sediments also contain an ancient record of human occupation that includes the earliest human fossils yet found on the Australian continent. To date, the lake-level and palaeochannel records in the Lachlan-Willandra system have not been fully integrated, making it difficult to establish the regional significance of hydrological change. Here, we compare the Willandra Lakes environmental record with the morphology and location of fluvial systems in the lower Lachlan. An ancient channel belt of the Lachlan, Willandra Creek, acted as the main feeder channel to Willandra Lakes before channel avulsion caused the lakes to dry out in the late Pleistocene. Electromagnetic surveys, geomorphological and sedimentary evidence are used to reconstruct the evolution of the first new channel belt following the avulsion. Single grain optical dating of floodplain sediments indicates that sedimentation in the new Middle Billabong Palaeochannel had commenced before 18.4 ± 1.1 ka. A second avulsion shifted its upper reaches to the location of the present Lachlan River by 16.2 ± 0.9 ka. The timing of these events is consistent with palaeohydrological records reconstructed from Willandra Lakes and with the record of

Sedimentology and marine geology of the Banda Arc, Eastern Indonesia

NARCIS (Netherlands)

Situmorang, M.

1992-01-01

The aim of this study is to analyze and to relate several aspects of the sedimentological, petrological and geotechnical characteristics of the Quaternary sea floor lithofacies deposited in tectonically active basins in the Banda Sea region. The combined sedimentological, petrological, and

Geomorphology subprogram: Geomorphological map of Occidental region of Bolivia, utilizing ERTS imagery

Science.gov (United States)

Brockmann, C. E. (Principal Investigator); Suarez, M. M.

1973-01-01

The author has identified the following significant results. Due to the receipt of ERTS-1 imagery, Bolivia will have for the first time a geomorphological map at a scale of 1:100,000. Now the researcher and the student will be able to compare the distribution of the existing shapes of the country, which have been modelled by diverse processes, factors, and agents. This geomorphological information will be very useful in its application to mining, especially alluvial beds, engineering work, and other geological studies. This map is divided into ten geomorphological units which coincide with the geostructural units of the western region of the country.

Sedimentology and marine geology of the Banda Arc, Eastern Indonesia

NARCIS (Netherlands)

Situmorang, M

1992-01-01

The aim of this study is to analyze and to relate several aspects of the sedimentological, petrological and geotechnical characteristics of the Quaternary sea floor lithofacies deposited in tectonically active basins in the Banda Sea region. The combined sedimentological, petrological, and faunal

Curriculum Development in Geomorphology.

Science.gov (United States)

Gregory, Kenneth J.

1988-01-01

Examines the context of present curriculum development in geomorphology and the way in which it has developed in recent years. Discusses the content of the geomorphology curriculum in higher education and the consequences of curriculum development together with a consideration of future trends and their implications. (GEA)

Hydrological and Climatic Significance of Martian Deltas

Science.gov (United States)

Di Achille, G.; Vaz, D. A.

2017-10-01

We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

Geomorphological hazards and environmental impact: Assessment and mapping

Science.gov (United States)

Panizza, Mario

In five sections the author develops the methods for the integration of geomorphological concepts into Environmental Impact and Mapping. The first section introduces the concepts of Impact and Risk through the relationships between Geomorphological Environment and Anthropical Element. The second section proposes a methodology for the determination of Geomorphological Hazard and the identification of Geomorphological Risk. The third section synthesizes the procedure for the compilation of a Geomorphological Hazards Map. The fourth section outlines the concepts of Geomorphological Resource Assessment for the analysis of the Environmental Impact. The fifth section considers the contribution of geomorphological studies and mapping in the procedure for Environmental Impact Assessment.

Geology and geomorphology of the Carolina Sandhills, Chesterfield County, South Carolina

Science.gov (United States)

Swezey, Christopher; Fitzwater, Bradley A.; Whittecar, G. Richard

2016-01-01

This two-day field trip focuses on the geology and geomorphology of the Carolina Sandhills in Chesterfield County, South Carolina. This area is located in the updip portion of the U.S. Atlantic Coastal Plain province, supports an ecosystem of longleaf pine (Pinus palustris) and wiregrass (Aristida stricta), and contains three major geologic map units: (1) An ~60–120-m-thick unit of weakly consolidated sand, sandstone, mud, and gravel is mapped as the Upper Cretaceous Middendorf Formation and is interpreted as a fluvial deposit. This unit is capped by an unconformity, and displays reticulate mottling, plinthite, and other paleosol features at the unconformity. The Middendorf Formation is the largest aquifer in South Carolina. (2) A 0.3–10-m-thick unit of unconsolidated sand is mapped as the Quaternary Pinehurst Formation and is interpreted as deposits of eolian sand sheets and dunes derived via remobilization of sand from the underlying Cretaceous strata. This unit displays argillic horizons and abundant evidence of bioturbation by vegetation. (3) A geomorphologic feature in the study area is a north-trending escarpment (incised by headwater streams) that forms a markedly asymmetric drainage divide. This drainage divide, as well as the Quaternary terraces deposits, are interpreted as evidence of landscape disequilibrium (possibly geomorphic responses to Quaternary climate changes).

Forensic geoscience: applications of geology, geomorphology and geophysics to criminal investigations

Science.gov (United States)

Ruffell, Alastair; McKinley, Jennifer

2005-03-01

One hundred years ago Georg Popp became the first scientist to present in court a case where the geological makeup of soils was used to secure a criminal conviction. Subsequently there have been significant advances in the theory and practice of forensic geoscience: many of them subsequent to the seminal publication of "Forensic Geology" by Murray and Tedrow [Murray, R., Tedrow, J.C.F. 1975 (republished 1986). Forensic Geology: Earth Sciences and Criminal Investigation. Rutgers University Press, New York, 240 pp.]. Our review places historical development in the modern context of how the allied disciplines of geology (mineralogy, sedimentology, microscopy), geophysics, soil science, microbiology, anthropology and geomorphology have been used as tool to aid forensic (domestic, serious, terrorist and international) crime investigations. The latter half of this paper uses the concept of scales of investigation, from large-scale landforms through to microscopic particles as a method of categorising the large number of geoscience applications to criminal investigation. Forensic geoscience has traditionally used established non-forensic techniques: 100 years after Popp's seminal work, research into forensic geoscience is beginning to lead, as opposed to follow other scientific disciplines.

Geomorphology

Science.gov (United States)

1982-01-01

The study of geomorphology and terrain analysis using TM and MSS data are discussed. The spatial and spectral characteristics of a variety of landforms are also investigated. An outline of possible experiments and a summary of data requirements are included.

Advances in global mountain geomorphology

Science.gov (United States)

Slaymaker, Olav; Embleton-Hamann, Christine

2018-05-01

Three themes in global mountain geomorphology have been defined and reinforced over the past decade: (a) new ways of measuring, sensing, and analyzing mountain morphology; (b) a new emphasis on disconnectivity in mountain geomorphology; and (c) the emergence of concerns about the increasing influence of anthropogenic disturbance of the mountain geomorphic environment, especially in intertropical mountains where population densities are higher than in any other mountain region. Anthropogenically induced hydroclimate change increases geomorphic hazards and risks but also provides new opportunities for mountain landscape enhancement. Each theme is considered with respect to the distinctiveness of mountain geomorphology and in relation to important advances in research over the past decade. The traditional reliance on the high energy condition to define mountain geomorphology seems less important than the presence of unique mountain landforms and landscapes and the distinctive ways in which human activity and anthropogenically induced hydroclimate change are transforming mountain landscapes.

Geomorphology: A Canadian Perspective

Science.gov (United States)

Pizzuto, Jim

Geomorphology is a hot discipline. Recent interest in river restoration, climate change, geomorphic hazards such as landslides and tsunamis, controlled floods, and other issues has increased the visibility of geomorphology as a profession. New methods involving the Global Positioning System, remote sensing, numerical simulation, laboratory experimentation, and novel dating techniques have created new research opportunities. The number of jobs in academia, industry, and the public sector is rising. What is the best way to convey this excitement to students, while at the same time properly training them? The traditional approach is an introductory course at the undergraduate level, built around a general textbook. When I teach geomorphology, I do not use a textbook but rather rely on original readings and field-based exercises to introduce students to geomorphic concepts and methods.

Radioactive tracers in Sedimentology

International Nuclear Information System (INIS)

Rodrigues, H.T.

1973-01-01

First is given a broad description of the uses of radioactive tracers in Sedimentology. The general method is established, including determinations of probability and standard deviation. Following are determined: the response law of the detector, the minimum mass for statistical detection, and the minimum mass for dynamic detection. The granularity is an important variable in these calculations. Final conclusions are given, and results are compared with existing theories

The role of geomorphology in environmental impact assessment

Science.gov (United States)

Cavallin, A.; Marchetti, M.; Panizza, M.; Soldati, M.

1994-04-01

This paper aims to define the role of Geomorphology in the assessment of the impact of human activities on the environment. Environmental impact assessment (EIA) should be carried out for specific projects, in order to evaluate their suitability for the quality of the environment. In fact, each planned activity may have an impact on various environmental components. Among these, the natural component must be examined in terms of geomorphological hazards, which may endanger a project, and of geomorphological assets (elements forming the educational and cultural heritage of the landscape), which may be damaged to various extents by human activities. The relationships between humans and environment are taken into account, with particular attention to the effects of a project on the geomorphological environment. From a geomorphological point of view, after having assessed the suitability of a certain location, mainly with respect to its morphography and morphometry, the geomorphological hazards of the area which may threaten the project (risk) must be considered; then the geomorphological assets, which may be damaged by the same project (direct impact) have to be individuated. Human activities may produce two other kinds of effect: the first refers to the consequences of the geomorphological hazards induced by a project on the project itself (direct risk) and on the surronding areas (indirect risk); the second takes into account the potential deterioration of a geomorphological asset due to hazards induced by the project (indirect impact). Examples of these different cases are presented.

Tundra landform and vegetation productivity trend maps for the Arctic Coastal Plain of northern Alaska

Science.gov (United States)

Lara, Mark J.; Nitze, Ingmar; Grosse, Guido; McGuire, A. David

2018-01-01

Arctic tundra landscapes are composed of a complex mosaic of patterned ground features, varying in soil moisture, vegetation composition, and surface hydrology over small spatial scales (10–100 m). The importance of microtopography and associated geomorphic landforms in influencing ecosystem structure and function is well founded, however, spatial data products describing local to regional scale distribution of patterned ground or polygonal tundra geomorphology are largely unavailable. Thus, our understanding of local impacts on regional scale processes (e.g., carbon dynamics) may be limited. We produced two key spatiotemporal datasets spanning the Arctic Coastal Plain of northern Alaska (~60,000 km2) to evaluate climate-geomorphological controls on arctic tundra productivity change, using (1) a novel 30 m classification of polygonal tundra geomorphology and (2) decadal-trends in surface greenness using the Landsat archive (1999–2014). These datasets can be easily integrated and adapted in an array of local to regional applications such as (1) upscaling plot-level measurements (e.g., carbon/energy fluxes), (2) mapping of soils, vegetation, or permafrost, and/or (3) initializing ecosystem biogeochemistry, hydrology, and/or habitat modeling.

Biostratigraphy, sedimentology and paleoenvironments of the northern Danube Basin: Ratkovce 1 well case study

Directory of Open Access Journals (Sweden)

Rybár Samuel

2015-02-01

Full Text Available The Ratkovce 1 well, drilled in the Blatné depocenter of the northern Danube Basin penetrated the Miocene sedimentary record with a total thickness of 2000 m. Biostratigraphically, the NN4, NN5 and NN6 Zones of calcareous nannoplankton were documented; CPN7 and CPN8 foraminifer Zones (N9, 10, 11 of the global foraminiferal zonation; and MMi4a; MMi5 and MMi6 of the Mediterranean foraminiferal zonation were recognized. Sedimentology was based on description of well core material, and together with SP and RT logs, used to characterize paleoenvironmental conditions of the deposition. Five sedimentary facies were reconstructed: (1 fan-delta to onshore environment which developed during the Lower Badenian; (2 followed by the Lower Badenian proximal slope gravity currents sediments; (3 distal slope turbidites were deposited in the Lower and Upper Badenian; (4 at the very end of the Upper Badenian and during the Sarmatian a coastal plain of normal marine to brackish environment developed; (5 sedimentation finished with the Pannonian-Pliocene shallow lacustrine to alluvial plain deposits. The provenance analysis records that the sediment of the well-cores was derived from crystalline basement granitoides and gneisses and from the Permian to Lower Cretaceous sedimentary cover and nappe units of the Western Carpathians and the Eastern Alps. Moreover, the Lower Badenian volcanism was an important source of sediments in the lower part of the sequence.

Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden

Science.gov (United States)

Gustavsson, Marcus; Seijmonsbergen, Arie C.; Kolstrup, Else

2008-03-01

This paper presents the structure and contents of a standardised geomorphological GIS database that stores comprehensive scientific geomorphological data and constitutes the basis for processing and extracting spatial thematic data. The geodatabase contains spatial information on morphography/morphometry, hydrography, lithology, genesis, processes and age. A unique characteristic of the GIS geodatabase is that it is constructed in parallel with a new comprehensive geomorphological mapping system designed with GIS applications in mind. This close coupling enables easy digitalisation of the information from the geomorphological map into the GIS database for use in both scientific and practical applications. The selected platform, in which the geomorphological vector, raster and tabular data are stored, is the ESRI Personal geodatabase. Additional data such as an image of the original geomorphological map, DEMs or aerial orthographic images are also included in the database. The structure of the geomorphological database presented in this paper is exemplified for a study site around Liden, central Sweden.

Geomorphology, tectonics, and exploration

Science.gov (United States)

Sabins, F. F., Jr.

1985-01-01

Explorationists interpret satellite images for tectonic features and patterns that may be clues to mineral and energy deposits. The tectonic features of interest range in scale from regional (sedimentary basins, fold belts) to local (faults, fractures) and are generally expressed as geomorphic features in remote sensing images. Explorationists typically employ classic concepts of geomorphology and landform analysis for their interpretations, which leads to the question - Are there new and evolving concepts in geomorphology that may be applicable to tectonic analyses of images?

Investigating palaeo-subglacial lakes in the central Barents Sea

Science.gov (United States)

Esteves, M.; Shackleton, C.; Winsborrow, M.; Andreassen, K.; Bjarnadóttir, L. R.

2017-12-01

In the past decade hundreds of subglacial lakes have been detected beneath the Antarctic Ice Sheet, and several more beneath the Greenland Ice Sheet. These are important components of the subglacial hydrological system and can influence basal shear stress, with implications for ice sheet dynamics and mass balance, potentially on rapid timescales. Improvements in our understanding of subglacial hydrological systems are therefore important, but challenging due to the inaccessibility of contemporary subglacial environments. Whilst the beds of palaeo-ice sheets are easier to access, few palaeo-subglacial lakes have been identified due to uncertainties in the sedimentological and geomorphological diagnostic criteria. In this study we address these uncertainties, using a suite of sedimentological, geomorphological and modelling approaches to investigate sites of potential palaeo-subglacial lakes in the central Barents Sea. Geomorphological signatures of hydraulic activity in the area include large meltwater channels, tunnel valleys, and several interlinked basins. Modelling efforts indicate the potential for subglacial hydraulic sinks within the area during the early stages of ice retreat since the Last Glacial Maximum. In support of this, sedimentological observations indicate the presence of a dynamic glaciolacustrine depositional environment. Using the combined results of the modelling, geomorphology, and sedimentological analyses, we conclude that palaeo-subglacial lakes are likely to have formed on the northwestern banks of Thor Iversenbanken, central Barents Sea, and suggest that numerous other subglacial lakes may have been present beneath the Barents Sea Ice Sheet. Furthermore, we investigate and refine the existing diagnostic criteria for the identification of palaeo-subglacial lakes.

Blueprint for a coupled model of sedimentology, hydrology, and hydrogeology in streambeds

Science.gov (United States)

Partington, Daniel; Therrien, Rene; Simmons, Craig T.; Brunner, Philip

2017-06-01

The streambed constitutes the physical interface between the surface and the subsurface of a stream. Across all spatial scales, the physical properties of the streambed control surface water-groundwater interactions. Continuous alteration of streambed properties such as topography or hydraulic conductivity occurs through erosion and sedimentation processes. Recent studies from the fields of ecology, hydrogeology, and sedimentology provide field evidence that sedimentological processes themselves can be heavily influenced by surface water-groundwater interactions, giving rise to complex feedback mechanisms between sedimentology, hydrology, and hydrogeology. More explicitly, surface water-groundwater exchanges play a significant role in the deposition of fine sediments, which in turn modify the hydraulic properties of the streambed. We explore these feedback mechanisms and critically review the extent of current interaction between the different disciplines. We identify opportunities to improve current modeling practices. For example, hydrogeological models treat the streambed as a static rather than a dynamic entity, while sedimentological models do not account for critical catchment processes such as surface water-groundwater exchange. We propose a blueprint for a new modeling framework that bridges the conceptual gaps between sedimentology, hydrogeology, and hydrology. Specifically, this blueprint (1) fully integrates surface-subsurface flows with erosion, transport, and deposition of sediments and (2) accounts for the dynamic changes in surface elevation and hydraulic conductivity of the streambed. Finally, we discuss the opportunities for new research within the coupled framework.

Environmental changes in the central Po Plain (northern Italy) due to fluvial modifications and anthropogenic activities

Science.gov (United States)

Marchetti, Mauro

2002-05-01

The fluvial environment of the central Po Plain, the largest plain in Italy, is discussed in this paper. Bounded by the mountain chains of the Alps and the Apennines, this plain is a link between the Mediterranean environment and the cultural and continental influences of both western and eastern Europe. In the past decades, economic development has been responsible for many changes in the fluvial environment of the area. This paper discusses the changes in fluvial dynamics that started from Late Pleistocene and Early Holocene due to distinct climatic changes. The discussion is based on geomorphological, pedological, and archaeological evidences and radiocarbon dating. In the northern foothills, Late Pleistocene palaeochannels indicate several cases of underfit streams among the northern tributaries of the River Po. On the other hand, on the southern side of the Po Plain, no geomorphological evidence of similar discharge reduction has been found. Here, stratigraphic sections, together with archaeological remains buried under the fluvial deposits, show a reduction in the size of fluvial sediments after the 10th millennium BC. During the Holocene, fluvial sedimentation became finer, and was characterised by minor fluctuations in the rate of deposition, probably related to short and less intense climatic fluctuations. Given the high rate of population growth and the development of human activities since the Neolithic Age, human influence on fluvial dynamics, especially since the Roman Age, prevailed over other factors (i.e., climate, tectonics, vegetation, etc.). During the Holocene, the most important changes in the Po Plain were not modifications in water discharge but in sediment. From the 1st to 3rd Century AD, land grants to war veterans caused almost complete deforestation, generalised soil erosion, and maximum progradation of the River Po delta. At present, land abandonment in the mountainous region has led to reafforestation. Artificial channel control in the

Planetary Geomorphology.

Science.gov (United States)

Baker, Victor R.

1984-01-01

Discusses various topics related to planetary geomorphology, including: research techniques; such geomorphic processes as impact, volcanic, degradational, eolian, and hillslope/mass movement processes; and channels and valleys. Indicates that the subject should be taught as a series of scientific questions rather than scientific results of…

MULTI-DECADAL FLUVIO-GEOMORPHOLOGICAL AND BANKLINE CHANGES OF THE GANGA RIVER AROUND BALLIA AND RUDRAPUR USING REMOTE SENSING AND GIS TECHNIQUES

Directory of Open Access Journals (Sweden)

A. J. Desai

2012-09-01

Full Text Available Fluvial landforms are developed due to river action and these processes help in understanding the development of various landforms on the earth's surface. Gangetic plain is vast alluvial tract made up of sand, silt and clay. This region receives heavy rainfall causing flash floods which results in bank-line shifting as well as various fluvio-geomorphological changes. Fluvial processes such as erosion and deposition not only play an important role in shaping of different fluvial landscapes but also contribute towards the braiding and meandering pattern which causes change in the flow pattern of the river channel. Transportation and deposition of the suspended load also contributes towards such changes. The present work describes various fluvio-geomorphological features and their changes during different time intervals in and around Ballia and Rudrapur. The paper also deals in understanding the problems like bank-line shifting, erosion and deposition caused by the continuous change in the fluvial patterns, bank erosion and sedimentation in this region over past 8 decades.

Periglacial Geomorphology.

Science.gov (United States)

Potter, Noel, Jr.

1984-01-01

Describes preglacial processes, focusing on weathering, rate and timing of movement of material, snow and snow avalanches, rock glaciers, gelifluction, pingos, patterned ground, and the thaw of permafrost. This information is provided for individuals teaching introductory geology/geomorphology and whose specialty is not cold-climate phenomena. (JN)

Geomorphology of Minnesota

Data.gov (United States)

Minnesota Department of Natural Resources — 1:100,000 scale geomorphology data describing a wide variety of conditions related to surficial geology within a hierarchical classification scheme that was devised...

Object-based classification of global undersea topography and geomorphological features from the SRTM30_PLUS data

Science.gov (United States)

Dekavalla, Maria; Argialas, Demetre

2017-07-01

The analysis of undersea topography and geomorphological features provides necessary information to related disciplines and many applications. The development of an automated knowledge-based classification approach of undersea topography and geomorphological features is challenging due to their multi-scale nature. The aim of the study is to develop and evaluate an automated knowledge-based OBIA approach to: i) decompose the global undersea topography to multi-scale regions of distinct morphometric properties, and ii) assign the derived regions to characteristic geomorphological features. First, the global undersea topography was decomposed through the SRTM30_PLUS bathymetry data to the so-called morphometric objects of discrete morphometric properties and spatial scales defined by data-driven methods (local variance graphs and nested means) and multi-scale analysis. The derived morphometric objects were combined with additional relative topographic position information computed with a self-adaptive pattern recognition method (geomorphons), and auxiliary data and were assigned to characteristic undersea geomorphological feature classes through a knowledge base, developed from standard definitions. The decomposition of the SRTM30_PLUS data to morphometric objects was considered successful for the requirements of maximizing intra-object and inter-object heterogeneity, based on the near zero values of the Moran's I and the low values of the weighted variance index. The knowledge-based classification approach was tested for its transferability in six case studies of various tectonic settings and achieved the efficient extraction of 11 undersea geomorphological feature classes. The classification results for the six case studies were compared with the digital global seafloor geomorphic features map (GSFM). The 11 undersea feature classes and their producer's accuracies in respect to the GSFM relevant areas were Basin (95%), Continental Shelf (94.9%), Trough (88

Regional controls on geomorphology, hydrology, and ecosystem integrity in the Orinoco Delta, Venezuela

Science.gov (United States)

Warne, A.G.; Meade, R.H.; White, W.A.; Guevara, E.H.; Gibeaut, J.; Smyth, R.C.; Aslan, A.; Tremblay, T.

2002-01-01

Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km2 Orinoco delta plain support diverse fresh and brackish water ecosystems. To develop environmental baseline information for this largely unpopulated region, we evaluate major coastal plain, shallow marine, and river systems of northeastern South America, which serves to identify principal sources and controls of water and sediment flow into, through, and out of the Orinoco Delta. The regional analysis includes a summary of the geology, hydrodynamics, sediment dynamics, and geomorphic characteristics of the Orinoco drainage basin, river, and delta system. Because the Amazon River is a major source of sediment deposited along the Orinoco coast, we summarize Amazon water and sediment input to the northeastern South American littoral zone. We investigate sediment dynamics and geomorphology of the Guiana coast, where marine processes and Holocene history are similar to the Orinoco coast. Major factors controlling Orinoco Delta water and sediment dynamics include the pronounced annual flood discharge; the uneven distribution of water and sediment discharge across the delta plain; discharge of large volumes of water with low sediment concentrations through the Rio Grande and Araguao distributaries; water and sediment dynamics associated with the Guayana littoral current along the northeastern South American coast; inflow of large volumes of Amazon sediment to the Orinoco coast; development of a fresh water plume seaward of Boca Grande; disruption of the Guayana Current by Trinidad, Boca de Serpientes, and Gulf of Paria; and the constriction at Boca de Serpientes. ?? 2002 Elsevier Science B.V. All rights reserved.

Radioisotopes in sedimentology

International Nuclear Information System (INIS)

Courtois, G.

1967-01-01

Radioisotopes have two main uses in sedimentology: they are used for the study of sediment movements in rivers and seas, and for continuous measurements of the amount of sediment suspended in a given medium. These two uses are considered in detail, and brief accounts given of some other uses. Study of sediment movements. After describing the basic technique used in sediment movement studies (injection of a labelled sediment or a simulator into the current, followed by tracking the radioactivity), the author enumerates as fully as possible the problems that can be solved with the help of this technique. Essentially, these problems fall into two groups: 1. Problems related to civil engineering works in coastal areas: the siltation of harbour channels and docks, the formation of banks and bars, the choice of sites for disposing of dredged sediment, the siting of ports, coastline protection, etc. Problems associated with civil engineering works in and near rivers; siting of the water intakes of hydroelectric and nuclear power stations, the effects of construction work on the transport of solids, the construction of dams, the protection of river banks, the construction of jetties, the siltation of lakes, etc. Problems common to these include the transport of effluent and the calibration of hydraulic models. The bibliography is based mainly on fairly recent references and on current research work. 2. Problems related to basic or applied research conducted mainly by universities and research centres: the study of the Quarternary of a particular region, pure sedimentology, the investigation of major sediment transport currents, the confirmation or refutation of transport theories, research into fundamental transport phenomena associated with channel experiments. After referring to the possible exploitation of natural tracers (contained in radioactive waste and fallout), the author discusses the technical aspects of using artificial tracers: the choice of radioisotope

Geomorphology and spatial planning

Directory of Open Access Journals (Sweden)

Matija Zorn

2006-01-01

Full Text Available Applicability of geomorphological knowledge for prevention against some natural disasters, also known as geomorphological disasters, is presented. Some home and foreign experience of applicability of this knowledge are introduced. It is known that the ratio between means put into sanitation of, for example, landslides and savings with prevention measures, are from 1:10 to 1:2.000. The use of geomorpholgical knowledge and corresponding cartographic works in Slovene spatial planning legislation is defined, but it is not carried out consistently. We recommend municipalities and spatial planners that they should also take in account geomorphic processes and characteristic of the relief.

Possibilities for a valorisation of geomorphologic research deliverables

Science.gov (United States)

Geilhausen, M.; Götz, J.; Otto, J.-C.; Schrott, L.

2009-04-01

Many geomorphological studies focus on fundamental research questions in large parts, although there are lots of applied fields like landslide hazard assessment or water framework directive. As fundamental research is a common property, their outcomes should be more "open" and accessible to the public. This means that scientists have to find new ways presenting their results and outcomes besides publishing in scientific journals. This paper shows possibilities for a valorisation of geomorphologic research deliverables using print as well as digital media. Geotrails explain remarkable and exciting landscape features using information boards and become more and more popular and important for tourism in many parts of the world. With the growing interest in environmental change and outdoor activities, print media like field guides reach an increasing number of people. Field guides and Geotrails can be coupled in order to arise awareness about geomorphological landforms and to deliver more specific information on the site beyond the information given on the boards in the field. As field guides are designed for the general public they can be used for educational purposes as well. Today, this information can also be found in the internet offering virtual trips through landscapes using dynamic maps. Here, server side GIS technologies (WebGIS) using standardised interfaces provide new possibilities to show geomorphic data to the public and to share them with the scientific community. Furthermore, data formats like XML or KML are powerful tools for data exchange and can be used in interactive data viewers like Google Earth. We will present the Geotrail "Geomorphologischer Lehrpfad am Fuße der Zugspitze. Das Reintal - Eine Wanderung durch Raum und Zeit" (Bavarian Alps, Germany). Additionally, three geomorphologic WebGIS applications (Geomorphologic map Turtmanntal, Permafrostmap of Austria, Geomorphologic maps of Germany) will exemplify how geomorphologic information and

Urban geomorphological heritage - A new field of research

Science.gov (United States)

Reynard, Emmanuel; Pica, Alessia; Coratza, Paola

2017-04-01

Urbanization is one of the major challenges that the world faces. In 2015, 54% of the world population was living in urban areas and in some countries this percentage is close to 100% (Singapore 100%; Qatar 99%; Belgium 98%). In several parts of the world annual urbanization rates exceed 5% (e.g. Oman 8.54%; Rwanda 6.43%; Burkina Faso 5.87%), which means that urban sprawl is a widespread phenomenon. Urbanization and correlated infrastructure building highly impact and sometimes completely destroy natural landforms. Geomorphological heritage research has traditionally focused on rural or natural regions, in particular protected areas (nature parks, geoparks). We consider that urban areas, which have been poorly investigated until now, are particularly interesting in a geomorphological heritage point of view for almost three reasons: (i) The geomorphological context (site) of some cities is part of their "image" and their fame (e.g. the sugarloaf of Rio de Janeiro); (ii) Urban sprawl often interacts with landforms, which addresses the challenge of geoheritage protection in fast urbanizing areas; (iii) Cities are often tourist destinations, which creates a potential for a geotourist promotion of their geomorphological heritage. This study addresses the main challenges research on geomorphological heritage is facing in urban contexts: (i) the complex interrelationships between natural landforms and urban forms; (ii) the partial or total invisibility of landforms and sediments that are covered or destroyed by urban infrastructures; (iii) man-made landforms as part of urban geomorphological heritage; (iv) the suitability of some landforms (valleys, gullies, mounts) for specific urban uses; (v) the geomorphic constraints of landforms on urban development; and (vi) the importance of some landforms for the urban landscape and the image of the cities. To address these challenges a methodological framework is proposed, which combines: (i) the geomorphological analysis of the

INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR TECHNOLOGY AND GEOMORPHOLOGY INTERPRETATION

Directory of Open Access Journals (Sweden)

M. Maghsoudi

2013-09-01

Full Text Available Geomorphology is briefly the study of landforms and their formative processes on the surface of the planet earth as human habitat. The landforms evolution and the formative processes can best be studied by technologies with main application in study of elevation. Interferometric Synthetic Aperture Radar (InSAR is the appropriate technology for this application. With phase differences calculations in radar waves, the results of this technology can extensively be interpreted for geomorphologic researches. The purpose of the study is to review the geomorphologic studies using InSAR and also the technical studies about InSAR with geomorphologic interpretations. This study states that the InSAR technology can be recommended to be employed as a fundamental for geomorphology researches.

Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

Science.gov (United States)

Lovell, Harold; Benn, Douglas I.; Lukas, Sven; Spagnolo, Matteo; Cook, Simon J.; Swift, Darrel A.; Clark, Chris D.; Yde, Jacob C.; Watts, Tom

2018-01-01

Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of

Geomorphologic and sedimentologic controls on records of flood-induced alluviation in Las Cajas National Park, Ecuador

Science.gov (United States)

Rodbell, D. T.; Bustamante, M. G.; Marks, S.; Abbott, M. B.; Moy, C. M.

2017-12-01

The sediment record from Laguna Pallcacocha in Las Cajas National Park, southern Ecuador (4060 masl; 2°46'S; 79°14'W) has been interpreted to record El Niño floods spanning the Holocene (Rodbell et al., 1999; Moy et al., 2002). The sediment record is unusual for the nearly continuous dark- and light-colored laminations (0.1-2.0 cm thick) that comprise the Holocene. Light laminae typically have erosive basal contacts and fine-upwards, whereas dark laminae possess abrupt or gradational lower contacts and reveal no grain size trends. Light laminae contain 7%), and contain 3-10% biogenic silica. Light laminae represent deposition during periods of increased precipitation, mobilization of unvegetated sediment above the lake, and increased stream discharge, all of which generate density-driven undercurrents. Conversely, dark laminae are deposited relatively slowly by sedimentation of organic matter, some derived from surface soil horizons. Time series analysis of light laminae reveal the ENSO spectral signature (2-8 yr) that evolves through the Holocene. However, none of the sediment cores taken from many nearby lakes reveal an alluvial record comparable in terms of frequency and magnitude to that preserved in Pallcacocha thus raising questions as to the factors responsible for the rich stratigraphy preserved in Pallcacocha, and, moreover, the regional paleoclimatic significance of the Pallcacocha record. A review of lacustrine sediment cores obtained from Las Cajas National Park suggests that drainage basin factors are the primary control on the sedimentologic signal recorded. These factors include bedrock geology, presence of unvegetated sediment exposed on slopes, connectivity of exposed sediment to primary inflow streams, drainage basin slope, drainage basin:lake surface area ratio, and position of lake in paternoster sequence of lakes. Bedrock is comprised of Quaternary silicic ignimbrite, rhyolite, and andesite of the Tarqui Formation. Ignimibrite provides the

Development of a transient, lumped hydrologic model for geomorphologic units in a geomorphology based rainfall-runoff modelling framework

Science.gov (United States)

Vannametee, E.; Karssenberg, D.; Hendriks, M. R.; de Jong, S. M.; Bierkens, M. F. P.

2010-05-01

We propose a modelling framework for distributed hydrological modelling of 103-105 km2 catchments by discretizing the catchment in geomorphologic units. Each of these units is modelled using a lumped model representative for the processes in the unit. Here, we focus on the development and parameterization of this lumped model as a component of our framework. The development of the lumped model requires rainfall-runoff data for an extensive set of geomorphological units. Because such large observational data sets do not exist, we create artificial data. With a high-resolution, physically-based, rainfall-runoff model, we create artificial rainfall events and resulting hydrographs for an extensive set of different geomorphological units. This data set is used to identify the lumped model of geomorphologic units. The advantage of this approach is that it results in a lumped model with a physical basis, with representative parameters that can be derived from point-scale measurable physical parameters. The approach starts with the development of the high-resolution rainfall-runoff model that generates an artificial discharge dataset from rainfall inputs as a surrogate of a real-world dataset. The model is run for approximately 105 scenarios that describe different characteristics of rainfall, properties of the geomorphologic units (i.e. slope gradient, unit length and regolith properties), antecedent moisture conditions and flow patterns. For each scenario-run, the results of the high-resolution model (i.e. runoff and state variables) at selected simulation time steps are stored in a database. The second step is to develop the lumped model of a geomorphological unit. This forward model consists of a set of simple equations that calculate Hortonian runoff and state variables of the geomorphologic unit over time. The lumped model contains only three parameters: a ponding factor, a linear reservoir parameter, and a lag time. The model is capable of giving an appropriate

A New Global Geomorphology?

Science.gov (United States)

Baker, V. R.

1985-01-01

Geomorphology is entering a new era of discovery and scientific excitement centered on expanding scales of concern in both time and space. The catalysts for this development include technological advances in global remote sensing systems, mathematical modeling, and the dating of geomorphic surfaces and processes. Even more important are new scientific questions centered on comparative planetary geomorphology, the interaction of tectonism with landscapes, the dynamics of late Cenozoic climatic changes, the influence of cataclysmic processes, the recognition of extremely ancient landforms, and the history of the world's hydrologic systems. These questions all involve feedback relationships with allied sciences that have recently yielded profound developments.

Geochemical and sedimentologic problems of uranium deposits of Texas Gulf Coastal Plain

International Nuclear Information System (INIS)

Huang, W.H.

1978-01-01

Exploration targets for sedimentary uranium ore bodies in the Texas Gulf Coastal Plain include: (1) favorable source rocks for uranium, (2) favorable conditions for uranium leached and transported out of the source rocks, and (3) favorable geologic characteristics of the host rocks for the accumulation of uranium of economic importance. However, data available from known deposits point out more questions of research than answers. Mobility and accumulation of uranium of economic importance in host rocks are controlled by at least three factors - physical, chemical-mineralogic, and hydrologic - that interact dynamically. Physical factors include the nature (viscosity) of the transporting fluid, the permeability of host rock with respect to transporting solution in terms of medium rate, potential differentials, and temperature of the uranium-bearing solution in the macroenvironment. Chemical-mineralogic factors include the ionic strength of solution, chemical activities of species in the solution, chemical activities of pore water in host rocks, surface activity and surface energy of mineral constituents in host rocks, solubilities of ore and gangue minerals, pH, and Eh in the microenvironment. Hydrologic factors include fluctuation of the depth of the oxidation-reduction interfaces in the paleoaquifer host rocks, and their subsequent modification by present hydrologic factors. Geochemical mechanisms that are likely to have been in operation for uranium accumulation are precipitation, adsorption, and/or complexing. 4 figures

SANCOR marine sedimentology programme January 1984-December 1988

CSIR Research Space (South Africa)

Rust, IC

1984-03-01

Full Text Available to marine sedimentation; the synthesis of palaeo-oceanographic and palaeo-geographic models applicable to the geological record, and; the prediction of expected variations in sedimentological and other trends in the South African marine environment. Research...

Landscape trajectories during the Lateglacial and the Holocene in the Loir River Valley (France) : the contribution of Geoarchaeology

Science.gov (United States)

Piana, Juliene

2015-04-01

A multidisciplinary research has been initiated in the Loir River valley where investigations revealed high-potential fluvial records and landforms for environmental and socio-environmental reconstructions. Investigations provide the opportunity to reconstruct landscape trajectories between climate, environmental and societal changes during the last 16000 years, using geoarchaeological and archaeogeographical approaches: sedimentology, soil micromorphology, geochemistry, archaeology, geomatics, geochronology (AGES Program: Ancient Geomorphological EvolutionS of Loire Basin hydrosystem). In the sector of Vaas (Sarthe, France) the research on the Lateglacial and the Holocene sedimentary sequences from the alluvial plain leads to a general overview of the valley evolution from the end of the Weichselian Upper Pleniglacial to the Present. Joined to archaeological (Protohistoric and Antic sites) and historical data (engineering archives, 18th century cadastral registers) this research highlights the importance of anthropogenic and geomorphological heritages in the current fluvial landscape (microtopography, wetlands, archaeological remains, land use). This knowledge constitutes a basis for skills transfer to planners and managers, in sustainable management of hydrological resources (reducing the vulnerability to flooding and low flows), preservation of biodiversity (wetlands protection) and valorization of landscapes (cultural tourism development).

Beach-ridge sedimentology as an archive of terrestrial climate change: Insights from a geochemical and stratigraphic study of the Tijucas Strandplain, southern Brazil

Science.gov (United States)

Krask, J. L.; Hein, C. J.; Galy, V.; FitzGerald, D.; Henrique de Fontoura Klein, A.

2017-12-01

Whereas millennial-scale variations in climate forcing drives changes in terrestrial processes, which are in turn directly linked to fluvial sediment loads (e.g., weathering and erosion), the impact of decadal- to centennial- scale climate fluctuations on downstream coastal sedimentation patterns and landscape evolution remains unclear. Specifically, the connection between long-term (decades or more) precipitation seasonality and sediment export from river systems has not been established. This study examines the manner in which sub-millennial-scale fluctuations in precipitation over river catchments may be recorded in coastal progradational sedimentary archives. The 5-km wide Tijucas Strandplain (southern Brazil) formed over the last 5800 years through the rapid reworking of sediment discharged from the Tijucas River in a regime of falling sea level. In an overall regime shift from sand- to mud- dominance (linked to a long-term reduction in wave energy caused by bay shoaling) are nearly 70 distinct transitions between shore-parallel sand- and mud- dominated facies. Bulk organic carbon and terrestrial plant-wax fatty acid stable hydrogen (δD) and carbon (δ13C) isotopic measurements from sediments from select sandy and muddy ridges across the plain reveal that these two sedimentological regimes are geochemically distinct. Specifically, waxes from sediments deposited during periods of sandy progradation had δD values, on average, >10 ‰ higher than those from mud-dominated periods, indicating that these sedimentary units reflect different hydroclimatic conditions within the river drainage basin at the time of deposition. Comparison of plant wax isotopic signatures of river, bay, and beach sediments during the current period of mud-dominated progradation reveals a close correlation with earlier periods of mud deposition within the Tijucas Strandplain. Thus, decadal- to centennial- scale sedimentologic transitions within the plain are interpreted to reflect climate

The tracer techniques and the problems in hydrology and sedimentology. 1974 status report

International Nuclear Information System (INIS)

Sauzay, G.

1974-01-01

Two kinds of nuclear techniques are used in sedimentology. Determination of the sediment mass at a given place using radiometric gages; determination of a sediment mass in motion using nuclear tracer techniques. Some recent applications are described: studies on dredging wastes; study of sedimentation mechanisms in a estuary; study of the possible transport of coarse materials by the swell; adjustement of sedimentological models [fr

On the issue of equifinality in glacial geomorphology

Science.gov (United States)

Möller, Per; Dowling, Thomas; Cleland, Carol; Johnson, Mark

2016-04-01

A contemporary trend in glacial geomorphology is the quest for some form of unifying theory for drumlin and/or ribbed moraine formation: there MUST be ONE explanation. The result of this is attempts to apply 'instability theory' to the formation of all drumlinoid and ribbed moraine formation or, as an alternative to this, the 'erodent layer hypothesis' for single processes driven formation. However, based on field geology evidence on internal composition and architecture and the internals relation to the exterior, i.e. the shape of drumlins or ribbed moraine, many glacial sedimentologists would argue that it is instead different processes in their own or in combination that lead to similar form, i.e. look-alike geomorphologic expression or equifinality in spite of different process background for their formation. As expressed by Cleland (2013) from a philosophical point of view of a 'common cause explanation', as exemplified with mass extinctions through geologic time, there is probably a 'common cause explanation' for the K/T boundary extinction (massive meteorite impact on Earth), but this is not a common explanation for every other mass extinction. The parallel to our Quaternary enigma is that there can of course be a single common cause for explaining a specific drumlinoid flow set (a particular case), but that does not have to be the explanation of another flow set showing other sedimentological/structural attributes, in turn suggesting that the particular case cause cannot be used for explaining the general case, i.e. all drumlins over glaciated terrain on the globe. We argue in the case of streamlined terrain, which often have considerable morphologic difference between features at local landscape scale whilst still remaining part of the drumlinoid continuum on regional scale, is a product of different processes or process combinations (erosion/deformation/accumulation) in the subglacial system, tending towards the most efficient obstacle shape and thus

Physicochemical Properties, Micromorphology and Clay Mineralogy of Soils Affected by Geological Formations, Geomorphology and Climate

Directory of Open Access Journals (Sweden)

A. Bayat

2017-01-01

Full Text Available Introduction: Soil genesis and development in arid and semi-arid areas are strongly affected by geological formations and geomorphic surfaces. Various morphological, physical, and geochemical soil properties at different geomorphic positions are usually attributed to different soil forming factors including parent material and climate. Due to variations in climate, geological formations (Quaternary, Neogene and Cretaceous and geomorphology, the aim of the present research was the study of genesis, development, clay mineralogy, and micromorphology of soils affected by climate, geology and geomorphology in Bardsir area, Kerman Province. Materials and Methods: The study area, 25000 ha, starts from Bardsir and extends to Khanesorkh elevations close to Sirjan city. The climate of the area is warm and semi-arid with mean annual temperature and precipitation of 14.9 °C and 199 mm, respectively. Soil moisture and temperature regimes of the area are aridic and mesic due to 1:2500000 map, provided by Soil and Water Research Institute. Moving to west and southwest, soil moisture regime of the area changes to xeric with increasing elevation. Using topography and geology maps (1:100000 together with Google Earth images, geomorphic surfaces and geologic formations of the area were investigated. Mantled pediment (pedons 1, 3, 7, and 8, rock pediment (pedon 2, semi-stable alluvial plain (pedon 6, unstable alluvial plain (pedon 5, piedmont plain (pedons 9 and 11, intermediate surface of alluvial plain and pediment (pedon 4, and old river terrace (pedon 10 are among geomorphic surfaces investigated in the area. Mantled pediment is composed of young Quaternary sediments and Cretaceous marls. Rock pediments are mainly formed by Cretaceous marls. Quaternary formations are dominant in alluvial plains. Alluvial terraces and intermediate surface of alluvial plain and pediment are dominated by Neogene conglomerates. Siltstone, sandstone, and Neogene marls together with

Quaternary and Geomorphology.

Science.gov (United States)

Andrews, J. T.; Graf, W. L.

1983-01-01

Highlights conferences and meetings of organizations involved with quaternary geology and geomorphology, including International Union of Quaternary Research Conference held in Moscow. The impetus of a revision of "The Quaternary of the United States" resulted from this conference. Includes activities/aims of "Friends of the…

Isotopic and sedimentological clues to productivity change in Late

Indian Academy of Sciences (India)

610Ma) intracratonic carbonate successions viz., Bhander Limestone of Vindhyan Basin and Raipur Limestone of Chattisgarh Basin suggest higher organic productivity during this period. This view is supported by sedimentological evidence of ...

Sedimentological analysis of a contaminated groundwater aquifer

International Nuclear Information System (INIS)

Towse, D.

1991-01-01

The use of sedimentological reservoir analysis techniques adapted from standard oilfield practice can improve the efficiency and reduce the costs of the evaluation of groundwater aquifers and the design of restoration programs. An evaluation/restoration program at a site in California drilled over 200 test wells in about 750 ac. All wells were logged lithologically and with wireline. The shallow aquifer is a complex braided alluvial floodplain deposit of Late Quaternary age. Analysis demonstrates depositional and erosional responses to periodic hinterland uplifts and to changing climatic conditions. Channel, overbank, lacustrine, and minor deltaic deposits can be recognized. The aquifer architecture has been interpreted to explain the movement of fuel and halogenated hydrocarbon solvents in the sediments and water. Routine engineering geology techniques and hydrologic tests were used to evaluate contamination and to design experimental restoration processes. As demonstrated here, sedimentological techniques show promise in reducing the costs and time required for this type of study. The abundant detailed data will be used in an attempt to develop a microcomputer-based expert system for rapid preliminary analyses of similar aquifers or reservoirs

Contemporary Conceptual Approaches in Fluvial Geomorphology

Directory of Open Access Journals (Sweden)

Mônica dos Santos Marçal

2016-06-01

Full Text Available Contemporary fluvial geomorphology faces challenging questions, especially as it goes by understanding the Late Holocene/Anthropocene period, which has repercussions today and are intrinsically important to understand the human river disturbance. Given the scale that physical rates operate in complex river systems, two conceptual paths were developed to analyze the spatial and temporal organization. The network view emphasizes controls on catchment-scale and a reach approach focuses on discontinuity and local controls. Fluvial geomorphology has seek to understand the organization of complex river systems from the integrated view of the continuity and discontinuity paradigm. This integrated approach has stimulated within the geomorphology, the emergence of new theoretical-methodological instruments. It is recognized that rivers management is an ongoing process, part of the socio-cultural development, which refers to both a social movement and scientific exercise.

Proceedings of the 14. Symposium on Geology from Northeast

International Nuclear Information System (INIS)

1991-01-01

Works on geology, including topics about sedimentology, stratigraphy, paleontology, geomorphology, environmental, hydrogeology, petrology, geochemistry, geochronology, geophysics, geotectonics and structural geology are described in this symposium. (C.G.C.)

Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden

NARCIS (Netherlands)

Gustavsson, M.; Seijmonsbergen, A.C.; Kolstrup, E.

2008-01-01

This paper presents the structure and contents of a standardised geomorphological GIS database that stores comprehensive scientific geomorphological data and constitutes the basis for processing and extracting spatial thematic data. The geodatabase contains spatial information on

Stratigraphy, sedimentology and bulk organic geochemistry of black ...

Indian Academy of Sciences (India)

Stratigraphy, sedimentology and bulk organic geochemistry of black shales from the Proterozoic. Vindhyan Supergroup (central India). S Banerjee1,∗. , S Dutta. 2. , S Paikaray. 1 and U Mann. 2. 1. Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India. 2. Forschungszentrum ...

Evolution of Golpazari-Huyuk karst system (Bilecik-Turkey: indications of morpho-tectonic controls

Directory of Open Access Journals (Sweden)

Ekmekci Mehmet

2004-12-01

Full Text Available The Golpazari-Huyuk karst system is located in the Central Sakarya Basin whose geomorphologic evolution is mainly controlled by the Post-Miocene epirogenic continental rise. Drastic change in the drainage pattern and dissection of the carbonate platform were the major consequences of this tectonic movement. Rapid incision of the Sakarya river changed the position of the erosion base which consequently distorted the direction of surface and subsurface flow. The Golpazari and Huyuk plains are two topographically distinct, flat bottomed geomorphic features separated by a carbonate rock relief. The difference in elevation between these 10 km distant plains is 350 m. Morphological, geological and hydrological behavior of the plains suggests that the both have functioned as closed basins connected to each other through subsurface flow paths. Drainage has changed from subsurface to surface after the emplacement of the Sakarya river into its modern course. In this study, the authors suggest a conceptual model to reconstruct the hydrological-geomorphological processes that have been effective in the evolution of this karst area. The methodology is based on the records preserved in the morphological and sedimentological archives as well as the hydrogeological setting in the study area. According to the suggested model, the present landscape which exhibits a late stage of karstification has evolved in three main phases, after an initial stage attributed to Lower Miocene. The first phase represents karstification of carbonate rocks of Jurassic age at the Huyuk area and the limestone of Paleocene age at the Golpazari area. This region must have been significantly elevated from the karstification (erosion base. The geomorphologic and drainage setting reveal that the karstification was controlled mainly by major drainage elements in Late Miocene-Early Pliocene.The second phase is characterized by the uplift of the region and the subsequent rapid incision of

Across the Gap: Geochronological and Sedimentological Analyses from the Late Pleistocene-Holocene Sequence of Goda Buticha, Southeastern Ethiopia

Science.gov (United States)

Asrat, Asfawossen; Bahain, Jean-Jacques; Chapon, Cécile; Douville, Eric; Fragnol, Carole; Hernandez, Marion; Hovers, Erella; Leplongeon, Alice; Martin, Loïc; Pleurdeau, David; Pearson, Osbjorn; Puaud, Simon; Assefa, Zelalem

2017-01-01

Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications of these observations, sedimentological analyses combined with optically stimulated luminescence (OSL) were conducted. The OSL data now extend the radiocarbon chronology up to 63 ± 7 ka; they also confirm the existence of the chronological gap between 24.8 ± 2.6 ka and 7.5 ± 0.3 ka. The sedimentological analyses suggest that the origin and mode of deposition were largely similar throughout the whole sequence, although the anthropic and faunal activities increased in the younger levels. Regional climatic records are used to support the sedimentological observations and interpretations. We discuss the implications of the sedimentological and dating analyses for understanding cultural processes in the region. PMID:28125597

The sedimentology of uranium-bearing sandstones on the farm Ryst Kuil 351 Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1979-06-01

A study of the sedimentology of some uranium-bearing sandstones on the farm Ryst Kuil 351 was made in order to assess possible relationships between the mineralisation and the sedimentary facies and/or the palaeo-environment. Use was made of 6 vertical profiles, derived from horizontal traverses. 12 sedimentary facies were recognised according to grain-size and sedimentary structure. The transitions between these facies, as derived from the vertical profiles, were subjected to Markov analysis. Only 3 Markov-dependent transitions were derived, but several facies transitions and associations occurred with greater than random frequency. These, together with the vertical profiles, were used to interpret the palaeo-environmental succession. This succession is fluvial meandering and two sub-environments - channel and flood plain - were delineated according to the prevalence of sandstone or mudstone facies. The uranium-bearing sandstones occur in the lower part of a thick (29 - 46m) multistorey point bar sequence within the channel sub-environment. The mineralisation is associated with koffieklip and is restricted to two sedimentary facies - massive very fine-to-finegrained sandstone and horizontally bedded, very fine- to fine-grained sandstone. The mineralisation normally occurs near the bases of the point bars

Reading and Abstracting Journal Articles in Sedimentology and Stratigraphy.

Science.gov (United States)

Conrad, Susan Howes

1991-01-01

An assignment centered on reading journal articles and writing abstracts is an effective way to improve student reading and writing skills in sedimentology and stratigraphy laboratories. Each student reads two articles and writes informative abstracts from the author's point of view. (PR)

Humans as major geological and geomorphological agents in the Anthropocene: the significance of artificial ground in Great Britain.

Science.gov (United States)

Price, Simon J; Ford, Jonathan R; Cooper, Anthony H; Neal, Catherine

2011-03-13

Since the first prehistoric people started to dig for stone to make implements, rather than pick up loose material, humans have modified the landscape through excavation of rock and soil, generation of waste and creation of artificial ground. In Great Britain over the past 200 years, people have excavated, moved and built up the equivalent of at least six times the volume of Ben Nevis. It is estimated that the worldwide deliberate annual shift of sediment by human activity is 57,000 Mt (million tonnes) and exceeds that of transport by rivers to the oceans (22,000 Mt) almost by a factor of three. Humans sculpt and transform the landscape through the physical modification of the shape and properties of the ground. As such, humans are geological and geomorphological agents and the dominant factor in landscape evolution through settlement and widespread industrialization and urbanization. The most significant impact of this has been since the onset of the Industrial Revolution in the eighteenth century, coincident with increased release of greenhouse gases to the atmosphere. The anthropogenic sedimentological record, therefore, provides a marker on which to characterize the Anthropocene.

Relief inversion in the geomorphological evolution of sub-Saharan West Africa

Science.gov (United States)

Butt, C. R. M.; Bristow, A. P. J.

2013-03-01

The geomorphology of much of sub-Saharan West Africa is dominated by the presence of plateaux and plains with ferruginous and, locally, aluminous (bauxitic) duricrusts. The plateaux occur at different elevations and have been correlated as two or more palaeosurfaces across much of the region. The duricrusts have generally been considered to be residual, formed by conformable erosion and chemical wasting of immediately underlying bedrock. This concept has been central to interpretations as diverse as the formation and evolution of the landscape and the development of geochemical exploration models. Recent regolith landform mapping, field observations and experience from mineral exploration in southern Mali and Burkina Faso, however, demonstrate that the duricrusts are mainly ferricretes, i.e., Fe oxide-cemented sediments. These observations require a re-interpretation of the geomorphological evolution of the region during the Cenozoic. The landscape has evolved by several cycles of weathering and erosion-deposition, triggered by climatic, tectonic or other environmental changes. It is proposed that an initial bauxitic/lateritic regolith was partly eroded following uplift and/or a change to a more arid climate, and that the detritus, rather than being removed, was deposited on slopes and valleys. During a subsequent humid period of lateritic weathering, Fe oxide cementation of this detritus formed ferricrete. Dehydration and hardening of the ferricrete after further uplift or aridity increased its resistance to erosion, resulting in relief inversion, with the detritus, in turn, being deposited downslope. This too has been weathered and cemented, to form a younger ferricrete. The occurrence of ferricrete landforms in adjacent countries, noted by field observation and inferred from satellite imagery, demonstrates that relief inversion is a very widespread and important phenomenon in southern Mali, Burkina Faso and adjacent countries in semi-arid West Africa.

The Teaching of Geomorphology and the Geography/Geology Debate.

Science.gov (United States)

Petch, Jim; Reid, Ian

1988-01-01

Examines the place of geomorphology in undergraduate programs in the United Kingdom. A questionnaire survey reveals that geomorphology is widely taught in all geo- and environmental sciences, but that teaching methods and the size of the curriculum vary significantly between disciplines. (LS)

Detailed geomorphological map sheet Bela Palanka at scale 1:100,000

Directory of Open Access Journals (Sweden)

Menković Ljubomir

2011-01-01

Full Text Available The Geomorphological Map Sheet Bela Palanka is a graphical representation of landforms in the area covered by the Topographical Map Sheet Bela Palanka at scale 1:100,000. The map is published in 2008 by the Serbian Academy of Sciences and Arts (SASA and the SASA Geodynamics Board. It is the first detailed geomorphological map edited in Serbia. This paper presents the methods used in preparing the geomorphological map, the contents and the mode of data presentation, geologic structure, genetic types of landforms and the subtypes, and the geomorphological history since the Neogene.

Geomorphosites and the history of geomorphology

Science.gov (United States)

Giusti, Christian

2013-04-01

Geomorphosites are geosites of geomorphological significance, with a now well admitted distinction between central or scientific values on the one hand, and additional values such as ecological, economical or aesthetical values on the other hand. Among the scientific values, some are directly linked to the climatic forcings through geomorphological processes in the case of active geomorphosites, for example the meaning of a waterfall in a post-glacial trough valley. In the case of passive geomorphosites, the central values rather lie in structural features, ancient landforms, inherited regoliths such as the clay-with-flints of the Chalklands of Southern England and Northern France. Sometimes, the scientific value is not fully determined by the type of geomorphosite, active or passive, but rather by the fact this geosite has a special importance concerning the history of the Earth sciences, especially in geomorphology. This is well exemplified with the famous case of the Nant d'Arpenaz waterfall S-folds in the lower Arve valley between Geneva and Chamonix, first described by Horace Benedict de Saussure in 1774 and invoked to explain the formation of the Alps by folding. This structural geosite (history of tectonics) is also a geomorphosite. Concerning geomorphology, the current Nant d'Arpenaz waterfall is quite similar to the Pissevache waterfall in the Rhone valley: they are both examples of postglacial geomorphosites due to hanging valleys. When erosion is more advanced narrow gorges appear, for example Diosaz gorge (Haute-Savoie, France) or Dailley, Trient and Triège gorges (Valais, Switzerland). All these geomorphosites (main trough valleys, tributary valleys, waterfalls and postglacial gorges) were studied by pionneers of fluvial and glacial geomorphology such as Jean Bruhnes and Emmanuel de Martonne before World War I. The former has played an important role at the University of Fribourg (Switzerland) and has devoted many studies about the potholes and eddies

Teaching Geomorphology at University

Science.gov (United States)

Sugden, David; Hamilton, Patrick

1978-01-01

Geomorphology courses in British universities emphasize the main landform/process systems rather than more abstract concepts. Recommends a more theoretical focus on fundamental geomorphic processes and methodological problems. Available from: Faculty of Modern Studies, Oxford Polytechnic, Headington, Oxford OX3 OBP, England. (Author/AV)

Latest Pannonian and Quaternary evolution at the transition between Eastern Alps and Pannonian Basin: new insights from geophysical, sedimentological and geochronological data

Science.gov (United States)

Zámolyi, A.; Salcher, B.; Draganits, E.; Exner, U.; Wagreich, M.; Gier, S.; Fiebig, M.; Lomax, J.; Surányi, G.; Diel, M.; Zámolyi, F.

2017-07-01

The transition zone between Eastern Alps and Pannonian Basin is a key area for the investigation of the interplay between regional uplift, local tectonic subsidence and depositional environment. Our study area, the western margin of the Little Hungarian Plain, is characterized by gentle hills, plateaus and depressions, of which several are filled by lakes—including one of Austria's largest and shallowest lakes, Lake Neusiedl. Geological investigation is hampered by the scarcity of outcrops, and thus direct observation of sedimentological or structural features is difficult. Despite a long research history in the area, a consistent landscape evolution model considering all relevant constraints is lacking so far. In this study, we apply multidisciplinary methods to decipher the complex tectonic and fluvial depositional evolution of the region. Local data from shallow-lake drilling and seismic investigation are combined with regional data from industrial seismics and core data to gain new insights into the latest Pannonian (Late Miocene) and Quaternary evolution. Shallow-lake seismic data show the erosionally truncated Pannonian sediments dipping and thickening toward southeast, toward the modern depocenter of the Little Hungarian Plain. Overlying Quaternary fluvial sediments show a very similar thickening trend except for the area on the plateau north of the lake indicating ongoing subsidence in major parts of the basin. Drill cores from locations along the lake seismic lines were analyzed concerning their age, mineralogy and heavy minerals and compared with outcrop samples from the surrounding plains and the plateau to derive indications on sediment provenance. A key observation is the apparent lack of a significant gravel layer on top of the tilted Pannonian sediments beneath Lake Neusiedl. Small-scale faults can be observed in the lake seismic sections along with key sedimentary features. Significant differences of the current elevation of the top Pannonian

Petroacoustic Modelling of Heterolithic Sandstone Reservoirs: A Novel Approach to Gassmann Modelling Incorporating Sedimentological Constraints and NMR Porosity data

Science.gov (United States)

Matthews, S.; Lovell, M.; Davies, S. J.; Pritchard, T.; Sirju, C.; Abdelkarim, A.

2012-12-01

Heterolithic or 'shaly' sandstone reservoirs constitute a significant proportion of hydrocarbon resources. Petroacoustic models (a combination of petrophysics and rock physics) enhance the ability to extract reservoir properties from seismic data, providing a connection between seismic and fine-scale rock properties. By incorporating sedimentological observations these models can be better constrained and improved. Petroacoustic modelling is complicated by the unpredictable effects of clay minerals and clay-sized particles on geophysical properties. Such effects are responsible for erroneous results when models developed for "clean" reservoirs - such as Gassmann's equation (Gassmann, 1951) - are applied to heterolithic sandstone reservoirs. Gassmann's equation is arguably the most popular petroacoustic modelling technique in the hydrocarbon industry and is used to model elastic effects of changing reservoir fluid saturations. Successful implementation of Gassmann's equation requires well-constrained drained rock frame properties, which in heterolithic sandstones are heavily influenced by reservoir sedimentology, particularly clay distribution. The prevalent approach to categorising clay distribution is based on the Thomas - Stieber model (Thomas & Stieber, 1975), this approach is inconsistent with current understanding of 'shaly sand' sedimentology and omits properties such as sorting and grain size. The novel approach presented here demonstrates that characterising reservoir sedimentology constitutes an important modelling phase. As well as incorporating sedimentological constraints, this novel approach also aims to improve drained frame moduli estimates through more careful consideration of Gassmann's model assumptions and limitations. A key assumption of Gassmann's equation is a pore space in total communication with movable fluids. This assumption is often violated by conventional applications in heterolithic sandstone reservoirs where effective porosity, which

Geomorphological characterization of endorheic basins in northern Chile

Science.gov (United States)

Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

2011-12-01

Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1

Sea floor geomorphology: Discussion

Digital Repository Service at National Institute of Oceanography (India)

Evsykov, Y.D.; Murthy, K.S

stream_size 1 stream_content_type text/plain stream_name Mem_Geol_Soc_India_1998_39_38.pdf.txt stream_source_info Mem_Geol_Soc_India_1998_39_38.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Elaboration Of A Classification Of Geomorphologic Units And The Basis Of A Digital Data-Base For Establishing Geomorphologic Maps In Egypt

International Nuclear Information System (INIS)

EI Gammal, E.A.; Cherif, O.H.; Abdel Aleem, E.

2003-01-01

A database for the classification and description of basic geomorphologic land form units has been prepared for establishing geomorphologic maps in Egyptian terrains. This database includes morpho-structural, lithological, denudational and depositional units. The database.is included in tables with proper coding to be used for establishing automatically the color, symbols and legend of the maps. Also the system includes description of various geomorphic units. The system is designed to be used with the ARC Map software. The AUTOCAD 2000 software has been used to trace the maps. The database has been applied to produce five new geomorphologic maps with a scale of I: 100 000. These are: Wadi Feiran Sheet, Wadi Kid Sheet, Gabal Katherina Sheet in South Sinai, Shelattein area (South Eastern Desert) and Baharia Oasis area (Western Desert)

Geomorphology of Minnesota - Isolated Landform Structures

Data.gov (United States)

Minnesota Department of Natural Resources — Geomorphology of Minnesota - Isolated Landform Structures are essentially cartographic arcs representing isolated glacial features that were mapped in conjunction...

Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

International Nuclear Information System (INIS)

East, T.J.

1985-01-01

Current and future research into the geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes. Process rates during the next few thousand years might be predictable by extrapolation of contemporary and past (i.e. Holocene) climates, sea-levels and depositional environments, evidence for which is preserved in the sedimentary record. In current projects, the Late Quarternary stratigraphy of Magela Creek are examined to provide data for modelling of present and future sedimentological processes. Site stability evaluation entails recognition of present and future geomorphic hazards at impoundment sites, and includes fluvial and hillslope erosion, extreme flood events and mass movements. The life of a tailings impoundment is further determined by the intensity of erosional processes acting upon its slopes and their cover materials. A knowledge of present and future erosion rates will allow the optimisation of slope characteristics and materials in the impoundment design

Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology

Science.gov (United States)

Last, William M; Ginn, Fawn M

2005-01-01

spatial trends and regional variations controlled by groundwater input, climate, and geomorphology. Short-term temporal variations in the brine composition, which can have significant effects on the composition of the modern sediments, have also been well documented in several individual basins. From a sedimentological and mineralogical perspective, the wide range of water chemistries exhibited by the lakes leads to an unusually large diversity of modern sediment composition. Over 40 species of endogenic precipitates and authigenic minerals have been identified in the lacustrine sediments. The most common non-detrital components of the modern sediments include: calcium and calcium-magnesium carbonates (magnesian calcite, aragonite, dolomite), and sodium, magnesium, and sodium-magnesium sulfates (mirabilite, thenardite, bloedite, epsomite). Many of the basins whose brines have very high Mg/Ca ratios also have hydromagnesite, magnesite, and nesquehonite. Unlike salt lakes in many other areas of the world, halite, gypsum, and calcite are relatively rare endogenic precipitates in the Great Plains lakes. The detrital fraction of the lacustrine sediments is normally dominated by clay minerals, carbonate minerals, quartz, and feldspars. Sediment accumulation in these salt lakes is controlled and modified by a wide variety of physical, chemical, and biological processes. Although the details of these modern sedimentary processes can be exceedingly complex and difficult to discuss in isolation, in broad terms, the processes operating in the salt lakes of the Great Plains are ultimately controlled by three basic factors or conditions of the basin: (a) basin morphology; (b) basin hydrology; and (c) water salinity and composition. Combinations of these parameters interact to control nearly all aspects of modern sedimentation in these salt lakes and give rise to four 'end member' types of modern saline lacustrine settings in the Great Plains: (a) clastics-dominated playas; (b) salt

Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: Project Introduction and First Year Work Plan

Science.gov (United States)

Skiner, J. A., Jr.; Rogers, A. D.; Seelos, K. D.

2009-01-01

The highland-lowland boundary (HLB) of Mars is interpreted to be a complex tectonic and erosional transition that may hold evidence for past geologic processes and environments. The HLB-abutting margin of the Libya Montes and the interbasin plains of northern Tyrrhena Terra display an exceptional view of the earliest to middle history of Mars that has yet to be fully characterized. This region contains some of the oldest exposed materials on the Martian surface as well as aqueous mineral signatures that may be potential chemical artifacts of early highland formational processes. However, a full understanding of the regions geologic and stratigraphic evolution is remarkably lacking. Some outstanding questions regarding the geologic evolution of Libya Montes and northern Tyrrhena Terra in-clude: Does combining geomorphology and composition advance our understanding of the region s evolution? Can highland materials be subdivided into stratigraphically discrete rock and sediment sequences? What do major physiographic transitions imply about the balanced tectonism, climate change, and erosion? Where is the erosional origin and what is the post-depositional history of channel and plains units? When and in what types of environments did aqueous mineral signatures arise? This abstract introduces the geologic setting, science rationale, and first year work plan of a recently-funded 4-year geologic mapping proposal (project year = calendar year). The objective is to delineate the geologic evolution of Libya Montes and northern Tyrrhena Terra at 1:1M scale using both classical geomorphological and compositional mapping techniques. The funded quadrangles are MTMs 00282, -05282, -10282, 00277, -05277, and -10277.

Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil.

Science.gov (United States)

Luiz, Amom Mendes; Leão-Pires, Thiago Augusto; Sawaya, Ricardo J

2016-01-01

Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorphological factors are more important in structuring anuran beta diversity than climatic and spatial factors. We obtained species composition via field survey (N = 766 individuals), museum specimens (N = 9,730) and literature records (N = 4,763). Sampling area was divided in four spatially explicit geomorphological units, representing historical predictors. Climatic descriptors were represented by the first two axis of a Principal Component Analysis. Spatial predictors in different spatial scales were described by Moran Eigenvector Maps. Redundancy Analysis was implemented to partition the explained variation of species composition by geomorphological, climatic and spatial predictors. Moreover, spatial autocorrelation analyses were used to test neutral theory predictions. Beta diversity was spatially structured in broader scales. Shared fraction between climatic and geomorphological variables was an important predictor of species composition (13%), as well as broad scale spatial predictors (13%). However, geomorphological variables alone were the most important predictor of beta diversity (42%). Historical factors related to geomorphology must have played a crucial role in structuring amphibian beta diversity. The complex relationships between geomorphological history and climatic gradients generated by the Serra do Mar Precambrian basements were also important. We highlight the importance of combining spatially explicit historical and contemporary predictors for understanding

Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil.

Directory of Open Access Journals (Sweden)

Amom Mendes Luiz

Full Text Available Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorphological factors are more important in structuring anuran beta diversity than climatic and spatial factors. We obtained species composition via field survey (N = 766 individuals, museum specimens (N = 9,730 and literature records (N = 4,763. Sampling area was divided in four spatially explicit geomorphological units, representing historical predictors. Climatic descriptors were represented by the first two axis of a Principal Component Analysis. Spatial predictors in different spatial scales were described by Moran Eigenvector Maps. Redundancy Analysis was implemented to partition the explained variation of species composition by geomorphological, climatic and spatial predictors. Moreover, spatial autocorrelation analyses were used to test neutral theory predictions. Beta diversity was spatially structured in broader scales. Shared fraction between climatic and geomorphological variables was an important predictor of species composition (13%, as well as broad scale spatial predictors (13%. However, geomorphological variables alone were the most important predictor of beta diversity (42%. Historical factors related to geomorphology must have played a crucial role in structuring amphibian beta diversity. The complex relationships between geomorphological history and climatic gradients generated by the Serra do Mar Precambrian basements were also important. We highlight the importance of combining spatially explicit historical and contemporary predictors for

Sedimentology of the Paleogene succession at Calypsostranda, Svalbard

OpenAIRE

Poole, Louise Kristiansen

2018-01-01

The following study encompasses sedimentological investigations of the Calypsostranda Group. The Calypsostranda Group is comprised of Paleogene sediments where outcrops are well exposed in a coastal section at Renardodden (Calypsostranda area), on the southern shores of Bellsund in western Spitsbergen. The aim of the study is to: i) generate reliable depositional models for the evolution of the sediments of the Calypsostranda Group, through facies recognition and break-down ii) investigate an...

GEOMORPHOLOGICAL HAZARDS AND RISKS IN JIU DEFILE

Directory of Open Access Journals (Sweden)

I. SĂNDULACHE

2014-05-01

Full Text Available Jiu Defile has a length of 33 km and is located in the Southern Carpathians, between Parâng Mountains (east and Vâlcan Mountains (west. This paper stars from the analysis of field mapping and measurements (based on topographic maps, scale of 1:25 000, and data from local institutions and other sources (web, press. In Jiu Defile, geomorphological hazards results from the combined action of meteorological conditions and other factors such as geology, geomorphology and socio-economic development. They may affect transport infrastructure, which is at risk especially in spring and summer.

Using Miniature Landforms in Teaching Geomorphology.

Science.gov (United States)

Petersen, James F.

1986-01-01

This paper explores the uses of true landform miniatures and small-scale analogues and suggests ways to teach geomorphological concepts using small-scale relief features as illustrative examples. (JDH)

Holocene evolution of the Tabasco delta – Mexico : impact of climate, volcanism and humans

NARCIS (Netherlands)

Nooren, C.A.M.

2017-01-01

This research revealed the impact of climate, volcanism and humans on the late Holocene evolution of a tropical delta in southern Mexico. Palynological, tephrochronological, limnological, geomorphological and sedimentological techniques have been applied to reconstruct the evolution of the

Academician Ivan Gams and his influence on development of geomorphology in the Republic of Croatia

Directory of Open Access Journals (Sweden)

Andrija Bognar

2003-12-01

Full Text Available The author presents the role of academician Ivan Gams in the reorientation and modernization of Croatian geomorphology during 1970's and 1980's. The causes for losing contact with contemporary development of geomorphology in the world are analyzed in detail, and the way of reestablishing the former reputation and importance of Croatian geomorphology is presented, especially through the implementation of detailed geomorphological mapping, new methods of geomorphological investigation and education of younger scientific personnel at the university of Zagreb.

Earth Surface Processes, Landforms and Sediment Deposits

Science.gov (United States)

Bridge, John; Demicco, Robert

Earth surface processes, landforms and sediment deposits are intimately related - involving erosion of rocks, generation of sediment, and transport and deposition of sediment through various Earth surface environments. These processes, and the landforms and deposits that they generate, have a fundamental bearing on engineering, environmental and public safety issues; on recovery of economic resources; and on our understanding of Earth history. This unique textbook brings together the traditional disciplines of sedimentology and geomorphology to explain Earth surface processes, landforms and sediment deposits in a comprehensive and integrated way. It is the ideal resource for a two-semester course in sedimentology, stratigraphy, geomorphology, and Earth surface processes from the intermediate undergraduate to beginning graduate level. The book is also accompanied by a website hosting illustrations and material on field and laboratory methods for measuring, describing and analyzing Earth surface processes, landforms and sediments.

Source of uranium in the Elblag formation (upper buntsandstein): sedimentological approach

International Nuclear Information System (INIS)

Jaworowski, K.

1986-01-01

On the basis of results of sedimentological survey of area of typical development of the Elblag formation, the evidence supporting previously published hypothesis on source of uranium in this formation is presented. 10 refs., 9 figs. (M.F.W.)

Superstorm Sandy-related Morphologic and Sedimentologic Changes in an Estuarine System: Barnegat Bay-Little Egg Harbor Estuary, New Jersey

Science.gov (United States)

Miselis, J. L.; Ganju, N. K.; Navoy, A.; Nicholson, R.; Andrews, B.

2013-12-01

Despite the well-recognized ecological importance of back-barrier estuaries, the role of storms in their geomorphic evolution is poorly understood. Moreover, the focus of storm impact assessments is often the ocean shorelines of barrier islands rather than the exchange of sediment from barrier to estuary. In order to better understand and ultimately predict short-term morphologic and sedimentologic changes in coastal systems, a comprehensive research approach is required but is often difficult to achieve given the diversity of data required. An opportunity to use such an approach in assessing the storm-response of a barrier-estuary system occurred when Superstorm Sandy made landfall near Atlantic City, New Jersey on 29 October 2012. Since 2011, the US Geological Survey has been investigating water circulation and water-quality degradation in Barnegat Bay-Little Egg Harbor (BBLEH) Estuary, the southern end of which is approximately 25 kilometers north of the landfall location. This effort includes shallow-water geophysical surveys to map the bathymetry and sediment distribution within BBLEH, airborne topo-bathymetric lidar surveys for mapping the shallow shoals that border the estuary, and sediment sampling, all of which have provided a recent picture of the pre-storm estuarine geomorphology. We combined these pre-storm data with similar post-storm data from the estuary and pre- and post-storm topographic data from the ocean shoreline of the barrier island to begin to understand the response of the barrier-estuary system. Breaches in the barrier island resulted in water exchange between the estuary and the ocean, briefly reducing residence times in the northern part of the estuary until the breaches were closed. Few morphologic changes in water depths greater than 1.5 m were noted. However, morphologic changes observed in shallower depths along the eastern shoreline of the estuary are likely related to overwash processes. In general, surficial estuarine sediments

Stream Tables and Watershed Geomorphology Education.

Science.gov (United States)

Lillquist, Karl D.; Kinner, Patricia W.

2002-01-01

Reviews copious stream tables and provides a watershed approach to stream table exercises. Results suggest that this approach to learning the concepts of fluvial geomorphology is effective. (Contains 39 references.) (DDR)

Communicating Geomorphology. JGHE Annual Lecture

Science.gov (United States)

Brierley, Gary

2009-01-01

Communication strategies emphasize concerns for "content" (what is said) and "process" (the way things are said). Scientists have a responsibility to communicate the findings of their research, enhancing prospects that their insights can meaningfully inform management practice. When used effectively, principles from geomorphology provide critical…

Coastal geomorphology and mineral resources

Digital Repository Service at National Institute of Oceanography (India)

Paropkari, A.L.

stream_size 10 stream_content_type text/plain stream_name Trg_Course_Coast_Zone_Manage_1993_9.pdf.txt stream_source_info Trg_Course_Coast_Zone_Manage_1993_9.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

Prediction of downstream geomorphological changes after dam construction: A stream power approach

DEFF Research Database (Denmark)

Brandt, Anders

2000-01-01

physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry......physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry...

Zand in banen : zanddieptekaarten van het Rivierengebied en het IJsseldal in de provincies Gelderland en Overijssel

NARCIS (Netherlands)

Cohen, K.M.; Stouthamer, E.; Hoek, W.Z.; Berendsen, H.J.A.; Kempen, H.F.J.

2009-01-01

Over the past decades, the Rhine-Meuse delta in the Netherlands has been studied extensively at Utrecht University. A unique dataset exists of unique potential for investigations on various aspects of fluvial sedimentology, delta geomorphology, Quaternary geology, river-engineering, hydrocarbon

Indications of an extreme event deposits along the west coast of India: evidences from GPR investigations

Digital Repository Service at National Institute of Oceanography (India)

Loveson, V.J.; Gujar, A.R.; Iyer, S.D.; Srivastava, P.; Tirodkar, G.; Luis, R.A.A.

to an extreme event. Sand samples were collected from two trial pits along the GPR profiles to understand the sedimentology and mineralogy in the backshore area. These data together with beach profiles and geomorphological maps suggest that the sands were...

Geological map of Uruguay Esc 1,100,000. Piriapolis Sheet G-29

International Nuclear Information System (INIS)

Preciozzi, F; Pena, S; Masquelin, E; Pias, J; Tabo, F

1990-01-01

This work is about the geological map of Uruguay Esc.1.100.000 (Piriapolis) and the explanatory memoranda which describes the geological , lithological and sedimentological characteristics soils. Geomorphologically Piriapolis fotoplano is dominated by Las Animas and an important Cenozoic coverage

Fluvial geomorphology: where do we go from here?

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Smith, Derald G.

1993-07-01

The evolution of geomorphology and in particular, fluvial geomorphology, is at a crossroads. Currently, the discipline is dismally organized, without focus or direction, and is practised by individualists who rarely collaborate in numbers significant enough to generate major research initiatives. If the discipline is to mature and to prosper, we must make some very difficult decisions that will require major changes in our ways of thinking and operating. Either the field stays in its current operational mode and becomes a backwater science, or it moves forward and adopts the ways of the more competitive sectors of the earth and biosciences. For the discipline to evolve, fluvial geomorphologists must first organize an association within North America or at the international level. The 3rd International Geomorphology Conference may be a start, but within that organization we must develop our own divisional and/or regional organizations. Within the Quaternary geology/geomorphology divisions of the Geological Socieity of America (GSA), Association of American Geographers (AAG), American Geophysical Union (AGU) and British Geomorphology Research Group (BGRG) the voice of fluvial geomorphology is lost in a sea of diverse and competitive interests, though there is reason for hope resulting from some recent initiatives. In Canada, we have no national geomorphology organization per se; our closest organization is Canqua (Canadian Quaternary Association). Next, fluvial researchers must collaborate, by whatever means, to develop "scientific critical mass" in order to generate ideas and long-range goals of modest and major scientific importance. These projects will help secure major research funding without which, research opportunities will diminish and initiating major new research will become nearly impossible. Currently, we are being surpassed by the glaciologists, remote sensors, ecologists, oceanographers, climatologists-atmospheric researchers and some Quaternary

Bio-geomorphology and resilience thinking: Common ground and challenges

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Thoms, Martin C.; Meitzen, Kimberly M.; Julian, Jason P.; Butler, David R.

2018-03-01

Geomorphology plays a fundamental role in shaping and maintaining landscapes, as well as influencing the social and ecological systems that occupy and utilize these landscapes. In turn, social-ecological systems can have a profound influence on geomorphic forms and processes. These interactions highlight the tightly coupled nature of geomorphic systems. Over the past decade, there has been a proliferation of research at the interface of geomorphology and resilience thinking, and the 2017 Binghamton Symposium brought together leading researchers from both communities to address mutual concerns and challenges of these two disciplines. This paper reviews some of the key intersections between the disciplines of bio-geomorphology and resilience thinking, and the papers presented at the symposium. The papers in this volume illustrate the current status of the disciplines, the difficulties in bridging the disciplines, and the issues that are emerging as research priorities.

Distribution, typology and assessment of degraded soils Piedmont Plains Zhetysu Ridge, Kazakhstan

Directory of Open Access Journals (Sweden)

Maira Kussainova

2017-04-01

Full Text Available Identification of land degradation is essential to check the problem and to implement the remedial measures needed. The study area falls under parts of foothill plains Zhetysu Ridge, Kazakhstan, that is an arid region in climate. Recent data on the status of study area refer to the 80s of the last century, and the intensive use of them led to a significant anthropogenic transformation. This study was carried out in 2015-2016 as part of a project aimed to study features and causes of land degradation in foothill plains Zhetysu Ridge, Kazakhstan. Under the conditions of rainfed soil degradation manifests itself in the development of erosion processes, agro depletion of soils, reducing the productivity of agriculture. The use of land for irrigation often accompanied by secondary salinization. In this regard, at present there is need to assess current state of the soil, with the identification of changes in their properties as a result of the impact of various anthropogenic factors and creation of new electronic soil maps and applied the powerful capabilities of advanced remote sensing (RS and geographic information system (GIS techniques to identify the geomorphological units and degradation risk assessment. Satellite imagery in addition to the field and laboratory studies to identify salinity-induced soil degradation was adopted in this study. Morphological, chemical and physical characteristics of soils in degraded sites in foothill plains Zhetysu Ridge, Kazakhstan, were depicted. The main results of a thorough evaluation of soil degradation in foothill plains Zhetysu Ridge, Kazakhstan, are presented. The data revealed that extent of salinity-induced degradation was generally related to some physical properties of soil, uncontrolled livestock grazing and previous soil management practices. These results are useful as the basis for designing soil conservation and restoration programs, as a base line for evaluating the performance of conservation

The geomorphology of Southeast Kenya

NARCIS (Netherlands)

Oosterom, A.P.

1988-01-01

A geomorphological map of an area of 66 500 km ² in the southeastern part of Kenya has been prepared. In the littoral zone eight major terrace levels occurring between the present shore and approximately 160 m +MSL have been described. Analysis of radiometric datings and

Sedimentological Investigations of the Martian Surface using the Mars 2001 Robotic Arm Camera and MECA Optical Microscope

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Rice, J. W., Jr.; Smith, P. H.; Marshall, J. R.

1999-01-01

The first microscopic sedimentological studies of the Martian surface will commence with the landing of the Mars Polar Lander (MPL) December 3, 1999. The Robotic Arm Camera (RAC) has a resolution of 25 um/p which will permit detailed micromorphological analysis of surface and subsurface materials. The Robotic Ann will be able to dig up to 50 cm below the surface. The walls of the trench will also be inspected by RAC to look for evidence of stratigraphic and / or sedimentological relationships. The 2001 Mars Lander will build upon and expand the sedimentological research begun by the RAC on MPL. This will be accomplished by: (1) Macroscopic (dm to cm): Descent Imager, Pancam, RAC; (2) Microscopic (mm to um RAC, MECA Optical Microscope (Figure 2), AFM This paper will focus on investigations that can be conducted by the RAC and MECA Optical Microscope.

A martian case study of segmenting images automatically for granulometry and sedimentology, Part 2: Assessment

Science.gov (United States)

Karunatillake, Suniti; McLennan, Scott M.; Herkenhoff, Kenneth E.; Husch, Jonathan M.; Hardgrove, Craig; Skok, J. R.

2014-02-01

In a companion work, we bridge the gap between mature segmentation software used in terrestrial sedimentology and emergent planetary segmentation with an original algorithm optimized to segment whole images from the Microscopic Imager (MI) of the Mars Exploration Rovers (MER). In this work, we compare its semi-automated outcome with manual photoanalyses using unconsolidated sediment at Gusev and Meridiani Planum sites for geologic context. On average, our code and manual segmentation converge to within ∼10% in the number and total area of identified grains in a pseudo-random, single blind comparison of 50 samples. Unlike manual segmentation, it also locates finer grains in an image with internal consistency, enabling robust comparisons across geologic contexts. When implemented in Mathematica-8, the algorithm segments an entire MI image within minutes, surpassing the extent and speed possible with manual segmentation by about a factor of ten. These results indicate that our algorithm enables not only new sedimentological insight from the MER MI data, but also detailed sedimentology with the Mars Science Laboratory’s Mars Hand Lens Instrument.

Toward a new system approach of complexity in geomorphology

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Masson, E.

2012-04-01

Since three decades the conceptual vision of catchment and fluvial geomorphology is strongly based on the "fluvial system" (S. A. Schumm, 1977) and the "river continuum system" (R. L. Vannote et al., 1980) concepts that can be embedded in a classical physical "four dimensions system" (C. Amoros and G.-E. Petts, 1993). Catchment and network properties, sediment and water budgets and their time-space variations are playing a major role in this geomorpho-ecological approach of hydro-geomorphosystems in which human impacts are often considered as negative externalities. The European Water Framework Directive (i.e. WFD, Directive 2000/60/EC) and its objective of good environmental status is addressing the question of fluvial/catchment/landscape geomorphology and its integration into IWRM in such a sustainable way that deeply brings back society and social sciences into the water system analysis. The DPSIR methodology can be seen as an attempt to cope with the analysis of unsustainable consequences of society's water-sediment-landscape uses, environmental pressures and their consequences on complex fluvial dynamics. Although more and more scientific fields are engaged in this WFD objective there's still a lack of a global theory that could integrate geomorphology into the multi-disciplinary brainstorming discussion about sustainable use of water resources. Our proposition is to promote and discuss a trans-disciplinary approach of catchments and fluvial networks in which concepts can be broadly shared across scientific communities. The objective is to define a framework for thinking and analyzing geomorphological issues within a whole "Environmental and Social System" (i.e. ESS, E. Masson 2010) with a common set of concepts and "meta-concepts" that could be declined and adapted in any scientific field for any purpose connected with geomorphology. We assume that geomorphological research can benefit from a six dynamic dimensions system approach based on structures

Recent Trends in Karst Geomorphology.

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Palmer, Arthur N.

1984-01-01

Recent trends related to the karst processes and the evolution of karst landscapes are discussed. The hydrochemical processes responsible for the origin of karst are expanded on to illustrate the present scope of karst studies. These geomorphological studies are combined with concepts and techniques from hydraulics, chemistry, and mathematics. (JN)

Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

Science.gov (United States)

McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

2013-01-01

Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

Geomorphology-based interpretation of sedimentation rates from radiodating, lower Passaic River, New Jersey, USA.

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Erickson, Michael J; Barnes, Charles R; Henderson, Matthew R; Romagnoli, Robert; Firstenberg, Clifford E

2007-04-01

Analysis of site geomorphology and sedimentation rates as an indicator of long-term bed stability is central to the evaluation of remedial alternatives for depositional aquatic environments. In conjunction with various investigations of contaminant distribution, sediment dynamics, and bed stability in the Passaic River Estuary, 121 sediment cores were collected in the early 1990s from the lower 9.7 km of the Passaic River and analyzed for lead-210 (210Pb), cesium-137 (137Cs), and other analytes. This paper opportunistically uses the extensive radiochemical dataset to examine the spatial patterns of long-term sedimentation rates in, and associated geomorphic aspects of, this area of the river. For the purposes of computing sedimentation rates, the utility of the 210Pb and 137Cs depositional profiles was assessed to inform appropriate interpretation. Sedimentation rates were computed for 90 datable cores by 3 different methods, depending on profile utility. A sedimentation rate of 0 was assigned to 17 additional cores that were not datable and for which evidence of no deposition exists. Sedimentation patterns were assessed by grouping results within similar geomorphic areas, delineated through inspection of bathymetric data. On the basis of channel morphology, results reflect expected patterns, with the highest sedimentation rates observed along point bars and channel margins. The lowest rates of sedimentation (and the largest percentage of undatable cores) were observed in the areas along the outer banks of channel bends. Increasing sedimentation rates from upstream to downstream were noted. Average and median sedimentation rates were estimated to be 3.8 and 3.7 cm/y, respectively, reflecting the highly depositional nature of the Passaic River estuary. This finding is consistent with published descriptions of long-term geomorphology for Atlantic Coastal Plain estuaries.

Student-Produced Podcasts as an Assessment Tool: An Example from Geomorphology

Science.gov (United States)

Kemp, Justine; Mellor, Antony; Kotter, Richard; Oosthoek, Jan W.

2012-01-01

The emergence of user-friendly technologies has made podcasting an accessible learning tool in undergraduate teaching. In a geomorphology course, student-produced podcasts were used as part of the assessment in 2008-2010. Student groups constructed radio shows aimed at a general audience to interpret and communicate geomorphological data within…

Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

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G. L. Gilbert

2017-05-01

Full Text Available The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2 formed during relative sea-level (RSL fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL dating. We identify four facies associations in sections (4 to 22 m in height exposed along the modern Zackenberg River and coast. Facies associations relate to (I overriding glaciers, (II retreating glaciers and quiescent glaciomarine conditions, (III delta progradation in a fjord valley, and (IV fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka. Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

Science.gov (United States)

Gilbert, Graham L.; Cable, Stefanie; Thiel, Christine; Christiansen, Hanne H.; Elberling, Bo

2017-05-01

The Zackenberg River delta is located in northeast Greenland (74°30' N, 20°30' E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

Volcanology and volcano sedimentology of Sahand region

International Nuclear Information System (INIS)

Moine Vaziri, H.; Amine Sobhani, E.

1977-01-01

There was no volcano in Precambrian and Mesozoic eras in Iran, but in most place of Iran during the next eras volcanic rocks with green series and Dacites were seen. By the recent survey in Sahand mountain in NW of Iran volcanography, determination of rocks and the age of layers were estimated. The deposits of Precambrian as sediment rocks are also seen in the same area. All of volcanic periods in this place were studied; their extrusive rocks, their petrography and the result of their analytical chemistry were discussed. Finally volcano sedimentology of Sahand mountain were described

Geomorphological applications of environmental radionuclides

International Nuclear Information System (INIS)

Quine, T.A.; Walling, D.

1998-01-01

Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

Significance of beach geomorphology on fecal indicator bacteria levels.

Science.gov (United States)

Donahue, Allison; Feng, Zhixuan; Kelly, Elizabeth; Reniers, Ad; Solo-Gabriele, Helena M

2017-08-15

Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Facies sedimentology, mineralogy and genetic stratigraphy of the lower-Lias silici-clastic reservoirs of Cere-La-Ronde; Sedimentologie de facies, mineralogie et stratigraphie genetique des reservoirs silicoclastiques du Lias inferieur de Cere-La-Ronde

Energy Technology Data Exchange (ETDEWEB)

Geiller, M.

1997-11-21

Some sandstone reservoirs in the South West of the Parisian Basin (Sologne) are used for gas storage in the underground aquifer by GDF. The study aims to reconstruct the geometry of these reservoirs and to establish the factors controlling their deposition in the Sologne basin during Rhaetian and Hettangian times. This study combines palynological, sedimentological, mineralogical and sequential analyses. It is applied to channel deposits as well as to flood-plain and over-bank deposits which are rarely considered. The formations are deposited in a continental transgressive context associated to a decreasing subsidence. The different depositional environments varied from the alluvial fan to the coastal plain with different intermediate alluvial plains. They get organized in three depositional profiles which are emphasized by hydrodynamic discontinuities due to irreversible modifications in depositional conditions. The clayey associations change with each depositional profile according to detrital source modifications. They characterize discontinuities due to geodynamic events affecting the Sologne basin (depositional profile changes, pedogenesis). In this continental context, the genetic sequences record a cycle of variation of the river longitudinal profile slope. They determine the sediments geometry which results from the relative sea-level variations. Local tectonics creates an heterogenous subsidence and consequently controls the distribution of the sediments. During tectonic instability periods, the subsiding areas migrate while they do not during tectonic stability periods. The latter end with irreversible change in depositional profile. (author) 135 refs.

Reconstruction of Mid-Holocene sedimentary environments in the central part of the Thessaloniki Plain (Greece), based on microfaunal identification, magnetic susceptibility and grain-size analyses

Science.gov (United States)

Ghilardi, Matthieu; Kunesch, Stéphane; Styllas, Mixalis; Fouache, Eric

2008-05-01

The study aims to estimate the relative contributions of the two drainage basins of the Aliakmon and Axios rivers which, since the Mid-Holocene, have been responsible for building the largest deltaic area in Greece. Sediments from five cores located in the central part of the Thessaloniki Plain have been studied for their environmental changes using paleontological and sedimentological methods. Chronostratigraphical evidence was obtained from 14C AMS dating of marine shells, peat and organic sediment samples. During the Holocene marine transgression, this large coastal plain was a shallow marine bay reaching approx. 35 km inland circa the 4th millennium BC, from which the sea subsequently regressed to the east. Around the middle of the 3rd millennium BC, strong fluvial deposition of Aliakmon, to the east, and of Axios, to the north, occurred and was responsible of a gradual change to lagoonal and limnic environmental conditions. Around the 5th Century BC, a freshwater lake occupied the westernmost part of the plain. Microfaunal identification, together with magnetic susceptibility measurements, and grain-size analysis reveal three main environments of sediment deposition that reflect combinations of both concentrated and dispersed sources of magnetic/source minerals. Using remote sensing and a combination of spectral bands (LANDSAT TM imagery), we identify former fluvial levees and a freshwater lake, and give a spatial interpretation of the rivers' influences in building this deltaic complex. The mechanisms of edification of the plain as well as the roles played by Aliakmon and Axios sedimentation are described.

Geo-archaeological aspects of the Modena plain (Northern Italy

Directory of Open Access Journals (Sweden)

Doriano Castaldini

2007-12-01

Full Text Available This paper traces the various stages of geomorphological evolution of the plain area around Modena from the VIth millennium B.C.E. (Neolithic to the Present, through a reconstruction of the ancient landscape and human settlements.By means of a GIS platform, geomorphological investigations led to the implementation of a Microrelief Map, a Digital Elevation Model (DEM, a Map of Surface Deposits and a Geomorphological Map.The most striking altimetric features in the study area are the morphological changes of the Rivers Secchia and Panaro: south of Modena they run deep in the alluvial plain whereas north of the town they flow elevated over the plain. The surface lithology consists mainly of silt, with bands of sand and clay; mainly gravel deposits crop out only near southern tracks of the main Apennine watercourses. The geomorphological landscape is mainly characterised by alluvial fans, fluvial ridges paleo-riverbeds fluvial scarps, natural springs and some depressed areas; worth of note are also forms connected with human activity.There have been several attempts to cross–date geological and geomorphological evidence with archaeological data, on both detailed and wide territorial scales. A further advancement can now be attempted by comparing data obtained from systematic research on fluvial forms with data contained in the archives.In the area studied, some 800 archaeological sites were identified and catalogued. Such a high number of archaeological sites can give a great deal more information than is found in any other place in northern Italy.The research took into account the overlapping of archaeological and geomorphological data, with the implementation into a GIS (ArcGis 8.3 of geoarchaeological maps divided in main periods and here represented from the Neolithic to the to Iron Age and from Roman period to the Early Middle Ages. The dating thus obtained for fluvial forms was mainly based on the relationship between these forms and

Middle Holocene marine flooding and human response in the south Yangtze coastal plain, East China

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Wang, Zhanghua; Ryves, David B.; Lei, Shao; Nian, Xiaomei; Lv, Ye; Tang, Liang; Wang, Long; Wang, Jiehua; Chen, Jie

2018-05-01

Coastal flooding catastrophes have affected human societies on coastal plains around the world on several occasions in the past, and are threatening 21st century societies under global warming and sea-level rise. However, the role of coastal flooding in the interruption of the Neolithic Liangzhu culture in the lower Yangtze valley, East China coast has been long contested. In this study, we used a well-dated Neolithic site (the Yushan site) close to the present coastline to demonstrate a marine drowning event at the terminal stage of the Liangzhu culture and discuss its linkage to relative sea-level rise. We analysed sedimentology, chronology, organic elemental composition, diatoms and dinoflagellate cysts for several typical profiles at the Yushan site. The field and sedimentary data provided clear evidence of a palaeo-typhoon event that overwhelmed the Yushan site at ∼2560 BCE, which heralded a period of marine inundation and ecological deterioration at the site. We also infer an acceleration in sea-level rise at 2560-2440 BCE from the sedimentary records at Yushan, which explains the widespread signatures of coastal flooding across the south Yangtze coastal plain at that time. The timing of this mid-Holocene coastal flooding coincided with the sudden disappearance of the advanced and widespread Liangzhu culture along the lower Yangtze valley. We infer that extreme events and flooding accompanying accelerated sea-level rise were major causes of vulnerability for prehistoric coastal societies.

Geomorphology in North American Geology Departments, 1971

Science.gov (United States)

White, Sidney E.; Malcolm, Marshall D.

1972-01-01

Presents results of a 1970-71 survey of 350 geomorphologists and geology departments to determine what sort of geomorphology is being taught in the colleges and universities of the United States and Canada. (PR)

Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: First Year Results and Second Year Work Plan

Science.gov (United States)

Skinner, J. A., Jr.; Rogers, A. D.; Seelos, K. D.

2010-01-01

The Libya Montes-Tyrrhena Terra highland-lowland transitional zone of Mars is a complex tectonic and erosional region that contains some of the oldest exposed materials on the Martian surface as well as aqueous mineral signatures that may be potential chemical artifacts of early highland formational processes. Our 1:1M scale mapping project includes the geologic materials and landforms contained within MTMs 00282, -05282, -10282, 00277, - 05277, and -10277, which cover the highland portion of the transitional zone. The map region extends from the Libya Montes southward into Tyrrhena Terra and to the northern rim of Hellas basin and includes volcanic rocks of Syrtis Major Planum and a broad lowlying plain (palus) that forms a topographic divide between Isidis and Hellas basins. The objective of this project is to describe the geologic history of regional massif and plains materials by combining geomorphological and compositional mapping observations. This abstract summarizes the technical approaches and interim scientific results of Year 1 efforts and the expected work plan for Year 2 efforts.

Appraisal of geomorphology of the Goa coast

Digital Repository Service at National Institute of Oceanography (India)

Wagle, B.G.; Kunte, P.D.

The National Institute of Oceanography is carrying out a comprehensive geological and geophysical survey of the continental margin of India. As a part of this project, a geomorphologic study of the coastal area was carried to understand...

National Seabed Mapping Programmes Collaborate to Advance Marine Geomorphological Mapping in Adjoining European Seas

Science.gov (United States)

Monteys, X.; Guinan, J.; Green, S.; Gafeira, J.; Dove, D.; Baeten, N. J.; Thorsnes, T.

2017-12-01

Marine geomorphological mapping is an effective means of characterising and understanding the seabed and its features with direct relevance to; offshore infrastructure placement, benthic habitat mapping, conservation & policy, marine spatial planning, fisheries management and pure research. Advancements in acoustic survey techniques and data processing methods resulting in the availability of high-resolution marine datasets e.g. multibeam echosounder bathymetry and shallow seismic mean that geological interpretations can be greatly improved by combining with geomorphological maps. Since December 2015, representatives from the national seabed mapping programmes of Norway (MAREANO), Ireland (INFOMAR) and the United Kingdom (MAREMAP) have collaborated and established the MIM geomorphology working group) with the common aim of advancing best practice for geological mapping in their adjoining sea areas in north-west Europe. A recently developed two-part classification system for Seabed Geomorphology (`Morphology' and Geomorphology') has been established as a result of an initiative led by the British Geological Survey (BGS) with contributions from the MIM group (Dove et al. 2016). To support the scheme, existing BGS GIS tools (SIGMA) have been adapted to apply this two-part classification system and here we present on the tools effectiveness in mapping geomorphological features, along with progress in harmonising the classification and feature nomenclature. Recognising that manual mapping of seabed features can be time-consuming and subjective, semi-automated approaches for mapping seabed features and improving mapping efficiency is being developed using Arc-GIS based tools. These methods recognise, spatially delineate and morphologically describe seabed features such as pockmarks (Gafeira et al., 2012) and cold-water coral mounds. Such tools utilise multibeam echosounder data or any other bathymetric dataset (e.g. 3D seismic, Geldof et al., 2014) that can produce a

Use of radioactive tracers in dynamic sedimentology

International Nuclear Information System (INIS)

Tola, Francois.

1982-01-01

In the first part, developments in the use of radioactive tracers in sedimentology are recalled together with the corresponding fields of application and the identities of the main users. The state-of-the-art in France is also discussed; The main characteristics of the method are then described and compared with those of more classical methods. The results that can be obtained with tracer methods are then outlined. The criteria employed to establish the granulometry characteristics of the tracer, the particular radioisotope to be used, and the masses and activities involved, are treated. A list is then given of the main isotopes available in France and their characteristics. The various different labelling techniques employed are studied together with their respective advantages and disadvantages. The special case of pelitic sediments is mentioned. The use of reduced model isotope generators, double labelling and applications to studies of the mud plug in the Gironde Estuary are also discussed. The methods and materials used for injecting and detecting tracers are described, emphasis being given to the economic factors associated with the use of radioactive tracers in sedimentology. The second part of the report contains two chapters: - studies of transport by driftage: presentation and analysis of results and the application of the Count Rate Balance method to obtain quantitative information on transport; - studies of in-suspension transport of fine sediments in the sea: the procedures adopted from the moment when the tracer is introduced up to the time when the results are analyzed and interpreted, enables the trajectories and mean velocities of the transported sediments to be determined together with their degree of dilution and their settling speeds and rates; it is also possible to investigate the evolution and horizontal dispersion of the sediments in this way. Results from recent experiments are presented in both parts of the report

Recent advances in research on the aeolian geomorphology of China's Kumtagh Sand Sea

Science.gov (United States)

Dong, Z.; Lv, P.

2014-02-01

The Kumtagh Sand Sea in the hyper-arid region of northwestern China remained largely unexplored until the last decade. It deserves study due to its significance in understanding the evolution of the arid environments in northwestern China, and even central Asia. Aeolian geomorphology in the sand sea has received unprecedented study in the last decade. Encouraging advances have been made in types of aeolian landforms, geological outlines, wind systems, the formation of aeolian landforms, several unique aeolian landforms, aeolian geomorphic regionalization, aeolian geomorphological heritages and tourism development, and aeolian sand hazards and their control. These advances expand our knowledge of aeolian geomorphology.

Hybrid geomorphological maps as the basis for assessing geoconservation potential in Lech, Vorarlberg (Austria)

Science.gov (United States)

Seijmonsbergen, Harry; de Jong, Mat; Anders, Niels; de Graaff, Leo; Cammeraat, Erik

2013-04-01

Geoconservation potential is, in our approach, closely linked to the spatial distribution of geomorphological sites and thus, geomorphological inventories. Detailed geomorphological maps are translated, using a standardized workflow, into polygonal maps showing the potential geoconservation value of landforms. A new development is to semi-automatically extract in a GIS geomorphological information from high resolution topographical data, such as LiDAR, and combine this with conventional data types (e.g. airphotos, geological maps) into geomorphological maps. Such hybrid digital geomorphological maps are also easily translated into digital information layers which show the geoconservation potential in an area. We present a protocol for digital geomorphological mapping illustrated with an example for the municipality of Lech in Vorarlberg (Austria). The protocol consists of 5 steps: 1. data preparation, 2. generating training and validation samples, 3. parameterization, 4. feature extraction, and 5. assessing classification accuracy. The resulting semi-automated digital geomorphological map is then further validated, in two ways. Firstly, the map is manually checked with the help of a series of digital datasets (e.g. airphotos) in a digital 3D environment, such as ArcScene. The second validation is field visit, which preferably occurs in parallel to the digital evaluation, so that updates are quickly achieved. The final digital and coded geomorphological information layer is converted into a potential geoconservation map by weighting and ranking the landforms based on four criteria: scientific relevance, frequency of occurrence, disturbance, and environmental vulnerability. The criteria with predefined scores for the various landform types are stored in a separate GIS attribute table, which is joined to the attribute table of the hybrid geomorphological information layer in an automated procedure. The results of the assessment can be displayed as the potential

Age of depositional and weathering events in Central Amazonia

Science.gov (United States)

Sant'Anna, Lucy Gomes; Soares, Emílio Alberto do Amaral; Riccomini, Claudio; Tatumi, Sonia Hatsue; Yee, Marcio

2017-08-01

In the last three decades, several studies have been devoted to understanding the role of Late Pleistocene-Holocene climate changes in the Amazonia lowlands environment. However, most of these studies used data obtained from sedimentary deposits (lakes, swamps, and colluvium) located away from the central plain or on the edges of the Amazonia region. This article integrates optically stimulated luminescence and accelerated mass spectrometry 14C ages with sedimentological and geomorphological data obtained during this study or compiled from the literature for fluvial and lacustrine deposits of the central alluvial plain of the Solimões-Amazon River. The age data allow us to present a chronological framework for the Late Pleistocene-Holocene deposits and conclude that (i) the dryness of the LGM in central Amazonia lowlands is recorded by the formation of fluvial terraces and their weathering to pedogenic hematite between 25.3 ka and 17.7 ka; (ii) floodplain deposition was contemporaneous with terrace weathering and occurred in a context of decreased water volume in fluvial channels, lowering of river base level and sea level, and isostatic rebound of the continent; and (iii) lateral and mid-channel fluvial bars in the Solimões-Amazon River have a minimum age of 11.5 ± 1.5 ka, and their deposition responded to increased precipitation at the beginning of the Holocene.

Late Quaternary high resolution micropaleontological and sedimentological records in the Gulf of Cadiz.

Science.gov (United States)

Balestra, B.; Ducassou, E.; Zarikian, C.; Bout-Roumazeilles, V.; Flores, J. A.; Paytan, A.

2017-12-01

We present preliminary micropaleontological and sedimentological data from IODP Site U1390 (Expedition 339), located in the central middle slope of the Gulf of Cadiz, since the last glaciation. This site has been targeted for reconstruction of regional paleo-circulation as it shows particularly high sedimentation rates, throughout the Holocene and the Last Glacial Maximum (LGM). We use micropaleontological and sedimentological proxies to understand the bottom current variations through time and the ecological conditions at the sea surface (planktonic foraminifer, pteropod and nannofossil assemblages), and the sea bottom (ostracod assemblages). Eleven samples, chosen at transitions of planktonic foraminifer assemblages, have been dated by AMS radiocarbon analyses. Preliminary results from benthic ostracod assemblages show variations in bottom water ventilation and food supply. Planktonic foraminifer assemblages clearly show the well-known cold events of this period such as the Younger Dryas and Heinrich stadial associated to coarser sediment, and warmer phases such as the Bölling-Allerød associated to muddy sediment. Other bio-events within the Holocene period are also recorded. The preservation of the coccolithophore assemblages is good to moderate. Coccolith abundances (expressed in coccoliths/gr of sediment) show higher values during the Holocene and generally are like assemblages previously reported for the same area. Implications for characterization of the Holocene, the last termination and LGM ecological conditions at high resolution and their potential fluctuations (i.e. amplitude and magnitude) under the influence of the lower core of the Mediterranean Outflow Water (MOW), with this multi proxy approach based on sedimentological, and paleontological data will be discussed.

Surficial geological tools in fluvial geomorphology: Chapter 2

Science.gov (United States)

Jacobson, Robert B.; O'Connor, James E.; Oguchi, Takashi

2016-01-01

Increasingly, environmental scientists are being asked to develop an understanding of how rivers and streams have been altered by environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored, and how they will respond to future environmental change. These questions present substantive challenges to the discipline of fluvial geomorphology, especially since decades of geomorphologic research have demonstrated the general complexity of fluvial systems. It follows from the concept of complex response that synoptic and short-term historical views of rivers will often give misleading understanding of future behavior. Nevertheless, broadly trained geomorphologists can address questions involving complex natural systems by drawing from a tool box that commonly includes the principles and methods of geology, hydrology, hydraulics, engineering, and ecology.

Sedimentological time-averaging and 14C dating of marine shells

International Nuclear Information System (INIS)

Fujiwara, Osamu; Kamataki, Takanobu; Masuda, Fujio

2004-01-01

The radiocarbon dating of sediments using marine shells involves uncertainties due to the mixed ages of the shells mainly attributed to depositional processes also known as 'sedimentological time-averaging'. This stratigraphic disorder can be removed by selecting the well-preserved indigenous shells based on ecological and taphonomic criteria. These criteria on sample selection are recommended for accurate estimation of the depositional age of geologic strata from 14 C dating of marine shells

Geomorphological change detection using object-based feature extraction from multi-temporal LIDAR data

NARCIS (Netherlands)

Seijmonsbergen, A.C.; Anders, N.S.; Bouten, W.; Feitosa, R.Q.; da Costa, G.A.O.P.; de Almeida, C.M.; Fonseca, L.M.G.; Kux, H.J.H.

2012-01-01

Multi-temporal LiDAR DTMs are used for the development and testing of a method for geomorphological change analysis in western Austria. Our test area is located on a mountain slope in the Gargellen Valley in western Austria. Six geomorphological features were mapped by using stratified Object-Based

Global Geomorphology

Science.gov (United States)

Douglas, I.

1985-01-01

Any global view of landforms must include an evaluation of the link between plate tectonics and geomorphology. To explain the broad features of the continents and ocean floors, a basic distinction between the tectogene and cratogene part of the Earth's surface must be made. The tectogene areas are those that are dominated by crustal movements, earthquakes and volcanicity at the present time and are essentially those of the great mountain belts and mid ocean ridges. Cratogene areas comprise the plate interiors, especially the old lands of Gondwanaland and Laurasia. Fundamental as this division between plate margin areas and plate interiors is, it cannot be said to be a simple case of a distinction between tectonically active and stable areas. Indeed, in terms of megageomorphology, former plate margins and tectonic activity up to 600 million years ago have to be considered.

The Plains of Venus

Science.gov (United States)

Sharpton, V. L.

2013-12-01

Volcanic plains units of various types comprise at least 80% of the surface of Venus. Though devoid of topographic splendor and, therefore often overlooked, these plains units house a spectacular array of volcanic, tectonic, and impact features. Here I propose that the plains hold the keys to understanding the resurfacing history of Venus and resolving the global stratigraphy debate. The quasi-random distribution of impact craters and the small number that have been conspicuously modified from the outside by plains-forming volcanism have led some to propose that Venus was catastrophically resurfaced around 725×375 Ma with little volcanism since. Challenges, however, hinge on interpretations of certain morphological characteristics of impact craters: For instance, Venusian impact craters exhibit either radar dark (smooth) floor deposits or bright, blocky floors. Bright floor craters (BFC) are typically 100-400 m deeper than dark floor craters (DFC). Furthermore, all 58 impact craters with ephemeral bright ejecta rays and/or distal parabolic ejecta patterns have bright floor deposits. This suggests that BFCs are younger, on average, than DFCs. These observations suggest that DFCs could be partially filled with lava during plains emplacement and, therefore, are not strictly younger than the plains units as widely held. Because the DFC group comprises ~80% of the total crater population on Venus the recalculated emplacement age of the plains would be ~145 Ma if DFCs are indeed volcanically modified during plains formation. Improved image and topographic data are required to measure stratigraphic and morphometric relationships and resolve this issue. Plains units are also home to an abundant and diverse set of volcanic features including steep-sided domes, shield fields, isolated volcanoes, collapse features and lava channels, some of which extend for 1000s of kilometers. The inferred viscosity range of plains-forming lavas, therefore, is immense, ranging from the

Indian Ocean Islands, coastal ecology and geomorphology

Digital Repository Service at National Institute of Oceanography (India)

Wafar, M.V.M.; Wafar, S.; Yennavar, P.

stream_size 8 stream_content_type text/plain stream_name Encyclopedia_Coast_Sci_2005_557.pdf.txt stream_source_info Encyclopedia_Coast_Sci_2005_557.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Geomorphology and sedimentology of badlands system in the southwest coastline of Castle Araya, Sucre State, Venezuela

Directory of Open Access Journals (Sweden)

Franklin Antonio Nuñez Ravelo

2017-03-01

Full Text Available The study area is located in the south-west coast of Araya in Sucre State, between 10° 33’30’’ N , 10°33’59’’ N y 64°15’32’’ W, 64°15’36’’ W, which it is affected by erosion processes impacting the population center that sits there. Hence the research is to analyze the geomorphological processes developed, based on a model no-experimental and design field, in descriptive and explanatory levels, operationalized in three phases: a field, to collect 21 samples of surface sediment (0-20 cm distributed in 12 samples in the first badlands and 9 samples in the second and lift the morphometry of these landforms erosion; (b image analysis, three stages such as the development of thematic maps from the Topographical maps of Cumana, Geological Araya Peninsula and The Cadastral Charter covered: Punta Caracare; followed by drawing sketches of gullies, from the data collected in the field, refer to height, length and width of the land. Corresponding to the last two variables data were corrected by the equation suggested by Wolf and Ghilani (2008, for data collected on slopes using measuring tape; and finally drawing the sketch of the apical cliff line drawn from the interpretation of the captured images of Google Earth for the years 2003, 2006, 2009 and 2011, based on the proposal of Soriano (2009 and (c laboratory, to analyze the comportamientode physical properties such as: hygroscopic water content, determined by gravimetric method, based on the arguments presented by Rivera, et al. (2006 and Toledo (2009; size distribution of the particles (Method Bouyoucos following the protocol reported by Lara (1985; Percentage of dispersion and soil (double hydrometer method based on the specifications referred by porters and Alva (1999. As for the chemical-mineralogical properties, it was determined from 10 samples analysis of total rocks and clay mineralogy, for both analyzes samples were prepared, processed and analyzed in the laboratory

Directions in Geoheritage Studies: Suggestions from the Italian Geomorphological Community

Science.gov (United States)

Panizza, Valeria

2015-04-01

More and more attention has been focused on geological and geomorphological heritage in the past years, leading to several researches in the framework of conservation projects, both at administrative and at scientific level, involving national and international research groups whose purposes are the promotion of Earth Sciences knowledge and the conservation of geological heritage. This paper presents an overview of research and conservation projects in Italy, mainly focused on the geomorphological heritage. Members of the AIGEO Working Group on geomorphosites and cultural landscape analyzed the historical development, methodological issues and main results of these research projects in order to identify possible innovation lines to improve the awareness and knowledge on geodiversity and geoheritage by a wide public, including education, tourism and conservation sectors. In Italy numerous projects of research have been realized with the main aim of geomorphosites inventory and the proposal of assessment methodologies, and so to the improvement and to the analysis of risks and impacts related to their fruition. At an international level, many Italian researchers have also been involved in studies carried out in the Working Group "Geomorphological sites" of the International Association of Geomorphologists (IAG). At a national level several research lines are under development, offering different responses to methodological issues within the general topic of geodiversity and geoheritage: Geosites inventories and assessment activities are performed with powerful digital techniques and new reference models: among these, the investigation on the ecologic support role for increasing geomorphosites global value and the elaboration of quantitative assessment methods of the scientific quality of Geomorphosites, carried out specifically for territorial planning. Improvements in field data collection and visual representation of landforms lead to new findings in

Multi-Site Calibration of Linear Reservoir Based Geomorphologic Rainfall-Runoff Models

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Bahram Saeidifarzad

2014-09-01

Full Text Available Multi-site optimization of two adapted event-based geomorphologic rainfall-runoff models was presented using Non-dominated Sorting Genetic Algorithm (NSGA-II method for the South Fork Eel River watershed, California. The first model was developed based on Unequal Cascade of Reservoirs (UECR and the second model was presented as a modified version of Geomorphological Unit Hydrograph based on Nash’s model (GUHN. Two calibration strategies were considered as semi-lumped and semi-distributed for imposing (or unimposing the geomorphology relations in the models. The results of models were compared with Nash’s model. Obtained results using the observed data of two stations in the multi-site optimization framework showed reasonable efficiency values in both the calibration and the verification steps. The outcomes also showed that semi-distributed calibration of the modified GUHN model slightly outperformed other models in both upstream and downstream stations during calibration. Both calibration strategies for the developed UECR model during the verification phase showed slightly better performance in the downstream station, but in the upstream station, the modified GUHN model in the semi-lumped strategy slightly outperformed the other models. The semi-lumped calibration strategy could lead to logical lag time parameters related to the basin geomorphology and may be more suitable for data-based statistical analyses of the rainfall-runoff process.

Intensity of geomorphological processes in NW sector of Pacific rim marginal mountain belts

Science.gov (United States)

Lebedeva, Ekaterina; Shvarev, Sergey; Gotvansky, Veniamin

2014-05-01

Continental marginal mountains, including the mountain belts of Russian Far East, are characterized by supreme terrain contrast, mosaic structure of surface and crust, and rich complex of modern endogenous processes - volcanism, seismicity, and vertical movements. Unstable state of geomorphological systems and activity of relief forming processes here is caused also by deep dissected topography and the type and amount of precipitation. Human activities further stimulate natural processes and increase the risk of local disasters. So these territories have high intensity (or tension) of geomorphological processes. Intensity in the authors' understanding is willingness of geomorphological system to be out of balance, risk of disaster under external and internal agent, both natural and human. Mapping with quantitative accounting of intensity of natural and human potential impact is necessary for indication the areal distribution trends of geomorphological processes intensity and zones of potential risk of disasters. Methods of map drowning up are based on several criteria analyzing: 1) total terrain-form processes and their willingness to be a hazard-like, 2) existence, peculiarity and zoning of external agents which could cause extreme character of base processes within the territory, 3) peculiarity of terrain morphology which could cause hazard way of terrain-form processes. Seismic activity is one of the most important factors causing activation of geomorphological processes and contributing to the risk of dangerous situations. Earthquake even small force can provoke many catastrophic processes: landslides, mudslides, avalanches and mudflows, tsunami and others. Seismic gravitational phenomenons of different scale accompany almost all earthquakes of intensity 7-8 points and above, and some processes, such as avalanches, activated by seismic shocks intensity about 1-3 points. In this regard, we consider it important selection of high intensity seismic zones in

The elevation and its distribution in geomorphological regions of the European Russia

Science.gov (United States)

Kharchenko, S. V.; Ermolaev, O. P.; Mukharamova, S. S.

2018-01-01

Spatial differences of elevation were analysed by side of view of geomorphological boundaries on the European Russia territory. Geomorphological pattern of the studied territory was taken from Geomorphological Map of the USSR at scale of 1: 2 500 000. There 2401 fragments for combinations of 58 types of structural landforms and 22 types of sculptural landforms were allocated. The elevation values computed by digital elevation model (cell size - 200 m, number of cells - 322M) based on SRTM (south of 60 nl.) and GDEM 2010 (north of 60 nl.) resampled data. It was founded that some types of structural (16 types) and sculptural (6 types) landforms located in the relatively thin intervals of elevation. Using of elevation above sea level is needed for effective automatic recognizing these landform regions.

Geotourist itineraries along the Italian territory: examples of mapping the geoheritage in different geomorphological and historical contexts

Science.gov (United States)

Panizza, Valeria; Brandolini, Pierluigi; Laureti, Lamberto; Nesci, Olivia; Russo, Filippo; Savelli, Daniele

2016-04-01

In the framework of the studies dealing with geomorphosites mapping, many researches were carried out in the last years presenting both applied examples and proposals for tourist fruition. Researchers had to face many different challenges in transferring the knowledge about the geomorphological heritage on maps. The most relevant are those concerning the use of maps for tourist promotion, taking into account the requirements of clearness of representation of landforms and also the need of pointing out possible geomorphological hazards along tourist paths. Within the activity of the Working Group "Geomorphosites and Cultural Landscape" of AIGeo (Italian Association of Physical Geography and Geomorphology), some Italian itineraries, focused on the promotion of the geomorphological heritage by means of geotourist maps, are presented. They have the goal of: promoting landscape through its geomorphological and geological heritage; disseminating geoheritage knowledge focusing its relationships with cultural landscape and human history; assessing geomorphological hazards and possible risk situations The proposed itineraries are localised in different Italian regions and they concern: - the area around the remains of the Roman town of Ostra. The town is placed on the left side of the Misa River (Marche region, Italy), atop a stream terrace dating back to the uppermost Pleistocene-early Holocene. Detailed geomorphological field and remote-sensing mapping started in 2015. The surveying is aimed at focusing the geomorphological evolution as well as at assessing possible geomorphological hazard for both conservation and exploitation scopes. A geotourist trail is proposed with the aim of highlighting and integrating geomorphological and archaeological elements and information. - a geotourist trail along the coastal terraced slopes of Cinque Terre (Liguria, NW Italy): worldwide considered as one of the most outstanding examples of human integration with the natural landscape

Geomorphological change and river rehabilitation : case studies on lowland fluvial ystems in the Netherlands

NARCIS (Netherlands)

Wolfert, Hendrik Pieter

2001-01-01

Integrated spatial planning for river rehabilitation requires insight in the geomorphology of river systems. Procedures are elaborated to implement a functional-geographical approach in geomorphology, in which a view of rivers as four-dimensional systems and the use of a process-based hierarchy of

Recent Geomorphological Evolution in the Southern Part of the Middle Russian Upland (Russia)

Science.gov (United States)

Romanovskaya, Maria; Sukhanova, Tatyana; Krilkov, Nikita

2017-04-01

The Middle Russian Upland occupies the central part of the East European Plain. Our structural and geomorphological study of the Upland's southern segment (mostly of the Ostrogozhsk Uplift) exposed the presence of differently aged erosion-shaped denudational, erosion-shaped accumulational and purely accumulational surfaces, each with its own complex of recent deposits. The entire landscape is a system of altitudinal 'steps', or 'levels', which we believe were formed by uneven neotectonic movements and also influenced by climate fluctuations. The highest (220 - 230 m above sea level) and the oldest day light surface of the Ostrogozhsk Uplift lies on Poltava- and Shapkino-type deposit suites and dates from the Late Miocene. A surface at about 200 m dates from the Late Miocene and the Pliocene. Surfaces at 180 m and 150 m date from the Eopleistocene and the Early Pleistocene, respectively. The former lies on Kiev-type deposits, and the latter - on fluvioglacial deposits from the time of the maximum Dnepr (or Don) Glaciations. The valleys of the rivers Don and Tikhaya Sosna have fluvial terraces above their floodplains all formed under the influence of the Don, Dnepr, Moscow and, Valdai Glaciations. Terrace IV (at about 60 m above river level) formed in the opening half of the Middle Neopleistocene. Terrace III (40 m), formed in the closing half of the Middle Neopleistocene. Terrace II (30 m), formed in the opening half of the Late Neopleistocene. Terrace II (at 10 to 12 m), formed in the closing half of the Late Neopleistocene. The floodplain (at 2 to 4 m), formed in the Holocene. There is ample evidence of neotectonic activity in the surveyed area, namely: changes in the flow direction of the rivers Don and Tikhaya Sosna, forced to bypass the growing upland forming tectonic meanders; instances of damming up, which have led to waterlogging in floodplains; increase in the density of the erosion grid; fall of the groundwater table; intensification of erosion and slope

Implications of sedimentological studies for environmental pollution assessment and management: Examples from fluvial systems in North Queensland and Western Australia

Science.gov (United States)

Eyre, Bradley; McConchie, David

1993-05-01

Sedimentology is of increasing importance in environmental research, particularly environmental pollution studies, where past trends in environmental processes need to be combined with data on present conditions to predict likely future changes—the past and present as a key to the future. Two examples are used to illustrate the role of sedimentology in assessing the influence of major processes on the transport, accumulation, deposition and modification of contaminants in fluvial/estuarine systems and in developing environmental management plans. Example 1 shows that when assessing nutrient behaviour in fluvial/estuarine depositional settings, it is important to examine the partitioning of phosphorus between grain size fractions to evaluate the sedimentological processes which control the dispersion and trapping of these contaminants. Example 2 shows that in studies of anthropogenic metal inputs to modern depositional settings, lateral and stratigraphic trends in sediment texture and mineralogy should be examined, in addition to trends in metal loads and evaluation of the prevailing physical, chemical and biological processes that may influence metal mobility and dispersion. Clearly, basic sedimentological data should form part of any assessment of potentially contaminated sites and part of investigations into the dispersion and trapping of contaminants in fluvial systems. These data are also required for rational environmental management to ensure that planning decisions are compatible with natural environmental constraints.

Drought variability over Thessaly plain, Greece. Present and future changes

Science.gov (United States)

Nastos, Panagiotis T.; Kapsomenakis, John; Dalezios, Nicolas R.; Kotsopoulos, Spyridon; Poulos, Serafim

2015-04-01

The diachronic variability of precipitation is of major scientific concern, because it is linked to water availability or deficiency on regional scale. The latter, resulted from a prolonged period of abnormally low precipitation or permanent absence of precipitation, is associated with dryness, having on one hand, a substantial impact on agricultural production and thus the society itself, and on the other hand, the redistribution of flora and fauna. In some cases, dryness drive climate refugees, and this is a great challenge - threat - that must be faced - mitigated - by stake holders in international organizations and fora. The Aridity Index (AI) measures the degree of dryness of the climate at a given region, and according to the United Nations Environmental Programme (UNEP) it is defined as the ratio of precipitation to the potential evapotranspiration. In this study, we investigate the climate change impacts on AI over Thessaly plain, Greece. Thessaly, the largest plain and granary of Greece, includes a total area of 14,036 km2, which represents almost 11% of the Greek territory. Regarding the geomorphology, the ground is 50% mountainous-hilly and 50% flat, irrigated by Peneus, the third largest river in the country, which flows through the axis east-west. The assessment of AI was conducted utilizing daily evapotranspiration losses, based on the modified FAO-56 Penman-Monteith formula, and daily precipitation totals from a number of Regional Climate Models (RCMs), within the ENSEMBLE European Project. Further, the projected changes of AI between the period 1961-1990 (reference period) and the periods 2021-2050 (near future) and 2071-2100 (far future) along with the inter-model standard deviations are presented, under SRES A1B. The findings of the analysis revealed significant spatiotemporal changes of AI over Thessaly plain, focusing on their societal aspects. Acknowlegdements. This work is supported by the project AGROCLIMA (11SYN_3_1913), which is funded by

Deformation of textural characteristics and sedimentology along micro-tidal estuarine beaches

Digital Repository Service at National Institute of Oceanography (India)

Dora, G.U.; SanilKumar, V.; Philip, C.S.; Johnson, G.

Indian Journal of Geo Marine Sciences Vol. 45 (11), November 2016, pp. 1432-1444 *Corresponding author Deformation of textural characteristics and sedimentology along micro- tidal estuarine beaches G. Udhaba Dora, V. Sanil Kumar*, C... sediment is a foremost parameter for a coastal researcher/engineer/designer due to its various applications for sorting out a coastal environment. Sedimentary process at foreshore zone is a highly dynamical whereas textural characteristics...

Highlighting landslides and other geomorphological features using sediment connectivity maps

Science.gov (United States)

Bossi, Giulia; Crema, Stefano; Cavalli, Marco; Marcato, Gianluca; Pasuto, Alessandro

2016-04-01

Landslide identification is usually made through interpreting geomorphological features in the field or with remote sensing imagery. In recent years, airborne laser scanning (LiDAR) has enhanced the potentiality of geomorphological investigations by providing a detailed and diffuse representation of the land surface. The development of algorithms for geomorphological analysis based on LiDAR derived high-resolution Digital Terrain Models (DTMs) is increasing. Among them, the sediment connectivity index (IC) has been used to quantify sediment dynamics in alpine catchments. In this work, maps of the sediment connectivity index are used for detecting geomorphological features and processes not exclusively related to water-laden processes or debris flows. The test area is located in the upper Passer Valley in South Tyrol (Italy). Here a 4 km2 Deep-seated Gravitational Slope Deformation (DGSD) with several secondary phenomena has been studied for years. The connectivity index was applied to a well-known study area in order to evaluate its effectiveness as an interpretative layer to assist geomorphological analysis. Results were cross checked with evidence previously identified by means of in situ investigations, photointerpretation and monitoring data. IC was applied to a 2.5 m LiDAR derived DTM using two different scenarios in order to test their effectiveness: i) IC derived on the hydrologically correct DTM; ii) IC derived on the original DTM. In the resulting maps a cluster of low-connectivity areas appears as the deformation of the DGSD induce a convexity in the central part of the phenomenon. The double crests, product of the sagging of the landslide, are extremely evident since in those areas the flow directions diverge from the general drainage pattern, which is directed towards the valley river. In the crown area a rock-slab that shows clear evidence of incumbent detachment is clearly highlighted since the maps emphasize the presence of traction trenches and

Geomorphology of Goa and Goa Coast. A review

Digital Repository Service at National Institute of Oceanography (India)

Wagle, B.G.

This review on the geomorphology of Goa and the Goa coast included studies on the interpretation of LANDSAT images, aerial photographs and extensive field work. Physiographically the region can be broadly classified into: 1) the coastal tract; 2...

Incorporating Concept Sketching into Teaching Undergraduate Geomorphology

Science.gov (United States)

Reusser, Lucas J.; Corbett, Lee B.; Bierman, Paul R.

2012-01-01

Constructing concept sketches (diagrams annotated with short captions in which students demonstrate their understanding of form, process, and interactions) provides a new and different way to teach Earth surface processes and assess the depth of student learning. During a semester-long course in Geomorphology, we used concept sketches as an…

GEOMORPHOLOGICAL MAPPING AND GEODIVERSITY: STUDY AT THE MINAS DO CAMAQUÃ GEOSITE PROTECTION AREA (BRAZIL

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Maurício Mendes Von Ahn

2017-05-01

Full Text Available Geomorphological mapping allows the evaluation of geoheritage and subsidizes geoconservation efforts. This work aimed at identifying and analyzing the landforms at the Minas do Camaquã Geosite Protection Area (MCGPA – Rio Grande do Sul state – Brazil, emphasizing the anthropogenic morphologies to subsidize the conservation of the studied area’s geomorphological heritage. A geomorphological map (2015 of the MCGPA was made (1:25.000 to recognize and identify the natural and anthropogenic landforms. Based on this map, four sectors were identified according to the representativeness of the landforms: (1 Mineral extraction sector; (2 Tailings deposition sector; (3 Structural features sector; and (4 Boundary sector. The mining activities were the main reason for the geomorphological alterations and the creation of anthropogenic morphologies in the site. Despite the significant disturbance caused by the mining activity, there are still features of geologic-geomorphological interest fairly preserved. The identified and analyzed anthropogenic morphologies can describe the history of the mining activities that took place in the area and which formed a set of landforms currently present in the MCGPA. Although the surface features are not originated from natural morphogenesis, they belong to the area’s geodiversity. Furthermore, considering these features as geoheritage would create the need for management aiming at avoiding the collapse and degradation of these forms. Nowadays, the mining activities have remained inactive, and this set of anthropogenic morphologies need to be understood under a geomorphological point of view which will allow future exploitation of its potential touristic, scientific, pedagogical and cultural uses. The best way to promote and develop strategies of geoconservation for this place is to create and foment geotourism in this area.

SOILS VULNERABILITY OF CATCHMENT ALMAŞ AT GEOMORPHOLOGIC CONTEMPORARY PROCESSES

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MĂDĂLINA-IOANA RUS

2015-03-01

Full Text Available Soils vulnerability of the Catchment Almas geomorphologic processes. Almas Basin, signed lower lithologic Miocene soils deposits, shows six classes: Cernisols, Cambisols, Luvisols, Hydrosols, Pelisols, Protosols (after SRTS, 2003. The largest share is attributed to Luvisols class (60%, followed by undeveloped soil represented by Protosols and Antrisols (15%, followed by the remaining classes with lower weights: Cambisols (13%, Cernisols (7%, Pelisols (4%, Hydrosols (1%. Contemporary geomorphological processes (surface and deep erosion, mass movements change agricultural areas and forest ratio or flow out of economic network tens of hectares annually. Soil vulnerability to the manifestation of these processes is expressed by disturbing soil horizons, coastal springs appearance and growth of the adjoining excess moisture, soil sealing productive by dropping or by alienation.

Flood risk mitigation and anthropogenic modifications of a coastal plain in southern Italy: combined effects over the past 150 years

Directory of Open Access Journals (Sweden)

O. Petrucci

2007-06-01

Full Text Available A study of the effects of human modification of a coastal plain mainly involving land reclamation and flood protection is proposed. The approach involves historical, geomorphological and hydrological data as a whole, taking into account the equilibrium of rivers, plains and coastal areas.

The test area, a telling example of profound economic and social transformation of a coastal plain, is the Piana di Sibari (Calabria, southern Italy, subject to major human modifications over the last 150 years. The study area, at most 300 m a.s.l., is 450 km² wide and comprises 24 hydrographic basins.

The approach is based on the creation and analysis of four databases: 1 a historical series of geo-coded flood damage (DAMAGES database, concerning damaging floods which occurred over the past few centuries in the study area; 2 a geocoded series of protection works for land reclamation, protection from floods and improvement of soil stability in steep areas (WORKS database, gathered from the archives of the agencies that carried out the works, organized in a GIS-format; 3 a historical series of maximum flood discharges and extreme rainy events (HYMAX database aimed at defining the trends of occurrence and the intensity of flooding; 4 a coastal line position and migration over time (COASTAL database, created using mainly literature data based on discontinuous data such as historical maps and images.

The work describes the complex succession of floods, protection and reclamation works, human transformation of the plain and major land use changes over the last two centuries in the test area. The new characteristics of the plain and its modifications, including major engineering works, land-use transformation and urbanisation, are illustrated. The damaging floods of the last 200 years, the modifications of runoff and flooding due to works built over the basins, hydrological data and the records concerning coastal

Sedimentology and paleoecology of an Eocene Oligocene alluvial lacustrine arid system, Southern Mexico

Science.gov (United States)

Beraldi-Campesi, Hugo; Cevallos-Ferriz, Sergio R. S.; Centeno-García, Elena; Arenas-Abad, Concepción; Fernández, Luis Pedro

2006-10-01

A depositional model of the Eocene-Oligocene Coatzingo Formation in Tepexi de Rodríguez (Puebla, Mexico) is proposed, based on facies analysis of one of the best-preserved sections, the Axamilpa Section. The sedimentary evolution is interpreted as the retrogradation of an alluvial system, followed by the progressive expansion of an alkaline lake system, with deltaic, palustrine, and evaporitic environments. The analysis suggests a change towards more arid conditions with time. Fossils from this region, such as fossil tracks of artiodactyls, aquatic birds and cat-like mammals, suggest that these animals traversed the area, ostracods populated the lake waters, and plants grew on incipient soils and riparian environments many times throughout the history of the basin. The inferred habitat for some fossil plants coincides with the sedimentological interpretation of an arid to semiarid climate for that epoch. This combined sedimentological-paleontological study of the Axamilpa Section provides an environmental context in which fossils can be placed and brings into attention important biotic episodes, like bird and camelid migrations or the origin of endemic but extinct plants in this area.

Process and form in geomorphology

National Research Council Canada - National Science Library

Stoddart, D. R

1997-01-01

... the world. The book is in two parts. The first presents state-of-the-art reports on fluvial, tectonic and climatic geomorphology by leading experts in their fields, all Chorley's colleagues and students. The second brings revisionary views to many aspects of the history of the discipline, on which Chorley is the world authority. Together they present not only new views on the landforms of the world but also incisive insights into how we have made sense of the environment around us from the early eighteenth centu...

Habitat hydrology and geomorphology control the distribution of malaria vector larvae in rural Africa.

Science.gov (United States)

Hardy, Andrew J; Gamarra, Javier G P; Cross, Dónall E; Macklin, Mark G; Smith, Mark W; Kihonda, Japhet; Killeen, Gerry F; Ling'ala, George N; Thomas, Chris J

2013-01-01

Larval source management is a promising component of integrated malaria control and elimination. This requires development of a framework to target productive locations through process-based understanding of habitat hydrology and geomorphology. We conducted the first catchment scale study of fine resolution spatial and temporal variation in Anopheles habitat and productivity in relation to rainfall, hydrology and geomorphology for a high malaria transmission area of Tanzania. Monthly aggregates of rainfall, river stage and water table were not significantly related to the abundance of vector larvae. However, these metrics showed strong explanatory power to predict mosquito larval abundances after stratification by water body type, with a clear seasonal trend for each, defined on the basis of its geomorphological setting and origin. Hydrological and geomorphological processes governing the availability and productivity of Anopheles breeding habitat need to be understood at the local scale for which larval source management is implemented in order to effectively target larval source interventions. Mapping and monitoring these processes is a well-established practice providing a tractable way forward for developing important malaria management tools.

Geomorphologic specificities of selected sites for nuclear power plants in Czechoslovakia

International Nuclear Information System (INIS)

Kalvoda, J.; Demek, J.

1991-01-01

The contribution of geomorphology to the complex evaluation of properties of sites for the construction and operation of nuclear facilities is demonstrated. The unique manifestation of the present geodynamics at the Jaslovske Bohunice nuclear power plant locality and the spatial correlations of annals of the specific morphotectonic development of georeliefs of that nuclear power plant with the location of the epicentral earthquake zones are shown. The results of the geomorphological survey in the surroundings of the Temelin nuclear power plant construction site are described and a drawing is reproduced showing how the georelief of this locality divides into areas with different categories of occurrence of morpho-structural formations. For the Tetov locality, where the construction of a nuclear power plant is planned, the changes in the course of the Labe (Elbe) river which occurred in the Pleistocene are of importance in the assessment of the intensity of geodynamic processes. The geomorphological and geotectonic complexity of the planned Blahutovice nuclear power plant construction site is demonstrated. A drawing shows the morphotectonic situation in the surroundings of that construction site. (Z.S.). 4 figs

Global Mega-geomorphology

Science.gov (United States)

Hayden, R. S. (Editor)

1985-01-01

The extension of space exploration to the Moon and to other planets has broadened the scope of geomorphology by providing information on landforms which have developed in environments that differ significantly in fundamental factors such as temperature, pressure and gravity from the environments in which Earth's landforms have been shaped. In some cases the landforming processes themselves appear to be significantly different than any found in the terrestrial environment. Some investigators have suggested that features observed on other planets, such as chaos terrian and labryinths on Mars, can help us understand Earth's early history better because they may have been formed by processes which were important in the early ages of Earth but have long ceased to be active here. Corresponding terrestrial landforms would have long since been altered or obliterated by subsequent activity.

Teaching Topographic Map Skills and Geomorphology Concepts with Google Earth in a One-Computer Classroom

Science.gov (United States)

Hsu, Hsiao-Ping; Tsai, Bor-Wen; Chen, Che-Ming

2018-01-01

Teaching high-school geomorphological concepts and topographic map reading entails many challenges. This research reports the applicability and effectiveness of Google Earth in teaching topographic map skills and geomorphological concepts, by a single teacher, in a one-computer classroom. Compared to learning via a conventional instructional…

Relationships between sea-bed radionuclide activities and some sedimentological variables

International Nuclear Information System (INIS)

Ligero, R.A.; Ramos-Lerate, I.; Barrera, M.; Casas-Ruiz, M.

2001-01-01

Natural radionuclides ( 232 Th, 226 Ra, 40 K) and 137 Cs, coming from atmospheric radioactive fallout, have been measured in sea-bed sediments of the Bay of Cadiz (South Western Spain). In this report, multivariate analysis methods have been employed to study the relationships between the activities of the radionuclides and some sedimentological variables like granulometric facies, organic content and apparent density. The correlation functions found show that it is possible to determine, with a satisfactory degree of approximation, the granulometric facies of the sediments using only radiometric information

Basin Scale Assessment of Landslides Geomorphological Setting by Advanced InSAR Analysis

Directory of Open Access Journals (Sweden)

Francesca Bozzano

2017-03-01

Full Text Available An extensive investigation of more than 90 landslides affecting a small river basin in Central Italy was performed by combining field surveys and remote sensing techniques. We thus defined the geomorphological setting of slope instability processes. Basic information, such as landslides mapping and landslides type definition, have been acquired thanks to geomorphological field investigations and multi-temporal aerial photos interpretation, while satellite SAR archive data (acquired by ERS and Envisat from 1992 to 2010 have been analyzed by means of A-DInSAR (Advanced Differential Interferometric Synthetic Aperture Radar techniques to evaluate landslides past displacements patterns. Multi-temporal assessment of landslides state of activity has been performed basing on geomorphological evidence criteria and past ground displacement measurements obtained by A-DInSAR. This step has been performed by means of an activity matrix derived from information achieved thanks to double orbital geometry. Thanks to this approach we also achieved more detailed knowledge about the landslides kinematics in time and space.

The contribution of geomorphological research to environmental issues in Mexico

Directory of Open Access Journals (Sweden)

Gerardo Bocco

2013-07-01

Full Text Available The paper analyzes the development of Mexican geomorphology and specially its contribution to environmental issues. To this end, a thorough literature review was carried out; papers were differentiated according to the type of journal (Mexican and international. Special emphasis was placed on analyzing whether the interest on environment was derived from a well defined theoretical framework, in particular in terms of the insertion of geomorphology in the geographic arena in Mexico. The review has focused on secientific papers duly refereed and available at the Internet. Thus other research was not included. However, that the database described in this paper represents a solid sample of the entire universe of the efforts of Mexican geomorphologists.

Plain formation on Mercury: tectonic implications

International Nuclear Information System (INIS)

Thomas, P.

1980-01-01

Four major plain units, plus intermediates, are distinguished on Mercury. The chronologic relationships between these plains indicate that plains formation was a permanent process on Mercury. Their location and morphology seem to indicate a possible volcanic origin for these plains. The relationships between tectonism and volcanism seems to indicate the global contraction is not the only tectonic process on Mercury. (Auth.)

A sedimentological approach to refining reservoir architecture in a mature hydrocarbon province: the Brent Province, UK North Sea

Energy Technology Data Exchange (ETDEWEB)

Hampson, G.J.; Sixsmith, P.J.; Johnson, H.D. [Imperial College, London (United Kingdom). Dept. of Earth Science and Engineering

2004-04-01

Improved reservoir characterisation in the mature Brent Province of the North Sea, aimed at maximising both in-field and near-field hydrocarbon potential, requires a clearer understanding of sub-seismic stratigraphy and facies distributions. In this context, we present a regional, high-resolution sequence stratigraphic framework for the Brent Group, UK North Sea based on extensive sedimentological re-interpretation of core and wireline-log data, combined with palynostratigraphy and published literature. This framework is used to place individual reservoirs in an appropriate regional context, thus resulting in the identification of subtle sedimentological and tectono-stratigraphic features of reservoir architecture that have been previously overlooked. We emphasise the following insights gained from our regional, high-resolution sequence stratigraphic synthesis: (1) improved definition of temporal and spatial trends in deposition both within and between individual reservoirs, (2) development of regionally consistent, predictive sedimentological models for two enigmatic reservoir intervals (the Broom and Tarbert Formations), and (3) recognition of subtle local tectono-stratigraphic controls on reservoir architecture, and their links to the regional, Middle Jurassic structural evolution of the northern North Sea. We discuss the potential applications of these insights to the identification of additional exploration potential and to improved ultimate recovery. (author)

Sedimentology and preservation of aeolian sediments on steep terrains: Incipient sand ramps on the Atacama coast (northern Chile)

Science.gov (United States)

Ventra, Dario; Rodríguez-López, Juan Pedro; de Boer, Poppe L.

2017-05-01

The origin of topographically controlled aeolian landforms in high-relief settings is difficult to synthesize under general models, given the dependence of such accumulations on local morphology. Quaternary sand ramps have been linked to palaeoclimate, regional geomorphology and wind patterns; however, controls on the early development and preservation of such landforms are poorly known. This study describes the morphology and sedimentology of complex sedimentary aprons along steep coastal slopes in the Atacama Desert (Chile). Direct slope accessibility and continuous stratigraphic exposures enable comparisons between active processes and stratigraphic signatures. Stratigraphic facies distribution and its links with patterns of aeolian deposition show that the preservation of wind-laid sediments depends on the morphology and processes of specific slope sectors. The spatial organization of runoff depends on bedrock configuration and directly controls the permanence or erosion of aeolian sediment. The occurrence of either water or mass flows depends on the role of aeolian fines in the rheology of flash floods. In turn, the establishment of a rugged surface topography controlled by patterns of mass-flow deposition creates local accommodation for aeolian fines, sustaining the initial aggradation of a colluvial-aeolian system. By contrast, slopes subject to runoff develop a thin, extensive aeolian mantle whose featureless surface is subject mostly to sediment bypass down- and across-slope; the corresponding stratigraphic record comprises almost exclusively thin debris-flow and sheetflood deposits. Slope morphology and processes are fundamental in promoting or inhibiting aeolian aggradation in mountain settings. Long-term sand-ramp construction depends on climate and regional topography, but the initial development is probably controlled by local geomorphic factors. The observed interactions between wind and topography in the study area may also represent a process

Learning Desert Geomorphology Virtually versus in the Field

Science.gov (United States)

Stumpf, Richard J., II; Douglass, John; Dorn, Ronald I.

2008-01-01

Statistical analyses of pre-test and post-test results, as well as qualitative insight obtained by essays, compared introductory physical geography college students who learned desert geomorphology only virtually, in the field and both ways. With the exception of establishing geographic context, the virtual field trip was statistically…

Geomorphology from space: A global overview of regional landforms

Science.gov (United States)

Short, Nicholas M. (Editor); Blair, Robert W., Jr. (Editor)

1986-01-01

This book, Geomorphology from Space: A Global Overview of Regional Landforms, was published by NASA STIF as a successor to the two earlier works on the same subject: Mission to Earth: LANDSAT views the Earth, and ERTS-1: A New Window on Our Planet. The purpose of the book is threefold: first, to serve as a stimulant in rekindling interest in descriptive geomorphology and landforms analysis at the regional scale; second, to introduce the community of geologists, geographers, and others who analyze the Earth's surficial forms to the practical value of space-acquired remotely sensed data in carrying out their research and applications; and third, to foster more scientific collaboration between geomorphologists who are studying the Earth's landforms and astrogeologists who analyze landforms on other planets and moons in the solar system, thereby strengthening the growing field of comparative planetology.

Changing sedimentary environment during the late Quaternary: Sedimentological and isotopic evidence from the distal Bengal Fan

Digital Repository Service at National Institute of Oceanography (India)

Kessarkar, P.M.; Rao, V.P.; Ahmad, S.M.; Patil, S.K.; AnilKumar, A.; AnilBabu, G.; Chakraborty, S.; SounderRajan, R

The sediments recovered from two gravity cores of the lower and distal Bengal Fan were investigated for sedimentological properties and Sr -Nd isotopes.Each core exhibits two distinct units, the lower unit 2 and upper unit 1 sediments. The unit 2...

Laser altimetry and terrain analysis: A revolution in geomorphology

NARCIS (Netherlands)

Anders, N.; Seijmonsbergen, H.

2008-01-01

Terrain analysis in geomorphology has undergone a serious quantitative revolution over recent decades. Lidar information has been efficiently used to automatically classify discrete landforms, map forest structures, and provide input for models simulating landscape development, e.g. channel incision

Sedimentology of the upper Karoo fluvial strata in the Tuli Basin, South Africa

Science.gov (United States)

Bordy, Emese M.; Catuneanu, Octavian

2001-08-01

The sedimentary rocks of the Karoo Supergroup in the Tuli Basin (South Africa) may be grouped in four stratigraphic units: the basal, middle and upper units, and the Clarens Formation. This paper presents the findings of the sedimentological investigation of the fluvial terrigenous clastic and chemical deposits of the upper unit. Evidence provided by primary sedimentary structures, palaeontological record, borehole data, palaeo-flow measurements and stratigraphic relations resulted in the palaeo-environmental reconstruction of the upper unit. The dominant facies assemblages are represented by sandstones and finer-grained sediments, which both can be interbedded with subordinate intraformational coarser facies. The facies assemblages of the upper unit are interpreted as deposits of a low-sinuosity, ephemeral stream system with calcretes and silcretes in the dinosaur-inhabited overbank area. During the deposition of the upper unit, the climate was semi-arid with sparse precipitation resulting in high-magnitude, low-frequency devastating flash floods. The current indicators of the palaeo-drainage system suggest flow direction from northwest to southeast, in a dominantly extensional tectonic setting. Based on sedimentologic and biostratigraphic evidence, the upper unit of the Tuli Basin correlates to the Elliot Formation in the main Karoo Basin to the south.

Sedimentological parameters of beach sediments on the East Coast of India

Digital Repository Service at National Institute of Oceanography (India)

Chauhan, O.S.

stream_size 13 stream_content_type text/plain stream_name J_Coast_Res_6_573.pdf.txt stream_source_info J_Coast_Res_6_573.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

A new integrative methodology for desertification studies based on magnetic and short-lived radioisotope measurements

International Nuclear Information System (INIS)

Oldfield, F.; Higgitt, S.R.; Maher, B.A.; Appleby, P.G.; Scoullos, M.

1986-01-01

The use of mineral magnetic measurements and short-lived radioisotope studies with 210 Pb and 137 Cs is discussed within the ecosystem watershed conceptual framework. Used in conjunction with geomorphological, sedimentological, palaeoecological and geochemical techniques, these methods can form the core of an integrated multidisciplinary study of desertification and erosion processes on all relevant temporal and spatial scales. 30 refs.; 4 figs

Geological map of Uruguay Esc 1,100,000. Piraraja Sheet F-23

International Nuclear Information System (INIS)

Preciozzi, F

1990-01-01

This work is about the geological map of Uruguay Esc.1.100.000 (Piraraja) and the explanatory memoranda which describes the geological , lithological and sedimentological characteristics soils belong to Cenozoic, Cretaceous, Jurassic and Precambrian period.The Pirafja fotoplano is located in Lavalleja and geomorphologically is constituted by the Lavalleja group, the Atlantic socket, Piraraja granite and the Barriga Negra group

Sepetiba Bay: an integrated study of an harbour location

International Nuclear Information System (INIS)

Bandeira, J.V.; Aun, P.E.; Castro, J.O.N.M. de; Moreira, R.M.

1984-01-01

Several aspects of the construction of an iron-ore and coal terminal in Sepetiba bay (RJ, Brazil) in the region of south of Madeira Island, are presented. The studies include a general view of the geomorphology of the region, analyses of current measurements, water circulation and sedimentology of the bay by conventional methods and by radioactive tracers. (M.A.C.) [pt

The inner structure of landslides and landslide-prone slopes in south German cuesta landscapes assessed by geophysical, geomorphological and sedimentological approaches

Science.gov (United States)

Schwindt, Daniel; Sandmeier, Christine; Büdel, Christian; Jäger, Daniel; Wilde, Martina; Terhorst, Birgit

2016-04-01

Investigations on landslide activity in the cuesta landscape of Germany, usually characterized by an interbedding of morphologically hard (e.g. sand-/limestones) and soft (clay) sedimentary rocks are relatively sparse. However, spring 2013 has once again revealed a high susceptibility of the slopes in the Franconian and Swabian Alb to mass movements, when enduring rainfalls initiated numerous landslides causing considerable damage to settlements and infrastructure. Many aspects like the spatial distribution of landslides, triggering factors, and process dynamics - especially with view on the reactivation of landslides - require intensive investigations to allow for assessment of the landslide vulnerability and the development of reliable early-warning systems. Aim of the study is to achieve a deeper insight into the triggering factors and the process dynamics of landslides in the cuesta landscape with special regard on landslide proneness of slopes and the potential reactivation of old landslides. A multi-methodological approach was conducted based on geophysical investigations (seismic refraction tomography - SRT, electrical resistivity tomography - ERT), geomorphological mapping, morphometric GIS-based analysis, core soundings and substrate mapping. Study sites are located in the Swabian Alb (southwestern Germany) in the Jurassic escarpment where where Oxfordian marls and limestones superimpose Callovian clays, as well as in the northeastern Franconian Alb, within the escarpment of the so called Rhätolias with with red claystones of the late Norian (Feuerletten formation) below interbedding layers of sand- and claystones of the Rhaetian (Upper Triassic) and Hettangian ( Lower Jurassic). The investigated landslides strongly differ with respect to their age, from young landslides originated in spring 2013 to ancient landslides. Investigations reveal a distinct diversity of landslide types composed of a complex combination of processes. The applied methods allow

Petrophysical and sedimentological characterization of the Zuata field in Orinoco Oil Belt. Venezuela

International Nuclear Information System (INIS)

Blanco, M.; Baena, L.

2010-01-01

The Zuata field is in the middle of the Jun in block in Orinoco Oil Belt and its production is handled by the district of Cabrutica which planning to develop a comprehensive reservoir model that allows leverage a correct management of hydrocarbon reserves. The purpose of this study is to generate a sedimentological and petrophysical model to know the architecture and quality of the rocks

Geomorphology of coastal environments from satellite images

International Nuclear Information System (INIS)

Da Rocha Ribeiro, R.; Velho, L.; Schossler, V.

2010-01-01

This study aims at recognizing coastal environments supported by data from the Landsat Thematic Mapper (TM) satellite. The digital processing of images, System Information Geographic (SIG) techniques and field observation in one section of the “Província Costeira do Rio Grande do Sul” between the Rio Grande and the São Gonçalo channels - resulted in a geomorphologic profile and mapping

Geomorphological condition and sea bottom sediment characteristics of Sebagin coast for NPP site evaluation in South Bangka

International Nuclear Information System (INIS)

Yuliastuti; Heni Susiati; Yarianto Sugeng Budi Susilo

2015-01-01

Study on geomorphological condition and sea bottom sediment in the coastal area of Sebagin, South Bangka Regency, Bangka Belitung Province has been performed. Geomorphological of the seabed was valuable to identify geological structures that exist on the seabed layers. Whereas, sediments seabed characteristics was useful to provide portrait of seabed layer due to the stability of NPP site concerning the seismic aspect and the determination of water intake position. The objective of the study was to evaluate geomorphological condition and sea bed sediment characteristics in the South Bangka sea. Methodology used for evaluating geomorphological of the sea bed were Multi Beam Echo Sounder (MBES) and Single Beam Echo Sounder (SBES), while for sea bottom sediment characteristics, high resolution seismic reflection using SBP together with sediment sample analysis were used. The result of the study showed that the study area was a shallow water sea with a depth range of 1-59 m. Geomorphological profile of the sea bed tend to be irregular and based on the seismic interpretation, there were no fault exists. Result analysis on the sea bottom sediment showed that clay distribution dominated the study area. (author)

Geomorphodiversity derived by a GIS-based geomorphological map: case study the Czech Republic

Czech Academy of Sciences Publication Activity Database

Demek, J.; Kirchner, Karel; Mackovčin, P.; Slavík, P.

2011-01-01

Roč. 55, č. 4 (2011), s. 415-436 ISSN 0372-8854 Institutional research plan: CEZ:AV0Z30860518 Keywords : geomorphodiversity * GIS geomorphological data base * GIS-geomorphological map * Czech Republic Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.642, year: 2011 http://www.ingentaconnect.com/content/schweiz/zfg/2011/00000055/00000004/art00001?token=004d10697e442f2067217d763b442c233e46533f34687627504541676249266d656cbe1a808f2

Boulders, biology and buildings: Why weathering is vital to geomorphology (Ralph Alger Bagnold Medal Lecture)

Science.gov (United States)

Viles, Heather A.

2015-04-01

Weathering is vital to geomorphology in three main senses. First, it is vital in the sense of being a fundamental and near-ubiquitous earth surface process without which landscapes would not develop, and which also provides a key link between geomorphology and the broader Earth system. Second, weathering is vital in the sense that, as it is heavily influenced by biotic processes, it demonstrates the importance of life to geomorphology and vice versa. In particular, weathering illustrates the many cross-linkages between microbial ecosystems and geomorphology. Finally, it is vital in the sense that weathering provides an important practical application of geomorphological knowledge. Geomorphologists in recent years have contributed much in terms of improving understanding the deterioration of rocks, stone and other materials in heritage sites and the built environment. This knowledge has also had direct implications for heritage conservation. This lecture reviews recent research on each of these three themes and on their linkages, and sets an integrated research agenda for the future. Weathering as a key process underpinning geomorphology and Earth system science has been the subject of much recent conceptual and empirical research. In particular, conceptual research advances have involved improving conceptualisation of scale issues and process synergies, and understanding weathering in terms of non-linear dynamical systems. Empirical advances have included the development of larger datasets on weathering rates, and the application of a wide range of non-destructive and remote sensing techniques to quantify weathering morphologies on boulder and rock surfaces. In recent years, understanding of the complex linkages between ecology and geomorphology (sometimes called biogeomorphology) has advanced particularly strongly in terms of weathering. For example, the influences of disturbance on biota and weathering have been conceptualised and investigated empirically in a

Sedimentology and Stratigraphy of the Stevns-2 core

DEFF Research Database (Denmark)

Boussaha, Myriam

The 350 m long Stevns-2 core (drilled in the Stevns peninsula, south of Copenhagen, DK) was the subject of a multidisciplinary study combining sedimentology, isotopic geochemistry and micropaleontology, whose main results and interpretations have been the subject of papers presented in this thesis...... along with complementary results. A new Boreal biozonation based on calcareous nannofossils has been erected for the upper Campanian–Maastrichtian interval, based on results from this new drilled core, compiled with results of three additional sites spanning the same time interval in the Danish basin...... and clay input seem to be the most likely controlling factors to explain the long-term changes in sedimentation of the Boreal epicontinental chalk sea. Time series analysis was performed in these three intervals, based on the bulk carbonate carbon isotopes and facies successions, demonstrating...

Multiple origins of large hummock deposits in Alai Valley, Northern Pamir: Implications for palaeoclimate reconstructions

Science.gov (United States)

Reznichenko, N. V.; Andrews, G. R.; Geater, R. E.; Strom, A.

2017-05-01

This paper interprets the origin of several of the largest hummocky landform assemblages in the Alai Valley, Northern Pamir - a formerly glaciated intermontane depression. The vast hummocky deposits in the Koman-Suu and Achik-Tash river catchments are found to be of two contrasting modes of formation: glacial hummocks deposited during Koman and Lenin Glaciers withdraw and avalanche hummocks produced during catastrophic Koman and Lenin rock avalanches. The origins of the deposits we assessed through remote and field-based geomorphological mapping, as well as sedimentological investigations, which included clast analysis and the identification of micro-scale agglomerates indicative of rock avalanche emplacement. Both the Koman and Lenin rock avalanches were large, catastrophic events (with run-outs of 34 and 24 km, respectively, and a volume over 1 × 109 m3 each) that occurred subsequent to glacier withdrawal from the area. The complex conditions on the moment of the rock avalanche emplacement promoted unusual deposits geomorphology and extensive run-outs. The landslide landforms formed over the pre-existing glacial hummocks and fluvial deposits, and are geomorphologically and sedimentologically distinct from the larger glacial hummocks. The reconstruction of this sequence of events has implications for how hummock dating should be interpreted. This research illustrates large scale catastrophic landsliding in the glacial environment, and adds to the ongoing debate about the misidentification of rock avalanche deposits as of glacial origin, and their relevance to palaeoclimatological and palaeoseismological reconstructions.

Geomorphologically effective floods from moraine-dammed lakes in the Cordillera Blanca, Peru

Science.gov (United States)

Emmer, Adam

2017-12-01

Outburst floods originating in moraine-dammed lakes represent a significant geomorphological process as well as a specific type of threat for local communities in the Cordillera Blanca, Peru (8.5°-10° S; 77°-78° W). An exceptional concentration of catastrophic floods has been reported from the Cordillera Blanca in the first half of 20th Century (1930s-1950s), leading to thousands of fatalities. The main objective of this paper is to provide a revised and comprehensive overview of geomorphologically effective floods in the area of interest, using various documentary data sources, verified by analysis of remotely sensed images (1948-2013) and enhanced by original field data. Verified events (n = 28; 4 not mentioned before) are analysed from the perspective of spatiotemporal distribution, pre-flood conditions, causes, mechanisms and geomorphological impacts as well as socioeconomical consequences, revealing certain patterns and similar features. GLOFs are further classified according to their magnitude: 5 extreme events, 8 major events and 15 minor events are distinguished, referring to the quantified geomorphological and socioeconomical impacts. Selected moraine dams and flood deposits are dated using lichenometric dating. Special attention is given to moraine dam breaches - the most frequent type of water release with the most significant consequences. Selected major events and their consequences are studied in detail in a separate section. Finally, a general schematic model of lake formation, growth and post-flood evolution reflecting initial topographical setting and glacier retreat is introduced and the utilization of the obtained results is outlined.

Geomorphology and soil survey

Science.gov (United States)

Laura A. Murray; Bob Eppinette; John H. Thorp

2000-01-01

The Coosawhatchie River, through erosion and downcutting, carved a fluvial valley through the Wicomico and Pamlico marine terraces during the late Pleistocene-Holocene period. The floodplain is relatively small and immature compared to the major river systems of the South Carolina Lower Coastal Plain. Consequently, the classic geomorphic features of a larger fluvial...

Introducing Field-Based Geologic Research Using Soil Geomorphology

Science.gov (United States)

Eppes, Martha Cary

2009-01-01

A field-based study of soils and the factors that influence their development is a strong, broad introduction to geologic concepts and research. A course blueprint is detailed where students design and complete a semester-long field-based soil geomorphology project. Students are first taught basic soil concepts and to describe soil, sediment and…

Remote sensing, planform, and facies analysis of the Plain of Tineh, Egypt for the remains of the defunct Pelusiac River

Science.gov (United States)

Quintanar, Jessica; Khan, Shuhab D.; Fathy, Mohamed S.; Zalat, Abdel-Fattah A.

2013-11-01

The Pelusiac Branch was a distributary river in the Nile Delta that splits off from the main trunk of the Nile River as it flowed toward the Mediterranean. At approximately 25 A.D., it was chocked by sand and silt deposits from prograding beach accretion processes. The lower course of the river and its bifurcation point from the trunk of the Nile have been hypothesized based on ancient texts and maps, as well as previous research, but results have been inconsistent. Previous studies partly mapped the lower course of the Pelusiac River in the Plain of Tineh, east of the Suez Canal, but rapid urbanization related to the inauguration of the Peace Canal mega-irrigation project has covered any trace of the linear feature reported by these previous studies. The present study used multispectral remote sensing data of GeoEYE-1 and Landsat-TM to locate and accurately map the course of the defunct Pelusiac River within the Plain of Tineh. Remote sensing analysis identified a linear feature that is 135 m wide at its maximum and approximately 13 km long. It extends from the Pelusium ruins to the Suez Canal, just north of the Peace Canal. This remotely located linear feature corresponds to the path of the Pelusiac River during Roman times. Planform geomorphology was applied to determine the hydrological regime and paleodischarge of the river prior to becoming defunct. Planform analysis derived a bankfull paleodischarge value of ~ 5700 m3 s- 1 and an average discharge of 650 m3 s- 1, using the reach average for the interpreted Pelusiac River. The derived values show a river distributary similar in discharge to the modern dammed Damietta river. Field work completed in April of 2012 derived four sedimentary lithofacies of the upper formation on the plain that included pro-delta, delta-front and delta-plain depositional environments. Diatom and fossil mollusk samples were also identified that support coastal beach and lagoonal environments of deposition. Measured section columns

Quantitative palaeodrainage analysis in the Pleistocene of the Po Plain (Italy)

Science.gov (United States)

Vezzoli, G.; Garzanti, E.; Sciunnach, D.

2009-04-01

During the Pleistocene, Po Plain deposits recorded repeated waxing and waning of Alpine ice caps, and thus provide an excellent opportunity to investigate the interactions between pronounced climatic fluctuations and background tectonic activity (Scardia et al., 2006), resulting in frequent changes of drainage patterns. A high-resolution Pleistocene stratigraphy, with a complete sedimentological, paleontological, petrographic-mineralogical, magneto-stratigraphic, and seismic data base, was recently obtained from eleven continuous cores drilled in the Lombardy Po Plain north of the Po River (ENI and Regione Lombardia, 2002). In the present study we focus on two cores in the proximal (Cilavegna) and distal plain (Pianengo), which best exemplify the drastic change in sedimentary systems and drainage patterns associated with the onset of major Pleistocene glaciations in the Alps (˜870ky; Muttoni et al., 2003). This climatic event is recorded by a regional unconformity (named R-unconformity by Muttoni et al., 2003), traced all across the Po Basin and encountered at -81 m depth in the Pianengo Core and at -98 m depth in the Cilavegna Core. The Cilavegna Core consists of metamorphiclastic floodplain sediments, capped by the R-unconformity and overlain by quartzofeldspathic braidplain deposits. The Pianengo Core consists of metamorphiclastic deltaic to floodpain sediments, capped by the R-unconformity and overlain by alluvial-fan gravels rich in carbonate pebbles; another unconformity at -39 m depth is overlain by metamorphiclastic braidplain deposits. Our quantitative approach to paleodrainage analysis is based on comprehensive information obtained from modern settings (Garzanti et al., 2004; 2006). End-member modelling and similarity analysis allows us to objectively compare detrital modes from modern and ancient deposits, and to reconstruct the evolution of sediment pathways through geologic time (Vezzoli and Garzanti 2009). The Cilavegna Core documents stepwise south

49 CFR 229.64 - Plain bearings.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

Landscape changes based on sedimentological and geochemical studies in the region of Brudzeń Duży

Directory of Open Access Journals (Sweden)

Smolska Ewa

2014-03-01

Full Text Available Sedimentological and geochemical research carried out in North- West Mazovia, central Poland, allowed the determination of landscape transformation in relation to the history of human settlement. The types of sediments subject to analysis included palaeochannel filling, accumulation on the river floodplain and colluvial deposits. The absolute ages of sediments and their sedimentological features allow the conclusion that the first response to human activity in the area is recorded in the overbank deposits in the Skrwa River valley as a result of the Wielbarska Culture in 200-300 AD. Subsequently, fan accumulation at the mouths of gullies started around the 12th-13th centuries AD. Frequent changes of sediment properties have been observed since the early Middle Ages. The subsequent anthropogenic impact on homogenous deposits is recorded in increased heavy metal concentration in vertical geological profiles.

Interaction between continental and estuarine waters in the wetlands of the northern coastal plain of Samborombón Bay, Argentina

International Nuclear Information System (INIS)

Carol, Eleonora; Mas-Pla, Josep; Kruse, Eduardo

2013-01-01

Highlights: • Inland and estuarine water flows define wetland hydrology on the Samborombón Bay. • Hydrochemistry in shell-ridges and tidal plains is due to water–rock interaction. • Mixing, evaporation and halite dissolution determine salinity in marshes. • Water flow from the shell-ridges control the overall wetland water quality. • These wetlands are complex hydrological systems with vulnerable water resources. - Abstract: On the Samborombón Bay coastline, located in the Río de la Plata estuary in Buenos Aires province (Argentina), a complex hydrological system has developed at the interface between continental and estuarine water, where significant wetlands develop. The main hydrogeological units, namely the shell ridges, the tidal plain and the marsh areas, have been identified using geomorphological criteria. Water table, hydrochemical and isotopic data have been used to determine their hydrological features, as well as those of the streams and canals. Evaporation processes, in particular, have been considered when depicting chemical and isotopic changes in surface waters in streams and marsh areas. The shell ridges represent a hydrogeological unit in which rainwater is stored, constituting a lens-shaped freshwater aquifer. In this unit, just as in the tidal plain, carbonate dissolution and ion exchange are the main processes regulating water chemistry. On the other hand, in the marsh and surface waters, processes such as mixing with estuarine water and evaporation predominate. These processes control water fluxes and the salinity of the wetland areas and, consequently, their ability to preserve the existing biodiversity. This study shows the importance of knowledge of hydrochemical processes in any proposal concerning the management and preservation of this type of wetland

Geomorphology and reflectance patterns of vegetation-covered dunes at the Tsodilo Hills, north-west Botswana

Science.gov (United States)

Jacobberger, P. A.; Hooper, D. M.

1991-01-01

Seasonal reflectance variations in semigrid environments provide a means of assessing vegetation health and density as well as monitoring landform processes. Multitemporal Landsat Thematic Mapper scenes with field measurements are used to map geomorphology and vegetation density in a stabilized dune environment and to measure seasonal reflectance changes for a series of ten geomorphological and vegetation units on the Kalahari-age linear dunes. Units were chosen based on differences in landform and proportion of trees, forbs and bare soil. Reflectance curves and normalized-difference vegetation indices (NDVI) show that dune crests have the strongest seasonal variability in color and brightness. The geomorphological link with reflectance and NDVI values are linked to biomass production and zoning of vegetation with slope, drainage and subtle soil differences.

Pedogenesis and root development in a complex geomorphologic setting of the Faroe Islands

DEFF Research Database (Denmark)

Veihe, Anita; Thers, Mie

2007-01-01

Studies of pedogenesis in basaltic soils within the cool, temperate zone were fairly limited. This study looked at pedogenesis and root development in Norðradalur of the Faroe Islands. To a large extent, soil physical and chemical characteristics were determined by sedimentological rather than pe...

The potential for dams to impact lowland meandering river floodplain geomorphology.

Science.gov (United States)

Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

2014-01-01

The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

Directory of Open Access Journals (Sweden)

Philip M. Marren

2014-01-01

Full Text Available The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection and active impacts (changes in geomorphological processes and functioning. These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows.

Climate variability and Great Plains agriculture

International Nuclear Information System (INIS)

Rosenberg, N.J.; Katz, L.A.

1991-01-01

The ways in which inhabitants of the Great Plains, including Indians, early settlers, and 20th century farmers, have adapted to climate changes on the Great Plains are explored. The climate of the Great Plains, because of its variability and extremes, can be very stressful to plants, animals and people. It is suggested that agriculture and society on the Great Plains have, during the last century, become less vulnerable to the stresses imposed by climate. Opinions as to the sustainability of agriculture on the Great Plains vary substantially. Lockeretz (1981) suggests that large scale, high cost technologies have stressed farmers by creating surpluses and by requiring large investments. Opie (1989) sees irrigation as a climate substitute, however he stresses that the Ogallala aquifer must inevitably become depleted. Deborah and Frank Popper (1987) believe that farming on the Plains is unsustainable, and destruction of shelterbelts, out-migration of the rural population and environmental problems will lead to total collapse. With global warming, water in the Great Plains is expected to become scarcer, and although improvements in irrigation efficiency may slow depletion of the Ogallala aquifer, ultimately the acreage under irrigation must decrease to levels that can be sustained by natural recharge and reliable surface flows. 23 refs., 2 figs

Geomorphological map as a tool for visualisation of geodiversity - example from Cave Park Grabovaca (Croatia)

Science.gov (United States)

Buzjak, Nenad; Bocic, Neven; Pahernik, Mladen

2014-05-01

Cave Park Grabovaca is located near Perusic in Lika region (central Croatia). It was established in 2006 at the area of 5.95 km2 (protection category: significant landscape). The main task is management and protection of Samograd, Medina and Amidzina caves that were declared as geomorphological monuments, and 6 other caves located close to each other. Owing to the central geographic location in Croatian Dinaric karst area, good traffic connections between central Europe and tourist centres of the Adriatic coast, preserved nature and easy accessible karst features typical for the Dinaric Karst, it has good potential to develop as an research, educational and tourist centre. In 2013. Cave Park management and the Department of Geography (University of Zagreb, Faculty of Science) established a core team that started to develop the project of Geoeducational centre (GEC) with following goals: exploration-evaluation-presentation-education. According to the accepted strategy, the first step in the project process is to enlarge the area and change the protection category. During the consultation process team members take into account protection, environmental, local economy, tourism and local population issues and proposed that protected area should be increased to 52,2 km2. This enlargement provides more efficient protection, greater geodiversity and biodiversity by occupying geotope, biotope, and landscape units typical for the whole Lika karst region. The next step was inventorying, evaluation, analysis and visualisation of geological, geomorphological and speleological phenomena. This 2 year task was made in cooperation between Croatian Geomorphological Society, Department of Geography, Speleological Society Karlovac and Caving Club Samobor. The inventory was made using field-work mapping and geotagged photographs, cave mapping and DEM analysis. It resulted in GIS oriented geodatabase consisting of geomorphological forms, processes and cave inventory. From those data

Fluvial geomorphology and river engineering: future roles utilizing a fluvial hydrosystems framework

Science.gov (United States)

Gilvear, David J.

1999-12-01

River engineering is coming under increasing public scrutiny given failures to prevent flood hazards and economic and environmental concerns. This paper reviews the contribution that fluvial geomorphology can make in the future to river engineering. In particular, it highlights the need for fluvial geomorphology to be an integral part in engineering projects, that is, to be integral to the planning, implementation, and post-project appraisal stages of engineering projects. It should be proactive rather than reactive. Areas in which geomorphologists will increasingly be able to complement engineers in river management include risk and environmental impact assessment, floodplain planning, river audits, determination of instream flow needs, river restoration, and design of ecologically acceptable channels and structures. There are four key contributions that fluvial geomorphology can make to the engineering profession with regard to river and floodplain management: to promote recognition of lateral, vertical, and downstream connectivity in the fluvial system and the inter-relationships between river planform, profile, and cross-section; to stress the importance of understanding fluvial history and chronology over a range of time scales, and recognizing the significance of both palaeo and active landforms and deposits as indicators of levels of landscape stability; to highlight the sensitivity of geomorphic systems to environmental disturbances and change, especially when close to geomorphic thresholds, and the dynamics of the natural systems; and to demonstrate the importance of landforms and processes in controlling and defining fluvial biotopes and to thus promote ecologically acceptable engineering. Challenges facing fluvial geomorphology include: gaining full acceptance by the engineering profession; widespread utilization of new technologies including GPS, GIS, image analysis of satellite and airborne remote sensing data, computer-based hydraulic modeling and

Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 2: Matching Family-Level Indices to Geomorphological Response Units (GRUs

Directory of Open Access Journals (Sweden)

Anna Grace Nostbakken Meissner

2016-03-01

Full Text Available Many rivers are intensely managed due to anthropogenic influences such as dams, channelization, and water provision for municipalities, agriculture, and industry. With this growing pressure on fluvial systems comes a greater need to evaluate the state of their ecosystems. The purpose of this research is to use a geospatial model of the Qu’Appelle River in Saskatchewan to distinguish instream macroinvertebrate habitats at the family level. River geomorphology was assessed through the use of ArcGIS and digital elevation models; with these tools, the sinuosity, slope, fractal dimension, and stream width of the river were processed. Subsequently, Principal Component Analysis, a clustering technique, revealed areas with similar sets of geomorphological characteristics. These similar typology sequences were then grouped into geomorphological response units (GRUs, designated a color, and mapped into a geospatial model. Macroinvertebrate data was then incorporated to reveal several relationships to the model. For instance, certain GRUs contained more highly sensitive species and healthier diversity levels than others. Future possibilities for expanding on this project include incorporating stable isotope data to evaluate the food-web structure within the river basin. Although GRUs have been very successful in identifying fish habitats in other studies, the macroinvertebrates may be too sessile and their habitat too localized to be identified by such large river units. Units may need to be much shorter (250 m to better identify macroinvertebrate habitat.

An approach for quantifying geomorphological impacts for EIA of transportation infrastructures: a case study in northern Spain

Science.gov (United States)

Bonachea, Jaime; Bruschi, Viola Maria; Remondo, Juan; González-Díez, Alberto; Salas, Luis; Bertens, Jurjen; Cendrero, Antonio; Otero, César; Giusti, Cecilia; Fabbri, Andrea; González-Lastra, José Ramón; Aramburu, José María

2005-03-01

A methodological proposal for the assessment of impacts due to linear infrastructures such as motorways, railways, etc. is presented. The approach proposed includes a series of specific issues to be addressed for each geomorphological feature analysed—both 'static' and 'dynamic'—as well as a series of steps to be followed in the process. Geomorphic characteristics potentially affected were initially identified on the basis of a conceptual activities/impacts model that helps to single out geomorphic impacts related to environmental concerns for the area. The following issues were addressed for each individual impact: nature of potential effects; indicators that can be used to measure impacts; criteria of 'geomorphologic performance'; procedure for measurement/prediction of changes; translation of geomorphologic impacts into significant terms from the viewpoint of human concerns; possible mitigation and/or compensation measures. The procedure has been applied to a case study corresponding to a new motorway in the Basque Country, northern Spain. Geomorphological impacts considered in this analysis included: (1) consumable resources; (2) sites of geomorphological interest; (3) land units with high potential for use, high productivity or value for conservation; (4) visual landscape; (5) slope instability processes. The procedure has been designed for implementation in a Geographic Information System (GIS) environment. Details are given on the application of the method to each individual impact analysed and results are presented in both numerical and map form. Impacts assessed were initially expressed by means of heterogeneous magnitudes, depending on the geomorphological feature considered. Those geomorphological impacts were then translated into significant terms and homogeneous magnitudes. Integration was carried out on the basis of impact values thus obtained. Final integrated results were also expressed in numerical and map form. The method proposed enables

The geomorphology of Ceres.

Science.gov (United States)

Buczkowski, D L; Schmidt, B E; Williams, D A; Mest, S C; Scully, J E C; Ermakov, A I; Preusker, F; Schenk, P; Otto, K A; Hiesinger, H; O'Brien, D; Marchi, S; Sizemore, H; Hughson, K; Chilton, H; Bland, M; Byrne, S; Schorghofer, N; Platz, T; Jaumann, R; Roatsch, T; Sykes, M V; Nathues, A; De Sanctis, M C; Raymond, C A; Russell, C T

2016-09-02

Analysis of Dawn spacecraft Framing Camera image data allows evaluation of the topography and geomorphology of features on the surface of Ceres. The dwarf planet is dominated by numerous craters, but other features are also common. Linear structures include both those associated with impact craters and those that do not appear to have any correlation to an impact event. Abundant lobate flows are identified, and numerous domical features are found at a range of scales. Features suggestive of near-surface ice, cryomagmatism, and cryovolcanism have been identified. Although spectroscopic analysis has currently detected surface water ice at only one location on Ceres, the identification of these potentially ice-related features suggests that there may be at least some ice in localized regions in the crust. Copyright © 2016, American Association for the Advancement of Science.

Geomorphology and River Management

Directory of Open Access Journals (Sweden)

GARY BRIERLEY

2008-01-01

Full Text Available Engineering-dominated practices, visible in a "command and control" outlook on natural systems, have induced enormous damage to the environment. Biodiversity losses and declining provision of ecosystem services are testimony to the non-sustainable outcomes brought about by such practices. More environmentally friendly approaches that promote a harmonious relationship between human activities and nature are required. Moves towards an "ecosystem approach" to environmental management require coherent (integrative scientific guidance. Geomorphology, the study of the form of the earth, provides a landscape template with which to ground this process. This way of thinking respects the inherent diversity and complexity of natural systems. Examples of the transition toward such views in environmental practice are demonstrated by the use of science to guide river management, emphasising applications of the River Styles framework.

Influence Of Crop Management And Soil On Plantain [Musa spp. z AAB Group Response To Black Sigatoka Infection In Southeastern Nigeria

Directory of Open Access Journals (Sweden)

Mobambo, KN.

1994-01-01

Full Text Available An on-farm survey was carried out to assess the severity of black sigatoka caused by Mycosphaerella fijiensis Morelet on plantain in southeastern Nigeria. Two different geomor-phological zones (Meander belts and Coastal plain sands were surveyed. Four locations were selected for each zone and two traditional farming systems (backyard and field were studied in each location. Based on geomorphological zones, less black sigatoka infection was observed in the Meander belts than in the Coastal plain sands. On farming systems basis, plantain grown in the backyard gardens had lower disease severity than that planted in the field plots. This difference in black sigatoka severity is attributable to the higher soil fertility in the Meander belts than in the Coastal plain sands and in the backyards than in the fields.

Geomorphological criteria applied to the study of the neotectonic of the internal areas of Spain

International Nuclear Information System (INIS)

Gutierrez Elorza, M.; Pena, J.L.; Rodriguez Vidal, J.; Simon Gomez, J.L.

1984-01-01

Some geomorphological criteria, based on the study of erosion surfaces, glacis, terraces and slopes, after a brief discussion of the geomorphological methodology, are here applied in several internal areas of NE. Spain, specially in the Iberian Cordillera. Several episodes of neotectonic activity are recognised within this Cordillera: a more intense one at the base of Villafranchian times, a second one at the Pliocene/Pleistocene transitional levels, and a latent, more sporadic, intraquaternary activity. (author)

Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

Science.gov (United States)

Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

2017-04-01

Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

Holocene relative sea level variations at the spit system Feddet (Denmark) resolved by ground-penetrating radar and geomorphological data

DEFF Research Database (Denmark)

Hede, Mikkel Ulfeldt; Bendixen, Mette; Clemmensen, Lars B

Estimates of Holocene sea-level variations have been presented in a range of studies based on different approaches, including interpretation of internal beach ridge characteristics from ground-penetrating radar (GPR) and geomorphological data. We present GPR data and geomorphological observations...... of independent GPR and geomorphologic data collected across the recent and sub-recent beach ridge deposits. The data analyses include coastal topography, internal dips of beach ridge layers, and sea-level measurements. A clear change in characteristic layer dip is observed between beach face and upper shoreface...

Geomorphological hazard and tourist vulnerability along Portofino Park trails (Italy)

Science.gov (United States)

Brandolini, P.; Faccini, F.; Piccazzo, M.

2006-06-01

The many trails existing in the coastal area of Portofino Promontory are used by tourists for trekking or as pathways to small villages and beaches. The aim of this paper is to define geomorphological hazard and tourist vulnerability in this area, within the framework of the management and planning of hiking activities in Portofino Natural Park. In particular, processes triggered by gravity, running waters and wave motion, affecting the slopes and the cliff, are considered. The typology of the trails and trail maintenance are also taken into account in relation to weather conditions that can make the excursion routes dangerous for tourists. In conclusion, an operative model is applied for the definition of possible risk scenarios. This model is founded on an inventory and the quantification of geomorphological hazards and tourist vulnerability, in comparison with trail rescue data. The model can be applied to other environments and tourist areas.

Geomorphological Analyses Integrating Geophysical Methods for Hydrocarbon Exploration in the Majaguillar-Corralillo Sector, Cuba

Directory of Open Access Journals (Sweden)

María Victoria Pérez-Peña

2016-10-01

Full Text Available A more detailed geomorphological study compared to the previous ones was carried out in order to demarcate the potential areas for petroleum exploration. A diagram that integrates geological, geomorphological and geophysical results was prepared. Two structurally surveyed morphological areas (I and II are proposed to address exploration. Area I is recommended to be the one with a higher probability given the presence of rocks of the continental margin at depth, which are the most potential location of petroleum occurrence in Cuba.

Vegetation Response and Landscape Dynamics of Indian Summer Monsoon Variations during Holocene: An Eco-Geomorphological Appraisal of Tropical Evergreen Forest Subfossil Logs

Science.gov (United States)

Kumaran, Navnith K. P.; Padmalal, Damodaran; Nair, Madhavan K.; Limaye, Ruta B.; Guleria, Jaswant S.; Srivastava, Rashmi; Shukla, Anumeha

2014-01-01

The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere. PMID:24727672

Kinds and problems of geomorphological explanation

Science.gov (United States)

Cox, Nicholas J.

2007-07-01

What characterises satisfactory explanations in geomorphology is a key methodological question deserving continued analysis. In turn it raises the issue of the role played by methodology within the science. At its best, methodology can provide helpful distinctions, identify key issues and yield guidance for researchers. The substantive context for debates on explanation is the apparent complexity and difficulty of geomorphology as a science, which is arguably no greater than that of other Earth or environmental sciences. The logical view of explanation dominant in the 1950s and 1960s still has value, but a broader view is needed of explanations, related to the questions geomorphologists (and others) ask and to the answers that they find interesting. Answers may be sought in terms of purpose, history, mechanisms and statistics. Arguments over what is supposed to be reductionism can be clarified by underlining that both micro- and macro-explanations may be helpful. Although many geomorphologists aspire to mechanistic explanations, they often stop short at statistical explanations, making use of convenient functional forms such as power laws. Explanations have both social and psychological dimensions, the former much stressed in history of science and recent science studies, the latter deserving greater emphasis at present. Complicated models raise the question of how far it can be said that geomorphologists understand them in totality. A bestiary of poor explanations is needed, so that geomorphologists are not seduced by weak arguments and because they often serve as steps towards better explanations. Circular arguments, ad hoc explanations, and mistaking the name of the problem for the solution are cases in point.

44 CFR 10.14 - Flood plains and wetlands.

Science.gov (United States)

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44 CFR...

Defining 'plain language' in contemporary South Africa | Cornelius ...

African Journals Online (AJOL)

Defining the concept 'plain language' has been hugely problematic since the origins of the socalled Plain Language Movement in the 1970s in the United States and elsewhere in the world. Definitions of 'plain language' abound, yet James (2008: 6) warns, in relation to plain language practitioners, that “we can't yet call ...

7 CFR 650.25 - Flood-plain management.

Science.gov (United States)

2010-01-01

... user how alternative land use decisions may affect the aquatic and terrestial ecosystems, human safety... Flood-plain management. Through proper planning, flood plains can be managed to reduce the threat to... encourages sound flood-plain management decisions by land users. (a) Policy—(1) General. NRCS provides...

The sedimentology and uranium mineralisation of the Matjieskloof (GT7) deposit, Fraserburg district

International Nuclear Information System (INIS)

Le Roux, J.P.

1982-08-01

A sedimentological investigation was carried out on the Matjieskloof prospect of JCI, 40 km south of Fraserburg at the foot of the Teekloof pass. The deposit is located in a thick, tabular sandstone forming part of the Poortjie Member at the base of the Teekloof Formation. A study of sedimentary structures, grain sizes and palaeocurrents in the sandstone sequence at Matjieskloof suggests a general decrease in energy conditions upward in the succession, indicating denudation of the source areas to the south-west. The depositional environment of the mineralised S1-sandstone as revealed by field work and borehole analysis, is that of a low-sinuosity, braided river of the Bijou Creek type, deposited during ephemeral flash floods in a semi-arid environment. Three main flow systems are revealed by the palaeocurrent analysis, showing good correspondence with the reconstructed palaeoriver system. In the areas where these flow systems cross, scouring of the S2-sandstone into the underlying S1-sandstone occured. These regions also correspond to the confluence areas of channels within the braided river system, and apparently formed favourable environments for uranium mineralisation. This may be due to the presence of erosion surfaces within these areas, the increased thickness of sandstones and the accumulation of plant material, controlled by current velocities. Molybdenum shows a similar distribution to the uranium mineralisation, and both are clearly controlled by the sedimentological sub-environments

Census plan of environmental and cultural heritage of Latium Region. The Pontina and Fondi coastal plains; I beni culturali a carattere geologico del Lazio. La Pianura Pontina, Fondana e i Monti Ausoni meridionali

Energy Technology Data Exchange (ETDEWEB)

Casto, L. [Regione Lazio, Rome (Italy). Assessorato alle Politiche per la Promozione della Cultura, dello Spettacolo, del Turismo e dello Sport. Centro Regionale di Documentazione; Zarlenga, F. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente. Settore Informazione e Diffusione

1997-12-31

The geological heritage also indicated as `Geosites` or `Geotopes` in the `Area 4` defined in the Census Plan of Environmental and Cultural Heritage of Latium Region (Delivery R.C. n. 642/1979) in this paper is hereby described. In this area the Pontina and Fondi coastal plains, the Alban Hills Volcanic District Northward, the Mounts Volsci Range Eastward and Southward the Circeo Promontory is present. The geological context is described referring to the geomorphology and the landscape, the paleontology, the stratigraphy, the hydrogeology and the building materials. The museums set in the area also described. Geological history began during Upper Trias (Volsci Range and Circeo promontory) has continued until recent times (Pontina and Fondi plains and Alban Hills Volcanic District). The Mount Volsci Range is mostly constituted by carbonatic rocks (`Latium-Abruzzi series`) with shelf facies, ranging in age from the Upper Trias to the Paleocene, with scarce evidence of the Miocene transgression. From a structural point of view the Volsci chain shows main tectonic alignments trending NW-SE, NE-SW and N-S, folds and overthrusts verging NE.

Study on the application of seismic sedimentology in a stratigraphic-lithologic reservoir in central Junggar Basin

Science.gov (United States)

Yu, Yixin; Xia, Zhongmou

2017-06-01

This paper discusses the research idea of description for stratigraphic-lithologic reservoir based on seismic sedimentology methods. The sandstone reservoir of Jurrassic XiShanyao Formation in Junggar Basin is studied according to the theory and approaches of seismic sedimentology. By making full use of borehole data, the technologies of layer correlation based on the stratigraphic sequence framework, the forward seismic modeling, the stratal slicing and lithologic inversion are applied. It describes the range of denudation line, the distribution characteristics of sedimentary facies of the strata, the vertical and horizontal distribution of sand bodies and the favourable oil-gas bearing prospective area. The results shows that study area are dominated braided delta deposition including underwater distributary channel and distributary bay microfacies, the nip-out lines of the formation are northeast to southwest from north to south, the second Middle Jurassic sand body is the most widely distributed one among three sand bodies, the prospective oil-gas bearing area located in the south part and around the YG2 well area. The study result is effective on the practice of exploration in study area.

A new symbol-and-GIS based detailed geomorphological mapping system: Renewal of a scientific discipline for understanding landscape development

NARCIS (Netherlands)

Gustavvson, M.; Kolstrup, E.; Seijmonsbergen, A.C.

2006-01-01

Abstract This paper presents a comprehensive and flexible new geomorphological combination legend that expands the possibilities of current geomorphological mapping concepts. The new legend is presented here at scale of 1:10,000 and it combines symbols for hydrography, morphometry/morphography,

Climate and Sedentism in the Middle Missouri Subarea of the Plains.

Science.gov (United States)

Toom, Dennis Lee

1992-01-01

The development of village life in the Middle Missouri subarea of the Great Plains of North America is examined in this study, particularly in regard to the role that the improved climatic conditions of the proposed Neo -Atlantic episode might have played in this process. It is concluded that the early Middle Missouri villagers were, for the most part, immigrants from the east. Thus, the question becomes not one of why did sedentism evolve in this region of marginal agricultural potential, but one of why was sedentism transferred to and maintained in one of the optimum areas of the world for nomadic hunting and gathering adaptations. To understand this question, considerable insight must be gained into the demographic, economic, and climatic factors pertaining to the early Middle Missouri villagers. The demographic and economic data for the study were drawn from the available literature. The paleoclimatic data were generated from detailed stratigraphic studies of cutbank exposures in the Lake Sharpe area of central South Dakota. The paleoclimatic research is based on geological methods and concepts involving theoretical relationships between climate, geomorphology, and pedology. Archaeological features were used to provide precise contextual and chronological controls for the stratigraphic work, resulting in a cross -disciplinary geoarchaeological approach for this aspect of the study. The findings of the paleoclimatic research indicate that the generally warmer and moister conditions of the Neo-Atlantic episode probably did encourage and even enable the initial establishment of agricultural-based villages in the Middle Missouri. However, the cooler and drier conditions of the succeeding Pacific episode, while eliciting certain adaptive responses from the then resident village peoples, were not sufficiently detrimental to actually discourage village life in the region. Rather, it would appear that the economic diversity afforded by the Middle Missouri setting

Contribution to the geology of the Niari basin: sedimentology and metallogeny of the mining region

International Nuclear Information System (INIS)

Bigotte, G.

1956-01-01

This thesis is divided in two parts: a detailed petrographical and stratigraphical study of the upper layers of calcareous schist in Congo which lead to some sedimentological considerations, and a metallogenic study of the ores of Niari basin which lead to a theoretical description of the metallogeny in Congo. In the first part, after a brief description of the methods used, a petrographical survey of the rocks of the upper layers of calcareous schist of the Boko-Congo area is given as well as sedimentological conclusions and stratigraphical data. The studies and conclusions related to this limited area are extended to a region scale. A structural study and precised descriptions of this region lead to an attempt of tectonic explanation. In the second part, an inventory and description of known mineralisation points in the Niari basin are given and in particular the detailed descriptions of four deposits: La Grande-Mine, M'Passa, Diangala and Djenguile. The interpretations and conclusions are based on the study of the general characters of the mineralisation in Niari basin and its comparison with the mineralisation in Katanga (now Shaba region) and North Rhodesia (now Zambia). (M.P.)

Learning Geomorphology Using Aerial Photography in a Web-Facilitated Class

Science.gov (United States)

Palmer, R. Evan

2013-01-01

General education students taking freshman-level physical geography and geomorphology classes at Arizona State University completed an online laboratory whose main tool was Google Earth. Early in the semester, oblique and planimetric views introduced students to a few volcanic, tectonic, glacial, karst, and coastal landforms. Semi-quantitative…

Geomorphological hazard and tourist vulnerability along Portofino Park trails (Italy

Directory of Open Access Journals (Sweden)

P. Brandolini

2006-01-01

Full Text Available The many trails existing in the coastal area of Portofino Promontory are used by tourists for trekking or as pathways to small villages and beaches. The aim of this paper is to define geomorphological hazard and tourist vulnerability in this area, within the framework of the management and planning of hiking activities in Portofino Natural Park. In particular, processes triggered by gravity, running waters and wave motion, affecting the slopes and the cliff, are considered. The typology of the trails and trail maintenance are also taken into account in relation to weather conditions that can make the excursion routes dangerous for tourists. In conclusion, an operative model is applied for the definition of possible risk scenarios. This model is founded on an inventory and the quantification of geomorphological hazards and tourist vulnerability, in comparison with trail rescue data. The model can be applied to other environments and tourist areas.

Sea floor geomorphology: Bathymetry investigations in the S22 cruise

Digital Repository Service at National Institute of Oceanography (India)

Evsykov, Y.D.; Subrahmanyam, C.; Murthy, K.S; Rai, S

stream_size 9 stream_content_type text/plain stream_name Mem_Geol_Soc_India_1998_39_29.pdf.txt stream_source_info Mem_Geol_Soc_India_1998_39_29.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Sedimentology and geomorphology of a large tsunamigenic landslide, Taan Fiord, Alaska

Science.gov (United States)

Dufresne, A.; Geertsema, M.; Shugar, D. H.; Koppes, M.; Higman, B.; Haeussler, P. J.; Stark, C.; Venditti, J. G.; Bonno, D.; Larsen, C.; Gulick, S. P. S.; McCall, N.; Walton, M.; Loso, M. G.; Willis, M. J.

2018-02-01

On 17 October 2015, a landslide of roughly 60 × 106 m3 occurred at the terminus of Tyndall Glacier in Taan Fiord, southeastern Alaska. It caused a tsunami that inundated an area over 20 km2, whereas the landslide debris itself deposited within a much smaller area of approximately 2 km2. It is a unique event in that the landslide debris was deposited into three very different environments: on the glacier surface, on land, and in the marine waters of the fjord. Part of the debris traversed the width of the fjord and re-emerged onto land, depositing coherent hummocks with preserved source stratigraphy on an alluvial fan and adjacent moraines on the far side of the fjord. Imagery from before the landslide shows that the catastrophic slope failure was preceded by deformation and sliding for at least the two decades since the glacier retreated to its current terminus location, exposing steep and extensively faulted slopes. A small volume of the total slide mass remains within the source area and is topped by striated blocks (> 10 m across) and standing trees that were transported down the slope in intact positions during the landslide. Field work was carried out in the summer of 2016, and by the time this paper was written, almost all of the supraglacial debris was advected into the fjord and half the subaerial hummocks were buried by glacial advance; this rapid change illustrates how highly active sedimentary processes in high-altitude glacial settings can skew any landslide-frequency analyses, and emphasizes the need for timely field investigations of these natural hazards.

Geomorphological analysis and classification of foredune ridges based on Terrestrial Laser Scanning (TLS) technology

Science.gov (United States)

Fabbri, Stefano; Giambastiani, Beatrice M. S.; Sistilli, Flavia; Scarelli, Frederico; Gabbianelli, Giovanni

2017-10-01

Along the North Adriatic Sea coast (Italy), vulnerability to climate change is further aggravated by anthropogenic influences, such as strong subsidence rate due to deep groundwater and gas abstraction, tourism and industry impacts. In this context, conservation and restoration of coastal sand dunes become extremely important especially because of their importance in terms of 'natural' coastal defense. This paper proposes an innovative geomorphological approach based on Terrestrial Laser Scanning - TLS, which allows us to measure and monitor morphometric dune evolution with high precision and details. Several TLS surveys were performed along the Ravenna coast (Adriatic Sea, Italy) and the resulting Digital Elevation Models (DEMs) were analyzed in order to classify the foredune ridges in three geomorphological sub-zones. The topographic, areal and volumetric variations over time of geomorphological units were calculated by GIS tools in order to identify seasonal trends or particular pattern. Meteo-marine climate conditions were also analyzed and Principal Component Analysis (PCA) was performed to correlate changes in morphology with meteo-marine forcing factors, highlighting the ones that most influence dune evolution and dynamics.

Multi-proxy Characterization of Two Recent Storm Deposits Attributed to Hurricanes Rita and Ike in the Chenier Plain of Southwestern Louisiana

Science.gov (United States)

Yao, Q.; Liu, K. B.; Ryu, J.

2017-12-01

The Chenier Plain in southwestern Louisiana owes its origin to dynamic depositional processes that are dominated by delta-switching of the Mississippi River to the east, while frequent hurricane activities also play an important role in its geomorphology and sedimentary history. However, despite several studies in the literature, the sediment-stratigraphic characteristics of recent or historic hurricane deposits are still not well documented from the Chenier Plain. In 2005 and 2008, Hurricane Rita (category 3) and Ike (category 2) made landfall on the coasts of Louisiana and Texas. Remote sensing images confirm that the Rockefeller Wildlife Refuge, located at the east end of the Louisiana Chenier Plain, was heavily impacted by both hurricanes. We analyzed the lithology and chemical stratigraphy of three 30 cm sediment monoliths (ROC-1, ROC-2, and ROC-3) recovered from a coastal saltmarsh in the Rockefeller Wildlife Refuge to identify the event deposits attributed to these two storms. Each monolith contains 2 distinct light-colored clastic sediment layers imbedded in brown organic clay. The loss-on-ignition and X-ray fluorescence results show that the hurricane layers have increased contents of Ca, Sr, Zr, and carbonates and decreased contents of water and organics. Surprisingly, despite its greater intensity and more severe impacts, Hurricane Rita left a much thinner storm deposit than did Hurricane Ike in all monoliths. Satellite data reveal that Hurricane Rita caused significant coastal erosion and shoreline recession, rendering the sampling sites much closer to the beach and ocean and therefore more prone to storm surges and overwash deposition than when Hurricane Ike struck three years later. Our results suggest that site-to-sea distance, which affects a study site's paleotempestological sensitivity, can play a bigger role in affecting the thicknesses of storm deposits than the intensity of the hurricane.

Feedbacks between geomorphology and biota controlling Earth surface processes and landforms: A review of foundation concepts and current understandings

Science.gov (United States)

Corenblit, Dov; Baas, Andreas C. W.; Bornette, Gudrun; Darrozes, José; Delmotte, Sébastien; Francis, Robert A.; Gurnell, Angela M.; Julien, Frédéric; Naiman, Robert J.; Steiger, Johannes

2011-06-01

This review article presents recent advances in the field of biogeomorphology related to the reciprocal coupling between Earth surface processes and landforms, and ecological and evolutionary processes. The aim is to present to the Earth Science community ecological and evolutionary concepts and associated recent conceptual developments for linking geomorphology and biota. The novelty of the proposed perspective is that (1) in the presence of geomorphologic-engineer species, which modify sediment and landform dynamics, natural selection operating at the scale of organisms may have consequences for the physical components of ecosystems, and particularly Earth surface processes and landforms; and (2) in return, these modifications of geomorphologic processes and landforms often feed back to the ecological characteristics of the ecosystem (structure and function) and thus to biological characteristics of engineer species and/or other species (adaptation and speciation). The main foundation concepts from ecology and evolutionary biology which have led only recently to an improved conception of landform dynamics in geomorphology are reviewed and discussed. The biogeomorphologic macroevolutionary insights proposed explicitly integrate geomorphologic niche-dimensions and processes within an ecosystem framework and reflect current theories of eco-evolutionary and ecological processes. Collectively, these lead to the definition of an integrated model describing the overall functioning of biogeomorphologic systems over ecological and evolutionary timescales.

49 CFR 215.111 - Defective plain bearing.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing. 215.111 Section 215.111... § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has a plain bearing— (a) That is missing, cracked, or broken; (b) On which the bearing liner— (1) Is...

The igapó of the Negro River in central Amazonia: Linking late-successional inundation forest with fluvial geomorphology

Science.gov (United States)

Montero, Juan Carlos; Latrubesse, Edgardo M.

2013-10-01

Despite important progress on Amazonian floodplain research, the flooded forest of the Negro River "igapó" has been little investigated. In particular, no study has previously focused the linkage between fluvial geomorphology and the floristic variation across the course of the river. In this paper we describe and interpret relations between igapó forest, fluvial geomorphology and the spatial evolution of the igapó forest through the Holocene. Therefore, we investigate the effect of geomorphological units of the floodplain and channel patterns on tree diversity, composition and structural parameters of the late-successional igapó forest. Our results show that sites sharing almost identical flooding regime, exhibit variable tree assemblages, species richness and structural parameters such as basal area, tree density and tree heights, indicating a trend in which the geomorphologic styles seem to partially control the organization of igapó's tree communities. This can be also explained by the high variability of well-developed geomorphologic units in short distances and concentrated in small areas. In this dynamic the inputs from the species pool of tributary rivers play a crucial role, but also the depositional and erosional processes associated with the evolution of the floodplain during the Holocene may control floristic and structural components of the igapó forests. These results suggest that a comprehensive approach integrating floristic and geomorphologic methods is needed to understand the distribution of the complex vegetation patterns in complex floodplains such as the igapó of the Negro River. This combination of approaches may introduce a better comprehension of the temporal and spatial evolutionary analysis and a logic rationale to understand the vegetation distribution and variability in function of major landforms, soil distributions and hydrology. Thus, by integrating the past into macroecological analyses will sharpen our understanding of the

Applications of geomorphology, tectonics, geology and geophysical interpretation of, East Kom Ombo depression, Egypt, using Landsat images

Directory of Open Access Journals (Sweden)

El Sayed A. El Gammal

2013-12-01

Full Text Available In the Southern Eastern Desert of Egypt, A NW–SE oriented structural graben extends from the North of Aswan to the Red Sea coast with a length of about 400 km and an average width of 30 km. The area has significant potential for development as it may be provided with water from surface and subsurface sources and is the site of prospection for petroleum. The present paper is an attempt to understand the structural evolution and genetic development of the geomorphologic features of the area and constructing presently a new geomorphological map at a scale of 1:250,000 using Landsat ETM images and field checks. Available geological maps and the produced geomorphological map are digitized by using the ARC-GIS software. The same program is also used to produce a 3D DEM for surface and subsurface features. Based on new interpretations of aeromagnetic and radiometric data, the subsurface features of the basement cover were illustrated on a 3D map. Geological–geomorphological profiles have been constructed in different directions in the area to identify present and ancient geomorphologic features. The place and shape of subsurface deep seated NW–SE trending faults have been determined. The faults, which generated the graben have downthrows in the order of 900–5800 m. The surface and subsurface observations delineate the dominant downthrow of about 3750 m. Three E–W subsurface faults have been detected under Nubia sandstone, one of them, displaying a downthrow of about 845 m, cuts through the basement rocks.

Relationship between radionuclides and sedimentological variables in the South Atlantic Continental Margin

International Nuclear Information System (INIS)

Ferreira, Paulo A.L.; Figueira, Rubens C.L.

2015-01-01

There is a lack of information regarding marine radioactivity in sediments of the Continental Margin of the South Atlantic. "1"3"7Cs and "4"0K radioactivity and sedimentological variables were determined in superficial sediment samples. It was demonstrated that "4"0K is a good indicator for sediment granulometry, whilst "1"3"7Cs presents a good correlation with its chemical composition. Moreover, it was identified through the radiometric data the occurrence of input of allochtonous matter to the Brazilian southernmost compartment from the Rio de La Plata estuary, as previously reported in the literature. (author)

Chenier plain development: feedbacks between waves, mud and sand

Science.gov (United States)

Nardin, W.; Fagherazzi, S.

2015-12-01

Cheniers are sandy ridges parallel to the coast established by high energy waves. Here we discuss Chenier plains ontogeny through dimensional analysis and numerical results from the morphodynamic model Delft3D-SWAN. Our results show that wave energy and shelf slope play an important role in the formation of Chenier plains. In our numerical experiments waves affect Chenier plain development in three ways: by winnowing sediment from the mudflat, by eroding mud and accumulating sand over the beach during extreme wave events. We further show that different sediment characteristics and wave climates can lead to three alternative coastal landscapes: strand plains, mudflats, or the more complex Chenier plains. Low inner-shelf slopes are the most favorable for strand plain and Chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation.

Quantifying the performance of automated GIS-based geomorphological approaches for riparian zone delineation using digital elevation models

Directory of Open Access Journals (Sweden)

D. Fernández

2012-10-01

Full Text Available Riparian zone delineation is a central issue for managing rivers and adjacent areas; however, criteria used to delineate them are still under debate. The area inundated by a 50-yr flood has been indicated as an optimal hydrological descriptor for riparian areas. This detailed hydrological information is usually only available for populated areas at risk of flooding. In this work we created several floodplain surfaces by means of two different GIS-based geomorphological approaches using digital elevation models (DEMs, in an attempt to find hydrologically meaningful potential riparian zones for river networks at the river basin scale. Objective quantification of the performance of the two geomorphologic models is provided by analysing coinciding and exceeding areas with respect to the 50-yr flood surface in different river geomorphological types.

Tectonic and sedimentological environments of sandstone-hosted uranium deposits, with special reference to the Karoo Basin of South Africa

International Nuclear Information System (INIS)

Le Roux, J.P.

1985-01-01

The principal tectonic and sedimentological settings for sandstone-hosted uranium deposits are described. Back-arc basins filled with post-Silurian, fluvial sediments bordering subduction zone magmatic arcs of calc-alkaline composition are considered favourable tectonic environments. The basins should be closed to prevent excessive oxidation of the sediments. Uranium deposits are concentrated near basin rims in the transition zone between uplift and basin subsidence, because of favourable sedimentary facies in those areas. Syn- and post-depositional deformation could have affected the localisation of uranium ore-bodies, while intrusive centres or uplifted arcs commonly have surrounding aprons of potential host rocks. Stratigraphic zoning is also related to source area tectonics and can be used to predict favourable sedimentary environments. Sedimentological processes had a direct influence on the permeability and carbonaceous matter content of sandstones and therefore have often controlled the localisation of ore-bodies. (author)

A geomorphological characterisation of river systems in South Africa: A case study of the Sabie River

Science.gov (United States)

Eze, Peter N.; Knight, Jasper

2018-06-01

Fluvial geomorphology affects river character, behaviour, evolution, trajectory of change and recovery potential, and as such affects biophysical interactions within a catchment. Water bodies in South Africa, in common with many other water-stressed parts of the world, are generally under threat due to increasing natural and anthropogenic influences including aridity, siltation and pollution, as well as climate and environmental change. This study reports on a case study to characterise the geomorphology of different river systems in South Africa, with the aim of better understanding their properties, controls, and implications for biophysical interactions including water quality, biodiversity (aquatic and riparian), and human activity within the catchment. The approach adopted is based on the River Styles® framework (RSF), a geomorphology-based approach developed for rivers in New Zealand and Australia, but applied here for the first time to South Africa. Based on analysis of remote sensing imagery, SRTM-2 digital topographic data and field observations on sites through the entire river system, six geomorphic elements were identified along the Sabie River, northeast South Africa (gorge, bedrock-forced meander, low-moderate sinuosity planform controlled sand bed, meandering sand bed, low sinuosity fine grained sand bed, and floodouts), using the RSF classification scheme and based on the RSF procedural tree of Brierley and Fryirs (2005). Previous geomorphological studies along the Sabie River have shown that different reaches respond differently to episodic floods; we use these data to link river geomorphological character (as defined by the RSF) to the hydrodynamic conditions and processes giving rise to such character. This RSF approach can be used to develop a new management approach for river systems that considers their functional biophysical behaviour within individual reaches, rather than considering them as homogeneous and uniform systems.

Influence of Geomorphology on the Physiognomy of Colophospermum mopane and its Effect on Browsing in Central Namibia

OpenAIRE

TESHIROGI, Koki

2010-01-01

Colophospermum mopane is a characteristic tree species indigenous to Southern Africa, where it forms 'mopane vegetation.' Mopane plays an important role in livestock farming, and the physiognomy of mopane influences the availability of feed. This study clarified the relationship between the difference in mopane physiognomy and the browsing activity of goats with reference to geomorphology. The physiognomy of mopane corresponded to geomorphological characteristics of surface structures and soi...

Beach Geomorphology and Kemp's Ridley (Lepidochelys kempii) Nest Site Selection along Padre Island, Texas, USA

Science.gov (United States)

Culver, M.; Gibeaut, J. C.; Shaver, D. J.; Tissot, P.; Starek, M. J.

2017-12-01

The Kemp's ridley sea turtle (Lepidochelys kempii) is the most endangered sea turtle in the world, largely due to the limited geographic range of its nesting habitat. In the U.S., the majority of nesting occurs along Padre Island National Seashore (PAIS) in Texas. There has been limited research regarding the connection between beach geomorphology and Kemp's ridley nesting patterns, but studies concerning other sea turtle species suggest that certain beach geomorphology variables, such as beach slope and width, influence nest site selection. This research investigates terrestrial habitat variability of the Kemp's ridley sea turtle and quantifies the connection between beach geomorphology and Kemp's ridley nest site selection on PAIS and South Padre Island, Texas. Airborne topographic lidar data collected annually along the Texas coast from 2009 through 2012 was utilized to extract beach geomorphology characteristics, such as beach slope and width, dune height, and surface roughness, among others. The coordinates of observed Kemp's ridley nests from corresponding years were integrated with the aforementioned data in statistical models, which analyzed the influence of both general trends in geomorphology and individual morphologic variables on nest site selection. This research identified the terrestrial habitat variability of the Kemp's ridley and quantified the range of geomorphic characteristics of nesting beaches. Initial results indicate that dune width, beach width, and wind speed are significant variables in relation to nest presence, using an alpha of 0.1. Higher wind speeds and narrower beaches and foredunes favor nest presence. The average nest elevation is 1.13 m above mean sea level, which corresponds to the area directly below the potential vegetation line, and the majority of nesting occurs between the elevations of 0.68 m and 1.4 m above mean sea level. The results of this study include new information regarding Kemp's ridley beach habitat and its

Irrigation channels of the Upper Rhone valley (Switzerland). Geomorphological analysis of a cultural heritage

Science.gov (United States)

Reynard, Emmanuel

2016-04-01

The Upper Rhone valley (Canton of Valais, Switzerland) is characterised by dry climatic conditions that explain the presence of an important network (about 800 km) of irrigation channels - called Bisses in the French-speaking part of the canton or Suonen in the German-speaking area - dating back to the Middle Ages. This network constitutes a cultural heritage and during the last 30 years these agricultural infrastructures have sparked a renewed interest for tourist and cultural reasons. Indeed, the paths along the channels are used as tourist trails and several abandoned channels have been renovated for tourist use. Based on an inventory of the Bisses/Suonen of Valais, the proposed communication has three aims: (1) to analyse the geomorphological context (morphometric analysis, structural geomorphology, main processes) of various types of channels and to show the impact of the geomorphological context on the building techniques; (2) to identify particularly active processes along the channels; (3) to classify the Bisses/Suonen according to their geomorphological value and to their geomorphological sensitivity, and to propose managing measures. Structural and climatic conditions influence the geomorphological context of the channels. In a structural point of view, irrigation channels are developed in three main contexts: (1) in the Aar Massif crystalline basement; (2) in the limestone and marl cover nappes of the Helvetic Alps; (3) in the metamorphic cover nappes of the Penninic domain. The Rhone River valley is boarded by two high mountain ranges: the Penninic Alps in the South and the Bernese Alps in the North. Because of rain shadow effects, the climate is relatively dry and, between Brig and Martigny, annual rainfall is not more than 600 mm at 500 m ASL and 800 mm at 1600 m ASL. Nevertheless, due to important vertical precipitation gradients annual rainfall totals are high at high altitudes. On the southern facing tributary valleys, the dry climatic conditions

Geomorphological research of large-scale slope instability at Machu Picchu, Peru

Czech Academy of Sciences Publication Activity Database

Vilímek, V.; Zvelebil, J.; Klimeš, Jan; Patzelt, Z.; Astete, F.V.; Kachlík, F.; Hartvich, Filip

2007-01-01

Roč. 89, č. 3-4 (2007), s. 241-257 ISSN 0169-555X Institutional research plan: CEZ:AV0Z30460519 Keywords : natural hazard * Machu Picchu * landslides Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.854, year: 2007 www.elsevier.com/locate/geomorphology

Geomorphology: Perspectives on observation, history, and the field tradition

Science.gov (United States)

Vitek, John D.

2013-10-01

Other than a common interest in form and process, current geomorphologists have little in common with those who established the foundations of this science. Educated people who had an interest in Earth processes during the nineteenth century cannot be compared to the scholars who study geomorphology in the twenty-first century. Whereas Earth has undergone natural change from the beginning of time, the human record of observing and recording processes and changes in the surface Is but a recent phenomena. Observation is the only thread, however, that connects all practitioners of geomorphology through time. As people acquired knowledge related to all aspects of life, technological revolutions, such as the Iron Age, Bronze Age, agricultural revolution, the atomic age, and the digital age, shaped human existence and thought. Technology has greatly changed the power of human observation, including inward to the atomic scale and outward into the realm of space.Books and articles describe how to collect and analyze data but few references document the field experience. Each of us, however, has experienced unique circumstances during field work and we learned from various mentors how to observe. The surface of Earth on which we practice the vocation of geomorphology may not be much different from a hundred years ago but many things about how we collect data, analyze it and disseminate the results have changed. How we function in the field, including what we wear, what we eat, how we get there, and where we choose to collect data, clearly reflects the complexity of the human system on Earth and the processes and forms that arouse our interest. Computers, miniaturization of electronics, satellite communications and observation platforms in space provide access to data to aid in our quest to understand Earth surface processes. Once, people lived closer to nature in primitive shelters in contrast with life in urban environments. But as urban life continues to expand and people

Geomorphological Prerequisites of Recreation and Tourism Development in the Basin of Bolshaya Golubaya River

Directory of Open Access Journals (Sweden)

Vishnyakov Nikolay Vladimirovich

2014-12-01

Full Text Available The basin of the Bolshaya Golubaya river is a promising region for the development of recreation, due to the unique natural conditions and rich historical and cultural heritage of this territory. The article demonstrates geomorphological features of the basin of Bolshaya Golubaya and their influence on the prospects of recreational use of this area. The author analyses the literature data on the geomorphology of the region and supplements it with his own field studies. The nature of this region is picturesque and multifarious. There are a lot of ravines, gullies, terraces, chalk cliffs and other landforms here. The author discovers the opportunities of organization of different recreational types in the study area in light of its geomorphological features. Recreational characteristics of this territory make it suitable for hiking, skiing and cycling tourism, horse riding. The results of this research can be used at the stage of creating of tourist-recreational projects, when designing and conducting excursion trips, sports and health touristic events. These studies contribute to the expansion of practical knowledge about the geography of the territory which has a positive effect on the possibility of carrying out mentioned above recreational projects.

Geomorphology of New England

Science.gov (United States)

Denny, C.S.

1982-01-01

Widely scattered terrestrial deposits of Cretaceous or Tertiary age and extensive nearshore and fluvial Coastal Plain deposits now largely beneath the sea indicate that the New England region has been above sea level during and since the Late Cretaceous. Estimates of rates of erosion based on sediment load in rivers and on volume of sediments in the Coastal Plain suggest that if the New England highlands had not been uplifted in the Miocene, the area would now be largely a lowland. If the estimated rates of erosion and uplift are of the right order of magnitude, then it is extremely unlikely that any part of the present landscape dates back before Miocene time. The only exception would be lowlands eroded in the early Mesozoic, later buried beneath Mesozoic and Cenozoic deposits, and exhumed by stream and glacial erosion during the later Cenozoic. Many of the rocks in the New England highlands are similar to those that underlie the Piedmont province in the central and southern Appalachians, where the relief over large areas is much less than in the highlands of New England. These comparisons suggest that the New England highlands have been upwarped in late Cenozoic time. The uplift took place in the Miocene and may have continued into the Quaternary. The New England landscape is primarily controlled by the underlying bedrock. Erosion and deposition during the Quaternary, related in large part to glaciation, have produced only minor changes in drainage and in topography. Shale and graywacke of Ordovician, Cambrian, and Proterozoic age forming the Taconic highlands, and akalic plutonic rocks of Mesozoic age are all highland makers. Sandstone and shale of Jurassic and Triassic age, similar rocks of Carboniferous age, and dolomite, limestone, and shale of Ordovician and Cambrian age commonly underlie lowlands. High-grade metapelites are more resistant than similar schists of low metamorphic grade and form the highest mountains in New England. Feldspathic rocks tend to

Sedimentology of Fraser River delta peat deposits: a modern analogue for some deltaic coals

Energy Technology Data Exchange (ETDEWEB)

Styan, W B; Bustin, R M

1984-01-01

On the Recent lobe of the Fraser River delta, peat accumulation has actively occurred on the distal lower delta plain, the transition between upper and lower delta plains, and the alluvial plain. Distal lower delta plain peats developed from widespread salt and brackish marshes and were not influenced appreciably by fluvial activity. Lateral development of the marsh facies were controlled by compaction and eustatic sea-level rise. The resulting thin, discontinuous peat network contains numerous silty clay partings and high concentrations of sulphur. Freshwater marsh facies formed but were later in part eroded and altered by transgressing marine waters. Peats overlie a thin, fluvial, fining-upward sequence which in turn overlies a thick, coarsening-upward, prodelta-delta front succession. Lower- upper delta plain peats initially developed from interdistributary brackish marshes and were later fluvially influenced as the delta prograded. Thickest peats occur in areas where distributary channels were abandoned earliest. Sphagnum biofacies replace sedge-grass-dominated communities except along active channel margins, where the sedge-grass facies is intercalated with overbank and splay deposits. Peats are underlain by a relatively thin sequence of fluvial deposits which in turn is underlain by a major coarsening-upward delta front and pro-delta sequence. Alluvial plain peats accumulated in back swamp environments of the flood plain. Earliest sedge-clay and gyttja peats developed over thin fining-upward fluvial cycles or are interlaminated with fine-grained flood deposits. Thickest accumulations occur where peat fills small avulsed flood channels. Overlying sedge-grass and sphagnum biofacies are horizontally stratified and commonly have sharp boundaries with fine-grained flood sediments. At active channel margins, however, sedge-grass peats are intercalated with natural levee deposits consisting of silty clay.

Geomorphology of the Southern Gulf of California Seafloor

Science.gov (United States)

Eakins, B. W.; Lonsdale, P. F.; Fletcher, J. M.; Ledesma, J. V.

2004-12-01

A Spring 2004 multibeam sonar survey defined the seafloor geomorphology of the southern part of Gulf of California and the intersection of the East Pacific Rise with the North American continent. Survey goals included mapping structural patterns formed during the rifting that opened the Gulf and identifying the spatial transition from continental rifting to seafloor spreading. Multibeam sonar imagery, augmented with archival data and a subaerial DEM of Mexico, illuminates the principal features of this boundary zone between obliquely diverging plates: (i) active and inactive oceanic risecrests within young oceanic basins that are rich in evidence for off-axis magmatic eruption and intrusion; (ii) transforms with pull-apart basins and transpressive ridges along shearing continental margins and within oceanic crust; (iii) orphaned blocks of continental crust detached from sheared and rifted continental margins; and (iv) young, still-extending continental margins dissected by submarine canyons that in many cases are deeply drowned river valleys. Many of the canyons are conduits for turbidity currents that feed deep-sea fans on oceanic and subsided continental crust, and channel sediment to spreading axes, thereby modifying the crustal accretion process. We present a series of detailed bathymetric and seafloor reflectivity maps of this MARGINS Rupturing Continental Lithosphere focus site illustrating geomorphologic features of the southern part of the Gulf, from Guaymas Basin to the Maria Magdalena Rise.

High-Resolution Characterization of Intertidal Geomorphology by TLS

Science.gov (United States)

Guarnieri, A.; Vettore, A.; Marani, M.

2007-12-01

Observational fluvial geomorphology has greatly benefited in the last decades from the wide availability of digital terrain data obtained by orthophotos and by means of accurate airborne laser scanner data (LiDAR). On the contrary, the spatially-distributed study of the geomorphology of intertidal areas, such as tidal flats and marshes, remains problematic owing to the small relief characterizing such environments, often of the order of a few tens of centimetres, i.e. comparable to the accuracy of state-of-the-art LiDAR data. Here we present the results of Terrestrial Laser Scanner (TLS) acquisitions performed within a tidal marsh in the Venice lagoon. The survey was performed using a Leica HDS 3000 TLS, characterized by a large Field of View (360 deg H x 270 deg V), a low beam divergence (DSM and a DTM. This is important e.g. in eco-geomorphic studies of intertidal environments, where conventional LiDAR technologies cannot easily separate first and last laser returns (because of the low vegetation height) and thus provide models of the surface as well as of the terrain. Furthermore, the DTM is shown to provide unprecedented characterizations of marsh morphology, e.g. regarding the cross-sectional properties of small-scale tidal creeks (widths of the order of 10 cm), previously observable only through conventional topographic surveys, thus not allowing a fully spatially-distributed description of their morphology.

Alligator Rivers Analogue project. Geomorphology and paleoclimatic history

International Nuclear Information System (INIS)

Wyrwoll, K.H.

1992-01-01

The aim of this volume is to discuss the likely influence of geomorphological and palaeoclimatic controls on the development of the secondary dispersion fan at Koongarra. For the Koongarra area the Phanerozoic was a time of tectonic stability and predominantly subaerial denudation. The structural geology of the region facilitated the erosion of the Kombolgie Formation, setting in train the development of Koongarra Valley. With the removal of the Kombolgie cover the surface of the Cahill Formation could then be eroded. The geochemical controls on the development of the secondary dispersion fan require the orebody to be located in an oxidising weathering environment. Under the present weathering regimes it seems that this implies that the orebody is located at a depth of less than 30 m. From estimates of the present regional denudation rates of the area and wider geomorphological considerations, it is concluded that the top of the orebody would have reached such a depth at some time in the last 1-6 million years. The climates of the Late Quaternary provide some guide to Pleistocene climatic events. The most intense aridity coincided with times of global glacial maxima. There is also evidence that in the Late Cenozoic there were times of elevated rates of chemical weathering. However, the timing, nature and duration of such events is unclear. 171 refs., 4 tabs., 35 refs

An Evaluation of the Effectiveness of Stereo Slides in Teaching Geomorphology.

Science.gov (United States)

Giardino, John R.; Thornhill, Ashton G.

1984-01-01

Provides information about producing stereo slides and their use in the classroom. Describes an evaluation of the teaching effectiveness of stereo slides using two groups of 30 randomly selected students from introductory geomorphology. Results from a pretest/postttest measure show that stereo slides significantly improved understanding. (JM)

Tietkens Plain karst - Maralinga

International Nuclear Information System (INIS)

James, J.M.

1988-09-01

The Tietkens Plain karst is located to the north of Maralinga village which is on the crest of the Ooldea Range on the north and east margin of the Nullarbor Plain in western South Australia. The geology of the carbonate rocks in the Maralinga area is summarised. On Tietkens Plain from 1955 to 1963 nuclear weapons tests dispersed radioactive materials over the Maralinga area. Six nuclear devices were detonated in the air and one was exploded a few metres below the surface. The effect such explosions have on the karst and the possible rate of recovery of its surface are discussed. This report is the record of a visit to the Maralinga area from the 15th -21st November 1986 which involved an inspection of the karst surface together with collection of water, soil and rock samples. Results of the measurements made in order to assess water quality and water contamination by radioactive nuclides are presented. The implications arising from the presence of radioactive materials on the surface and the possibility of their entering and contaminating the groundwater in the area are discussed in the context of the chemistry of uranium and plutonium. The potential for transmission of contaminants through groundwater conduits and aquifers in the dolomite is discussed. Evidence is produced to show that the caves of the Nullabor Plain are not contaminated at present and are unlikely to be so in the future. 21 refs., 2 figs. 3 tabs., ills

Geomorphology and forest management in New Zealand's erodible steeplands: An overview

Science.gov (United States)

Phillips, Chris; Marden, Michael; Basher, Les R.

2018-04-01

In this paper we outline how geomorphological understanding has underpinned forest management in New Zealand's erodible steeplands, where it contributes to current forest management, and suggest where it will be of value in the future. We focus on the highly erodible soft-rock hill country of the East Coast region of North Island, but cover other parts of New Zealand where appropriate. We conclude that forestry will continue to make a significant contribution to New Zealand's economy, but several issues need to be addressed. The most pressing concerns are the incidence of post-harvest, storm-initiated landslides and debris flows arising from steepland forests following timber harvesting. There are three areas where geomorphological information and understanding are required to support the forest industry - development of an improved national erosion susceptibility classification to support a new national standard for plantation forestry; terrain analysis to support improved hazard and risk assessment at detailed operational scales; and understanding of post-harvest shallow landslide-debris flows, including their prediction and management.

Geomorphology and the uranium vein deposits of the Beira region of Portugal

International Nuclear Information System (INIS)

Cameron, J.

1982-01-01

Geomorphology, river drainage patterns and land form may be related to and indicative of, the presence of metalliferous vein structures, particularly if these are composed of either harder or softer gangue material than the enclosing host rock, and where the structures are relatively recent or uncomplicated by later tectonic movements. The Beira region of Portugal is an excellent example of the relationship between uranium-bearing vein and fault structures and the local geomorphology. The Serra da Estrela mountain range dominates the region and is a horst block whose long axis trends N48 0 E and is bounded by well-defined fracture systems N60 0 E on the north-west side and N35 0 E on the south-east side. The uranium veins, the main river courses and the diabase dyke structures to the north-west and south-east of the mountains are parallel to these two bounding fault systems. The close relationship between the uranium vein structures and the geomorphology, particularly the river courses, must indicate that the veins are young in age and closely related to, but immediately following, the uplift of the Serra da Estrela mountains. The uplift of the Serra da Estrela mountains is caused by the effects of the Alpine movements on the Iberian Peninsula and dated at a probable mid- to late Oligocene age. The uranium vein structures must therefore be close to and immediately following that age. (author)

Use of the catena principle in geomorphological impact assessment: a functional approach

NARCIS (Netherlands)

Wolfert, H.P.

1995-01-01

An integral method for assessing geomorphological landscape qualities is presented, to be used in environmental impact assessments. Five groups of landform functions are distinguished in the Netherlands, an area of low relief: orientation functions, information functions, ordering functions,

Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 1: Geological and Geomorphological Overview

Science.gov (United States)

Parker, T. J.; Pieri, D. C.

1985-01-01

Based upon Viking Orbiter 1 images of the southwestern portion of the Margaritifer Sinus Quadrangle, the northwestern portion of the Argyre Quadrangle, and a small portion of the southeastern Coprates Quadrangle, three major mountainous of plateau units, seven plains units, and six units related to valley forming processes were identified. The photomosaic is oriented such that it provides good areal coverage of the upper Chryse Trough from Argyre Planitia to just above Margaritifer Chaos as well as of plains units on either side of the Trough. The photomosaic was compiled from Viking Orbiter 1 images ranging in resolution from approximately 150 to 300 meters per pixel printed at a scale of about 1:2,000,000. The characteristics of each geomorphic unit are outlined.

The geomorphological evidences of subsidence in the Nile Delta: Analysis of high resolution topographic DEM and multi-temporal satellite images

Science.gov (United States)

El Bastawesy, M.; Cherif, O. H.; Sultan, M.

2017-12-01

This paper investigates the relevance of landforms to the subsidence of the Nile Delta using a high resolution topographic digital elevation model (DEM) and sets of multi-temporal Landsat satellite images. 195 topographic map sheets produced in 1946 at 1:25,000 scale were digitized, and the DEM was interpolated. The undertaken processing techniques have distinguished all the natural low-lying closed depressions from the artificial errors induced by the interpolation of the DEM. The local subsidence of these depressions from their surroundings reaches a maximum depth of 2.5 m. The regional subsidence of the Nile Delta has developed inverted topography, where the tracts occupied by the contemporary distributary channels are standing at higher elevations than the areas in between. This inversion could be related to the differences in the hydrological and sedimentological properties of underlying sediments, as the channels are underlain by water-saturated sands while the successions of clay and silt on flood plains are prone to compaction. Furthermore, the analysis of remote sensing and topographic data clearly show significant changes in the land cover and land use, particularly in the northern lagoons and adjacent sabkhas, which are dominated by numerous low subsiding depressions. The areas covered by water logging and ponds are increasing on the expense of agricultural areas, and aquaculture have been practiced instead. The precise estimation of subsidence rates and distribution should be worked out to evaluate probable changes in land cover and land use.

The Aysen Glacier Trail (AGT): Fostering leadership and personal growth towards understanding our place in the environment through experiential learning and scientific inquiry in northern Patagonia, Chile

Science.gov (United States)

Sincavage, R.; Chambers, F. B.; Leidich, J.

2017-12-01

The Colonia Glacier, a low elevation mid-latitude glacier, drains the lee side of the central division of the Northern Patagonian Ice Field (NPI). As such, it serves as a microcosm of conditions on the NPI as a whole. Glaciers of this type have experienced extreme variability in Holocene thickness and extent, making them excellent indicators of local and regional climate conditions. Glacial lake outburst floods (GLOFs) originating in the remote Cachet Basin, dammed by the Colonia Glacier, have increased in frequency from once every 10 years to 3 times annually since 2008. These flood events are important in that they 1.) directly impact the livelihoods of downstream residents, 2.) may be linked to the overall health of the Colonia Glacier and, to a larger extent, the NPI, 3.) provide a natural laboratory for studying the dynamics of large flood events, and 4.) have downcut the sediments sequestered in the upper basin, revealing a rich Holocene sedimentologic and climate record. With improved access to this remote region through local partners in recent years, outstanding opportunities for scientific discovery, education, and outreach exist in one of the most beautiful and least-studied glacial regions on Earth. We propose establishing an NSF REU site here to further develop the abundant educational and research opportunities in this spectacular locale. We envision students participating under the REU will receive a broad-based background in glaciology and sedimentology prior to the field experience, and then participate in basic field research led by the PIs into understanding recent and Holocene linkages between climate change and the glacio-fluvio geomorphology of the NPI. A pilot program of 13 U.S. and Chilean students with wide-ranging backgrounds and degree levels was conducted in the winter of 2015-16. A two week backcountry trek across rocky terrain, mountain streams, active glaciers, and proglacial lakes in this seldom-visited region immersed the students

Sedimentation within and among mangrove forests along a gradient of geomorphological settings

NARCIS (Netherlands)

Adame, Maria Fernanda; Neil, David; Wright, Sara F.; Lovelock, Catherine E.

2010-01-01

Coastal wetlands provide important ecological services to the coastal zone, one of which is sediment retention. In this study we investigated sediment retention across a range of geomorphological settings and across vegetation zones comprising coastal wetlands. We selected six coastal wetlands

Sedimentological reservoir characteristics of the Paleocene fluvial/lacustrine Yabus Sandstone, Melut Basin, Sudan

Science.gov (United States)

Mahgoub, M. I.; Padmanabhan, E.; Abdullatif, O. M.

2016-11-01

Melut Basin in Sudan is regionally linked to the Mesozoic-Cenozoic Central and Western African Rift System (CWARS). The Paleocene Yabus Formation is the main oil producing reservoir in the basin. It is dominated by channel sandstone and shales deposited in fluvial/lacustrine environment during the third phase of rifting in the basin. Different scales of sedimentological heterogeneities influenced reservoir quality and architecture. The cores and well logs analyses revealed seven lithofacies representing fluvial, deltaic and lacustrine depositional environments. The sandstone is medium to coarse-grained, poorly to moderately-sorted and sub-angular to sub-rounded, arkosic-subarkosic to sublitharenite. On the basin scale, the Yabus Formation showed variation in sandstone bodies, thickness, geometry and architecture. On macro-scale, reservoir quality varies vertically and laterally within Yabus Sandstone where it shows progressive fining upward tendencies with different degrees of connectivity. The lower part of the reservoir showed well-connected and amalgamated sandstone bodies, the middle to the upper parts, however, have moderate to low sandstone bodies' connectivity and amalgamation. On micro-scale, sandstone reservoir quality is directly affected by textures and diagenetic changes such as compaction, cementation, alteration, dissolution and kaolinite clays pore fill and coat all have significantly reduced the reservoir porosity and permeability. The estimated porosity in Yabus Formation ranges from 2 to 20% with an average of 12%; while permeability varies from 200 to 500 mD and up to 1 Darcy. The understanding of different scales of sedimentological reservoir heterogeneities might contribute to better reservoir quality prediction, architecture, consequently enhancing development and productivity.

49 CFR 215.113 - Defective plain bearing wedge.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing wedge. 215.113 Section 215... Suspension System § 215.113 Defective plain bearing wedge. A railroad may not place or continue in service a car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

A 2D hydrodynamic-sedimentological model for gravel-bed rivers. Part I: theory and validation

OpenAIRE

Gabriel Kaless; Mario A. Lenzi; Luca Mao

2013-01-01

This paper presents a novel 2D-depth average model especially developed for gravel-bed rivers, named Lican-Leufú (Lican=pebble and Leufu=river, in Mapuche’s language, the native inhabitants of Central Patagonia, Argentina). The model consists of three components: a hydrodynamic, a sedimentological, and a morphological model. The flow of water is described by the depth-averaged Reynolds equations for unsteady, free-surface, shallow water flows. It includes the standard k-e model for turbulence...

MÉTODOS DE SENSORIAMENTO REMOTO APLICADOS À GEOMORFOLOGIA - METHODS IN REMOTESENSING APPLY IN GEOMORPHOLOGY

Directory of Open Access Journals (Sweden)

Thiago Morato de Carvalho

2007-12-01

Full Text Available The mean of this papper is to present the methodology used by SRTM products, like an essential tool toproducts in geomorphology. The mapping of Goiás State and Brasília D.C. from SIEG-GOIAS was usedlike example. The SRTM products were obtained by sensor SIR-C/X-SAR (Spaceborn Imaging RadarC-band/X-band Synthetic Aperture Radar on board of Endeavour space shuttle, during 2000, to mappingthe relief topography just the 80º. N an S parallels. The results showed which the SRTM images have agood utility to geomorphologic mappings in small and middle scales, like this application in the Goiás state,Brazil.

Sedimentology of the Early Jurassic terrestrial Steierdorf Formation in Anina, Colonia Cehă Quarry, South Carpathians, Romania

Science.gov (United States)

Kędzior, Artur; Popa, Mihai E.

2013-06-01

Kędzior, A. and Popa, E.M. 2013. Sedimentology of the Early Jurassic terrestrial Steierdorf Formation in Anina, Colonia Cehă Quarry, South Carpathians, Romania. Acta Geologica Polonica, 63 (2), 175-199. Warszawa. The continental, coal bearing Steierdorf Formation, Hettangian - Sinemurian in age, is included in the Mesozoic cover of the Reşiţa Basin, Getic Nappe, South Carpathians, Romania. The Steierdorf Formation can be studied in Anina, a coal mining center and an exceptional locality for Early Jurassic flora and fauna, occurring in the middle of the Reşiţa Basin. This paper presents the results of sedimentological, stratigraphical and paleobotanical researches undertaken in Colonia Cehă open cast mine in Anina, where the Steierdorf Formation outcrops widely. Several sedimentary facies associations have been described, these associations permitting the reconstruction of various depositional systems such as alluvial fans, braided and meandering river systems, as well as lacustrine and coal generating marsh systems of the Steierdorf Formation. The sedimentary associations recorded within the Steierdorf Formation show a gradual fining upward trend, pointing to a rising marine water table and a decreasing relief within the source area.

Better Visualisation of Air-borne Laser Scanning for geomorphological and archaeological interpretation

DEFF Research Database (Denmark)

Ljungberg, Thomas; Scott, D; Kristiansen, Søren Munch

Digital elevation models derived from high-precision Air-borne Laser Scanning (ALS or LiDAR) point clouds are becoming increasingly available throughout the world. These elevation models presents a very valuable tool for locating and interpreting geomorphological as well as archaeological features...

Localised human impacts on the Harataonga coastal landscape, Great Barrier Island, northern New Zealand

International Nuclear Information System (INIS)

Horrocks, M.; Nichol, S.; Cockrem, J.; Shane, P.

2008-01-01

Here we present results of analyses of sediment profiles and cores, and coprolites, from Harataonga Bay, Great Barrier Island. Using a range of analyses (sedimentological, plant microfossils, parasitological, microbial, and steroids and myoglobin) we concentrate on human impact and reconstruction of the geomorphology and vegetation of the near-shore environments. Two different sub--environments are represented: dunes and alluvial plain. Dune instability coincides with a major increase in disturbance-related plants (especially ground ferns) as a result of forest clearance. The present form of much of the Harataonga dunes and the swamp at the eastern end of the bay is directly a result of human impact, no earlier than 737 ± 178 14 C yr BP. In the record from the alluvial plain of the main Harataonga watercourse, at the western end of the bay, it is difficult to clearly resolve sedimentary inputs that directly relate to human presence in this former tidal inlet that was open to storm surge and stream floods. The only exception is the slopewash materials forming the terrace surface, sediments of which bear pollen consistent with vegetation disturbance. The landforms are natural but the rate at which the tidal inlet was infilled to form a terrace was accelerated by human activity. The nature and timing of the localised human impacts at Harataonga are consistent with those observed elsewhere on Great Barrier Island and mainland New Zealand. Some of our techniques (e.g. bacteria, steroids) are newly applied to coprolites in New Zealand but none provided any useful information because of poor preservation. (author). 34 refs., 13 figs., 3 tabs

Capability of applying morphometric parameters of relief in river basins for geomorphological zoning of a territory

Science.gov (United States)

Ivanov, M. A.; Yermolaev, O. P.

2018-01-01

Information about morphometric characteristics of relief is necessary for researches devoted to geographic characteristics of territory, its zoning, assessment of erosion processes, geoecological condition and others. For the Volga Federal District for the first time a spatial database of geomorphometric parameters 1: 200 000 scale was created, based on a river basin approach. Watersheds are used as a spatial units created by semi-automated method using the terrain and hydrological modeling techniques implemented in the TAS GIS and WhiteBox GIS. As input data DEMs SRTM and Aster GDEM and hydrographic network vectorized from topographic maps were used. Using DEM highlighted above for each river basin, basic morphometric relief characteristics such as mean height, slope steepness, slope length, height range, river network density and factor LS were calculated. Basins belonging to the geomorphological regions and landscape zones was determined, according to the map of geomorphological zoning and landscape map. Analysis of variance revealed a statistically significant relationship between these characteristics and geomorphological regions and landscape zones. Consequently, spatial trends of changes of analyzed morphometric characteristics were revealed.

Geomorphology, facies architecture, and high-resolution, non-marine sequence stratigraphy in avulsion deposits, Cumberland Marshes, Saskatchewan

Science.gov (United States)

Farrell, K. M.

2001-02-01

proposed by Smith et al. (Sedimentology, vol. 36 (1989) 1) is revised to include facies and geometries consistent with a bayfill model. By analogy with delta lobes, the avulsion sequence is a parasequence, provided that its definition is modified to be independent from sea level. In non-marine settings, facies contacts at the tops of regional peats, coals, and paleosols are analogous to marine flooding surfaces. A parasequence is redefined here as a relatively conformable succession of genetically related strata or landforms that is bounded by regional flooding surfaces or their correlative surfaces. This broader definition incorporates the concept of landscape evolution between regional flooding surfaces in a variety of depositional settings. With respect to landscape evolution, accommodation space has three spatial dimensions — vertical ( x), lateral ( y), and down-the-basin ( z). A flood basin fills in as landforms vertically ( x) and laterally accrete ( y), and prograde down-the-basin ( z). Vertical aggradation is limited by the elevation of maximum flood stage (local base level). Differential tectonism and geomorphology control the slope of the flood basin floor and the direction of landscape evolution. These processes produce parasequences that include inclined stratal surfaces and oriented, stacked macroforms (clinoforms) that show the magnitude and direction of landscape evolution.

Quantitative geomorphology with geographical information systems (GIS) for evolving societies and science

Science.gov (United States)

Gomez, C.; Oguchi, T.; Evans, I. S.

2016-05-01

Based on the two sessions on spatial analysis, GIS and geostatistics convened by T. Oguchi, I. Evans and C. Gomez at the 2013 International Association of Geomorphology in Paris, the conveners have edited two special issues on the topic: volume 242 and the present one.

Soil and geomorphological parameters to characterize natural environmental and human induced changes within the Guadarrama Range (Central Spain)

Science.gov (United States)

Schmid, Thomas; Inclán-Cuartas, Rosa M.; Santolaria-Canales, Edmundo; Saa, Antonio; Rodríguez-Rastrero, Manuel; Tanarro-Garcia, Luis M.; Luque, Esperanza; Pelayo, Marta; Ubeda, Jose; Tarquis, Ana; Diaz-Puente, Javier; De Marcos, Javier; Rodriguez-Alonso, Javier; Hernandez, Carlos; Palacios, David; Gallardo-Díaz, Juan; Fidel González-Rouco, J.

2016-04-01

Mediterranean mountain ecosystems are often complex and remarkably diverse and are seen as important sources of biological diversity. They play a key role in the water and sediment cycle for lowland regions as well as preventing and mitigating natural hazards especially those related to drought such as fire risk. However, these ecosystems are fragile and vulnerable to changes due to their particular and extreme climatic and biogeographic conditions. Some of the main pressures on mountain biodiversity are caused by changes in land use practices, infrastructure and urban development, unsustainable tourism, overexploitation of natural resources, fragmentation of habitats, particularly when located close to large population centers, as well as by pressures related toclimate change. The objective of this work is to select soil and geomorphological parameters in order to characterize natural environmental and human induced changes within the newly created National Park of the Sierra de Guadarrama in Central Spain, where the presence of the Madrid metropolitan area is the main factor of impact. This is carried out within the framework of the Guadarrama Monitoring Network (GuMNet) of the Campus de ExcelenciaInternacionalMoncloa, where long-term monitoring of the atmosphere, soil and bedrock are priority. This network has a total of ten stations located to the NW of Madrid and in this case, three stations have been selected to represent different ecosystems that include: 1) an alluvial plain in a lowland pasture area (La Herreria at 920 m a.s.l.), 2) mid mountain pine-forested and pasture area (Raso del Pino at 1801 m a.s.l.) and 3) high mountain grassland and rock area (Dos Hermanas at 2225 m a.s.l.). At each station a site geomorphological description, soil profile description and sampling was carried out. In the high mountain area information was obtained for monitoring frost heave activity and downslope soil movement. Basic soil laboratory analyses have been carried out

Sedimentological measurements in the river Ghezel Uzan using the radioactive source Cs-137 and Ba-133

International Nuclear Information System (INIS)

Panahandeh, H.; Parvaresh, P.; Hadadi-Parsa, M.A.; Keshavarzi, C.

1981-01-01

A new gamma-backscattering sedimentological gauge has been designed to measure the high concentrations of suspended sediments of rivers in a stationary position for different depths at flooding times continuously for 9 hours. The instrument is capable of measuring concentrations from 5 to 95 g/l with a good accuracy and of higher concentrations as well. In comparison to common instruments based on gamma radiation absorption this one classifies for higher concentrations. (orig.) [de

The Borschovo section of the Gauja and Amata regional stages (Leningrad Region, Russia): sedimentology and biostratigraphy

OpenAIRE

Ervīns Lukševičs; Ģirts Stinkulis; Alexander Ivanov; Daiga Tirzmale

2018-01-01

The results of the detailed sedimentological study and bed-by-bed collecting of fossils from the Borschovo section exposing the upper Givetian–lower Frasnian boundary beds are discussed. The succession consists of sandstones alternating with argillaceous and clayey packages that contain vertebrate and plant remains in the upper part. The grain size, sedimentary structures and cross-bed orientation considerably differ in the Oredezh Beds and the Staritsa Beds. Fine- to coarse-grained cross-str...

[Agro-household livelihood vulnerability and influence factors of ethnic villages under different geomorphology backgrounds.

Science.gov (United States)

Han, Wen Wen; Liu, Xiao Peng; Pei, Yin Bao; An, Qiong; Li, Yong Hong

2016-04-22

The vulnerability and influence factors of agro-household livelihood in Haiyuan County, Ningxia were empirically analyzed utilizing set pair analysis and obstacle degree model, based on field survey data of impoverished agro-households in 2014. Results showed that vulnerability of agro-household livelihood in Haiyuan County was high in general while it exhibited geomorphological and ethnical differences. Vulnerability of agro-households livelihood in plain areas, valleys and intermountain depression areas were lower than that in earth-rock areas, loess ridge areas and moderately high mountain landform areas. Moreover, vulnerability of agro-household livelihood was higher in mixed Hui and Han ethnic villages than in mono Hui or Han ethnic villages. The villagers' lacking of necessities and the stress of sensitive external geographical environment were considered to be the fundamental reasons of vulnerability of agro-household livelihood. The unreasonable livelihood structure and the unvariant livelihood strategy caused the long-term accumulation of livelihood vulnerabi-lity. The nature of the local environment, which was not easy to change, decreased the accessibility of poverty alleviation resources. Building a clear village water rights allocation system, the implementation of counterpart-assistance to educate impoverished families, increasing investment in improving the diversities of means of living, developing the chains of comprehensive commodity market among villages, were necessary to improve the response capability of agro-household livelihood. The management of vulnerability of agro-household livelihood should put the 'Extending Roads to Every Village Project' on a more prominent position in the 'Extending Radio and TV Broadcasting Coverage to Every Village Project'. Furthermore, the combination of meteorological disaster prevention and insurance enterprise disaster reduction should be sought, and the agricultural production insurance system should be

Chemical weathering outputs from the flood plain of the Ganga

Science.gov (United States)

Bickle, Michael J.; Chapman, Hazel J.; Tipper, Edward; Galy, Albert; De La Rocha, Christina L.; Ahmad, Talat

2018-03-01

Transport of sediment across riverine flood plains contributes a significant but poorly constrained fraction of the total chemical weathering fluxes from rapidly eroding mountain belts which has important implications for chemical fluxes to the oceans and the impact of orogens on long term climate. We report water and bedload chemical analyses from the Ganges flood-plain, a major transit reservoir of sediment from the Himalayan orogen. Our data comprise six major southern tributaries to the Ganga, 31 additional analyses of major rivers from the Himalayan front in Nepal, 79 samples of the Ganga collected close to the mouth below the Farakka barrage every two weeks over three years and 67 water and 8 bedload samples from tributaries confined to the Ganga flood plain. The flood plain tributaries are characterised by a shallow δ18O - δD array, compared to the meteoric water line, with a low δDexcess from evaporative loss from the flood plain which is mirrored in the higher δDexcess of the mountain rivers in Nepal. The stable-isotope data confirms that the waters in the flood plain tributaries are dominantly derived from flood plain rainfall and not by redistribution of waters from the mountains. The flood plain tributaries are chemically distinct from the major Himalayan rivers. They can be divided into two groups. Tributaries from a small area around the Kosi river have 87Sr/86Sr ratios >0.75 and molar Na/Ca ratios as high as 6. Tributaries from the rest of the flood plain have 87Sr/86Sr ratios ≤0.74 and most have Na/Ca ratios waters have lost up to 70% of their Ca (average ∼ 50%) to precipitation of secondary calcite which is abundant as a diagenetic cement in the flood plain sediments. 31% of the Sr, 8% of the Ca and 45% of the Mg are calculated to be derived from silicate minerals. Because of significant evaporative loss of water across the flood plain, and in the absence of hydrological data for flood plain tributaries, chemical weathering fluxes from the

Geomorphological method in the elaboration of hazard maps for flash-floods in the municipality of Jucuarán (El Salvador)

Science.gov (United States)

Fernández-Lavado, C.; Furdada, G.; Marqués, M. A.

2007-07-01

This work deals with the elaboration of flood hazard maps. These maps reflect the areas prone to floods based on the effects of Hurricane Mitch in the Municipality of Jucuarán of El Salvador. Stream channels located in the coastal range in the SE of El Salvador flow into the Pacific Ocean and generate alluvial fans. Communities often inhabit these fans can be affected by floods. The geomorphology of these stream basins is associated with small areas, steep slopes, well developed regolite and extensive deforestation. These features play a key role in the generation of flash-floods. This zone lacks comprehensive rainfall data and gauging stations. The most detailed topographic maps are on a scale of 1:25 000. Given that the scale was not sufficiently detailed, we used aerial photographs enlarged to the scale of 1:8000. The effects of Hurricane Mitch mapped on these photographs were regarded as the reference event. Flood maps have a dual purpose (1) community emergency plans, (2) regional land use planning carried out by local authorities. The geomorphological method is based on mapping the geomorphological evidence (alluvial fans, preferential stream channels, erosion and sedimentation, man-made terraces). Following the interpretation of the photographs this information was validated on the field and complemented by eyewitness reports such as the height of water and flow typology. In addition, community workshops were organized to obtain information about the evolution and the impact of the phenomena. The superimposition of this information enables us to obtain a comprehensive geomorphological map. Another aim of the study was the calculation of the peak discharge using the Manning and the paleohydraulic methods and estimates based on geomorphologic criterion. The results were compared with those obtained using the rational method. Significant differences in the order of magnitude of the calculated discharges were noted. The rational method underestimated the

Geomorphological method in the elaboration of hazard maps for flash-floods in the municipality of Jucuarán (El Salvador

Directory of Open Access Journals (Sweden)

C. Fernández-Lavado

2007-07-01

Full Text Available This work deals with the elaboration of flood hazard maps. These maps reflect the areas prone to floods based on the effects of Hurricane Mitch in the Municipality of Jucuarán of El Salvador. Stream channels located in the coastal range in the SE of El Salvador flow into the Pacific Ocean and generate alluvial fans. Communities often inhabit these fans can be affected by floods. The geomorphology of these stream basins is associated with small areas, steep slopes, well developed regolite and extensive deforestation. These features play a key role in the generation of flash-floods. This zone lacks comprehensive rainfall data and gauging stations. The most detailed topographic maps are on a scale of 1:25 000. Given that the scale was not sufficiently detailed, we used aerial photographs enlarged to the scale of 1:8000. The effects of Hurricane Mitch mapped on these photographs were regarded as the reference event. Flood maps have a dual purpose (1 community emergency plans, (2 regional land use planning carried out by local authorities. The geomorphological method is based on mapping the geomorphological evidence (alluvial fans, preferential stream channels, erosion and sedimentation, man-made terraces. Following the interpretation of the photographs this information was validated on the field and complemented by eyewitness reports such as the height of water and flow typology. In addition, community workshops were organized to obtain information about the evolution and the impact of the phenomena. The superimposition of this information enables us to obtain a comprehensive geomorphological map. Another aim of the study was the calculation of the peak discharge using the Manning and the paleohydraulic methods and estimates based on geomorphologic criterion. The results were compared with those obtained using the rational method. Significant differences in the order of magnitude of the calculated discharges were noted. The rational method

Radiocarbon ages of upper quaternary deposit in central Nepal and their geomorphological significance

International Nuclear Information System (INIS)

Yamanaka, Hidetsugu

1982-01-01

The author visited Nepal from October, 1980, to February, 1981, investigated the geomorphology and upper Quaternary geology in Central Nepal, and collected a number of samples for radiocarbon dating. After returning to his university, he dated ten samples by himself. In Nepal, radiocarbon age has been scarcely reported as yet, besides in Kathmandu valley. Therefore, the author's ten data of the age are very important for the late Quaternary chronological study of Nepal Himalayas. In this paper, the author describes sampling localities and horizons, dating results and their geomorphological significance. These ten samples included Pokhara valley, Marsyandi Kohla, Modi Khola, Madi Khola and Muktinath samples. Some conclusion was derived as for the geomorphological development in central Nepal: The last Himalayan glacial age had already ended before 9,000 yr BP (years before A.D. 1950); In the Midland region, from 4,300 to 600 yr BP, some large-scale mudflows broke out nearly contemporaneously in the upper valleys, and they flowed down torrentially and catastrophically to deposit in the middle course of rivers. But the cause of vast quantity of material suddenly brought down from the Great Himalayas has been still left unexplained. The conclusion like this also was able to be applied to the middle Marsyandi Khola and the Pokhara valley. The wide-spread schema that the river was aggraded in the glacial age and degraded in the interglacial age may not be applicable to the rivers in the Midland region of Nepal Himalayas. (Wakatsuki, Y.)

Cold-climate slope deposits and landscape modifications of the Mid-Atlantic Coastal Plain, Eastern USA

Science.gov (United States)

Newell, Wayne L.; Dejong, B.D.

2011-01-01

The effects of Pleistocene cold-climate geomorphology are distributed across the weathered and eroded Mid-Atlantic Coastal Plain uplands from the Wisconsinan terminal moraine south to Tidewater Virginia. Cold-climate deposits and landscape modifications are superimposed on antecedent landscapes of old, weathered Neogene upland gravels and Pleistocene marine terraces that had been built during warm periods and sea-level highstands. In New Jersey, sequences of surficial deposits define a long history of repeating climate change events. To the south across the Delmarva Peninsula and southern Maryland, most antecedent topography has been obscured by Late Pleistocene surficial deposits. These are spatially variable and are collectively described as a cold-climate alloformation. The cold-climate alloformation includes time-transgressive details of climate deterioration from at least marine isotope stage (MIS) 4 through the end of MIS 2. Some deposits and landforms within the alloformation may be as young as the Younger Dryas. Southwards along the trend of the Potomac River, these deposits and their climatic affinities become diffused. In Virginia, a continuum of erosion and surficial deposits appears to be the product of ‘normal’ temperate, climate-forced processes. The cold-climate alloformation and more temperate deposits in Virginia are being partly covered by Holocene alluvium and bay mud.

Seismic echo character northern Hatteras Abyssal Plain

International Nuclear Information System (INIS)

McCreery, C.J.; Laine, E.P.

1985-01-01

Latest efforts in echo-character mapping of the northern Hatteras Abyssal Plain have discerned variations in thickness in a near-surface sedimentary sequence which has been designated seismic unit A. This unit probably represents the last episode of progradation of the Hatteras Deep Sea Fan in the southern part of the study area, and has infilled probable paleochannels from the Wilmington Canyon and Sohm Gap in the north. Unit A thins to a minimum in the central part of the plain, where older sediments come within 1 meter of the surface. Variations in the character of the surface reflector probably represent differing degrees of microtopography developed on a Late Pleistocene surface overlain by Holocene sediments. With the exception of one area identified as a relict surface outcropping in the western plain, this microtopography seems related to present-day thalweg locations on the abyssal plain. 11 references, 13 figures

Selected contributions from the 9th International Conference on Tidal Sedimentology, November 2015, Puerto Madryn, Patagonia, Argentina: an introduction

Science.gov (United States)

Scasso, Roberto A.; Cuitiño, José I.

2017-08-01

This special issue of Geo-Marine Letters presents selected contributions from the 9th International Conference on Tidal Sedimentology held on 17-19 November 2015 in Puerto Madryn, Chubut Province, Patagonia, Argentina. The guest editors are the conference organizers Roberto A. Scasso and José I. Cuitiño. Gerardo M. Perillo was the head of the Scientific Committee. The conferences on tidal sedimentology have been traditionally held every 4 years. However, only 3 years separated the last conference held in Caen (France, 2012) from this conference. Increasing numbers of contributions and the growing interest in tidal sedimentation have been the reasons for shortening the inter-conference period. The 2015 conference served as a discussion forum focusing on advances in modern and ancient tidal sedimentation at different locations worldwide. The papers presented in this Special Issue provide a selective view of the latest research results, the main topics dealing with tidal hydrodynamics and sediment transport, tidal coastal morphodynamics, modern and ancient tidal sedimentation, geotechnical processes in tidal environments, and tidal basins, facies and reservoirs.

Carbonate sedimentology of Seribu Islands patch reef complex: a literature review

Science.gov (United States)

Utami, D. A.; Hakim, A. R.

2018-02-01

Many oil and gas reservoirs in the world are reserved in fossil carbonate sediment. Knowledge of modern carbonate sedimentology is important for a better understanding of ancient carbonate sedimentation. Equatorial coral reefs comprise almost half of the world coral reef production, and yet their dynamics, distributions, and cycles are still not well understood. Contrary to their subtropical counterpart, South East Asian carbonate system is known to be strongly influenced by the combination of oceanographic and climatic conditions. Hence carbonate sediments in the tropics have a distinct depositional system, and ought to be treated differently since common distribution models were developed from the (sub-tropical) Atlantic and Pacific regions. This paper systematically summarizes carbonate sediment studies in Seribu Islands and its dominant oceanographic configuration to provide insights and a sense of research direction in the future.

How were the ditches filled? Sedimentological and micromorphological classification of formation processes within graben-like archaeological objects

Czech Academy of Sciences Publication Activity Database

Lisá, Lenka; Komoróczy, Balázs; Vlach, Marek; Válek, M.; Bajer, A.; Kovárník, J.; Rajtár, J.; Hüssen, C.-M.; Šumberová, Radka

2015-01-01

Roč. 370, 3 June (2015), s. 66-76 ISSN 1040-6182 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M300011201 Program:M Institutional support: RVO:67985831 ; RVO:68081758 ; RVO:67985912 Keywords : formation processes * micromorphology * Neolithic rondel structures * Roman ditch * sedimentology * V-shaped ditch Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 2.067, year: 2015

49 CFR 230.102 - Tender plain bearing journal boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing...

Sedimentological and paleoenvironmental constraints of the Statherian and Stenian Espinhaço rift system, Brazil.

OpenAIRE

Santos, Marcelo Nascimento dos; Chemale Júnior, Farid; Dussin, Ivo Antonio; Martins, Maximiliano de Souza; Assis, Tiago A. R.; Jelinek, Andréa Ritter; Guadagnin, Felipe; Armstrong, Richard

2013-01-01

The Espinhaço Basin in eastern Brazil contains depositional sequences developed in the São Francisco paleoplate and its margins. Detailed mapping was conducted and combined with U–Pb detrital zircon dating to determine the sedimentological-stratigraphic framework, provenance and minimum and maximum ages of the syn-rift-deposits. The two cycles have minimum ages of 1192 and 923 Ma and maximum ages of 1785 and 1685 Ma. The first depositional cycle, represented by the Bandeirinha and São João da...

New simple mathematical model to help evaluating the extent of the late-Quaternary valley glacier in the Upper Soča Region (NW Slovenia

Directory of Open Access Journals (Sweden)

Miloš Bavec

2002-06-01

Full Text Available A simple mathematical model was developed that enables an evaluation of a valley glacier extent independently of any geological data. Based on glaciological criteria and on quantitative analysis of the glacier’s accumulation-, and ablation-areas the modeloffers an opportunity for an independent test of paleoenvironmental interpretations that are traditionally based on (often vague and difficult-to-interpret geomorphological and sedimentological information. The model is presented here through a case study from theUpper Soča River Region.

GEOMORPHOLOGICAL ECOGEOGRAPHICAL VARIABLES DEFINIG FEATURES OF ECOLOGICAL NICHE OF COMMON MILKWEED (ASCLEPIAS SYRIACA L.

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O. M. Kunah

2016-04-01

Full Text Available The role of geomorphological ecogeographical variables have been shown, which are received by means of the digital elevation model created on the basis of remote sensing data as markers of an ecological niche of weeds on an example common milkweed (Asclepias syriaca L.. The research range chooses territory which is in settlement Vovnjanka district (the Poltava region. The range has the linear sizes of 26 kilometres in a direction from the east on the west and 15 kilometres in a direction from the north on the south, the range total area makes 390 км2. As geomorphological variables the topographical wetness index, topographic position index, mass balance index, erosion LS-factor, direct and disseminated insolation, altitude above channel network, multiresolution valley bottom flatness, multiresolution ridge top flatness index, vector ruggedness measure have been considered. It is established, that on set of the geomorphological indicators received by means of digital model of a relief, it is possible to assert, that within a separate agricultural field a wide variety of microconditions which is caused by relief features is formed. Possibly, the variation of thermal and water modes, moisture redistribution, and also productivity mechanical processings of soil and efforts under the control of number of weeds make a background in which limits there is possible a moving of weed plants, including common milkweed.

Quarrying: an anthropogenic geomorphological approach

International Nuclear Information System (INIS)

David, L.

2008-01-01

The study intends to give an introduction to the significance of quarrying from the point of view of anthropogenic geomorphology, indicating the level of surface forming due to the mining of mineral raw materials. The significance of this topic is supported by the existence of the so-called 'mining landscapes' that emerged since to the 19 th century. Authors focus on the geomorphic impact of quarrying with special emphasis on factors influencing its spatial distribution, as well as on the characteristics and classification of surface features produced by quarrying, providing an overview of the most important excavated and accumulated forms and form components, on the macro, meso and micro scales. Finally, international and Hungarian case studies illustrate some aspects of the opening and after-use of mining sites in order to observe how abandoned quarries can be turned into 'environmental values', and used as possible sites for exhibitions or for regional and tourism development projects. (author)

The Great Plains IDEA Gerontology Program: An Online, Interinstitutional Graduate Degree

Science.gov (United States)

Sanders, Gregory F.

2011-01-01

The Great-Plains IDEA Gerontology Program is a graduate program developed and implemented by the Great Plains Interactive Distance Education Alliance (Great Plains IDEA). The Great Plains IDEA (Alliance) originated as a consortium of Colleges of Human Sciences ranging across the central United States. This Alliance's accomplishments have included…

A Coastal Environment Field and Laboratory Activity for an Undergraduate Geomorphology Course

Science.gov (United States)

Ellis, Jean T.; Rindfleisch, Paul R.

2006-01-01

A field and laboratory exercise for an undergraduate geomorphology class is described that focuses on the beach. The project requires one day of fieldwork and two laboratory sessions. In the field, students measure water surface fluctuations (waves) with a pressure sensor, survey beach profiles, collect sediment samples, and observe the beach…

Morphology and sedimentology of the Itaipú Embayment - Niterói/RJ

Directory of Open Access Journals (Sweden)

SALVADOR MARCUS VINICIUS S.

2002-01-01

Full Text Available Bathymetric and sedimentological data from water depths between 3 and 28 meters are the basis of a detailed bathymetric map of the Itaipú Embayment and an understanding of its sedimentary dynamics. Shallower than 16 meters the contours are parallel to the shoreline whereas the morphology of the deeper bottom is influenced by the Menina, Mãe, and Pai islands. Medium sand is prevalent, with local variations in more protected or less protected areas. Minor amount of black mud possibly derives from the Itaipú Lagoon. Siliciclastic granules and pebbles may be relict. The Itaipú Embayment's bottom morphology is controlled by stormy waves and the calmer easternmost part of the embayment presents a tendency to accumulate finer sediments.

Incorporation of sedimentological data into a calibrated groundwater flow and transport model

International Nuclear Information System (INIS)

Williams, N.J.; Young, S.C.; Barton, D.H.; Hurst, B.T.

1997-01-01

Analysis suggests that a high hydraulic conductivity (K) zone is associated with a former river channel at the Portsmouth Gaseous Diffusion Plant (PORTS). A two-dimensional (2-D) and three-dimensional (3-D) groundwater flow model was developed base on a sedimentological model to demonstrate the performance of a horizontal well for plume capture. The model produced a flow field with magnitudes and directions consistent with flow paths inferred from historical trichloroethylene (TCE) plume data. The most dominant feature affecting the well's performance was preferential high- and low-K zones. Based on results from the calibrated flow and transport model, a passive groundwater collection system was designed and built. Initial flow rates and concentrations measured from a gravity-drained horizontal well agree closely to predicted values

Activites of the radioisotopes division of IPR-CDTN-NUCLEBRAS in the studies of sedimentology and hidric polution

International Nuclear Information System (INIS)

Aun, P.E.

1979-07-01

This work describes, in a very general way, the utilization of fluorescent and radioactive tracers in sedimentological studies. It presents the specific applications of those tracers in following the motion of sediments in suspension and in the bottom. The paper describes in short the labelling, detection and analysis techniques, as well as several actual applications of those techniques by the Radioisotopes Division of Centro de Desenvolvimento da Tecnologia Nuclear-CDTN-NUCLEBRAS. (author) [pt

Mountain-Plains Curriculum.

Science.gov (United States)

Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

Stratigraphy and sedimentology of the K/T boundary deposit in Haiti

Science.gov (United States)

Carey, S.; Sigurdsson, H.; Dhondt, S.; Espindola, J. M.

1993-01-01

The K/T boundary sequence is exposed in uplifted carbonate sediments of the southwest peninsula of Haiti. It is found at 15 localities within the Beloc formation, a sequence of limestone and marls interpreted as a monoclinal nappe structure thrust to the north. This tectonic deformation has affected the K/T boundary deposit to varying degrees. In some cases the less competent K/T deposit has acted as a slip plane leading to extensive shearing of the boundary layer, as well as duplication of the section. The presence of glassy tektites, shocked quartz, and an Ir anomaly directly link the deposit to a bolide impact. Stratigraphic and sedimentological features of the tripartite sequence indicate that it was formed by deposition from ballistic fallout of coarse tektites, emplacement of particle gravity flows and fine grained fallout of widely dispersed impact ejecta.

Geomorphology: now a more quantitative science

International Nuclear Information System (INIS)

Lal, D.

1995-01-01

Geomorphology, one of the oldest branches of planetary science, is now growing into a quantitative field with the development of a nuclear method capable of providing numeric time controls on a great variety of superficial processes. The method complement the conventional dating methods, e.g. 40 K/ 40 Ar, 87 Rb/ 87 Sr, by providing information on geomorphic processes., e.g. the dwell times of rocks on the earth's surface with strict geometrical constraints; e.g., rates of physical and chemical weathering in the past, chronology of events associated with glaciation, etc. This article attempts to discuss the new possibilities that now exist for studying a wide range of geomorphic processes, with examples of some specific isotopic changes that allow one to model glacial chronology, and evolutionary histories of alluvial fans and sand dunes. (author). 9 refs., 3 figs., 4 tabs

Investigation of Sediment Pathways and Concealed Sedimentological Features in Hidden River Cave, Kentucky

Science.gov (United States)

Feist, S.; Maclachlan, J. C.; Reinhardt, E. G.; McNeill-Jewer, C.; Eyles, C.

2016-12-01

Hidden River Cave is part of a cave system hydrogeologically related to Mammoth Cave in Kentucky and is a multi-level active cave system with 25km of mapped passages. Upper levels experience flow during flood events and lower levels have continuously flowing water. Improper industrial and domestic waste disposal and poor understanding of local hydrogeology lead to contamination of Hidden River Cave in the early 1940s. Previously used for hydroelectric power generation and as a source of potable water the cave was closed to the public for almost 50 years. A new sewage treatment plant and remediation efforts since 1989 have improved the cave system's health. This project focuses on sedimentological studies in the Hidden River Cave system. Water and sediment transport in the cave are being investigated using sediment cores, surface sediment samples and water level data. An Itrax core scanner is used to analyze sediment cores for elemental concentrations, magnetic susceptibility, radiography, and high resolution photography. Horizons of metal concentrations in the core allow correlation of sedimentation events in the cave system. Thecamoebian (testate amoebae) microfossils identified in surface samples allow for further constraint of sediment sources, sedimentation rates, and paleoclimatic analysis. Dive recorders monitor water levels, providing data to further understand the movement of sediment through the cave system. A general time constraint on the sediment's age is based on the presence of microplastic in the surface samples and sediment cores, and data from radiocarbon and lead-210 dating. The integration of various sedimentological data allows for better understanding of sedimentation processes and their record of paleoenvironmental change in the cave system. Sediment studies and methodologies from this project can be applied to other karst systems, and have important applications for communities living on karst landscapes and their water management policies.

Geologic and hydrologic research at the Western New York Nuclear Service Center, West Valley, New York. Final report, August 1982-December 1983

International Nuclear Information System (INIS)

Albanese, J.R.; Anderson, S.L.; Fakundiny, R.H.; Potter, S.M.; Rogers, W.B.; Whitbeck, L.F.; LaFleur, R.G.; Boothroyd, J.C.; Timson, B.S.

1984-06-01

This report is the last in a series by the New York State Geological Survey on studies funded by the US Nuclear Regulatory Commission. The report covers five important aspects of the geology and hydrology of the Western New York Nuclear Service Center, near West Valley, New York: geomorphology, stratigraphy, sedimentology, surface water, and radionuclide analyses. We reviewed past research on these subjects and present new data obtained in the final phase of NYSGS research at the site. Also presented are up-to-date summaries of the present knowledge of geomorphology and stratigraphy. The report contains a significant bibliography of previous West Valley studies. Appendices include a report on the Fall 1983 Drilling Project and the procedures used, history and prognosis of Cattaraugus Creek and tributaries down cutting, and bar modification and landslide processes of Buttermilk Valley. 100 references, 7 figures, 7 tables

Hydro-geomorphologic events in Portugal and its association with Circulation weather types

Science.gov (United States)

Pereira, Susana; Ramos, Alexandre M.; Rebelo, Luís; Trigo, Ricardo M.; Zêzere, José L.

2017-04-01

Floods and landslides correspond to the most hazardous weather driven natural disasters in Portugal. A recent improvement on their characterization has been achieved with the gathering of basic information on past floods and landslides that caused social consequences in Portugal for the period 1865-2015 through the DISASTER database (Zêzere et al., 2014). This database was built under the assumption that strong social impacts of floods and landslides are sufficient relevant to be reported consistently by national and regional newspapers. The DISASTER database contains detailed information on the location, date of occurrence and social impacts (fatalities, injuries, missing people, evacuated and homeless people) of each individual hydro-geomorphologic case (1677 flood cases and 292 landslide cases). These hydro-geomorphologic disaster cases are grouped in a restrict number of DISASTER events that were selected according to the following criteria: a set of at least 3 DISASTER cases sharing the same trigger in time (with no more than 3 days without cases), which have a widespread spatial extension related to the triggering mechanism and a certain magnitude. In total, the DISASTER database includes 134 events (3.7 average days of duration) that generated high social impacts in Portugal (962 fatalities and 40878 homeless people). Each DISASTER event was characterized with the following attributes: hydro-geomorphologic event type (e.g landslides, floods, flash floods, urban floods); date of occurrence (year, month and days); duration in days; spatial location in GIS; number of fatalities, injured, evacuated and homeless people; and weather type responsible for triggering the event. The atmospheric forcing at different time scales is the main trigger for the hydro-meteorological DISASTER events occurred in Portugal. In this regard there is an urge for a more systematic assessment of the weather types associated to flood and landslide damaging events to correctly

Study on ecological regulation of coastal plain sluice

Science.gov (United States)

Yu, Wengong; Geng, Bing; Yu, Huanfei; Yu, Hongbo

2018-02-01

Coastal plains are densely populated and economically developed, therefore their importance is self-evident. However, there are some problems related with water in coastal plains, such as low flood control capacity and severe water pollution. Due to complicated river network hydrodynamic force, changeable flow direction and uncertain flood concentration and propagation mechanism, it is rather difficult to use sluice scheduling to realize flood control and tackle water pollution. On the base of the measured hydrological data during once-in-a-century Fitow typhoon in 2013 in Yuyao city, by typical analysis, theoretical analysis and process simulation, some key technologies were researched systematically including plain river network sluice ecological scheduling, “one tide” flood control and drainage scheduling and ecological running water scheduling. In the end, single factor health diagnostic evaluation, unit hydrograph of plain water level and evening tide scheduling were put forward.

Morphological changes and hydrodynamic effects of the urbanization process of river Tamanduateí watershed – Metropolitan area of São Paulo

Directory of Open Access Journals (Sweden)

Isabel Cristina Moroz-Caccia Gouveia

2017-08-01

Full Text Available Relying on Anthropogenic and Historical Geomorphology, this paper presents methodology applied to the River Tamanduateí watershed for qualitative and quantitative analysis of changes resulting from the urbanization process in physical systems, from the geomorphological cartography. The approach has as its main premise consider the human actions into the landscape as geomorphological nature of actions whose effects can be measured using indicators and benchmarks. Among other analysis, the identification of the original or pre-urban characteristics and anthropogenic changes allowed us to estimate the loss of the water storage capacity due to the suppression of river plains and changes in hydrodynamic balance in the areas of hydrographic basin.

Comparison of Cottonwood Dendrochronology and Optically Stimulated Luminescence Geochronometers Along a High Plains Meandering River, Powder River, Montana, USA

Science.gov (United States)

Hasse, T. R.; Schook, D. M.

2017-12-01

Geochronometers at centennial scales can aid our understanding of process rates in fluvial geomorphology. Plains cottonwood trees (Populus deltoides ssp. Monilifera) in the high plains of the United States are known to germinate on freshly created deposits such as point bars adjacent to rivers. As the trees mature they may be partially buried (up to a few meters) by additional flood deposits. Cottonwood age gives a minimum age estimate of the stratigraphic surface where the tree germinated and a maximum age estimate for overlying sediments, providing quantitative data on rates of river migration and sediment accumulation. Optically Stimulated Luminescence (OSL) of sand grains can be used to estimate the time since the sand grains were last exposed to sunlight, also giving a minimum age estimate of sediment burial. Both methods have disadvantages: Browsing, partial burial, and other damage to young cottonwoods can increase the time required for the tree to reach a height where it can be sampled with a tree corer, making the germination point a few years to a few decades older than the measured tree age; fluvial OSL samples can have inherited age (when the OSL age is older than the burial age) if the sediment was not completely bleached prior to burial. We collected OSL samples at 8 eroding banks of the Powder River Montana, and tree cores at breast height (±1.2 m) from cottonwood trees growing on the floodplain adjacent to the OSL sample locations. Using the Minimum Age Model (MAM) we found that OSL ages appear to be 500 to 1,000 years older than the adjacent cottonwood trees which range in age (at breast height) from 60 to 185 years. Three explanations for this apparent anomaly in ages are explored. Samples for OSL could be below a stratigraphic unconformity relative to the cottonwood germination elevation. Shallow samples for OSL could be affected by anthropogenic mixing of sediments due to plowing and leveling of hay fields. The OSL samples could have

Control of the geomorphology and gas hydrate extent on widespread gas emissions offshore Romania (Black Sea)

Science.gov (United States)

Riboulot, V.; Cattaneo, A.; Sultan, N.; Ker, S.; Scalabrin, C.; Gaillot, A.; Jouet, G.; Marsset, B.; Thomas, Y.; Ballas, G.; Marsset, T.; Garziglia, S.; Ruffine, L.; Boulart, C.

2016-12-01

The Romanian sector of the Black Sea deserves attention because the Danube deep-sea fan is one of the largest sediment depositional systems worldwide and is considered the world's most isolated sea, the largest anoxic water body on the planet and a unique energy-rich sea. Due to the high sediment accumulation rate, presence of organic matter and anoxic conditions, the Black sea sediment offshore the Danube delta is rich in gas and thus show BSR. The cartography of the BSR over the last 20 years, exhibits its widespread occurrence, indicative of extensive development of hydrate accumulations and a huge gas hydrate potential. By combining old and new datasets acquired in 2015 during the GHASS expedition, we performed a geomorphological analysis of the continental slope north-east of the Danube canyon that reveals the presence of several landslides inside and outside several canyons incising the seafloor. It is a complex study area presenting sedimentary processes such as seafloor erosion and instability, mass wasting, formation of gas hydrates, fluid migration, gas escape, where the imprint of geomorphology seems to dictate the location where gas seep occurs. . Some 1409 gas seeps within the water column acoustic records are observed between 200 m and 800 m water depth. No gas flares were detected in deeper areas where gas hydrates are stable. Overall, 93% of the all gas seeps observed are above geomorphological structures. 78% are right above escarpment induced by sedimentary destabilizations inside or outside canyons. The results suggest a geomorphological control of degassing at the seafloor and gas seeps are thus constrained by the gas hydrates stability zone. The stability of the gas hydrates is dependent on the salinity gradient through the sedimentary column and thus on the Black Sea recent geological history. The extent and the dynamics of gas hydrates have a probable impact on the sedimentary destabilization observed at the seafloor.

27 CFR 9.207 - Outer Coastal Plain.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Outer Coastal Plain. 9.207... Outer Coastal Plain. (a) Name. The name of the viticultural area described in this section is “Outer Coastal Plain”. For purposes of part 4 of this chapter, “Outer Coastal Plain” is a term of viticultural...

Geomorphologic and geologic overview for water resources development: Kharit basin, Eastern Desert, Egypt

Science.gov (United States)

Mosaad, Sayed

2017-10-01

This study demonstrates the importance of geomorphologic, geologic and hydrogeologic assessment as an efficient approach for water resources development in the Kharit watershed. Kharit is one of largest watersheds in the Eastern Desert that lacks water for agricultural and drinking purposes, for the nomadic communities. This study aims to identify and evaluate the geomorphologic, geologic and hydrogeologic conditions in the Kharit watershed relative to water resource development using remote sensing and GIS techniques. The results reveal that the watershed contains 15 sub-basins and morphometric analyses show high probability for flash floods. These hazards can be managed by constructing earth dikes and masonry dams to minimize damage from flash floods and allow recharge of water to shallow groundwater aquifers. The Quaternary deposits and the Nubian sandstone have moderate to high infiltration rates and are relatively well drained, facilitating surface runoff and deep percolation into the underlying units. The sediments cover 54% of the watershed area and have high potential for groundwater extraction.

Analyzing the Various Approaches of Plain Language Laws.

Science.gov (United States)

Bowen, Betsy A., And Others

1986-01-01

Proposes a two-phase evaluation of the plain language laws that are designed to ensure that consumers can understand and use the personal business contracts they sign so that the best model for plain language legislation can be identified. (DF)

Relief of the Podyjí National Park and Geomorphologic Aspects of its Protection (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Kirchner, Karel; Demek, J.

2009-01-01

Roč. 83, č. 1 (2009), s. 91-98 Institutional research plan: CEZ:AV0Z30860518 Keywords : geomorphology * landscape protection * nature conservation * NP Podyji Subject RIV: DE - Earth Magnetism, Geodesy, Geography

International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain and for thromboplastin, recombinant, human, plain

DEFF Research Database (Denmark)

van den Besselaar, A M H P; Chantarangkul, V; Angeloni, F

2018-01-01

BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materia......) international standard (rTF/09). The candidate materials have been accepted by WHO as the 5(th) International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain. This article is protected by copyright. All rights reserved.......BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materials...... have been prepared. This report describes the calibration of the proposed 5(th) International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). METHODS: An international collaborative study was carried out for the assignment...

Plain packaging of cigarettes: do we have sufficient evidence?

Science.gov (United States)

Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren

2015-01-01

Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. PMID:25897269

Geomorphology and natural hazards of the selected glacial valleys, Cordillera Blanca, Peru

Czech Academy of Sciences Publication Activity Database

Klimeš, Jan

2012-01-01

Roč. 47, č. 2 (2012), s. 25-31 ISSN 0300-5402 R&D Projects: GA ČR(CZ) GAP209/11/1000 Institutional research plan: CEZ:AV0Z30460519 Keywords : geomorphologic map * natural hazards * glacial lakes Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://web.natur.cuni.cz/ksgrrsek/acta/2012/Geographica_2_2012_Klimes.pdf

Tobacco plain packaging: Evidence based policy or public health advocacy?

Science.gov (United States)

McKeganey, Neil; Russell, Christopher

2015-06-01

In December 2012, Australia became the first country to require all tobacco products be sold solely in standardised or 'plain' packaging, bereft of the manufacturers' trademarked branding and colours, although retaining large graphic and text health warnings. Following the publication of Sir Cyril Chantler's review of the evidence on the effects of plain tobacco packaging, the Ministers of the United Kingdom Parliament voted in March 2015 to implement similar legislation. Support for plain packaging derives from the belief that tobacco products sold in plain packs have reduced appeal and so are more likely to deter young people and non-smokers from starting tobacco use, and more likely to motivate smokers to quit and stay quit. This article considers why support for the plain packaging policy has grown among tobacco control researchers, public health advocates and government ministers, and reviews Australian survey data that speak to the possible introductory effect of plain packaging on smoking prevalence within Australia. The article concludes by emphasising the need for more detailed research to be undertaken before judging the capacity of the plain packaging policy to deliver the multitude of positive effects that have been claimed by its most ardent supporters. Copyright © 2015 Elsevier B.V. All rights reserved.

Introducing glacial geomorphology to secondary schools - an edutainment resource targeting the New Zealand curriculum

Science.gov (United States)

Hemmingsen, Maree; Winkler, Stefan

2015-04-01

Outreach has become an important undertaking for many tertiary institutions and government agencies. Quite often universities and other tertiary institutions view outreach solely as a tool for the recruitment of future students or as a cost-effective way of meeting governmental obtruded institutional obligations towards community engagement. But for every serious scientist outreach should have an importance beyond that. Competent scientists value the opportunities that an effective outreach programme brings, to inform others of the significance of their particular discipline within the wider framework of science. In this context, glacial geomorphology and related fields of research constitute no exception. Although outreach activities seem to be becoming increasingly popular among scientists in New Zealand, there is still a lack of understanding of what is actually useful for the end user. Often what scientists assume will be useful for school is not. An effective outreach programme needs to be aligned to and represent the school curriculum, regardless of the fact that this may not always be the main focus of the scientist. The most successful resources are those which are developed in collaboration with teachers, by practitioners with an ability to develop outreach activities appropriate for "real" school life with all its restrictions. Sadly, all too often academics and scientists assume they know what schools want and what is important. We cannot stress highly enough that the resources produced need to be accessible to the teachers, who often lack a deep enough scientific background or do not have an appropriate confidence in their own scientific knowledge as well as meet the needs of their students. Frequently educators report their frustration when they cannot properly access resources or run simulations because of IT incompatibility or limited supportive guidance. Geomorphology and its individual sub-disciplines like e.g. glacial geomorphology has an

Fluvial geomorphology and suspended-sediment transport during construction of the Roanoke River Flood Reduction Project in Roanoke, Virginia, 2005–2012

Science.gov (United States)

Jastram, John D.; Krstolic, Jennifer L.; Moyer, Douglas; Hyer, Kenneth

2015-09-30

Beginning in 2005, after decades of planning, the U.S. Army Corps of Engineers (USACE) undertook a major construction effort to reduce the effects of flooding on the city of Roanoke, Virginia—the Roanoke River Flood Reduction Project (RRFRP). Prompted by concerns about the potential for RRFRP construction-induced geomorphological instability and sediment liberation and the detrimental effects these responses could have on the endangered Roanoke logperch (Percina rex), the U.S. Geological Survey (USGS) partnered with the USACE to provide a real-time warning network and a long-term monitoring program to evaluate geomorphological change and sediment transport in the affected river reach. Geomorphological change and suspended-sediment transport are highly interdependent and cumulatively provide a detailed understanding of the sedimentary response, or lack thereof, of the Roanoke River to construction of the RRFRP.

Utopia Plain

Science.gov (United States)

2006-01-01

5 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dark-toned, cratered plain in southwest Utopia Planitia. Large, light-toned, windblown ripples reside on the floors of many of the depressions in the scene, including a long, linear, trough. Location near: 30.3oN, 255.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

Plain packaging of cigarettes: do we have sufficient evidence?

Directory of Open Access Journals (Sweden)

Smith CN

2015-04-01

Full Text Available Collin N Smith,1 John D Kraemer,2 Andrea C Johnson,1 Darren Mays1 1Department of Oncology, Georgetown University Medical Center, Lombardi Comprehensive Cancer Center, Washington, DC, USA; 2Department of Health Systems Administration, School of Nursing and Health Studies, Georgetown University, Washington, DC, USA Abstract: Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. Keywords: cigarette smoking, tobacco, plain packaging, regulation, policy

The sedimentology of uranium-bearing sandstones on the farm Riet Kuil 307, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1980-10-01

The sedimentology of four sandstones was studied in outcrop and in the subsurface on the farm Riet Kuil 307, near Beaufort West. Only two of these sandstones are mineralised. These are four surface and two subsurface uranium anomalies and one surface uranium anomaly. The sedimentological study was made by means of 47 vertical profiles measured across and adjacent to the surface anomalies as well as 11 core-logs, which intersected the subsurface anomalies. The unmineralised sandstones are included in this study. A total of 19 sedimentary facies was recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structure. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation is almost entirely confined to the coarser-grained sedimentary facies, which probably acted as suitable aquifers for the transport of uraniferous solutions prior to the precipitation of the uranium. Horizontally bedded sandstone facies comprises 60 per cent of the total cumulative thickness of mineralisation. The nature of the bedding of this facies may have provided a more effective permeability zone for the transport of uraniferous solutions. This facies contains an abundance of carbonaceous material which acted as an important indirect reductant for the precipitation of uranium from solution. The direct reductant was most probably H 2 S produced by enaerobic bacteria acting on this carbonaceous material shortly after deposition of the sediments. Carbonaceous material also occurs in the other mineralised facies and is considered to be the major control on the mineralisation in the uranium-bearing sandstones

Sedimentological study of a lagoon through natural radioactivity and 137Cs determinations

International Nuclear Information System (INIS)

San Miguel, E.G.; Perez-Moreno, J.P.; Aguado, J.L.; Bolivar, J.P.; Garcia-Tenorio, R.

2003-01-01

Profiles of artificial fallout (such as 137 Cs) and natural radioactivity radionuclides in sediment cores are useful tools to study sedimentological properties of different aquatic environments as well as to evaluate average sedimentation rates. In the Portil lagoon, a small natural reservoir located in Huelva province (southwest of Spain), and through the analysis of 210 Pb, 226 Ra, 137 Cs, 238 U and 210 Po vertical profiles in sediment cores, it is shown how the accumulative or transport character of the collection zones may be inferred. In the accumulation zone of the lagoon the influence of focusing effects has been analysed and an average sedimentation rate has been determined through 210 Pb in one sediment core. This 210 Pb-sedimentation rate is consistent with sediment dating based on the 137 Cs data. (author)

Plain Language to Communicate Physical Activity Information: A Website Content Analysis.

Science.gov (United States)

Paige, Samantha R; Black, David R; Mattson, Marifran; Coster, Daniel C; Stellefson, Michael

2018-04-01

Plain language techniques are health literacy universal precautions intended to enhance health care system navigation and health outcomes. Physical activity (PA) is a popular topic on the Internet, yet it is unknown if information is communicated in plain language. This study examined how plain language techniques are included in PA websites, and if the use of plain language techniques varies according to search procedures (keyword, search engine) and website host source (government, commercial, educational/organizational). Three keywords ("physical activity," "fitness," and "exercise") were independently entered into three search engines (Google, Bing, and Yahoo) to locate a nonprobability sample of websites ( N = 61). Fourteen plain language techniques were coded within each website to examine content formatting, clarity and conciseness, and multimedia use. Approximately half ( M = 6.59; SD = 1.68) of the plain language techniques were included in each website. Keyword physical activity resulted in websites with fewer clear and concise plain language techniques ( p websites with more clear and concise techniques ( p language techniques did not vary by search engine or the website host source. Accessing PA information that is easy to understand and behaviorally oriented may remain a challenge for users. Transdisciplinary collaborations are needed to optimize plain language techniques while communicating online PA information.

Long term effects on potential repository sites: climatic and geomorphological changes

International Nuclear Information System (INIS)

Seddon, M.B.; Worsley, P.

1985-05-01

A study of the effects of climatic variability on the geomorphological processes operating on the landscape are important in the study of radioactive waste repository sites. The effects of glacial erosion and deposition are fundamental to an examination of repository safety, particularly in North Britain. Rates of climatic shift need to be examined. Predictive simulation models, based on a knowledge of past climatic events, for future global climates are proposed. (UK)

Geochemical and sedimentological signature of catastrophic saltwater inundations (tsunami), New Zealand

International Nuclear Information System (INIS)

Chague-Goff, C.; Goff, J.R.

1999-01-01

Three tidal marshes in Able Tasman National Par, New Zealand, were studied using geochemical, sedimentological and radiometric dating techniques. Charcoal and plant material samples were taken from one core in each inlet for 14 C analysis. radiocarbon ages were converted to dendrocalibrated years . All samples produced a terrestrial 13 C signal. Near surface samples were date d by measuring 137 Cs. A 1700 year record of catastrophic saltwater inundations (CSI) events (Tsunami) was produced. Up to four such events were identified, with ruptures of one or more of the Wellington, Wairarapa and Alpine Faults being the most likely tsunamigenic source. CSI signatures include: peaks in Fe and/or S, a peak in fines and contemporaneous or delayed peaks in organic content and/or loss on ignition (LOI). Geochemical data in association with grain size analyses proved to be a valuable tool in the interpretation of these events

Expert-driven semi-automated geomorphological mapping for a mountainaous area using a laser DTM

NARCIS (Netherlands)

van Asselen, S.; Seijmonsbergen, A.C.

2006-01-01

n this paper a semi-automated method is presented to recognize and spatially delineate geomorphological units in mountainous forested ecosystems, using statistical information extracted from a 1-m resolution laser digital elevation dataset. The method was applied to a mountainous area in Austria.

Continental shelf drowned landscapes: Submerged geomorphological and sedimentary record of the youngest cycles

NARCIS (Netherlands)

Cohen, K.M.; Lobo, F.J.

2013-01-01

Continental shelves today find themselves largely submerged as a consequence of the sea-level rise in the last 20,000 years, the time since the Last Glacial Maximum (LGM), the period of maximum ice mass and minimum ocean volume within the Last Glacial Cycle. Their geomorphology, however, is far from

Stratigraphy of the Martian northern plains

Science.gov (United States)

Tanaka, K. L.

1993-01-01

The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

Geomorphology and surficial geology of the western continental shelf and slope of India: A review

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; Wagle, B.G.

Coastal geology and geomorphology of the area and nearshore currents played a significant role in the distribution of placer minerals off Kerala and Maharashtra. Transport and sedeimentation of fine-grained materials at places on the shelf...

Applying fluvial geomorphology to river channel management: Background for progress towards a palaeohydrology protocol

Science.gov (United States)

Gregory, K. J.; Benito, G.; Downs, P. W.

2008-06-01

Significant developments have been achieved in applicable and applied fluvial geomorphology as shown in publications of the last three decades, analyzed as the basis for using results of studies of environmental change as a basis for management. The range of types of publications and of activities are more pertinent to river channel management as a result of concern with sustainability, global climate change, environmental ethics, ecosystem health concepts and public participation. Possible applications, with particular reference to river channel changes, include those concerned with form and process, assessment of channel change, urbanization, channelization, extractive industries, impact of engineering works, historical changes in land use, and restoration with specific examples illustrated in Table 1. In order to achieve general significance for fluvial geomorphology, more theory and extension by modelling methods is needed, and examples related to morphology and process characteristics, integrated approaches, and changes of the fluvial system are collected in Table 2. The ways in which potential applications are communicated to decision-makers range from applicable outputs including publications ranging from review papers, book chapters, and books, to applied outputs which include interdisciplinary problem solving, educational outreach, and direct involvement, with examples summarized in Table 3. On the basis of results gained from investigations covering periods longer than continuous records, a protocol embracing palaeohydrological inputs for application to river channel management is illustrated and developed as a synopsis version (Table 4), demonstrating how conclusions from geomorphological research can be expressed in a format which can be considered by managers.

Ocean-Bottom Topography: The Divide between the Sohm and Hatteras Abyssal Plains.

Science.gov (United States)

Pratt, R M

1965-06-18

A compilation of precision echo soundings has delineated the complex topography between the Sohm and Hatteras abyssal plains off the Atlantic coast of the United States. At present the divide between the two plains is a broad, flat area about 4950 meters deep; however, the configuration of channels and depressions suggests spillage of turbidity currents from the Sohm Plain into the Hatteras Plain and a shifting of the divide toward the northeast. Hudson Canyon terminates in the divide area and has probably fed sediment into both plains.

Desert plains classification based on Geomorphometrical parameters (Case study: Aghda, Yazd)

Science.gov (United States)

Tazeh, mahdi; Kalantari, Saeideh

2013-04-01

This research focuses on plains. There are several tremendous methods and classification which presented for plain classification. One of The natural resource based classification which is mostly using in Iran, classified plains into three types, Erosional Pediment, Denudation Pediment Aggradational Piedmont. The qualitative and quantitative factors to differentiate them from each other are also used appropriately. In this study effective Geomorphometrical parameters in differentiate landforms were applied for plain. Geomorphometrical parameters are calculable and can be extracted using mathematical equations and the corresponding relations on digital elevation model. Geomorphometrical parameters used in this study included Percent of Slope, Plan Curvature, Profile Curvature, Minimum Curvature, the Maximum Curvature, Cross sectional Curvature, Longitudinal Curvature and Gaussian Curvature. The results indicated that the most important affecting Geomorphometrical parameters for plain and desert classifications includes: Percent of Slope, Minimum Curvature, Profile Curvature, and Longitudinal Curvature. Key Words: Plain, Geomorphometry, Classification, Biophysical, Yazd Khezarabad.

Geomorphologically effective floods from moraine-dammed lakes in the Cordillera Blanca, Peru

Czech Academy of Sciences Publication Activity Database

Emmer, Adam

2017-01-01

Roč. 177, DEC (2017), s. 220-234 ISSN 0277-3791 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : Andes * Documentary data * Geomorphology * glof * Lichenometry * Little Ice Age * Moraine-dammed lake * Outburst flood * South America Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.797, year: 2016

Late Quarternary evolution of the northern Hatteras Abyssal Plain

International Nuclear Information System (INIS)

Dickson, S.M.; Laine, E.P.

1986-05-01

The sedimentary history and seismic structure of a deep-water turbidite basin in the Western North Atlantic Ocean has been investigated to understand further the evolution of abyssal plains. This study integrates analyses of sedimentary and seismic facies in order to examine the temporal and spatial patterns of sedimentation on the northern Hatteras Abyssal Plain during the Late Quaternary. Forty deep-sea sediment cores and 6000 km of high resolution (3.5 kHz) seismic reflection profiles from within 31-34 0 N and 69-74 0 W include portions of the Hatteras Outer Ridge, Lower Continental Rise and Bermuda Rise as well as the northern Hatteras Abyssal Plain. Seismic profiles (within 32-33 0 N, 70-71.5 0 W) define two acoustically-transparent seismic units beneath the Plain. The composition of these seismic units has been investigated with sediment cores. This study has found two notable features in the sedimentary framework of the Plain that appear to have resulted from temporal changes in sediment supply. The most recent change, a postglacial decline in turbidity current activity, produced a diagenetic iron enrichment at the Pleistocene-Holocene boundary. The stratigraphic thickness affected by diagenesis is related spatially to patterns of turbidite sedimentation. An earlier change, discovered in this research, occurred during the Wisconsinian glaciation and brought coarser-grained turbidity currents to the northern Plain. Deposition of sands from these flows appears to have been locally controlled by a broad topographic feature with less than ten meters relief. As a result of the topographic influence, there are abrupt boundaries, both verically and laterally, between an older mud facies and a younger sandy turbidite facies of the Plain

The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa

OpenAIRE

Mills, SC; Barrows, TT; Telfer, MW; Fifield, LK

2017-01-01

publisher: Elsevier articletitle: The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa journaltitle: Geomorphology articlelink: http://dx.doi.org/10.1016/j.geomorph.2016.11.011 content_type: article copyright: Crown Copyright © 2016 Published by Elsevier B.V. All rights reserved.

Fluvial geomorphology on Earth-like planetary surfaces: A review.

Science.gov (United States)

Baker, Victor R; Hamilton, Christopher W; Burr, Devon M; Gulick, Virginia C; Komatsu, Goro; Luo, Wei; Rice, James W; Rodriguez, J A P

2015-09-15

Morphological evidence for ancient channelized flows (fluvial and fluvial-like landforms) exists on the surfaces of all of the inner planets and on some of the satellites of the Solar System. In some cases, the relevant fluid flows are related to a planetary evolution that involves the global cycling of a volatile component (water for Earth and Mars; methane for Saturn's moon Titan). In other cases, as on Mercury, Venus, Earth's moon, and Jupiter's moon Io, the flows were of highly fluid lava. The discovery, in 1972, of what are now known to be fluvial channels and valleys on Mars sparked a major controversy over the role of water in shaping the surface of that planet. The recognition of the fluvial character of these features has opened unresolved fundamental questions about the geological history of water on Mars, including the presence of an ancient ocean and the operation of a hydrological cycle during the earliest phases of planetary history. Other fundamental questions posed by fluvial and fluvial-like features on planetary bodies include the possible erosive action of large-scale outpourings of very fluid lavas, such as those that may have produced the remarkable canali forms on Venus; the ability of exotic fluids, such as methane, to create fluvial-like landforms, as observed on Saturn's moon, Titan; and the nature of sedimentation and erosion under different conditions of planetary surface gravity. Planetary fluvial geomorphology also illustrates fundamental epistemological and methodological issues, including the role of analogy in geomorphological/geological inquiry.

Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

Directory of Open Access Journals (Sweden)

Wotchoko Pierre

2016-07-01

Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

Geography and sciences for field work in geomorphology: Contributions in environmental education system

International Nuclear Information System (INIS)

Santos, C.

2010-01-01

This conference is about the possibility of a field study in Jaragua Peak in the metropolitan region of Sao Paulo, between the cities of Sao Paulo and Osasco. The main objective is to offer a new way of seeing the environment and the geomorphology as well as the best use at school

Tamarix, hydrology and fluvial geomorphology: Chapter 7

Science.gov (United States)

Auerbach, Daniel A.; Merritt, David M.; Shafroth, Patrick B.; Sher, Anna A; Quigley, Martin F.

2013-01-01

This chapter explores the impact of hydrology and fluvial geomorphology on the distribution and abundance of Tamarix as well as the reciprocal effects of Tamarix on hydrologic and geomorphic conditions. It examines whether flow-regime alteration favors Tamarix establishment over native species, and how Tamarix stands modify processes involved in the narrowing of river channels and the formation of floodplains. It begins with an overview of the basic geomorphic and hydrologic character of rivers in the western United States before analyzing how this setting has contributed to the regional success of Tamarix. It then considers the influence of Tamarix on the hydrogeomorphic form and function of rivers and concludes by discussing how a changing climate, vegetation management, and continued water-resource development affect the future role of Tamarix in these ecosystems.

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

OpenAIRE

Flint, Stephen; Hodgson, David; Spychala, Yvonne; Mountney, Nigel

2017-01-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown Formation, Karoo Basin, South Africa, permit analysis of the sedimentology and stacking patterns of three intraslope lobe complexes and their palaeogeographic reconstruction via bed-scale analysis...

An insight into the 'Fifty-Fathom-Flat' off India's west coast

Digital Repository Service at National Institute of Oceanography (India)

Mukhopadhyay, R.; Fernandes, W.A.; Naik, Y.S.; Karisiddaiah, S.M.

stream_size 35125 stream_content_type text/plain stream_name Geomorphology_118_465a.pdf.txt stream_source_info Geomorphology_118_465a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Author... of sediment is also found  at few places.     3. The data We imaged a portion of the FFF and the shelf break (Fig. 1b) by the EM‐1002 multibeam  echosounder system, a product of M/s Kongsberg Maritime, Norway. The system works on  the principle of dual sonar and echo processor...

Two depositional models for Pliocene coastal plain fluvial systems, Goliad Formation, south Texas Gulf Coastal plain

International Nuclear Information System (INIS)

Hoel, H.D.; Galloway, W.E.

1983-01-01

The Goliad Formation consists of four depositional systems-the Realitos and Mathis bed-load fluvial systems in the southwest and the Cuero and Eagle Lake mixed-load fluvial systems in the northeast. Five facies are recognized in the Realitos and Mathis bed-load fluvial systems: (1) primary channel-fill facies, (2) chaotic flood channel-fill facies, (3) complex splay facies, (4) flood plain facies, and (5) playa facies. A model for Realitos-Mathis depositional environments shows arid-climate braided stream complexes with extremely coarse sediment load, highly variable discharge, and marked channel instability. Broad, shallow, straight to slightly sinuous primary channels were flanked by wide flood channels. Flood channels passed laterally into broad, low-relief flood plains. Small playas occupied topographic lows near large channel axes. Three facies are recognized in the Cuero and Eagle Lake mixed-load fluvial systems: (1) channel-fill facies, (2) crevasse splay facies, and (3) flood plain facies. A model for Cuero-Eagle Lake depositional environments shows coarse-grained meander belts in a semi-arid climate. Slightly to moderately sinuous meandering streams were flanked by low, poorly developed natural levees. Crevasse splays were common, but tended to be broad and ill-defined. Extensive, low-relief flood plains occupied interaxial areas. The model proposed for the Realitos and Mathis fluvial systems may aid in recognition of analogous ancient depositional systems. In addition, since facies characteristics exercise broad controls on Goliad uranium mineralization, the proposed depositional models aid in defining target zones for Goliad uranium exploration

Second chance for the plains bison

Science.gov (United States)

Freese, Curtis H.; Aune, K.; Boyd, D.; Derr, James N.; Forrest, Steven C.; Gates, C. Cormack; Gogan, Peter J.; Grassel, Shaun M.; Halbert, Natalie D.; Kunkel, Kyran; Redford, Kent

2007-01-01

Before European settlement the plains bison (Bison bison bison) numbered in the tens of millions across most of the temperate region of North America. Within the span of a few decades during the mid- to late-1800s its numbers were reduced by hunting and other factors to a few hundred. The plight of the plains bison led to one of the first major movements in North America to save an endangered species. A few individuals and the American Bison Society rescued the remaining animals. Attempts to hybridize cattle and bison when bison numbers were low resulted in extensive cattle gene introgression in bison. Today, though approximately 500,000 plains bison exist in North America, few are free of cattle gene introgression, 96% are subject to anthropogenic selection for commodity production, and only 4% are in herds managed primarily for conservation purposes. Small herd size, artificial selection, cattle-gene introgression, and other factors threaten the diversity and integrity of the bison genome. In addition, the bison is for all practical purposes ecologically extinct across its former range, with multiple consequences for grassland biodiversity. Urgent measures are needed to conserve the wild bison genome and to restore the ecological role of bison in grassland ecosystems. Socioeconomic trends in the Great Plains, combined with new information about bison conservation needs and new conservation initiatives by both the public and public sectors, have set the stage for significant progress in bison conservation over the next few years.

Some examples of geomorphodiversity in Italy

Science.gov (United States)

Panizza, Mario

2014-05-01

The concept of geomorphodiversity (Panizza, 2009) is presented: "the critical and specific assessment of the geomorphological features of a territory, by comparing them in a way both extrinsic (comparison of the geomorphological characteristics with those from other territories) and intrinsic (comparison of the geomorphological characteristics with other areas within the territory itself) and taking into account the level of their scientific quality, the scale of investigation and the purpose of the research". A first example concerns the Dolomites: they have been included in the UNESCO World Heritage List because of their exceptional beauty and unique landscape, together with their scientific importance from the geological and geomorphological point of view. They are of international significance for geomorphodiversity, as the classic site for the development of mountains in dolomite limestone and present a wide range of landforms related to erosion, tectonics and glaciation. They represent a kind of high altitude, open air laboratory of geomorphological heritage of exceptional global value, among the most extraordinary and accessible in the world and ideal for researching, teaching, understanding and developing Earth Science theories. The second example concerns the Emilia-Romagna Apennines, candidate for enrolment in the List of European Geoparks: they show a multifaceted and complex image from the international and regional geomorphological (extrinsic and intrinsic geomorphodiversity) point of view and are an educational example for illustrating morphotectonic evolution, stratigraphic and sedimentological sequences and morpholithological peculiarities connected with gypsum karst and clay mass wasting phenomena. The third example concerns the Vesuvius, one of the National Italian Parks: it shows an extrinsic geomorphodiversity mainly referred to the type of eruptions, with some exemplary processes inserted in international volcanic nomenclature; it makes up an

Sedimentology and ichnology of Neogene Coastal Swamp deposits in the Niger Delta Basin, Nigeria

Directory of Open Access Journals (Sweden)

Ezeh Sunny C.

2016-09-01

Full Text Available Often analyses of depositional environments from sparse data result in poor interpretation, especially in multipartite depositional settings such as the Niger Delta. For instance, differentiating channel sandstones, heteroliths and mudstones within proximal environments from those of distal facies is difficult if interpretations rely solely on well log signatures. Therefore, in order to achieve an effective and efficient interpretation of the depositional conditions of a given unit, integrated tools must be applied such as matching core descriptions with wireline log signature. In the present paper cores of three wells from the Coastal Swamp depositional belt of the Niger Delta are examined in order to achieve full understanding of the depositional environments. The well sections comprise cross-bedded sandstones, heteroliths (coastal and lower shoreface and mudstones that were laid down in wave, river and tidal processes. Interpretations were made from each data set comprising gamma ray logs, described sedimentological cores showing sedimentary features and ichnological characteristics; these were integrated to define the depositional settings. Some portions from one of the well sections reveal a blocky gamma ray well log signature instead of a coarsening-upward trend that characterises a shoreface setting while in other wells the signatures for heteroliths at some sections are bell blocky in shaped rather than serrated. Besides, heteroliths and mudstones within the proximal facies and those of distal facies were difficult to distinguish solely on well log signatures. However, interpretation based on sedimentology and ichnology of cores from these facies was used to correct these inconsistencies. It follows that depositional environment interpretation (especially in multifarious depositional environments such as the Niger Delta should ideally be made together with other raw data for accuracy and those based solely on well log signatures should

Braid-plain dynamics and bank erosion along the Matanuska River, Alaska

Science.gov (United States)

Curran, J. H.

2009-12-01

Braid-plain activity and geomorphic features in the Matanuska River in southcentral Alaska between 1949 and 2006 were examined to support a bank erosion hazard assessment. The glacial Matanuska River drains 6,500 km2 and is braided for 85 percent of its 150 km course, which parallels a major highway and flows through the towns of Sutton and Palmer, Alaska. The historical braid plain was defined as the envelope of areas with active channels, unvegetated bars, or vegetated bars with evidence of channels since 1949 and delineated in a GIS from 1949, 1962, and 2006 aerial orthoimagery. We created a strip map of bank height and composition (primarily bedrock and unconsolidated sediment) at braid-plain margins and outlined valley bottom features (terraces and tributary fans) adjacent to the braid plain to assess erodibility. Braid-plain dynamism has created a mosaic of extensive lightly vegetated bars interspersed with forested bars in strips along the banks and in small mid-channel positions. Abandoned channels filled with groundwater or tributary streamflow have created clearwater side channels within these bars that serve as the primary spawning location for chum, sockeye, and coho salmon in the Matanuska River basin. Erosion magnitudes for the periods 1949-1962 and 1962-2006 were computed as braid-plain expansion at transects across the historical braid-plain boundaries. Episodic, spatially distributed erosion and the antiquity of some eroded surfaces suggests that average annual erosion rates at a location are not adequate for assessing future erosion at that location in a braid plain. Lateral expansion caused bank erosion of 100 -275 m at 20 locations over the full period, about half at tributary fans and most occurring in a single time period. Minor growth of tributary fans constricted the braid plain, and emerging terraces have the potential to shrink the braid plain. Eroded banks included undated but pre-historic fluvial terraces and tributary fans. Where

Applying NASA Imaging Radar Datasets to Investigate the Geomorphology of the Amazon's Planalto

Science.gov (United States)

McDonald, K. C.; Campbell, K.; Islam, R.; Alexander, P. M.; Cracraft, J.

2016-12-01

The Amazon basin is a biodiversity rich biome and plays a significant role into shaping Earth's climate, ocean and atmospheric gases. Understanding the history of the formation of this basin is essential to our understanding of the region's biodiversity and its response to climate change. During March 2013, the NASA/JPL L-band polarimetric airborne imaging radar, UAVSAR, conducted airborne studies over regions of South America including portions of the western Amazon basin. We utilize UAVSAR imagery acquired during that time over the Planalto, in the Madre de Dios region of southeastern Peru in an assessment of the underlying geomorphology, its relationship to the current distribution of vegetation, and its relationship to geologic processes through deep time. We employ UAVSAR data collections to assess the utility of these high quality imaging radar data for use in identifying geomorphologic features and vegetation communities within the context of improving the understanding of evolutionary processes, and their utility in aiding interpretation of datasets from Earth-orbiting satellites to support a basin-wide characterization across the Amazon. We derive maps of landcover and river branching structure from UAVSAR imagery. We compare these maps to those derived using imaging radar datasets from the Japanese Space Agency's ALOS PALSAR and Digital Elevation Models (DEMs) from NASA's Shuttle Radar Topography Mission (SRTM). Results provide an understanding of the underlying geomorphology of the Amazon planalto as well as its relationship to geologic processes and will support interpretation of the evolutionary history of the Amazon Basin. Portions of this work have been carried out within the framework of the ALOS Kyoto & Carbon Initiative. PALSAR data were provided by JAXA/EORC and the Alaska Satellite Facility.This work is carried out with support from the NASA Biodiversity Program and the NSF DIMENSIONS of Biodiversity Program.

Fire and water: volcanology, geomorphology, and hydrogeology of the Cascade Range, central Oregon

Science.gov (United States)

Katharine V. Cashman; Natalia I. Deligne; Marshall W. Gannett; Gordon E. Grant; Anne. Jefferson

2009-01-01

This field trip guide explores the interactions among the geologic evolution, hydrology, and fluvial geomorphology of the central Oregon Cascade Range. Key topics include the geologic control of hydrologic regimes on both the wet and dry sides of the Cascade Range crest, groundwater dynamics and interaction between surface and groundwater in young volcanic arcs, and...

Geomorphological evidences of Quaternary tectonic activities in the Santa Cruz river valley, Patagonia, Argentina

International Nuclear Information System (INIS)

Massabie, A.; Sanguinetti, A.; Nestiero, O.

2007-01-01

From Argentin lake, at west on Andean hills, to Puerto Santa Cruz on Atlantic coast, Santa Cruz river cross eastward Santa Cruz province over 250 km in Patagonia at southern Argentina. Present bed of the river has a meandering outline with first order meanders of great ratio bends and second order meanders of minor ratio bends. Principal wanderings are 45 to 55 km spaced from near Estancia La Julia or Rio Bote at west to Comandante Luis Piedrabuena at east. On river's bed middle sector these great curvatures are located at Estancia Condor Cliff and Estancia Rincon Grande. Regional and partial detailed studies allow to recognize structural control on river's bed sketch and valley s geomorphology that relates first order bends with reactivated principal faults. These faults fit well with parallel system of northwest strike of Austral Basin.On geological, geomorphologic and structural evidences recognized in Santa Cruz river, quaternary tectonic activity, related to Andean movements in southern Patagonian foreland, is postulated. (author)

Plains Energy Services Ltd. 1998 annual report

International Nuclear Information System (INIS)

1999-01-01

Plains Energy Services Ltd. (Plains) is a two year old public company in the oil and gas service industry. It provides an integrated pool of services, concentrating on the life cycle of oil and gas wells as the driver for its expansion. Although the industry saw a marked decrease in well drilling activity for 1998, Plains was able to sustain a consistent income and cash flow because of its focus on ensuring access to the well during drilling, completion, production and abandonment. For 1998, revenue reached a record $93.3 million, an 85 per cent increase over 1997. This report presented Plain's major achievements for 1998. These included the completed construction of a technical, machining and manufacturing facility to enhance the development and implementation of technology and equipment among all business units. The company also introduced coiled tubing drilling services in the North American marketplace, as well as the first commercial version of a casing inspection tool. Plain's also introduced production logging through their wireline services business and applied for four new patents in relation to downhole tool development. In 1998, the company consolidated their operations into four divisions including consolidation of administration, benefits, banking and related overhead services. This report also described the company's efforts in addressing the year 2000 challenge. The company's consolidated financial statements were presented for the benefit of shareholders. These included statements of earnings and deficit, balance sheets, as well as statements of changes in financial position. Notes to the consolidated financial statements included highlights of significant accounting policies, changes in accounting policies, acquisitions, discontinued operations, and capital assets. tabs., figs

Predicting multi-scale relationships between geomorphology and bedrock geology of the rocky intertidal in Central and Northern California

Science.gov (United States)

Wheeler, A.; Aiello, I. W.

2014-12-01

Substratum geology is fundamental in shaping rocky shore morphology. Specific lithologies have various responses to wave action, tectonic features (e.g. fractures, faults) and sedimentary structures (e.g. bedding), creating distinctive weathering profiles. Along with local oceanography and climate forcing, different rock substrata create coastal morphologies that can vary distinctly between scales, ranging from mm to km. Despite the complexity of the system, qualitative observations show coastal areas with similar rock types share similar geomorphologies. Thus, a statistic relationship between geomorphology (expressed for instance by surface parameter rugosity) and geology can be envisaged. There are multiple benefits of finding such a relationship, as rocky intertidal geomorphology can be an important determinant in which organisms can settle, grow, and survive in near shore communities: allowing the prediction of geomorphologic parameters determining coastal ecology solely based on substratum geology, a crucial aspect in guiding the selection of marine protected areas. This study presents preliminary results of multi-scale geospatial surveys (cm to tens of meters) of rocky intertidal outcrops from Central to Northern California using a Terrestrial Laser Scanner. The outcrops investigated are representative of the most common igneous and sedimentary rocks in California (granitoids, conglomerates, sandstones, mudstones) and metamorphic units. The statistical analysis of the survey data support the hypothesis that surface properties can change significantly with changing scale, each rock type having distinct surface characteristics which are similar to comparable lithologies exposed at different locations. These scale dependent variations are controlled by different lithologic and structural characteristics of the outcrop in question. Our data also suggests lithologic variability within a rock unit could be a very significant factor in controlling changes in

Sedimentology and preservation of aeolian sediments on steep terrains : Incipient sand ramps on the Atacama coast (northern Chile)

NARCIS (Netherlands)

Ventra, Dario; Rodríguez-López, Juan Pedro; de Boer, Poppe L.

2017-01-01

The origin of topographically controlled aeolian landforms in high-relief settings is difficult to synthesize under general models, given the dependence of such accumulations on local morphology. Quaternary sand ramps have been linked to palaeoclimate, regional geomorphology and wind patterns;

Necrotizing fasciitis : plain radiographic and CT findings

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Dae; Park, Jeong Hee; Jeon, Hae Jeong; Lim, Jong Nam; Heo, Tae Haeng; Park, Dong Rib [Konkuk Univ. College of Medicine, Seoul (Korea, Republic of)

1996-11-01

To evaluate the plain radiographic and CT findings of the necrotizing fasciitis. We retrospectively reviewed the radiologic findings of 4 cases with necrotizing fasciitis. Three cases were proven pathologically. We evaluated pattern and extent of the gas shadows in plain films. CT findings were analysed, with emphasis on : (a) gas pattern, (b) extent, (c) location and involved site, (d) associated focal abscess, and (e) swelling of the adjacent muscles. On plain radiographs, four cases showed streaky or mottled gas densities in the pelvis, three cases in the perineum, one case in the abdomen, and two cases in the thigh. On CT images, gas pattern was mottled and streaky appearance with swelling of the adjacent muscles. Gas shadows located in the extraperitoneal space in four cases, fascial layer in four cases, and subcutaneous layer in four cases. There were gas shadows in pelvic wall, perineum, abdominal wall, buttock, thigh, and scrotum. Focal low density lesion suggestive of focal abscess was not visualized. Plain radiography is useful for early diagnosis of the necrotizing fasciitis and CT is very useful for detection of precise location and extent of the disease. CT is also useful for differentiation of necrotizing fasciitis from focal abscess and cellulitis.

Porosity Prediction of Plain Weft Knitted Fabrics

Directory of Open Access Journals (Sweden)

Muhammad Owais Raza Siddiqui

2014-12-01

Full Text Available Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric, which are related to the porosity of fabric. In this work, a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D solid and multifilament weft knitted fabric models and accurately determine the porosity of fabrics in two steps. In this work, plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In the case of staple fiber yarn, intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric and the second step is to calculate the porosity of the fabric by using the geometrical parameter of 3D weft knitted fabric model generated in step one. The predicted porosity of plain weft knitted fabric is extracted in the second step and is displayed in the message area. The predicted results obtained from the plug-in have been compared with the experimental results obtained from previously developed models; they agreed well.

Geomorphology and sediment transport on a submerged back-reef sand apron: One Tree Reef, Great Barrier Reef

Science.gov (United States)

Harris, Daniel L.; Vila-Concejo, Ana; Webster, Jody M.

2014-10-01

Back-reef sand aprons are conspicuous and dynamic sedimentary features in coral reef systems. The development of these features influences the evolution and defines the maturity of coral reefs. However, the hydrodynamic processes that drive changes on sand aprons are poorly understood with only a few studies directly assessing sediment entrainment and transport. Current and wave conditions on a back-reef sand apron were measured during this study and a digital elevation model was developed through topographic and bathymetric surveying of the sand apron, reef flats and lagoon. The current and wave processes that may entrain and transport sediment were assessed using second order small amplitude (Stokes) wave theory and Shields equations. The morphodynamic interactions between current flow and geomorphology were also examined. The results showed that sediment transport occurs under modal hydrodynamic conditions with waves the main force entraining sediment rather than average currents. A morphodynamic relationship between current flow and geomorphology was also observed with current flow primarily towards the lagoon in shallow areas of the sand apron and deeper channel-like areas directing current off the sand apron towards the lagoon or the reef crest. These results show that the short-term mutual interaction of hydrodynamics and geomorphology in coral reefs can result in morphodynamic equilibrium.

Depositional setting analysis using seismic sedimentology: Example from the Paleogene Lishagang sequence in the Fushan depression, South China Sea

Directory of Open Access Journals (Sweden)

Yuan Li

2017-09-01

Full Text Available The Fushan depression is a classic lacustrine rifted sub-basin in the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the depression. Using three-dimensional (3-D seismic data and logging data, we analyzed depositional setting of the Liushagang sequence. We use wave impedance inversion to describe progradational directions of provenance and the general distribution of sand body. The seismic facies was analyzed by using the seismic sedimentology approach based on 3-D seismic data, and summed into eight types of seismic facies which could be well related to sedimentary facies. Seismic attributes with six objective sequence boundaries were extracted. Consequently, four provenance system of Liushagang sequence in the study area were confirmed by the corresponding relationship between the geologic information and the warm color and higher value area of seismic attributes: (i the Hainan uplift provenance area in the south, (ii the Linggao uplift provenance area in the west, (iii the Yunlong uplift provenance area in the east and (iv the northern provenance area. The seismic sedimentology used in this study may provide new insights into a better understanding of depositional setting in continental lacustrine rifted basins.

The sedimentology and stratigraphy of the Early Tertiary, Cusiana field, Colombia

International Nuclear Information System (INIS)

Pulham, Andrew J.

1995-01-01

The cusiana field (BP, Ecopetrol, Total and Triton is located in the llanos foothills of Eastern Colombia. There are three key reservoirs in the Cusiana field; the late Eocene to Early Oligocene Mirador Formation, the late Paleocene Barco Formation and the Santonian to Late Campanian Guadalupe Formation. The Mirador Formation contains over 50% of the original oil in place. Production for 1995 is planned at 130.000 barrels of oil per day (bopd; daily average), principally for the Mirador Formation with some production from the Guadalupe Formation. The mirador formation has therefore been the focus of a detailed reservoir description study aimed at understanding reservoir performance and putting a foundation in place for long-term reservoir management. The Mirador Formation comprises sandy (>60%), high frequency sequences dominated by the deposits of incised valleys. This paper describes the sedimentology and stratigraphy of the Mirador and the methodology chosen to construct a reservoir model fit for reservoir simulation

Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil

OpenAIRE

Luiz, Amom Mendes; Le?o-Pires, Thiago Augusto; Sawaya, Ricardo J.

2016-01-01

Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorph...

Sustainable Authorship in Plain Text using Pandoc and Markdown

Directory of Open Access Journals (Sweden)

Dennis Tenen

2014-03-01

Full Text Available In this tutorial, you will first learn the basics of Markdown—an easy to read and write markup syntax for plain text—as well as Pandoc, a command line tool that converts plain text into a number of beautifully formatted file types: PDF, .docx, HTML, LaTeX, slide decks, and more.1 With Pandoc as your digital typesetting tool, you can use Markdown syntax to add figures, a bibliography, formatting, and easily change citation styles from Chicago to MLA (for instance, all using plain text.

geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

NARCIS (Netherlands)

Seijmonsbergen, A.C.; de Graaff, L.W.S.

2006-01-01

Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village

Plain ABDO X-rays: a waste of time?

Science.gov (United States)

2002-03-01

Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study, 131 plain abdominal radiographs performed on the day of admission were prospectively analysed by the research team. In only 16 cases (12 per cent) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47 per cent), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24 per cent). The clinical management was influenced by plain abdominal radiographs in only nine cases (7 per cent). The researchers argue that most plain abdominal radiographs requested on acute medical emergencies are inappropriate. They suggest there is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

Jaquari-Mirim, Inhadiju and Piquiri Streams in their geomorphologic context

Directory of Open Access Journals (Sweden)

Eléia Righi

2009-10-01

Full Text Available The present article aims at the mapping of the Geomorphologic Units of the Hydrographic Basins of the Jaguari Mirim, Inhadiju, and Piquiri Streams, located in the west of Rio Grande do Sul – Brazil. Data analyzes defined six units characterized as: Unit I – Plane Top Relief in Volcanic Spill: shows plane relief with relatively low erosive processes and intemperism; Unit II – Hills in Volcanic Spill: slightly wavy areas underneath the plateau summit; Unit III – Hills and Small Size Hills in Volcanic Rock: formed by strongly wavy relief and with scarps; Unit IV – Small Size Hills in Sandstone: composed by isolated small size hills with origin associated to the existence of united sandstones that keeps the plane top relief; Unit V – Hills in Sandstone: Relief of hills located at the medium and low course of the streams, with the occurrence of accelerated erosive processes which produce sand dunes and accelerated erosions, and sometimes with the blooming of united sandstones in the half-slope or in the top; Unit IV -  Plane Relief in Low Altitude: Relief of plane topography that predisposes the superficial dynamic processes, generating the accumulation of sediments as well as the formation of fluvial terraces. The fragility of the natural systems, in face of the antropic interventions, is largely associated to its genetic characteristics. Thus, the geomorphologic analysis in the environmental studies is a tool for the maintainable planning of the activities introduced in the region.

Perceptions of branded and plain cigarette packaging among Mexican youth.

Science.gov (United States)

Mutti, Seema; Hammond, David; Reid, Jessica L; White, Christine M; Thrasher, James F

2017-08-01

Plain cigarette packaging, which seeks to remove all brand imagery and standardize the shape and size of cigarette packs, represents a novel policy measure to reduce the appeal of cigarettes. Plain packaging has been studied primarily in high-income countries like Australia and the UK. It is unknown whether the effects of plain packaging may differ in low-and-middle income countries with a shorter history of tobacco regulation, such as Mexico. An experimental study was conducted in Mexico City to examine perceptions of branded and plain cigarette packaging among smoking and non-smoking Mexican adolescents (n = 359). Respondents were randomly assigned to a branded or plain pack condition and rated 12 cigarette packages for appeal, taste, harm to health and smoker-image traits. As a behavioral measure of appeal, respondents were offered (although not given) four cigarette packs (either branded or plain) and asked to select one to keep. The findings indicated that branded packs were perceived to be more appealing (β = 3.40, p packaging may reduce brand appeal among Mexican youth, consistent with findings in high-income countries. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quantifying the Forcing Factors Responsible for the Tectono-Geomorphological Evolution of Neogene Rift Basins, Baja California

Science.gov (United States)

El-Sobky, H. F.; Dorobek, S. L.

2005-12-01

The Gulf of California and its surrounding land areas provide a classic example of recently rifted continental lithosphere, where back-arc stretching of a continental volcanic arc has culminated in the ongoing seafloor spreading that characterizes the present-day axis of the gulf. The recent tectonic history of eastern Baja California, which includes most of the land area eastward of the main drainage divide that extends north-south along the length of the peninsula, has been dominated by oblique rifting that began at about 5 Ma. Thus, extensional tectonics, bedrock lithology, long-term climatic changes, and evolving surface processes have controlled the tectono-geomorphological evolution of the eastern part of the peninsula since 5 Ma. No previous studies, however, examined the effect of these combined factors on the current tectono-geomorphological characteristics of eastern Baja California. We assume that although long-term climate may have changed along the peninsula over the last several million years, precipitation amounts are likely to have changed in a similar way along the entire length of the peninsula, regardless of the long-term climatic trend. This suggests that climatic variation can be largely ruled out as an explanation for the geomorphologic variability between basins. In an attempt to quantify the factors that affected the geomorphologic development along the eastern side of Baja California, thirty-four drainage basins were extracted from a 15-m-resolution absolute digital elevation model (DEM). The stacked-vector method was applied to utilize the different terrain attributes (e.g., hillshaded relief, aspect, slope, etc.) for supervised classification of bedrock lithologies using object-oriented techniques. Stream-length gradient indices were then measured for the main stream in each of the basins. Bedrock lithologies and alluvium were plotted along the stream profiles to identify any relationship between lithology, structure, and stream gradient

Environmental assessment of the area surrounding Dam Rio Verde - Parana/Brazil. An overview of environmental geomorphology.

Science.gov (United States)

Garcia, Claudia Moreira; Carrijo, Beatriz Rodrigues; Sessegolo, Gisele; Passos, Everton

2012-04-01

This paper presents a brief essay on the situation in which the environment of the dam of the Rio Verde Basin-Parana, from the vision of environmental geomorphology. The area is located between the cities of Campo Magro and Campo Largo, Paraná plateau in the first part of theAlto Iguaçu basin. This study aims to raise the concepts relating to environmental geomorphology, to identify the anthropogenic impacts caused in the reservoir areas, identify the environmental compartments found around the dam and characterize the geologic and physiographic region. It was found that the area has intense anthropogenic influence, as urban growth is present in areas and wavy and rough terrain, subject to mass movements and floods. Besides these aspects, the use of land for agriculture contributes to fragility of the area.

Glacial vs. Interglacial Period Contrasts in Midlatitude Fluvial Systems, with Examples from Western Europe and the Texas Coastal Plain

Science.gov (United States)

Blum, M.

2001-12-01

Mixed bedrock-alluvial valleys are the conveyor belts for sediment delivery to passive continental margins. Mapping, stratigraphic and sedimentologic investigations, and development of geochronological frameworks for large midlatitude rivers of this type, in Western Europe and the Texas Coastal Plain, provide for evaluation of fluvial responses to climate change over the last glacial-interglacial period, and the foundations for future quantitative evaluation of long profile evolution, changes through time in flood magnitude, and changes in storage and flux of sediments. This paper focuses on two issues. First, glacial vs. interglacial period fluvial systems are fundamentally different in terms of channel geometry, depositional style, and patterns of sediment storage. Glacial-period systems were dominated by coarse-grained channel belts (braided channels in Europe, large-wavelength meandering in Texas), and lacked fine-grained flood-plain deposits, whereas Holocene units, especially those of late Holocene age, contain appreciable thicknesses of flood-plain facies. Hence, extreme overbank flooding was not significant during the long glacial period, most flood events were contained within bankfull channel perimeters, and fine sediments were bypassed through the system to marine basins. By contrast, extreme overbank floods have been increasingly important during the relatively short Holocene, and a significant volume of fine sediment is sequestered in flood-plain settings. Second, glacial vs. interglacial systems exhibit different amplitudes and frequencies of fluvial adjustment to climate change. High-amplitude but low-frequency adjustments characterized the long glacial period, with 2-3 extended periods of lateral migration and sediment storage puncuated by episodes of valley incision. Low-amplitude but high-frequency adjustments have been more typical of the short Holocene, when there has been little net valley incision or net changes in sediment storage, but

Integrated Hydro-geomorphological Monitoring System of the Upper Bussento river basin (Cilento and Vallo Diano Geopark, S-Italy)

Science.gov (United States)

Guida, D.; Cuomo, A.; Longobardi, A.; Villani, P.; Guida, M.; Guadagnuolo, D.; Cestari, A.; Siervo, V.; Benevento, G.; Sorvino, S.; Doto, R.; Verrone, M.; De Vita, A.; Aloia, A.; Positano, P.

2012-04-01

The Mediterranean river ecosystem functionings are supported by river-aquifer interactions. The assessment of their ecological services requires interdisciplinary scientific approaches, integrate monitoring systems and inter-institutional planning and management. This poster illustrates the Hydro-geomorphological Monitoring System build-up in the Upper Bussento river basin by the University of Salerno, in agreement with the local Basin Autorities and in extension to the other river basins located in the Cilento and Vallo Diano National Park (southern Italy), recently accepted in the European Geopark Network. The Monitoring System is based on a hierarchical Hydro-geomorphological Model (HGM), improved in a multiscale, nested and object-oriented Hydro-geomorphological Informative System (HGIS, Figure 1). Hydro-objects are topologically linked and functionally bounded by Hydro-elements at various levels of homogeneity (Table 1). Spatial Hydro-geomorpho-system, HG-complex and HG-unit support respectively areal Hydro-objects, as basin, sector and catchment and linear Hydro-objects, as river, segment, reach and section. Runoff initiation points, springs, disappearing points, junctions, gaining and water losing points complete the Hydro-systems. An automatic procedure use the Pfafstetter coding to hierarchically divide a terrain into arbitrarily small hydro-geomorphological units (basin, interfluve, headwater and no-contribution areas, each with a unique label with hierarchical topological properties. To obtain a hierarchy of hydro-geomorphological units, the method is then applied recursively on each basin and interbasin, and labels of the subdivided regions are appended to the existing label of the original region. The monitoring stations are ranked consequently in main, secondary, temporary and random and located progressively at the points or sections representative for the hydro-geomorphological responses by validation control and modeling calibration. The datasets

The Andatza coarse-grained turbidite system (westernmost Pyrenees: Stratigraphy, sedimentology and structural control

Directory of Open Access Journals (Sweden)

A. Bodego

2017-06-01

Full Text Available This is a field-based work that describes the stratigraphy and sedimentology of the Andatza Conglomerate Formation. Based on facies analysis three facies associations of a coarse-grained turbidite system and the related slope have been identified: (1 an inner fan of a turbidite system (or canyon and (2 a low- and (3 a high-gradient muddy slope respectively. The spatial distribution of the facies associations and the palaeocurrent analysis allow to interpret a depositional model for the Andatza Conglomerates consisting of an L-shaped, coarse-grained turbidite system, whose morphology was structurally controlled by synsedimentary basement-involved normal faults. The coarse-grained character of the turbidite system indicates the proximity of the source area, with the presence of a narrow shelf that fed the turbidite canyon from the north.

The geomorphology and hydrogeology of the karstic Islands Maratua, East Kalimantan, Indonesia: the potential and constraints for tourist destination development

Science.gov (United States)

Haryono, E.; Sasongko, M. H. D.; Barianto, D. H.; Setiawan, J. B.; Hakim, A. A.; Zaenuri, A.

2018-04-01

Maratua Island is one of the islands of Berau District, East Kalimantan which has great potential of natural beauty for tourism development. The area currently is one of famous tourist destination in East Kalimantan which is a carbonate reef built-up or so-called karst island. This paper is an endeavor 1) to unveil geomorphological and hydrogeological characteristics of the island, and 2) to recommend Island development as a tourist destination. Maratua Island is a V shape atoll with the open lagoon. Six geomorphological units were found on the island, i.e., fringing reef, beach, marine terrace, karst ridge, structural valley, and lagoon. Caves are also found in the karst ridge and the coast as an inundated passage. Three structural depressions in the karst ridge are other unique geomorphological feature in the area of which a marine lake environment with jellyfish is inhabited. The island is typified by two different aquifer units, i.e., porous media and fractured media aquifer. Porous aquifer lies on the beach of Boibukut area. Fractured-aquifer characterizes the other geomorphological units in the area. Freshwater accordingly is found in the beach area with a limited amount. Unfortunately, the groundwater in the marine terrace and karst ridge are saline. Maratua Island has enormous potential for tourism destination development. The major tourist activities in the area based on the geomorphological unit are snorkeling and diving (in fringing reef and lagoo n), hiking, cave exploration and marine lake exploration and cave diving (in karst ridge and structural valley); recreation and picnic (beach). The major limitation in the area is a shortage of freshwater resource and land. Limited water supply should be extracted from the beach area of Bohe Bukut village. Groundwater extraction from the beach area of Bohe Bukut must be for drinking water only. Supply of drinking water should be substituted from collected rainwater or desalination from sea water and water in

Radiocarbon dating of sediment cores from Hachinohe, the Kamikita Plain

International Nuclear Information System (INIS)

Hitoki, Eri; Nakamura, Toshio; Matsumoto, Yui; Tsuji, Sei-ichiro; Fujine, Hisashi

2013-01-01

We investigated stratigraphy and chronology by analyses of Holocene sediments and radiocarbon dating of sediment cores from the Kamikita Plain. On the Kamikita Plain, which faces the Pacific coast of Northeast Japan, marine and fluvial terraces covered with tephras derived from Towada and Hakkoda volcanoes are well developed. We clarified that Towada Chuseri tephra and fluvial deposits consisted of volcanic sediments influenced an alluvial depositional system in the Kamikita Plain after a maximum of the Jomon Transgression. (author)

Unified Geomorphological Analysis Workflows with Benthic Terrain Modeler

Directory of Open Access Journals (Sweden)

Shaun Walbridge

2018-03-01

Full Text Available High resolution remotely sensed bathymetric data is rapidly increasing in volume, but analyzing this data requires a mastery of a complex toolchain of disparate software, including computing derived measurements of the environment. Bathymetric gradients play a fundamental role in energy transport through the seascape. Benthic Terrain Modeler (BTM uses bathymetric data to enable simple characterization of benthic biotic communities and geologic types, and produces a collection of key geomorphological variables known to affect marine ecosystems and processes. BTM has received continual improvements since its 2008 release; here we describe the tools and morphometrics BTM can produce, the research context which this enables, and we conclude with an example application using data from a protected reef in St. Croix, US Virgin Islands.

Controles hidrogeomorfológicos nas unidades vegetacionais da planície aluvial do rio Araguaia, Brasil - DOI: 10.4025/actascibiolsci.v30i4.5871 Hydro-geomorphologic controls in the vegetation of the Araguaia river floodplain, Brazil - DOI: 10.4025/actascibiolsci.v30i4.5871

Directory of Open Access Journals (Sweden)

Samia Aquino

2008-11-01

of the channel that consume the alluvial plain removed in particular large arboreal vegetation types, and the high rates of sedimentation contribute to the formation of the most recent geomorphologic unit of the plain, which is being colonized especially by herbaceous species.

Clinical and Plain Radiograph Pattern of Joint Dislocations and ...

African Journals Online (AJOL)

Plain radiograph is an integral part of early assessment of patients' evaluation, though newer imaging modalities such as magnetic resonance imaging (MRI), ... Conclusion: The shoulder joint is the most frequently dislocated and a conventional plain radiograph is still valuable as a first line investigative modality in ...

Analysis of High Plains Resource Risk and Economic Impacts

Energy Technology Data Exchange (ETDEWEB)

Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vargas, Vanessa N [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Shannon M [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dealy, Bern Caudill [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shaneyfelt, Calvin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Braeton James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moreland, Barbara Denise [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-04-01

The importance of the High Plains Aquifer is broadly recognized as is its vulnerability to continued overuse. T his study e xplore s how continued depletions of the High Plains Aquifer might impact both critical infrastructure and the economy at the local, r egional , and national scale. This analysis is conducted at the county level over a broad geographic region within the states of Kansas and Nebraska. In total , 140 counties that overlie the High Plains Aquifer in these two states are analyzed. The analysis utilizes future climate projections to estimate crop production. Current water use and management practices are projected into the future to explore their related impact on the High Plains Aquifer , barring any changes in water management practices, regulat ion, or policy. Finally, the impact of declining water levels and even exhaustion of groundwater resources are projected for specific sectors of the economy as well as particular elements of the region's critical infrastructure.

Regional geology, tectonic, geomorphology and seismology studies to interest to nuclear power plants at Itaorna beach

International Nuclear Information System (INIS)

Hasui, Y.; Almeida, F.F.M. de; Mioto, J.A.; Melo, M.S. de.

1982-01-01

The study prepared for the nuclear power plants to be located at Itaorna comprised, the analysis and integration of Geologic, tectonic, geomorphologic and seismologic information and satisfactory results of regional stability were obtained. (L.H.L.L.) [pt

Woodville Karst Plain, North Florida

OpenAIRE

2006-01-01

Map showing the largest mapped underwater cave systems and conduit flow paths confirmed by tracer testing relative to surface streams, sinkholes and potentiometric surface of the Florida aquifer in the Woodville Karst Plain, Florida

Geomorphology-based unit hydrograph models for flood risk management: case study in Brazilian watersheds with contrasting physiographic characteristics

Directory of Open Access Journals (Sweden)

SAMUEL BESKOW

2018-05-01

Full Text Available ABSTRACT Heavy rainfall in conjunction with an increase in population and intensification of agricultural activities have resulted in countless problems related to flooding in watersheds. Among the techniques available for direct surface runoff (DSR modeling and flood risk management are the Unit Hydrograph (UH and Instantaneous Unit Hydrograph (IUH. This study focuses on the evaluation of predictive capability of two conceptual IUH models (Nash and Clark, considering their original (NIUH and CIUH and geomorphological approaches (NIUHGEO and CIUHGEO, and their advantages over two traditional synthetics UH models - Triangular (TUH and Dimensionless (DUH, to estimate DSR hydrographs taking as reference two Brazilian watersheds with contrasting geomorphological and climatic characteristics. The main results and conclusions were: i there was an impact of the differences in physiographical characteristics between watersheds, especially those parameters associated with soil; the dominant rainfall patterns in each watershed had an influence on flood modeling; and ii CIUH was the most satisfactory model for both watersheds, followed by NIUH, and both models had substantial superiority over synthetic models traditionally employed; iii although geomorphological approaches for IUH had performances slightly better than TUH and DUH, they should not be considered as standard tools for flood modeling in these watersheds.

Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 1: Genus-Level Relationships with Geomorphic Typologies

Directory of Open Access Journals (Sweden)

Anna G. N. Meissner

2016-01-01

Full Text Available Modern river ecosystems undergo constant stress from disturbances such as bank stabilization, channelization, dams, and municipal, agricultural, and industrial water use. As these anthropogenic water requirements persist, more efficient methods of characterizing river reaches are essential. Benthic macroinvertebrates are helpful when evaluating fluvial health, because they are often the first group to react to contaminants that can then be transferred through them to other trophic levels. Hence, the purpose of this research is to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the fluvial geomorphology of the Qu’Appelle River in Saskatchewan (SK was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, and stream width and clustered through Principle Component Analysis (PCA, yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river. Macroinvertebrate data were aligned to the locations of the typologies, revealing several relationships with the fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons were completed with the macroinvertebrate data to pinpoint significant genera, as related to the geospatial model.

New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area

Directory of Open Access Journals (Sweden)

Emílio Alberto Amaral Soares

Full Text Available ABSTRACT The scarcity of stratigraphic data has hindered the demarcation of the outcropping area of Miocene deposits of the Amazon Basin, represented informally by the Novo Remanso Formation. Moreover, this unit is characterized by a sparse and irregular geographic distribution due to its sedimentological features and rare fossil content. Miocene deposits cropping out in central Amazonas Basin area were described in sedimentological terms and analyzed palynologically. All analyses were undertaken in samples collected at the Uatumã River banks (Itapiranga and São Sebastião do Uatumã cities. Lithostratigraphic data shows that Novo Remanso Formation consists of sandstones, with subordinate conglomerates and pelites, characteristic of a meandering fluvial paleosystem, with fluvial channel, point bar, floodplain and crevasse splay facies. The palynoflora retrieved from five samples consists exclusively of continental-origin palynomorphs dominated by angiosperms species. Trilete spores are well represented, while gymnosperms pollen grains are minor components. The presence of Psilastephanoporites tesseroporus, Syncolporites poricostatus, Jandufouria seamrogiformis and Polypodiaceoisporites potoniei ensure these deposits fits into the Grimsdalea magnaclavata palynozone (Regali et al. 1974a, b, and the Grimsdalea magnaclavata/Crassoretitriletes vanraadshooveni palynozones of Jaramillo et al. (2011 considered Middle Miocene age. This age is confirmed by the zonation of Jaramillo et al. (2011, based on the LADs of Bombacacidites baumfalki (11.57Ma and Crototricolpites annemariae (12.91Ma; and the FAD of Psilastephanoporites tesseroporus (14.00Ma. With these new data presented herein, it is possible to assume that the Miocene strata represented by the Novo Remanso Formation covers a larger area in the basin than previously considered, and that it may be extended for about 300 km until the Manacapuru village, indicating a Miocene subsidence phase.

Plain film diagnostic of the acromio-clavicular dislocation

International Nuclear Information System (INIS)

Vogel, H.; Thomae, J.; Jungbluth, K.H.; Hamburg Univ.

1980-01-01

The distance between the clavicula and the acromion, between the clavicula and the processus coracoideus and the step height between the acromion and the clavicula arch were measured on roentgen films. Evaluated were plain films of the shoulder and of the chest. 64 patients with dislocation of the acromio-clavicular joint were compared to patients without shoulder lesion. The comparance of both groups showed that measures exceeding the upper limits of the group without lesions are highly suggestive for acromio-clavicular dislocation. If one defines an acromio-clavicular dislocation as proved when two of the measured three distances exceed the upper limit, then an acromio-clavicular dislocation could be seen in 36% of the analysed cases on plain films of the shoulder and in 56% on plain chest films. (orig.) [de

A semi-automated approach for mapping geomorphology of El Bardawil Lake, Northern Sinai, Egypt, using integrated remote sensing and GIS techniques

Directory of Open Access Journals (Sweden)

Nabil Sayed Embabi

2014-06-01

Full Text Available Among the other coastal lakes of the Mediterranean northern coast of Egypt, Bardawil Lake is a unique lagoon, as it is fed only by seawater. The lagoon is composed of two main basins, and several other internal small basins interconnected to one another. Although the general geomorphologic characteristics are treated in some regional studies, we used a semi-automated approach based on a wide variety of digital image processing for mapping the major geomorphological landforms of the lake on a medium scale of 1:250,000. The approach is based primarily on data fusion of Landsat ETM+ image, and validated by other ancillary spatial data (e.g. topographic maps, Google images and GPS in situ data. Interpretations of high resolution space images by Google Earth and the large-scale topographic maps (1:25,000, in specific, revealed new microforms and some detailed geomorphologic aspects with the aid of GPS measurements. Small sand barriers, submerged sand dunes, tidal channels, fans and flats, and micro-lagoons are the recurrent forms in the lake. The approach used in this study could be widely applied to study the low-lying coastal lands along the Nile Delta. However, it is concluded from geological data and geomorphologic aspects that Bardawil Lake is of a tectonic origin; it was much deeper than it is currently, and has been filled with sediments mostly since the Flandrian transgression (∼8–6 ka bp.

18 CFR 801.8 - Flood plain management and protection.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flood plain management and protection. 801.8 Section 801.8 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.8 Flood plain management and protection. (a) Periodic inundation of lands...

Geomorphological investigations and GIS approach of the Tamiš loess plateau, Banat region (northern Serbia

Directory of Open Access Journals (Sweden)

Popov Dragan

2012-01-01

Full Text Available The focus of this study was the loess plateau located in the Tamiš River valley in the central part of Banat region (northern Serbia. This morphologic unit has been formed by the loess accumulation process during the last two glacial periods. Digital elevation model (DEM is based on the 1:25.000 scale topographic maps. Detailed geomorphologic and hypsometric maps are provided with selected cross sections. The borders of the plateau and spatial distribution of the micromorphology are precisely defined on DEM. The plateau rises gradually from the Upper Pleistocene terrace on the north and northwest, while to the east and south slopes and vertical bluffs were controlled by the lateral erosion process of surrounding channels and by the weathering process on the loess. The plateau has an atypical morphology characterized by reduced geomorphologic diversity. Loess topography is significantly flattened by human impact. Its micromorphology is characterised by shallow depressions and gullies.

GEOMORPHOLOGY OF JOÃO PESSOA MUNICIPALITY AND ITS ANTHROPOGENIC AND ENVIRONMENTAL ASPECTS

OpenAIRE

Max Furrier; Tamires Silva Barbosa

2016-01-01

The objective of this paper is to study the geomorphology of the municipality of João Pessoa, Paraíba State, Brazil, analyzing the outlines of the current natural landforms as well as technogenic relief. From this analysis, morphostructural and morphosculptural units, patterns and landforms, shape types and current morphogenetic processes were identified and quantified in the municipality along with landforms produced exclusively by human processes. The current forms and technogenic relief ob...

Geological and geomorphological methods for petroleum prospection in the center and west of Cuba

Directory of Open Access Journals (Sweden)

Lourdes Jimenez -de la Fuente

2017-01-01

Full Text Available The provinces of Holguin and Las Tunas have potential gas and oil resources which have not yet been fully discovered. Therefore, an assessment is completed to identify potential areas for hydrocarbon prospection based on the geological and geomorphological methods and supported by geophysical methods. Numerous proofs of the existence of oils in the surface and gas being reported in the petroleum wells are sufficient elements to think that there is an active petroleum system in the area. The analysis is supported by information given on the geological surface maps on scale of 1:100 000, satellite and radar images, information of surface occurrence of hydrocarbons, drilled wells and recent field work and geophysical interpretation results. The main results include the identification of two areas for petroleum exploration: the Maniabón-La Farola is identified as the most potential area and the second one is to the north of the Picanes well 1x. Neotectonic processes are identified to have a strong influence on the first area, which allowed delimitating petroleum system elements through geological and geomorphological methods.

Impact of multiple glacial surges - a geomorphological map from Brúarjökull, East Iceland

DEFF Research Database (Denmark)

Kjær, Kurt H.; Korsgaard, Niels Jákup; Schomacker, Anders

2008-01-01

of individual landforms. We mapped subglacial lineations such as flutes and drumlins on till plains, pitted outwash, eskers, minor meandering ridges, crevasse fill ridges, ice-free dead-ice moraine and concertina ridges, outwash fans and lake sediment plains. In addition, erosional drainage channels, ice...

Antifriction coating of Cu-Fe-Al-Pb system for plain bearings

Science.gov (United States)

Kotenkov, Pavel; Kontsevoi, Yurii; Mejlakh, Anna; Pastukhov, Eduard; Shubin, Alexey; Goyda, Eduard; Sipatov, Ivan

2017-09-01

Aluminium, copper and their compounds are used in common as basis for antifriction coatings of plain bearings. Antifriction testing of plain bearings (based on Al and Cu) made by leading automotive manufacturers from Germany, Japan, USA, United Kingdom and Russia were carried out to make judicious selection of basis for development of new antifriction material. Testing was carried out using friction machine. It was defined that materials based on Cu provide better durability and robustness of plain bearings in comparison with Al based ones. The new antifriction composite coatings based on copper were developed taking into account the requirements specified for plain bearings of internal-combustion engine. Pilot samples of plain bearings with antifriction coatings of Cu-Fe-Al-Pb system were produced. The antifriction composite having Cu-5Fe-5Al5Fe2-10Pb (mass %) composition has demonstrated low friction factor and high wear-resistance. Metallographic analysis of pilot samples was carried out by means of optical and scanning electron microscopy.

Isotope hydrological evidence of geomorphological changes in North-Eastern Hungary

International Nuclear Information System (INIS)

Hertelendi, E.; Marton, L.; Miko, L.

1991-01-01

Stable isotope and radiocarbon data of groundwater stored in Quaternary aquifers in North-Eastern Hungary can not be explained by climatic changes alone. More than two hundred δD, δ 18 O and radiocarbon ages of waters from 79 wells show that the recharge are changed during the time of upper pleniglacial and late glacial. Groundwaters of the studied are can be divided into three categories, which can explain their origin. The data are consistent with geomorphological results giving isotope evidence of hydrology for a geodynamical event during the mentioned periods. (R.P.) 3 refs.; 2 figs

Structural data, geomorphology and rock slides in the SW of Barles (The Alps of Northern Provence, France)

Energy Technology Data Exchange (ETDEWEB)

Bureau, D.

2016-10-01

The Alps of northern Provence in France is a familiar area to European geologists because numerous, long field studies have been organized by European universities and private petroleum companies during the 20th century and the beginning of the 21st century. Nevertheless, geologists have made few comments on the consequences of some topographic slides and, more broadly, on the manner by which nature has sculpted the local geomorphology. After having set the local tectonic data (the thrust of the Blayeul Massif on an already folded para-autochtonous formation and locally up and down reversals in the area of the Heights of Chine and Proussier), a geological and geomorphological summary introduces a discussion on slides and slope formations; then the details of the morphology analysis lead us to the conclusions. (Author)

49 CFR 215.107 - Defective plain bearing box: General.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing box: General. 215.107... Suspension System § 215.107 Defective plain bearing box: General. A railroad may not place or continue in... the bearing; or (2) Have a detrimental effect on the lubrication of the journal and the bearings. ...

High-performance plain bearings for diesel engines. Hochleistungs-Gleitlager fuer Dieselmotoren

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R.M.; Mathias, M.; Herrmann, B. (MTU, Friedrichshafen (Germany))

1992-01-01

The crankshaft bearings are among the most highly stressed engine components. Conventional plain bearings no longer fulfill the requirements of modern high-performance diesel engines. Introduction of the 'Sputter' technology, as a method of anti friction layer application, opened new perspectives in the field of plain bearing manufacture. In this presentation it is intended to compare various types of plain bearings and to demonstrate operation-oriented bearing testing. (orig.).

Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania.

Science.gov (United States)

Miller, Kirk; Yost, Berwood; Abbott, Christina; Thompson, Scottie; Dlugi, Emily; Adams, Zachary; Schulman, Meryl; Strauss, Nicole

2017-02-01

We performed a health needs assessment for three Plain communities in Lancaster County, Pennsylvania from a random sample of households. Compared with the general population of adults, Plain respondents were more likely to be married, to have children, and they had large families; they were more likely to drink well water, to eat fruit and vegetables, to drink raw milk, and to live on a farm. Plain respondents had better physical and mental health and were less likely to have been diagnosed with various medical conditions compared with the general population of adults in Lancaster County but Old Order Mennonite respondents were more likely to have been diagnosed compared with Old Order Amish respondents. Plain respondents usually have a regular doctor and often receive preventive care but Old Order Mennonite respondents were more likely to have a regular doctor, to receive preventive care, to have had their children vaccinated, and to receive routine dental care compared with Old Order Amish respondents. Despite their relative geographic and genetic isolation, and despite the small, relative differences noted, the health of Plain communities in Lancaster County is similar to that of other adults in the County.

Types, harms and improvement of saline soil in Songnen Plain

Science.gov (United States)

Wang, Zhengjun; Zhuang, Jingjing; Zhao, Anping; Li, Xinxin

2018-03-01

Saline soil is an extremely difficult and modified soil, widely distributed around the world. According to UN-UNESCO and FAO, the world’s saline soil area is about 9.54×108hm2, and there is a growing trend, every year in 1.0×106-1.5×106hm2 speed growth, the effective utilization of land resources to the world is the most serious threat. The total area of saline-alkali land in China is about 9.91×107hm2, including the Songnen Plain, which is called one of the three major saline soil concentrations in the world. The Songnen plain is an important grain producing area in China, and the saline soil occupies most of the Songnen plain, so it is of great significance to study the saline soil and improvement in Songnen plain.

Application of the nuclear gages in dynamic sedimentology for the solid transport study

International Nuclear Information System (INIS)

Lamdasni, Y.

1994-02-01

The problems caused by the solid particle transport in rivers, dams, harbors, estuaries and in navigation channels have considerable economical consequences. The technical difficulties met when trying to limit or manage these problems are very important because of lack of knowledge. The nuclear gages and the radioactive tracers can be the measurement and monitoring means which, associated to the conventional techniques, permit to develop strongly the knowledge in the solid transport field. This report gives the modes of solid transport and the problems caused by these transports and exposes the physical properties of the fine sediments and their behavior under the hydrodynamic effects. In the same way, it deals with the theory of the nuclear gages, often applied in dynamic sedimentology and gives some examples of their applications. 29 refs., 35 figs., 5 tabs. (F.M.)

The dilemma of dykes - Risk and opportunities in a simulation of geomorphology at mega timescales

NARCIS (Netherlands)

Hagen - Zanker, A.H.; de Vries, Ies; Hartholt, H.

2007-01-01

SimDelta dynamically simulates the geomorphology of the ‘Dutch Delta’ at a mega time scale. Scientifically a success, the model has scope for development as a game. Through challenging game play policy makers, spatial planners and students learn about the dilemmas posed by short and long term

Sedimentological regimes for turbidity currents: Depth-averaged theory

Science.gov (United States)

Halsey, Thomas C.; Kumar, Amit; Perillo, Mauricio M.

2017-07-01

Turbidity currents are one of the most significant means by which sediment is moved from the continents into the deep ocean; their properties are interesting both as elements of the global sediment cycle and due to their role in contributing to the formation of deep water oil and gas reservoirs. One of the simplest models of the dynamics of turbidity current flow was introduced three decades ago, and is based on depth-averaging of the fluid mechanical equations governing the turbulent gravity-driven flow of relatively dilute turbidity currents. We examine the sedimentological regimes of a simplified version of this model, focusing on the role of the Richardson number Ri [dimensionless inertia] and Rouse number Ro [dimensionless sedimentation velocity] in determining whether a current is net depositional or net erosional. We find that for large Rouse numbers, the currents are strongly net depositional due to the disappearance of local equilibria between erosion and deposition. At lower Rouse numbers, the Richardson number also plays a role in determining the degree of erosion versus deposition. The currents become more erosive at lower values of the product Ro × Ri, due to the effect of clear water entrainment. At higher values of this product, the turbulence becomes insufficient to maintain the sediment in suspension, as first pointed out by Knapp and Bagnold. We speculate on the potential for two-layer solutions in this insufficiently turbulent regime, which would comprise substantial bedload flow with an overlying turbidity current.

Discriminating impacts of geomorphological and human factors on vineyard soil erosion (Burgundy, France)

Science.gov (United States)

Chevigny, Emmanuel; Quiquerez, Amélie; Petit, Christophe; Curmi, Pierre

2014-05-01

The Burgundy vineyards have been recognized for the high diversity of Terroirs, controlled by complex interactions between natural features, historical parameters and soil management practices. Vineyards are known to undergo substantial soil loss in comparison with other types of agricultural land. Hydric erosion on vineyards is controlled by complex interactions of natural and anthropogenic factors leading to intra-plot spatial heterogeneities of topsoil at a scale of a metre. Studying the relationship between soils and their degradation is crucial in this situation where soil sustainability is threatened. This study explores the relative influences of historical and present-day anthropogenic factors and geomorphological processes controlling soil erosion on vineyard hillslopes. The selected area was located in the Monthelie vineyard (Côte de Beaune, France) where intensive erosion occurred during high-intensity rainfall events. Soil erosion quantification was performed at a square-metre scale using dendrogeomorphology. This method is based on the measurement of the unearthing of the stock located on the vine plants, considered as a passive marker of soil-surface vertical displacement since the year of plantation. The obtained maps, together with various complementary datasets, such as geological and geomorphological data, but also historical documents (cadastral plans, cadastral matrices and old aerial photographs) allow landscape evolution to be assessed. The combination of all these data shows that spatial distribution and intensity of erosion are controlled mainly by lithology and slope value. However, our study highlights that the sediment dynamics in this vineyard plot is highly related to historical former plot limits and present-day management practices. Nonetheless, quantification of sediment dynamic for the last decade reveals that the impacts of historical structures are disappearing gradually, in response to present-day management practices and

Evaluating the Use of Plain Language in a Cancer Clinical Trial Website/App.

Science.gov (United States)

Schultz, Paula L; Carlisle, Regina; Cheatham, Chesley; O'Grady, Melissa

2017-12-01

Medically complex titles and descriptions found on clinical trial websites and online applications present a barrier to comprehension for users from the general public. In this study, we examine the effectiveness of plain language trial descriptions for user comprehension of basic trial details. Two hundred seventeen volunteers recruited from patient waiting areas completed 441 user tests of ten plain language trial descriptions. The majority of volunteers adequately comprehended the cancer type and basic inclusion/exclusion criteria from plain language trial descriptions. Difficulty comprehending the treatment being studied was seen in seven of ten descriptions tested. Revision and retesting of the seven trial descriptions showed continued user challenges in comprehending the treatment being studied. Plain language clinical trial descriptions integrated into a website/app allowed users to understand basic inclusion/exclusion criteria. Despite plain language used, discerning the treatment being studied may be difficult for some users. Integration of plain language descriptions into clinical trial online applications can help users understand trial basics. Further research regarding effective use of plain language to communicate the treatment being studied is needed.

Artificial urethral sphincters: Value of plain film radiography in evaluation of prosthesis malfunction

International Nuclear Information System (INIS)

Rose, S.C.; Hansen, M.E.; Webster, G.; Dunnick, N.R.

1987-01-01

Case records were reviewed to determine the diagnostic efficacy of plain radiographs in the evaluation of inflatable artificial urethral sphincters. Of 84 patients with prostheses, 21 (25%) developed complications. Fluid leaks were found in 16 patients who presented with recurrent incontinence; plain radiographs demonstrated an interval decrease in balloon reservoir diameter. Kinked tubing, which was evident on plain films, caused acute urinary retention in three patients. However, plain radiographs failed to detect evidence of prosthesis erosion into the urethra in either of two patients with this complication. Although urethroscopy is needed to detect urethral erosion, plain radiographs are inexpensive and reliable in the initial evaluation of artifical sphincter malfunction

Sedimentologic indicators of the Miocene tectonic evolution in the Nunchia syncline

International Nuclear Information System (INIS)

Ramirez Arias, Juan Carlos; Mora, Andres; Parra, Mauricio

2010-01-01

The study area corresponds to the Nunchia syncline, which is located in the eastern foothills of the eastern cordillera of Colombia. This structure is bounded by the Yopal thrust to the east, and Guaicaramo thrust to the west. This syncline has mostly outcrops of Miocene units, which belong to the Carbonera (C1-C5), Leon and Guayabo formations. Here we use sedimentologic data, especially in the Guayabo Formation, in order to determine the influence of active tectonics during its deposition. Petrographic analyses of sandstones indicate the presence of components associated with upper Cretaceous - Paleocene formations in the eastern cordillera. Paleocurrent orientation shows a preferential trend towards the se during the deposition of most of the studied formations, with a reversal in flow direction towards the W-NW during the deposition of the middle Guayabo Formation preserved in the Nunchia syncline. The collected data allows establishing a structural evolution in the Nunchia syncline which was therefore active during most of the Miocene. This evolution appears to be continuous, although fragmentation of the geological record shows more specific periods of tectonic activity.

Sedimentology of the Teekloof formation to the east of Aberdeen (C.P.) with reference to uranium mineralization

International Nuclear Information System (INIS)

Simmonds, A.L.E.

1982-01-01

An area to the immediate east of Aberdeen (C.P.), banded in the north by the Rooiberge and to the east by the Sundays River, has been sedimentologically studied. A notable feature of the sediments investigated, is the presence of linear zones of increased sandstone. Some of the sediments also showed an exessive volume of argillaceous rocks. The sandstones cropping out in the Aberdeen District may be classified as lithic arkoses. Due to the manner in which the detrital grains appear to 'float' in calcite, an expansive growth mechanism is envisaged. This implies early crystallization of calcite, and emplacement of uranium

The influence of control parameter estimation on large scale geomorphological interpretation of pointclouds

Science.gov (United States)

Dorninger, P.; Koma, Z.; Székely, B.

2012-04-01

In recent years, laser scanning, also referred to as LiDAR, has proved to be an important tool for topographic data acquisition. Basically, laser scanning acquires a more or less homogeneously distributed point cloud. These points represent all natural objects like terrain and vegetation as well as man-made objects such as buildings, streets, powerlines, or other constructions. Due to the enormous amount of data provided by current scanning systems capturing up to several hundred thousands of points per second, the immediate application of such point clouds for large scale interpretation and analysis is often prohibitive due to restrictions of the hard- and software infrastructure. To overcome this, numerous methods for the determination of derived products do exist. Commonly, Digital Terrain Models (DTM) or Digital Surface Models (DSM) are derived to represent the topography using a regular grid as datastructure. The obvious advantages are a significant reduction of the amount of data and the introduction of an implicit neighborhood topology enabling the application of efficient post processing methods. The major disadvantages are the loss of 3D information (i.e. overhangs) as well as the loss of information due to the interpolation approach used. We introduced a segmentation approach enabling the determination of planar structures within a given point cloud. It was originally developed for the purpose of building modeling but has proven to be well suited for large scale geomorphological analysis as well. The result is an assignment of the original points to a set of planes. Each plane is represented by its plane parameters. Additionally, numerous quality and quantity parameters are determined (e.g. aspect, slope, local roughness, etc.). In this contribution, we investigate the influence of the control parameters required for the plane segmentation on the geomorphological interpretation of the derived product. The respective control parameters may be determined

CHANGING FLOOD FREQUENCY IN SCOTLAND: IMPLICATIONS FOR CHANNEL GEOMORPHOLOGY, ECOLOGY AND MANAGEMENT

OpenAIRE

Thompson, Fiona Hilary

2017-01-01

The effect of climate on the fluvial system has long been investigated due the significant impact it can have on a river’s hydrological regime and fluvial processes. In recent years this interest has increased as global changes in climate are expected to bring more frequent high magnitude flood events globally and to North West Europe in particular. Despite the knowledge that the frequency and magnitude of floods is to increase, less is known about the geomorphological implicat...

U-Pb SHRIMP ages of volcanic zircons from the Merrions and Turondale Formations, New South Wales, and the early devonian time-scale: a biostratigraphic and sedimentological assessment

International Nuclear Information System (INIS)

Packham, G.H.

2003-01-01

U-Pb ages for volcanic zircons from the Lower Devonian Turondale and Merrions Formations initially dated by Jagodzinski and Black (1999) have been recalculated by Compston (2000, 2001). The Turondale, Waterbeach and Merrions Formations are, in ascending stratigraphic order, three of the Lower Devonian deep-water formations of the Hill End Trough. The recent discovery of a Lochkovian conodont fauna of the delta zone in derived limestone blocks from the uppermost beds of the Turondale Formation has established a maximum age for that horizon. The principal lithological assemblages of the formations are volcanic (megaturbidite and lavas), epiclastic turbidites and essentially hemipelagic lithologies. The mean zircon ages, determined by Sensitive High-Resolution Ion MicroProbe (SHRIMP), suggest a long duration for the Merrions Formation, 615 m thick and 91% volcanic, and a very much shorter interval for the upper two-thirds of the Turondale Formation, 360 m thick and 34% volcanic, plus the intervening non-volcanic Waterbeach Formation, 512 m thick. A sedimentological model based on scaled depositional rates for the facies has been used to estimate the relative accumulation rates and durations of the succession from the base of the Turondale Formation to the top of the Merrions Formation The model indicates that the Merrions Formation accumulated in a much shorter time than the interval from the top of the lower Turondale Formation to the base of the Merrions Formation. The analytical uncertainties of the Jagodzinski and Black (1999) zircon ages are large enough to be compatible with the sedimentological model, but the smaller analytical uncertainties calculated by Compston (2000, 2001) fall far from the scaled sedimentological model. Grouping together of the lower Merrions Formation and lower Turondale Formation zircon dates in Compston (2000) for a single mid-Lochkovian age is in conflict with the biostratigraphic and sedimentological evidence available and the derived

Sedimentology of the Paestum travertines, Salerno, Southern Italy

Science.gov (United States)

Anzalone, E.; Ferreri, V.; D'Argenio, B.

2009-04-01

The Paestum travertines, outcrop in the southern part of the Sele plain (Campania, southern Italy)and span in age from the late Pleistocene to the Recent. We have considered both the travertines resting under the ancient town of Paestum (founded by Sybaris Greeks in the VII century b.C.) and in its vicinities, as well as the travertine incrustations that post-date the VII century a.C. and partly cover the archaeological area. The textures and sedimentary features of the above rocks allow the environmental dynamics of the ancient as well as of the recent travertine deposits to be interpreted. The age of the ancient travertines ranges from 30-40 ka to 70-75 ka, even though more recent times of deposition cannot be excluded. They are genetically related to the waters springing from the south- western margin of the Mesozoic-Tertiary carbonates of Monte Soprano and Monte Sottano. These waters flow also through the travertines and their neighbouring deposits, feeding other springs along the coast. The travertines, both in situ and forming the building blocks of the town walls, have been classified using the textural nomenclature of the primary incrustations. On this basis, different lithofacies have been recognized and grouped into 3 main lithofacies associations: 1) Microhermal and Stromatolitic Travertines associated with Grain Supported Phytoclastic Travertines (gentle to steep slope environments); this lithofacies association is largely represented in the foundation travertines as well as in the blocks used to build the walls and the monuments of the ancient town; 2) Phytohermal and Microhermal Travertines (rapid and waterfall environments); this lithofacies association is well exposed in the foundation travertines of Porta Marina (western side of the town) and in some wall blocks (e.g. nearby Porta Sirena, eastern side of the town); 3) Phytoclastic and Phytohermal Travertines (swamp and marsh environments); this lithofacies association is common in the blocks

Occurrence and variability of mining-related lead and zinc in the Spring River flood plain and tributary flood plains, Cherokee County, Kansas, 2009--11

Science.gov (United States)

Juracek, Kyle E.

2013-01-01

Historical mining activity in the Tri-State Mining District (TSMD), located in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma, has resulted in a substantial ongoing input of cadmium, lead, and zinc to the environment. To provide some of the information needed to support remediation efforts in the Cherokee County, Kansas, superfund site, a 4-year study was begun in 2009 by the U.S. Geological Survey that was requested and funded by the U.S. Environmental Protection Agency. A combination of surficial-soil sampling and coring was used to investigate the occurrence and variability of mining-related lead and zinc in the flood plains of the Spring River and several tributaries within the superfund site. Lead- and zinc-contaminated flood plains are a concern, in part, because they represent a long-term source of contamination to the fluvial environment. Lead and zinc contamination was assessed with reference to probable-effect concentrations (PECs), which represent the concentrations above which adverse aquatic biological effects are likely to occur. The general PECs for lead and zinc were 128 and 459 milligrams per kilogram, respectively. The TSMD-specific PECs for lead and zinc were 150 and 2,083 milligrams per kilogram, respectively. Typically, surficial soils in the Spring River flood plain had lead and zinc concentrations that were less than the general PECs. Lead and zinc concentrations in the surficial-soil samples were variable with distance downstream and with distance from the Spring River channel, and the largest lead and zinc concentrations usually were located near the channel. Lead and zinc concentrations larger than the general or TSMD-specific PECs, or both, were infrequent at depth in the Spring River flood plain. When present, such contamination typically was confined to the upper 2 feet of the core and frequently was confined to the upper 6 inches. Tributaries with few or no lead- and zinc-mined areas in the basin—Brush Creek

Trends in publications in fluvial geomorphology over two decades: A truly new era in the discipline owing to recent technological revolution?

Science.gov (United States)

Piégay, Hervé; Kondolf, G. Mathias; Minear, J. Toby; Vaudor, Lise

2015-01-01

Trends in the field of fluvial geomorphology have been reviewed by a number of authors, who have emphasized the dramatic change occuring in the field in the last two decades of the twentieth century, largely as a result of technological advances. Nevertheless, no prior authors have systematically compiled data on publications in fluvial geomorphology over a long period and statistically analyzed the resulting data set. In this contribution we present a quantitative analysis of fluvial geomorphology papers published in the twenty-two-year period 1987–2009 in five journals of the discipline with a more specific focus on Geomorphology and Earth Surface Processes and Landforms (ESPL), identifying authorships, geographic origin of authors, and spatial and temporal scales covered. We also documented the tools employed, demonstrating the transformation of the field with the emergence of new tools over this period, and conducted a cluster to highlight links between tools and a set of factors (country of author's origin, journals, time, and spatial and temporal scales). Of the 1717 papers published in the five journals during this period, the results showed an increased diversity in the nationality of the first author, mainly when dealing with present time scale, and channel feature. Our data show a significant change in methods used in the field as a result of the increase in data availability and new sources of information from remote sensing (ground, airborne and, satellite). Clearly, a new era in knowledge production is observed since 2000, showing the emergence of a second period of active quantification and an internationalization of the fields.

Geomorphology of the Ganges fluvial system in the Himalayan foreland: an update

Directory of Open Access Journals (Sweden)

Rajiv Sinha

2004-12-01

Full Text Available The Ganges is one of the largest fluvial systems in the world rising from the loftiest Himalaya and draining into the Bay of Bengal. Together with the Brahmaputra, it also constitutes the largest delta in the world before finally meeting the sea. The Ganges system passes through a variety of terrain from the rugged mountains through the flat alluvial plains and the sea margin, and also transects variable climatic zones. As a result, the processes, landforms and stratigraphy are strikingly different in different zones of the system. This paper attempts to provide an update on our understanding of this very large and diverse system. A global effort has been made in the last few decades, and the research has focused on a variety of themes. The mountainous catchments have attracted attention in view of the extent of glaciation and extensive erosional processes. The alluvial plains of the Ganges symbolizes the life line of one of the world's largest population. Consequently, a number of studies have been carried out on the morphology, hydrology including flooding history and sediment transport behaviour of the river system. The alluvial stratigraphy of the large valleys and the interfluves in the plains has provided insight about the sedimentation pattern and response to climate change. The deltaic plain is the final destination of this huge sediment dispersal system before it drains into the sea, and it also records the influence of sea level changes apart from the upstream catchment controls over a period of time.

Sensitivity Analysis for Hydraulic Behavior of Shiraz Plain Aquifer Using PMWIN

Directory of Open Access Journals (Sweden)

Ahmad Reza karimipour

2011-07-01

Full Text Available In this study, hydraulic behavior of Shirazplain aquifer, with an area of ~300 km2, was simulated using PMWIN model. The performance of recently constructed drainage system in the plain was modeled and parameters affecting hydraulic behavior of the aquifer were analyzed. Measured rainfall and evaporation rates in the plain, recharge and discharge rates through the aqueducts, Khoshk and Chenar Rahdar rivers, as well as amount of water discharged from production wells and recharge due to returned wastewater were considered in the model. Plain hydrodynamic coefficients were estimated via calibration and sensitivity analysis of the model was performed for four important parameters. Results showed that the model is most sensitive to recharge rate and hydraulic conductivity, respectively, such that a small variation in these two parameters causes a dramatic change in hydraulic head distribution in the plain. Furthermore, specific yield coefficient influences the seasonal water level fluctuations, but the aqueducts conductance coefficient only affects the aqueduct radius of influence with little effect on the overall hydraulic behavior of the plain.

On the LiDAR contribution for the archaeological and geomorphological study of a deserted medieval village in Southern Italy

International Nuclear Information System (INIS)

Lasaponara, Rosa; Coluzzi, Rosa; Gizzi, Fabrizio T; Masini, Nicola

2010-01-01

Airborne laser scanning (ALS) is an optical measurement technique for obtaining high-precision information about the Earth's surface including basic terrain mapping (digital terrain model, bathymetry, corridor mapping), vegetation cover (forest assessment and inventory) and coastal and urban areas. Recent studies examined the possibility of using ALS in archaeological investigations to identify earthworks, although the ability of ALS measurements in this context has not yet been studied in detail. This paper focuses on the potential of the latest generation of airborne ALS for the detection and the spatial characterization of micro-topographic relief linked to archaeological and geomorphological features. The investigations were carried out near Monteserico, an archaeological area in the Basilicata region (Southern Italy) which is characterized by complex topographical and morphological features. The study emphasizes that the DTM-LiDAR data are a powerful instrument for detecting surface discontinuities relevant for investigating geomorphological processes and cultural features. The LiDAR survey allowed us to identify the urban shape of a medieval village, by capturing the small differences in height produced by surface and shallow archaeological remains (the so-called shadow marks) which were not visible from ground or from optical dataset. In this way, surface reliefs and small elevation changes, linked to geomorphological and archaeological features, have been surveyed with great detail

Projected future climate changes in the context of geological and geomorphological hazards.

Science.gov (United States)

Liggins, Felicity; Betts, Richard A; McGuire, Bill

2010-05-28

On palaeoclimate time scales, enhanced levels of geological and geomorphological activity have been linked to climatic factors, including examples of processes that are expected to be important in current and future anthropogenic climate change. Planetary warming leading to increased rainfall, ice-mass loss and rising sea levels is potentially relevant to geospheric responses in many geologically diverse regions. Anthropogenic climate change, therefore, has the potential to alter the risk of geological and geomorphological hazards through the twenty-first century and beyond. Here, we review climate change projections from both global and regional climate models in the context of geohazards. In assessing the potential for geospheric responses to climate change, it appears prudent to consider regional levels of warming of 2 degrees C above average pre-industrial temperature as being potentially unavoidable as an influence on processes requiring a human adaptation response within this century. At the other end of the scale when considering changes that could be avoided by reduction of emissions, scenarios of unmitigated warming exceeding 4 degrees C in the global average include much greater local warming in some regions. However, considerable further work is required to better understand the uncertainties associated with these projections, uncertainties inherent not only in the climate modelling but also in the linkages between climate change and geospheric responses.

Acute paediatric ankle trauma: MRI versus plain radiography

Energy Technology Data Exchange (ETDEWEB)

Lohman, M. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Radiological Dept., Helsinki University Central Hospital (Finland); Kivisaari, A.; Kivisaari, L. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Kallio, P.; Puntila, J. [Dept. of Paediatric Surgery, Hospital for Children and Adolescents, Helsinki Univ. Central Hospital, Helsinki (Finland); Vehmas, T. [Finnish Institute of Occupational Health, Helsinki (Finland)

2001-09-01

Objective: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. Methods: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three ''masked'' radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. Results: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures. Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter- Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. Conclusions: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries. (orig.)

Acute paediatric ankle trauma: MRI versus plain radiography

International Nuclear Information System (INIS)

Lohman, M.; Kivisaari, A.; Kivisaari, L.; Vehmas, T.

2001-01-01

Objective: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. Methods: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three ''masked'' radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. Results: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures. Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter- Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. Conclusions: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries. (orig.)

Imaging suspected cervical spine injury: Plain radiography or computed tomography? Systematic review

Energy Technology Data Exchange (ETDEWEB)

Cain, Gavin [Diagnostic Radiographer, Colchester Hospital University NHS Foundation Trust, Colchester General Hospital, Turner Road, Colchester, CO4 5JL Essex (United Kingdom)], E-mail: gavincain8@hotmail.com; Shepherdson, Jane; Elliott, Vicki; Svensson, Jon [Faculty of Health and Social Care, Anglia Ruskin University, East Road, Cambridge, CB1 9PT Cambridgeshire (United Kingdom); Brennan, Patrick [UCD School of Medicine and Medical Sciences, Health Science Building, Belfield, Dublin 4 (Ireland)

2010-02-15

Aim: (1) to establish which modality offers the greatest accuracy in the detection of cervical spine injury (CSI) Following trauma: plain radiography or computed tomography (CT), and (2) make an evidence-based recommendation for the initial imaging modality of choice. Method: A systematic literature review was performed to identify primary research studies which compare the diagnostic accuracy of plain radiography and CT with the results of a reference standard in the detection of CSI. A search of MEDLINE, EMBASE, CINAHL, Science Direct and Pubmed Central databases was conducted. Results: Ten studies were identified. Critical appraisal identified limitations among all studies. There was heterogeneity in the sensitivity estimates for plain radiography, whereas estimates for CT were consistently high. Examination of the reported sensitivities shows that CT outperforms plain radiography in the detection of CSI. Conclusion: CT is superior to plain radiography in the detection of CSI. However, the optimal imaging strategy depends on the patients' relative risk of injury. If at high-risk cervical CT is indicated. If at low-risk the increased cost and radiation exposure mean that screening CT may not be warranted, good-quality plain radiographs are sufficient.

Plain language: a strategic response to the health literacy challenge.

Science.gov (United States)

Stableford, Sue; Mettger, Wendy

2007-01-01

Low health literacy is a major challenge confronting American and international health organizations. Research in the past decade has documented the prevalence of limited literacy and limited health literacy skills among adults worldwide. This creates a major policy challenge: how to create text-based health information - a common method of health communication - that is accessible to the public. Plain language is a logical, flexible response. While touted by American, Canadian, and European health policy makers, adoption and promotion of plain language standards and skills in health-focused organizations have lagged. Most text-based health information continues to be too hard for most adults to read. Barriers to more rapid diffusion of plain language are reflected in a set of myths perpetuated by critics. These myths are identified and refuted. While plain language is only one of many broad-based solutions needed to address low health literacy, the benefits to everyone demand increased use by health organizations.

Plain abdominal radiographs in acute medical emergencies: an abused investigation?

Science.gov (United States)

Feyler, S; Williamson, V; King, D

2002-02-01

Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

Geothermal Alteration of Basaltic Core from the Snake River Plain, Idaho

OpenAIRE

Sant, Christopher Joseph

2012-01-01

The Snake River Plain is located in the southern part of the state of Idaho. The eastern plain, on which this study focuses, is a trail of volcanics from the Yellowstone hotspot. Three exploratory geothermal wells were drilled on the Snake River Plain. This project analyzes basaltic core from the first well at Kimama, north of Burley, Idaho. The objectives of this project are to establish zones of geothermal alteration and analyze the potential for geothermal power production using sub-aquife...

Changes in plain bearing technology

CERN Document Server

Koring, Rolf

2012-01-01

A unique fusion of theoretical and practical knowledge, Changes in Plain Bearing Technology, by Rolf Koring, covers a meaningful range of expertise in this field.Drawing from years of experience in design development, materials selection, and their correlation to real-life part failure, this title, co-published by SAE International and expert Verlag (Germany), concentrates on hydrodynamic bearings lined with white metals, also known as Babbits.Written under the assumption that even the most mature body of knowledge can be revisited and improved, Changes in Plain Bearing Technology is a courageous and focused approach to questioning accepted test results and looking at alternative material compounds, and their application suitability.The process, which leads to innovative answers on how the technology is transforming itself to respond to new market requirements, shows how interdisciplinary thinking can recognize new potential in long-established industrial modus operandi.Tackling the highly complex issue of co...

The Mw 5.4 Reggio Emilia 1996 earthquake: active compressional tectonics in the Po Plain, Italy

Science.gov (United States)

Selvaggi, G.; Ferulano, F.; Di Bona, M.; Frepoli, A.; Azzara, R.; Basili, A.; Chiarabba, C.; Ciaccio, M. G.; Di Luccio, F.; Lucente, F. P.; Margheriti, L.; Nostro, C.

2001-01-01

We have analysed the seismic sequence that occurred in October 1996 near the town of Reggio Emilia on the southern edge of the Po Plain. The onset of the sequence was marked by a 5.4 moment magnitude main shock, located at 15km depth. The main-shock focal mechanism is a reverse solution with a strike-slip component and the scalar moment is 1.46×1017Nm. We used broad-band digital recordings from a borehole station, located at about 70km from the epicentre, for a spectral analysis in order to estimate attenuation and source parameters for the main shock. In addition, the empirical Green's function method has been applied to evaluate the source time function in terms of both moment rate and stress rate. We infer an asperity-like rupture process for the main shock, as suggested by the short duration of the stress release with respect to the overall duration of the moment rate function. This analysis also allows us to estimate the average dynamic stress drop of the main shock (600bar). We analysed the digital recordings of the temporary local seismic network deployed after the main shock and of a permanent local network maintained by the Italian Petroleum Agency (AGIP). During 15days of field experiments, we recorded more than 800 aftershocks, which delineate a 9km long, NE-elongated distribution, confined between 12 and 15km depth, suggesting that the basement is involved in the deformation processes. 102 focal mechanism of aftershocks have been computed from P-wave polarities, showing mainly pure reverse solutions. We calculate the principal stress axes from a selected population of earthquakes providing a constraint on the stress regime of this part of the Po Plain. The focal mechanisms are consistent with a N-S subhorizontal σ1. All the seismological data we have analysed confirm that this region is undergoing active compressional tectonics, as already inferred from recent earthquakes, geomorphological data and other stress indicators. Moreover, the elongation of

Geomorphological processes in Britain in a periglacial age

International Nuclear Information System (INIS)

Pitty, A.F.

1988-12-01

Significant changes in geomorphological processes can be anticipated over the timescales relevant to the Safety Assessments being formulated by United Kingdom Nirex Ltd. The opening sections of this Report emphasise the intrinsic uncertainties concerning the study and interpretation of periglacial phenomena, both in their present-day setting, and as presumed relict features in the British Isles. A section illustrates how emphases have veered and varied in this area of study. An implication, with particular reference to the British Isles, is that the study of periglacial phenomena is, itself, subject to significant short-term changes. The Report reviews the climate of a periglacial environment, emphasising the difficulties involved in translations from present-day analogue areas, which often have intrinsic differences, when compared with the British Isles. The significance of frost penetration, microclimate and snow cover is explained. (Author)

GIS- and field based mapping of geomorphological changes in a glacier retreat area: A case study from the Kromer valley, Silvretta Alps (Austria)

Science.gov (United States)

Guttmann, Markus; Pöppl, Ronald

2017-04-01

Global warming results in an ongoing retreat of Alpine glaciers, leaving behind large amounts of easily erodible sediments. As a consequence processes like rockfalls, landslides and debris flows as well as fluvial processes occur more frequently in pro- and paraglacial areas, often involving catastrophic consequences for humans and infrastructure in the affected valleys. The main objective of the presented work was to map and spatially quantify glacier retreat and geomorphological changes in the Kromer valley, Silvretta Alps (Austria) by applying GIS- and field-based geomorphological mapping. In total six geomorphological maps (1950s, 1970s, 2001, 2006, 2012, and 2016) were produced and analyzed in the light of the study aim. First results have shown a significant decrease of total glaciated area from 96 ha to 53 ha which was accompanied by increased proglacial geomorphic activity (i.e. fluvial processes, rockfalls, debris flows, shallow landslides) in the last 15 years. More detailed results will be presented at the EGU General Assembly 2017.

The input of geomorphology to oil-related developments in Shetland and Northeast Scotland

International Nuclear Information System (INIS)

Ritchie, W.

1991-01-01

In essence, the input of coastal geomorphology to most oil-related developments at the coastline has been descriptive environmental classification. The uses to which this information has been put are twofold: (1) as background reconnaissance data that are prepared in advance of a development, such as the exploitation of a nearshore drilling lease or a pipeline landfall, and (2) as a basic element in oil spill contingency mapping. A more specialized use of geomorphology has been environmental management advice relating to the construction, restoration, and operation of large-diameter oil and gas pipeline landfalls - all of which make their approach in Northeast Scotland through beach and dune complexes. The techniques consist of traditional morphological mapping considering form, aspect, materials, energy, and estimations of contemporary processes. Implicit in this mapping is the recognition of vulnerability which, in turn, relates closely to habitat recognition. Time is rarely available for process-type measurements. There is also a dependence on existing maps, aerial photographs, and reports. The survey may be done on foot, from boats, fixed-wing aircraft, or helicopters. Airborne video is increasingly being used as a supplementary means of data acquisition. Vertical airborne video used with an image-processing and G.I.S. system shows great potential and has been used experimentally for pipeline route selection

Young people's perceptions of cigarette packaging and plain packaging: an online survey.

Science.gov (United States)

Moodie, Crawford; Ford, Allison; Mackintosh, Anne Marie; Hastings, Gerard

2012-01-01

In the United Kingdom, with most marketing channels prohibited, packaging is one of the few remaining ways that tobacco companies can promote their products. An online survey with young people aged 10-17 years (N = 658) was used to explore why youth choose cigarettes, perceptions of pack color, and perceptions of plain (nonbranded) cigarette packaging. Young people were also shown an image of 3 plain packs, which differed by shape and method of opening, and asked which they liked most and thought others their age would smoke. Price and what significant others smoke were key factors for choosing cigarettes, with packaging also an important influence. More than a third of the sample associated lighter pack color with weak tasting and less harmful cigarettes. Plain packs were rated negatively as were perceptions of plain pack users. One in 3 showed a preference for either a narrow "perfume type" plain pack or a plain "slide" pack that opened from the side, and 1 in 3 also thought that young people would smoke these packs. Packaging appears to both attract young people and mislead them about product strength and relative harm. Innovative pack construction (novel pack shape and method of opening) and the use of color are instrumental in these effects. The findings therefore suggest that any move to plain packaging should not only consider the benefits of removing branding (including color) but also of standardizing pack construction in terms of shape and method of opening.

No (more) logo: plain packaging and communicative agency

OpenAIRE

Alain Pottage

2013-01-01

The tobacco industry’s archives suggest that the global campaign for the plain packaging of tobacco products originated in 1986, when the Canadian Medical Association passed a resolution calling for cigarettes to be sold in packages bearing only a brand name and the health message ‘this product is injurious to your health’. In most jurisdictions, regulations requiring the apposition of health warnings to cigarette packs have been in force for decades. Proposals for plain packaging aim to go f...

Identifying linkages between land use, geomorphology, and aquatic habitat in a mixed-use watershed.

Science.gov (United States)

McIlroy, Susan K; Montagne, Cliff; Jones, Clain A; McGlynn, Brian L

2008-11-01

The potential impacts of land use on large woody debris (LWD) were examined in Sourdough Creek Watershed, a rapidly growing area encompassing Bozeman, Montana, USA. We identified six land classes within a 250 m buffer extending on either side of Sourdough Creek and assessed aquatic habitat and geomorphologic variables within each class. All LWD pieces were counted, and we examined 14 other variables, including undercut bank, sinuosity, and substrate composition. LWD numbers were generally low and ranged from 0 to 8.2 pieces per 50 m of stream. Linear regression showed that LWD increased with distance from headwaters, riparian forest width, and sinuosity in four of the six land classes. Statistically significant differences between land classes for many aquatic habitat and geomorphologic variables indicated the impacts of different land uses on stream structure. We also found that practices such as active wood removal played a key role in LWD abundance. This finding suggests that managers should prioritize public education and outreach concerning the importance of in-stream wood, especially in mixed-use watersheds where wood is removed for either aesthetic reasons or to prevent stream flooding.

The Vie Cave Geomorphological Site in Southern Tuscany (Italy: Problems of Decay and Conservation

Directory of Open Access Journals (Sweden)

Elena Pecchioni

2015-06-01

Full Text Available The Vie Cave are a suggestive network of roads deeply entrenched in the rock, dating back to the Etruscan civilization; these ancient roads connect various settlements and necropolises existing mainly in the area of Sovana, Sorano and Pitigliano towns (Southern Tuscany, Italy. The Vie Cave are located in a peculiar geomorphological site, characterized by the presence of extensive pyroclastic deposits, which have been incised by a parallel network of deep gorges. In this paper, the geomorphological, geological and lithological setting of the Vie Cave area, where several Etruscan archaeological sites are found, are described. The precarious stability of the Vie Cave walls and the several archaeological structures carved into them, the high grade of decay shown by the constituent materials, together with the dense vegetation that has developed over the rocky scarps, are taken into account with the aim to provide a complete assessment of the conditions in which the site lies. Finally, we propose some targeted actions related to the preservation of this territory, showing so distinctive morphology, in order to protect the area from further decay to which it would be subjected if it remained abandoned.

Effective utilization of geomorphology in uranium exploration: a success story from Meghalaya, northeast India

International Nuclear Information System (INIS)

Mamallan, R.; Awati, A.B.; Gupta, K.R.; Kak, S.N.

1995-01-01

The southern fringe of Meghalaya plateau displays a spectacular development of erosional landforms in the thick sedimentary cover of Cretaceous-Tertiary formations. Mahadek formation, the lower member of this sequence, comprises both continental and marginal marine sediments while all the overlying formations are mainly of marine origin. In the study area all the tertiary formations are eroded away, leaving exposed the continental part of the Mahadek formation, which comprises channel-filled and floodplain sediments. Geomorphologically, both these units express themselves as cuestas but significant textural differences were observed, enabling us to discriminate them in aerial photographs. It is known that the channel-filled sedimentary unit incorporates many favourable geological and geochemical characters to host uranium mineralization. The domiasiat uranium deposit occurs in this unit only. By virtue of its distinct geomorphology, three domains of channel-filled sediments were demarcated in aerial photographs. Follow-up radiometric field checks on one of these domains, near the confluence of Wah Blei and Kynshiang rivers, have led to the discovery of significant uranium occurrences, opening up promising new avenues for uranium exploration in Megahalya. (author). 4 refs., 2 figs

Evidences of intraplate deformation in the West Madeira Abyssal Plain (eastern North Atlantic) from seismic reflection and multibeam swath bathymetry data

Science.gov (United States)

Roque, C.; Simões, M.; Lourenço, N.; Pinto de Abreu, M.

2009-04-01

The West Madeira Abyssal Plain is located in the eastern North Atlantic off Madeira Islands, forming part of the Canary Basin and reaching a mean water depth of 5300 m. This region is also located within Africa plate at about 500 km southwards from the Açores-Gibraltar plate boundary, and for that reason lacks seismic activity. Although this region being located in an intraplate setting, the presence of faulted sediments was reported in several works published during the eighties of last century following a study conducted in late 1970s to evaluate the feasibility of disposal of high-level radioactive wastes in the ocean. According these works, the Madeira Abyssal Plain sediments are cut by many normal growth faults and this deformation is a result of compaction and dewatering of the sediments. Evidences of tectonic deformation of oceanic sediments in intraplate settings are uncommon, but folded sediments and reverse faults extending into the basement, were recognized in the equatorial Indian Ocean and in the West African continental margin. Recently, during 2006 multi-channel seismic reflection and multibeam swath bathymetry surveys were carried out in the West Madeira Abyssal Plain by EMEPC in order to prepare the Portuguese proposal for the extension of the continental shelf. The seismic lines were acquired onboard R/V Akademik Shatskiy using a source of 5720 cu in bolt gun array, cable length of 7950 m and shot interval of 50.00 m. The multibeam swath bathymetry was acquired onboard NRP Gago Coutinho, and allowed a high resolution mapping of the main geomorphological features. The multichannel seismic lines, oriented WNW-ESE, image the Madeira island lower slope located at about 4000 m water depth and the almost flat abyssal plain at about 5300 m water depth. These seismic lines show a thick sedimentary succession that reaches a maximum thickness of about 1.5 sec twt in the deepest parts of the West Madeira Abyssal Plain, overlying an irregular diffractive

Geomorphology: the Shock of the Familiar

Science.gov (United States)

Dietrich, W. E.

2008-12-01

Everyone experiences landscapes and has a sense about how they work: water runs down hill, it erodes and carries sediments, and that's about it, right? Introductory earth science text books are uniformly qualitative about the field, and leave one with little sense of wonder, and certainly not "shock". But four shocks occur if one peels away the first impressions. First, landscapes are surprisingly similar: the same forms are repeated in virtually all environments, including under the ocean and on other planets. Second, we lack theory and mechanistic observations to answer many simple first-order questions, e.g. what controls the width of a river, how does rock type control hillslope form and erosion rate, or, is there a topographic signature of life. Third, there are unexpected connections between surface erosion, deep earth processes, and climate. And fourth, the field itself, despite having been a subject of study for well over 100 years, is currently experiencing a revolution of ideas and discoveries through new tools, observatories, centers, journals, books, contributions of researchers from other disciplines, and from a significant hiring of young researchers in geomorphology. Deep messages await discovery in the simple landforms surrounding us.

The morphodynamics and sedimentology of large river confluences

Science.gov (United States)

Nicholas, Andrew; Sambrook Smith, Greg; Best, James; Bull, Jon; Dixon, Simon; Goodbred, Steven; Sarker, Mamin; Vardy, Mark

2017-04-01

Confluences are key locations within large river networks, yet surprisingly little is known about how they migrate and evolve through time. Moreover, because confluence sites are associated with scour pools that are typically several times the mean channel depth, the deposits associated with such scours should have a high potential for preservation within the rock record. However, paradoxically, such scours are rarely observed, and the sedimentological characteristics of such deposits are poorly understood. This study reports results from a physically-based morphodynamic model, which is applied to simulate the evolution and resulting alluvial architecture associated with large river junctions. Boundary conditions within the model simulation are defined to approximate the junction of the Ganges and Jamuna rivers, in Bangladesh. Model results are supplemented by geophysical datasets collected during boat-based surveys at this junction. Simulated deposit characteristics and geophysical datasets are compared with three existing and contrasting conceptual models that have been proposed to represent the sedimentary architecture of confluence scours. Results illustrate that existing conceptual models may be overly simplistic, although elements of each of the three conceptual models are evident in the deposits generated by the numerical simulation. The latter are characterised by several distinct styles of sedimentary fill, which can be linked to particular morphodynamic behaviours. However, the preserved characteristics of simulated confluence deposits vary substantial according to the degree of reworking by channel migration. This may go some way towards explaining the confluence scour paradox; while abundant large scours might be expected in the rock record, they are rarely reported.

Temporal development of vegetation and geomorphology in a man-made beach-dune system by natural processes

DEFF Research Database (Denmark)

Vestergaard, Peter

2006-01-01

with F. rubra and the invasive alien Rosa rugosa. It was concluded, that the main trends in the geomorphological and vegetational development of the man-made beach-dune system is similar to the development in natural dunes. In the future, further accretion and seaward dune formation may be expected...

GIS-study and new Geomorphologic Mapping of Phobos

Science.gov (United States)

Kokhanov, Alexander; Lorenz, Cyrill; Karachevtseva, Irina

2016-04-01

Using raw images and processed orthoimages, obtained from "Mars Express", we have created a new GIS-catalog of grooves. During analysis, new grooves, not identified in earlier mapping attempts, were detected. For craters study the previously created catalog of craters with D >200 m [1] was used. The spatial orientation of individual grooves was estimated, which allows us to group them into several sets. All grooves in the catalog were divided into three morphological types: gutters (simple line depressions), chains of contiguous funnels, chains of noncontigual funnels. Studying craters we paid attention to its inner and outer morphology. The shape of some craters is different from the isometric. Among them were identified elliptical and polygonal craters. The study of inner morphology showed, that there prevails simple bowl-shaped craters. Also we identified a small population of craters with complex internal morphology [2], which, by analogy with similar lunar craters [3], divided into flat-bottomed, with a central mound and concentric craters. Moreover, based on elevation data, obtained from global digital elevation model [4] and calculation of relative depth, craters with D >2 km by the stage of degradation were classified. Focusing on a combination of grooves and craters, we have identified 15 morphological regions. A morphological unit was defined as a region with a certain type of relief, which differs from surrounding areas by the presence, orientation and spatial relations of groove systems and large craters (over 200 m). Each region may have its own geological history and consequently, specific history of regolith exposure. Finally, two geomorphologic maps of Phobos were created. One map represents the spatial distributions of grooves including their classifications by morphological types. The identified morphological regions are shown, and relief characteristics of these regions are briefly described. Geomorphologic map of craters shows the spatial

The Australian experience following plain packaging: the impact on tobacco branding.

Science.gov (United States)

Greenland, Steven J

2016-12-01

Brands are critical to tobacco marketing. Industry stakeholders predicted that plain packaging, by removing key tangible branding dimensions, would restrict new products and brand differentiation. However, manufacturers respond innovatively to limit regulatory impact. This study investigates brand strategy following plain packaging's introduction to Australia. Brand portfolios were determined using 2006-15 tobacco ingredient reports. These detail the brand and variant names sold and are provided annually as part of a voluntary agreement between the Australian Government and leading manufacturers. Post-plain packaging brand ranges were verified using retail price lists and a supermarket retail audit using a method used previously to verify a period of pre-plain packaging data. The verification process identified some data inaccuracies from one manufacturer which resulted in the issuing of corrected data. After plain packaging the leading manufacturers continued with extensive brand ranges differentiated by price. All launched new products. While total brand numbers fell from 29 to 24, the mean number of variants for the leading 12 brands grew from 8.9 to 9.7. Substantial variant name modifications occurred with 50 new or modified names in 2012-13. Among leading brands, the incidence of variant colour names increased from 49.5 to 79.3%. New brands and variants were not inhibited by the introduction of plain packaging in Australia. After plain packaging, leading brand variant numbers expanded by 9 to 116 and colour variant names increased by 73.6% and became the norm-lighter colours (blue, gold and silver) dominated, perpetuating notions of less harmful cigarettes. [Correction added on 09 September 2016, after first online publication: The figures in the last sentence of the Abstract are now corrected from 'expanded by 116' to 'expanded by 9 to 116'.]. © 2016 Society for the Study of Addiction.

Ages of plains volcanism on Mars

Science.gov (United States)

Hauber, Ernst; Jagert, Felix; Broz, Petr

2010-05-01

Plain-style volcanism [1] is widespread in the Tharsis and Elysium volcanic provinces on Mars, [2,3]. Detailed images and topographic data reveal the morphology and topography of clusters of low shields and associated lava flows. The landforms of plains volcanism on Mars have all well-known terrestrial analogues in basaltic volcanic regions, such as Hawaii, Iceland, and in particular the Snake River Plains [4]. The very gentle flank slopes (J. (1981) Icarus, 45, 586-601. [3] Hodges C.A. and Moore H.J. (1994) Atlas of volcanic features on Mars: USGS Prof. Paper 1534, 194 p. [4] Hauber E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 69-95. [5] Wilson L. et al. (2009) J. Volcanol. Geotherm. Res. 185, 28-46. [6] Vaucher, J. et al. (2009) Icarus 204, 418-442. [7] Baratoux D. et al. (2009) J. Volcanol. Geotherm. Res. 185, 47-68. [8] Bleacher J.E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 96-102. [9] Ivanov B.A. (2001) Space Sci. Rev. 96, 87-104. [10] Hartmann W.H. and Neukum G. (2001) Space Sci. Rev. 96, 165-194 [11] Kneissl T. et al. (2010) LPS XVI, submitted. [12] Michael, G.G. and Neukum G. (2010) Earth Planet. Sci. Lett., in press. . [13] Malin M.C. et al. (2007) JGR 112, E05S04, doi: 10.1029/2006JE002808.

A geomorphological strategy for conducting environmental impact assessments in karst areas

Science.gov (United States)

Veni, George

1999-12-01

In their efforts to protect regional groundwater supplies, governmental agencies are increasingly requiring studies of karst areas and their features. In areas where tracer tests or geophysics are not required, funded, or otherwise feasible, geomorphological methods remain as the primary tool for assessing karst. This study proposes a geomorphologically-based environmental impact assessment strategy for karst areas. While it is supported with results from a study of the karstic Edwards Aquifer recharge zone on the Camp Bullis Military Training Installation, TX, USA, it is based on the study of several karst areas and is generalized to accommodate and be fine-tuned for regional variations. Biological and other resource issues can also be assessed with this strategy. The assessment identifies environmentally sensitive features and areas, as is often required to meet regulatory directives. In karst areas with relatively small features, excavation is a key tool for accurate assessment. Although the results of this study will help to better manage karst areas, proper management must be done on a regional scale. The highly permeable nature of karst precludes adequate management solely on a feature-by-feature basis. Studies on the relationship of water quality to impervious cover show adverse environmental impacts significantly increase when impervious cover exceeds 15% of a surface watershed. The Camp Bullis study finds similar impacts in its groundwater drainage basin, supporting the argument of 15% impervious cover as a regionally effective means of also protecting karst aquifers when coupled with protection of critical areas identified by field surveys.

Small-scale opencast mining: an important research field for anthropogenic geomorphology

Directory of Open Access Journals (Sweden)

Byizigiro, R. Vaillant

2015-12-01

Full Text Available Artisanal and small-scale mining (A&SM is a growing economic sector in many third-world countries. This review focuses on anthropo-geomorphic factors and processes associated with small-scale opencast mining (SSOM, a form of A&SM in which near-surface ores are extracted by removing relatively thin covers of soil, bedrock or sediments. Being widespread and commonly conducted without proper planning and beyond the control of local authorities, this form of mining has potentially large impacts on landforms and landscape dynamics, often resulting in drastic consequences for the local environment and agriculture. SSOM should be regarded as a component of anthropogenic geomorphology because it involves the role of humans in creating landforms and modifying the operation of natural geomorphological processes, such as weathering, erosion, transport and deposition. By initiating new and modifying natural geomorphic processes, SSOM causes and/or accelerates geomorphic processes, resulting in various forms of land degradation. While the direct geomorphic impact of SSOM is in general easily discernible and leads to characteristic features, such as excavated pits and overburden spoil heaps, many secondary impacts are attributed to geomorphic processes triggered in the wake of the primary mining-induced landscape alterations. The magnitude of such secondary implications may well extend beyond the actual mining areas, but these effects have not been thoroughly addressed in the research so far. This review summarizes the known studies on the geomorphic impacts of SSOM operations and highlights common geomorphic processes and landforms associated with this type of anthropogenic activity, thus establishing a starting point for further in-depth research.

The innovation of nuclear science and technology supporting for the central plains economic zone construction

International Nuclear Information System (INIS)

Yang Xiaowei

2014-01-01

This paper discusses the nuclear agronomy support for the central plains economic zone construction, radiation chemical new material support for the central plains economic zone construction, nuclear medical support for the central plains economic zone construction, nuclear instrument and meter industry support for the central plains economic zone construction and the development trend of related disciplines. (author)

Geomorfología aplicada y desastres: Rol preventivo y Ordenamiento Territorial. / Applied Geomorphology and disasters: prevention and Land Management Role.

Directory of Open Access Journals (Sweden)

Ferrando A., Francisco J.

2005-11-01

Full Text Available El desarrollo sostenible de un país altamente expuesto a catástrofes de origen natural dependerá en gran medida, de la manera en que se ordene el territorio, considerando su base geográfica. En este contexto, la geomorfología debe ir más allá del academicismo y aportar al ordenamiento territorial./"Applied Geomorphology and Disasters: Preventive Roles and Territorial Planning". The sustainable development of a country which is prone to suffer natural catastrophes will depend greatly on the manner in which its territory is planned, taking into consideration its geography. Thus, geomorphology must go beyond the academic practice and contribute to Landscape and Territorial Planning.

Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

Science.gov (United States)

Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

Science.gov (United States)

Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

Tectonic geomorphology of the Andes with SIR-A and SIR-B

Science.gov (United States)

Bloom, Arthur L.; Fielding, Eric J.

1986-01-01

Data takes from SIR-A and SIR-B (Shuttle Imaging Radar) crossed all of the principal geomorphic provinces of the central Andes between 17 and 34 S latitude. In conjunction with Thematic Mapping images and photographs from hand-held cameras as well as from the Large Format Camera that was flown with SIR-B, the radar images give an excellent sampling of Andean geomorphology. In particular, the radar images show new details of volcanic rocks and landforms of late Cenozoic age in the Puna, and the exhumed surfaces of tilted blocks of Precambrian crystalline basement in the Sierras Pampeanas.

The reevaluation of plain roentgenological study in isolated splenic injury

International Nuclear Information System (INIS)

Kang, Seong Ihn; Ko, Seung Sook; Kim, Kil Jeong; Oh, Jae Hee; Kim, Young Chul

1986-01-01

The spleen is the most common intraabdominal organ injured in blunt trauma. Although physical signs and symptoms, coupled with abdominal paracentesis and peritoneal lavage confirm intraabdominal injury, but isolated splenic injury especially delayed rupture, the diagnosis and clinical course is variable. We are reevaluation of plain roentgenologic findings for the light of early diagnosis of isolated splenic injury. 24 patients of the autopsy and surgically proven isolated splenic injury at Chosun University Hospital in the period from 1980 January to 1986 June were analyzed plain roentgenogram retrospectively. The results were as follows: 1. Male patients predominate, constitution 87.5%. Incidence has been greatest in second to fourth decade. 2. Mode of trauma causing isolated splenic injury is most common in motor vehicle accident and others are fall down, struck by fist, blow to object, uncertain blunt trauma. 3. Delayed rupture of spleen occurred in 2 cases (8.3%). 4. Common patterns of splenic injury is simple laceration that involves both the capsule and the parenchyma and a laceration that involves the splenic pedicle. 5. Plain chest roentgenographic findings were abnormal in 4 cases (16.7%). The most common plain abdominal roentgenographic findings was the evidence of intaabdominal fluid in 21 cases (87.5%). The others are included in order of frequency; gastric dilatation, prominent mucosal folds on greater curvature of the stomach, evidence of pelvic fluid, displacement of stomach to the right or downward, mass density in the region of spleen. 6. No relationship can be shown between patterns of injury, time lapse after trauma and plain roentgenological findings. But the evidence of intraabdominal fluid is most important in the light of early diagnosis. 7. Diagnosis of splenic injury may be most helpful that in combination with clinical history, clinical symptoms and signs and plain film findings. In delayed rupture, diagnostic value of serial examination

The reevaluation of plain roentgenological study in isolated splenic injury

Energy Technology Data Exchange (ETDEWEB)

Kang, Seong Ihn; Ko, Seung Sook; Kim, Kil Jeong; Oh, Jae Hee; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)

1986-10-15

The spleen is the most common intraabdominal organ injured in blunt trauma. Although physical signs and symptoms, coupled with abdominal paracentesis and peritoneal lavage confirm intraabdominal injury, but isolated splenic injury especially delayed rupture, the diagnosis and clinical course is variable. We are reevaluation of plain roentgenologic findings for the light of early diagnosis of isolated splenic injury. 24 patients of the autopsy and surgically proven isolated splenic injury at Chosun University Hospital in the period from 1980 January to 1986 June were analyzed plain roentgenogram retrospectively. The results were as follows: 1. Male patients predominate, constitution 87.5%. Incidence has been greatest in second to fourth decade. 2. Mode of trauma causing isolated splenic injury is most common in motor vehicle accident and others are fall down, struck by fist, blow to object, uncertain blunt trauma. 3. Delayed rupture of spleen occurred in 2 cases (8.3%). 4. Common patterns of splenic injury is simple laceration that involves both the capsule and the parenchyma and a laceration that involves the splenic pedicle. 5. Plain chest roentgenographic findings were abnormal in 4 cases (16.7%). The most common plain abdominal roentgenographic findings was the evidence of intaabdominal fluid in 21 cases (87.5%). The others are included in order of frequency; gastric dilatation, prominent mucosal folds on greater curvature of the stomach, evidence of pelvic fluid, displacement of stomach to the right or downward, mass density in the region of spleen. 6. No relationship can be shown between patterns of injury, time lapse after trauma and plain roentgenological findings. But the evidence of intraabdominal fluid is most important in the light of early diagnosis. 7. Diagnosis of splenic injury may be most helpful that in combination with clinical history, clinical symptoms and signs and plain film findings. In delayed rupture, diagnostic value of serial examination

Estimation of groundwater residence time and evaluation of geomorphological processes using cosmogenic and terrigenic radionuclides and isotopes of noble gases

International Nuclear Information System (INIS)

Mahara, Yasunori; Ohta, Tomoko; Igarashi, Toshifumi

2013-01-01

In this paper, the estimation of groundwater residence time and geomorphological changing processes are discussed by focusing on isotopes of noble gases and radionuclides with a long half-life as an environmental tracer. Noble gases and radionuclides are produced in the atmospheric air and terrestrial rocks by spallation and various muon reactions during cosmic rays irradiation. Groundwater dating and geomorphological changing are estimated from changes in the number of atoms of cosmogenic and terrigenic nuclides in groundwater and terrestrial rock. The main tools of groundwater dating are combination of the dissolved helium and tritium (half-life T 1/2 =12.3 y) for younger groundwater less than 60 years of residence time, and of the dissolved helium and 36 Cl (T 1/2 =3.01 x 10 5 y) for older groundwater over million years. On the other hand, the main tools on the geomorphological changes are the estimation of exposure time using cosmogenic radionuclides ( 10 Be(half-life T 1/2 =1.6 x 10 6 y), 14 C (T 1/2 =5730 y), 26 Al (T 1/2 =7.16 x 10 5 y) and 36 Cl) and cosmogenic stable noble gases ( 3 He and 21 Ne) produced in rock. (author)

Wind measurement on the Linth plain; Windmessung in der Linthebene

Energy Technology Data Exchange (ETDEWEB)

Langraf, B.

2003-07-01

This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of wind measurements made on the Linth plain, a flat alluvial plain in eastern Switzerland located between mountain ranges. The data, which were collected using temporary measurement masts at two locations are presented in the form of tables, diagrams and maps showing the wind-energy potential of various areas of the plain. The actual measurements are compared with prognoses from a geo-information system. The wind measurement equipment and installations are described, as are the software models for the calculation of wind direction, wind intensity and of a prognosis for energy production. Particular attention was also paid to the question of wind turbulence. Further factors investigated included the possibility of icing-up in winter and the choice of a meteorological station in the neighbourhood with similar characteristics that could be used as a reference station. The report also presents the results of the evaluation of various possible locations for wind turbines on the Linth plain. Visual, noise and shadow-casing factors are considered.

An approach for quantifying geomorphological impacts for EIA of transportation infrastructures: a case study in northern Spain

NARCIS (Netherlands)

Bonachea, J.; Bruschi, V.M.; Remondo, J.; Alberto Gonzales-Diez, A.; Salas, L.; Bertens, J.; Cendrero, A.; Otero, C.; Giusti, C.; Fabbri, A.G.; Gonzalez-Lastra, J.R.; Aramburu, J.R.

2005-01-01

A methodological proposal for the assessment of impacts due to linear infrastructures such as motorways, railways, etc. is presented. The approach proposed includes a series of specific issues to be addressed for each geomorphological feature analysed - both 'static' and 'dynamic'- as well as a

Eco-geomorphological Response of an Estuarine Wetland to Changes in the Hydraulic Regime

Science.gov (United States)

Howe, A.; Rodrí Guez, J.

2006-12-01

In the Hunter Estuary, NSW, Australia, tidal regimes of numerous wetlands have been affected by extensive anthropomorphic intervention, including harbour dredging, land reclamation, and construction of infrastructure. The importance of these wetlands to ecosystem services such as primary productivity, flood attenuation and water quality enhancement has led to an increased effort to rehabilitate degraded sites by reintroduction of tidal flows. Because of the complex and dynamics interactions among hydraulic regime, vegetation and geomorphology, it is difficult to predict how wetlands will respond to the reintroduction of these flows and whether the resulting habitat distribution will achieve desired management outcomes. Eco-geomorphology research conducted at a rehabilitated wetland comprised of mangrove forest and saltmarsh has tracked the response of estuarine vegetation distribution and wetland geomorphology to reinstatement of tidal flows following removal of impediments in 1995. The wetland is an important site for migratory shorebirds and is highly compartmentalized due to the presence of roads and culverts. Our research methodology integrates historical analysis, field measurements and laboratory experiments. Historical analysis matched vegetation evolution obtained from aerial photography to bird roosting habitat use, which is in decline. Field data collection carried out in the last two years included topographic, vegetation and soil surveys; velocity, water quality and water level profiling; and high precision measurements of substrate shallow subsidence and vertical accretion. Laboratory studies focussed on the effects of estuarine vegetation on flow resistance. All this information has allowed for the characterization and conceptualization of the system, which includes zones with different tidal attenuation levels and vegetation distribution. It was found that an increased tidal frame resulting from hydraulic manipulation lead to a landward shift in

Danube paleohydrology: Hyperspectral and sedimentological high-resultion study of the last glacial Black Sea rythmites

Science.gov (United States)

Martinez Lamas, R.; Debret, M.; Deloffre, J.; Toucanne, S.

2017-12-01

The Black Sea has undergone alternating phases of lacustrine and marine environment over geological timescales directly related to its semi-enclosed character and to eustatic sea-level oscillations. During lowstand conditions, as during the last glacial period, the Black Sea was a giant lake disconnected from the global ocean. At that time, Black Sea water-level was controlled by regional climate, and by Eurasian rivers, including the Danube that acted as an outlet of European Ice Sheet and the Alpine ice cap. Thus, the paleo-mouth of the Danube river contains a high quality archive for the study of the paleohydrology of the Danube River and by extension of the European climate changes during the last 30 kyr. For this purpose, we have focused on the GAS-CS01 calypso long-piston core (33.4 m) which was taken during GHASS cruise (Ifremer, 2015) on the upper slope (240 m. depth) at about 25 km east of the Danube Canyon, i.e. in the sediment pile of the Danube paleo-mouth during the last glacial period. Our chronology reveals that core GAS-CS01 extends back to 31 cal kyr BP. The lithology of GAS-CS01 is characterized by clastic rythmites which are presented as a high-resolution Danube runoff proxy. Preliminary results of sedimentological and chronological analysis showed five peaks of terrestrial discharges between ca 31 and 14 ka BP, probably linked to five phases of the enhanced runoff during the studied period. In order to understand the origin and the depositional processes of this laminae, we combined sedimentary analysis (x-ray diffraction, x-ray fluorescence, grain size ...) and hyperspectral images analysis. Hyperspectral imagery is a non-destructive fast method classically used to quantify colour and provides data with high spatial (57-µm pixel size) and spectral (3 nm) resolution. The multi-proxy calibration is essential in order to obtain a high-resolution sedimentological dataset. This information allows us to reconstruct the nature and depositional

Intussusception in childhood: the role of plain abdominal radiographs

International Nuclear Information System (INIS)

Ji, Joo Yun; Kim, Min Joong; Kim, Young Mook; Park, Won Gyu; Ko, Kang Seok; Kim, Se Jong; Park, Byung Ran; Kim, Byong Geun

1995-01-01

The purposes of this study were to evaluate the plain radiologic findings of the childhood intussusception and to evaluate the role of plain abdominal films in predicting the success of air or barium reduction. We retrospectively reviewed 140 cases with the diagnosis of intussusception in childhood. The radiological signs that included soft tissue mass, dilatation of small bowel suggesting obstruction, crescent sign, and target sign were evaluated in terms of frequency. The relationship between radiological findings and outcome of reduction was analyzed. The site of soft tissue mass or crescent sign seen on plain radiographs was correlated with the position of the apex of the intussusceptum seen at the beginning of barium edema. The degree of dilated small bowel was evaluated by calculating the proportion of air-filled small bowel occupying peritoneal cavity and measuring the maximal diameter of dilated bowel lumen. The radiological finding for small bowel obstruction is determined by observation of the degree of small bowel dilatation and/or air-fluid levels. Ninety-two cases out of 140 showed one or more radiographic signs. Two most common signs were soft tissue mass and small bowel obstruction. The success rate of air or barium reduction was significantly lower in patients with most severe degree of dilatation of small bowel and/or more than 7 air-fluid levels on erect view. The suspected location of intussusception on plain radiographs correlated well with the true location of intussusception seen in the first few seconds of barium reduction. Plain abdominal radiography is useful in the diagnosis of intussusception and provides helpful information for the reduction procedure as well as for the exclusion of the contraindications such as bowel perforation

Clinical aspects of plain film radiography of the chest

International Nuclear Information System (INIS)

Ravin, C.E.

1988-01-01

In spite of the introduction of a number of intriguing new imaging modalities including Computed Tomography and Magnetic Resonance Imaging, the plain film of the chest remains the mainstay of thoracic imaging. It is estimated that more than fifty million chest radiographs are performed each year in the United States. In the attempt to compare newer imaging modalities with the standard plain film of the chest, investigators have been forced to adopt specific structures and or disease processes to be analyzed. To some extent identification of normally appearing structures in the mediastinum and lung parenchyma serves as a clue as to the ability of a newer technology to compete with or be compared with the plain film. However, as most authors would acknowledge, the ability to portray normal underlying anatomy is only the first step in analysis in intrathoracic disease. Experimental design becomes somewhat more complicated when one wishes to move beyond normal anatomy to analysis of disease processes. The challenge of digital radiography in whatever form it may take will be to equal or exceed the standard established by conventional plain film radiography and deliver such service at reasonable cost in a manner which allows for appropriate patient throughput

A comparison between geostatistical analyses and sedimentological studies at the Hartbeestfontien gold mine

International Nuclear Information System (INIS)

Magri, E.J.

1978-01-01

For life-of-mine planning, as well as for short- and medium-term planning of grades and mine layouts, it is extremely important to have a clear understanding of the patterns followed by the distribution of gold and uranium within the mining area. This study is an attempt to reconcile the geostatistical approach to the determination of ore-shoot directions, via an analysis of the spatial distribution of gold and uranium values, with the sedimentological approach, which is based on the direct measurement of geological features. For the routine geostatistical estimation of ore reserves, the Hartebeestfontein gold mine was divided into ll sections. In each of these sections, the ore-shoot directions were calculated for gold and uranium from the anisotropies disclosed by geostatistical variogram analyses. This study presents a comparison of these results with those obtained from direct geological measurements of paleo-current directions. The results suggest that geological and geostatistical studies could be of significant mutual benefit [af

Analysis of tumor-like shadows on abdominal plain x-ray film

International Nuclear Information System (INIS)

Hayashi, Hidehiro; Hiraki, Yoshio; Hashimoto, Keizi

1986-01-01

We found tumor-like shadows in the upper abdomen in 93 cases out of 400 abdominal plain films, although none of these 93 cases actually had a tumor. We analyzed these tumor-like shadows by computed tomography. For each of the 400 cases we measured the width of flank stripe on the abdominal plain film. Most of the tumor-like shadows in the left upper abdomen were gastric fundus, but it was significant for evaluating plain abdominal film that other organs such as a part of the left lobe of the liver, the upper pole of the left kidney, and a part of the spleen formed tumor-like shadows. The most important factors forming tumor-like shadows on plain abdominal film are the fat volume of the abdominal cauity as well as the fraciform ligament and alterations in the shape and volume of organs such as occur in liver cirrhosis. (author)

Geomorphology, acoustic backscatter, and processes in Santa Monica Bay from multibeam mapping.

Science.gov (United States)

Gardner, James V; Dartnell, Peter; Mayer, Larry A; Hughes Clarke, John E

2003-01-01

Santa Monica Bay was mapped in 1996 using a high-resolution multibeam system, providing the first substantial update of the submarine geomorphology since the initial compilation by Shepard and Emery [(1941) Geol. Soc. Amer. Spec. Paper 31]. The multibeam mapping generated not only high-resolution bathymetry, but also coregistered, calibrated acoustic backscatter at 95 kHz. The geomorphology has been subdivided into six provinces; shelf, marginal plateau, submarine canyon, basin slope, apron, and basin. The dimensions, gradients, and backscatter characteristics of each province is described and related to a combination of tectonics, climate, sea level, and sediment supply. Fluctuations of eustatic sea level have had a profound effect on the area; by periodically eroding the surface of Santa Monica plateau, extending the mouth of the Los Angeles River to various locations along the shelf break, and by connecting submarine canyons to rivers. A wetter glacial climate undoubtedly generated more sediment to the rivers that then transported the increased sediment load to the low-stand coastline and canyon heads. The trends of Santa Monica Canyon and several bathymetric highs suggest a complex tectonic stress field that has controlled the various segments. There is no geomorphic evidence to suggest Redondo Canyon is fault controlled. The San Pedro fault can be extended more than 30 km to the northwest by the alignment of a series of bathymetric highs and abrupt changes in direction of channel thalwegs.

The sedimentological characteristics and geochronology of the marshes of Dauphin Island, Alabama

Science.gov (United States)

Ellis, Alisha M.; Smith, Christopher G.; Marot, Marci E.

2018-03-22

In August 2015, scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center collected 11 push cores from the marshes of Dauphin Island and Little Dauphin Island, Alabama. Sample site environments included high marshes, low salt marshes, and salt flats, and varied in distance from the shoreline. The sampling efforts were part of a larger study to assess the feasibility and sustainability of proposed restoration efforts for Dauphin Island, Alabama, and to identify trends in shoreline erosion and accretion. The data presented in this publication can provide a basis for assessing organic and inorganic sediment accumulation rates and temporal changes in accumulation rates over multiple decades at multiple locations across the island. This study was funded by the National Fish and Wildlife Foundation, via the Gulf Environmental Benefit Fund. This report serves as an archive for the sedimentological and geochemical data derived from the marsh cores. Downloadable data are available and include Microsoft Excel spreadsheets (.xlsx), comma-separated values (.csv) text files, JPEG files, and formal Federal Geographic Data Committee metadata in a U.S. Geological Survey data release.

A geologic approach to field methods in fluvial geomorphology

Science.gov (United States)

Fitzpatrick, Faith A.; Thornbush, Mary J; Allen, Casey D; Fitzpatrick, Faith A.

2014-01-01

A geologic approach to field methods in fluvial geomorphology is useful for understanding causes and consequences of past, present, and possible future perturbations in river behavior and floodplain dynamics. Field methods include characterizing river planform and morphology changes and floodplain sedimentary sequences over long periods of time along a longitudinal river continuum. Techniques include topographic and bathymetric surveying of fluvial landforms in valley bottoms and describing floodplain sedimentary sequences through coring, trenching, and examining pits and exposures. Historical sediment budgets that include floodplain sedimentary records can characterize past and present sources and sinks of sediment along a longitudinal river continuum. Describing paleochannels and floodplain vertical accretion deposits, estimating long-term sedimentation rates, and constructing historical sediment budgets can assist in management of aquatic resources, habitat, sedimentation, and flooding issues.

General practitioners' willingness to request plain lumbar spine radiographic examinations

International Nuclear Information System (INIS)

Ryynaenen, Olli-Pekka; Lehtovirta, Jukka; Soimakallio, Seppo; Takala, Jorma

2001-01-01

Objectives: To examine general practitioners' attitudes to plain lumbar spine radiographic examinations. Design: A postal questionnaire consisting of questions on background data and doctors' opinions about plain lumbar spine radiographic examinations, as well as eight vignettes (imaginary patient cases) presenting indications for lumbar radiography, and five vignettes focusing on the doctors' willingness to request lumbar radiography on the basis of patients' age and duration of symptoms. The data were analysed according to the doctor's age, sex, workplace and the medical school of graduation. Setting: Finland. Subjects: Six hundred and fifteen randomly selected physicians working in primary health care (64% of original target group). Results: The vignettes revealed that the use of plain lumbar radiographic examination varied between 26 and 88%. Patient's age and radiation protection were the most prominent factors influencing doctors' decisions to request lumbar radiographies. Only slight differences were observed between the attitudes of male and female doctors, as well as between young and older doctors. Doctors' willingness to request lumbar radiographies increased with the patient's age in most vignettes. The duration of patients' symptoms had a dramatic effect on the doctor's decision: in all vignettes, doctors were more likely to request lumbar radiography when patient's symptoms had exceeded 4 weeks. Conclusions: General practitioners commonly use plain lumbar spine radiographic examinations, despite its limited value in the diagnosis of low back pain. Further consensus and medical education is needed to clarify the indications for plain lumbar radiographic examination

Observed inferences from sudden changes in the sedimentological processes during the December 26, 2004 tsunami along the east coast of India

Digital Repository Service at National Institute of Oceanography (India)

Loveson, V.J.; Angusamy, N.; Gujar, A; Chandrasekar, N.; Rajamanickam, G.V.

of erosion level caused by the tsunami was determined for several stations. Except for Nagoor, all other stations showed erosion of the beaches, with a maximum of 2.5 m, particularly in the Karaikkal area. The study identified two major geomorphologic parts...

Diagnostic value of pneumoperitoneum on plain abdominal film

International Nuclear Information System (INIS)

Frkovic, M.; Klapan, T.; Moscatello, I.; Frkovic, M.

2001-01-01

Background. Pneumoperitoneum is the presence of air outside the gut lumen as the hallmark of alimentary tract perforation. It can be spontaneous or traumatic in origin. The most frequent cause of spontaneous pneumoperitoneum is the perforation of gastric or duodenal ulcer and the aim of the study was to assess the diagnostic value of pneumoperitoneum on plain abdominal film. Patients and methods. This is a retrospective study based on the diagnostic value of pneumoperitoneum on plain abdominal film, with the patient in upright, supine and sometimes left lateral decubitus position. The study included 79 patients who were admitted to our hospital during a 2-year period of time (1998- 1999) and operated on for perforated gastroduodenal ulcer. Results. Ten (12.66 %) of 79 patients underwent operation without radiological procedure. Sixty-nine (87.34 %) patients were examined radiographically and 53 (76.81 %) of them had signs of pneumoperitoneum initially on the plain film. Conclusions. The most common cause of pneumoperitoneum was perforated duodenal ulcer in elderly male patients. The most frequent sign of pneumoperitoneum was the crescent shaped free air beneath the diaphragm. (author)

Two centuries of coastal change at Caesarea, Israel: natural processes vs. human intervention

Science.gov (United States)

Shtienberg, Gilad; Zviely, Dov; Sivan, Dorit; Lazar, Michael

2014-08-01

The coast at Caesarea, Israel, has been inhabited almost continuously for the last 2,400 years, and the archeological sites are today a major international tourist attraction. Because the sites straddle the shoreline, they are subject to constant damage by wave action, and must therefore be frequently restored. In this paper, local shoreline migrations over the last 200 years are investigated with the aim of distinguishing between natural and man-made coastal changes. In order to assess these changes accurately, geomorphological and sedimentological data were examined based on detailed beach profile measurements, bathymetric surveys, and grain-size analyses. In addition, series of old aerial photographs, as well as historical topographic maps and nautical charts were consulted. The results show that shoreline changes can be grouped into two main time periods. During the first period from 1862 to 1949 before the expansion of modern settlements, the position of the shoreline changed irregularly by up to 30 m. In the second period from 1949 onward, numerous coastal structures have been erected, and various coastal modifications have been carried out. The evaluation of the data suggests that human interventions have had relatively little effect on the overall position of the shoreline, as displacements ranged only from 5 to 18 m. Thus, coastal changes at Caesarea are predominantly due to natural wave action reflected in the heterogeneous geomorphological and sedimentological characteristics of the shore. This contradicts the common assumption that human activities are always mainly responsible for large-scale shoreline modifications in the region. It is concluded that, in order to implement meaningful mitigating countermeasures, coastal archeological sites need to be individually assessed with respect to the dominant factors causing local coastal change.

Report on the geological and geomorphological field operation in the Amundsen Bay region, western Enderby Land, 1998-99 (JARE-40

Directory of Open Access Journals (Sweden)

Yoichi Motoyoshi

1999-11-01

Full Text Available The 40th Japanese Antarctic Research Expedition (JARE-40 conducted field operations on geology and geomorphology in the Amundsen Bay region, Enderby Land, for 34 days from December 21,1998 to January 23,1999. This was a part of the 5-year SEAL (Structure and Evolution of East Antarctic Lithosphere project, and two helicopters were installed for field support. Geological and geomorphological teams established base camps at Tonagh Island and Mt. Riiser-Larsen, respectively, and tried to conduct surveys in western Enderby Land. At the early stage of the operation, an unexpected gusty wind destroyed one of the helicopters at Tonagh Island, and planned surveys have not been completed. This report gives details of the logistics including planning, preparation and results.

Anterior atlantodental and posterior atlantodental intervals on plain radiography, multidetector CT, and MRI

Energy Technology Data Exchange (ETDEWEB)

Cha, Seung Woo; Ryu, Jeong Ah; Park, Dong Woo [Dept. of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Yoon, Ki Bo; Lee, Seung Hun; Joo, Kyung Bin [Dept. of Radiology, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Seoul(Korea, Republic of)

2015-01-15

To determine the normal values of the anterior atlantodental interval (AADI) and posterior atlantodental interval (PADI) on plain radiography, multidetector CT (MDCT) and MRI, as well as the dural sac width and spinal cord diameter at the atlantoaxial joint level on MRI. In total, 60 subjects underwent plain radiography, MRI and MDCT. We obtained values for AADI and PADI on plain radiography, MDCT, and MRI, and for dural sac width and spinal cord diameter on MRI. Two radiologists independently measured each value and a consensus was reached. The average AADI was 1.5 +/- 0.5 mm on plain radiography, 1.4 +/- 0.3 mm on MDCT, and 1.6 +/- 0.5 mm on MRI. The average PADI was 20.6 +/- 2.4 mm on plain radiography, 18.0 +/- 2.1 mm on MDCT, and 17.7 +/- 1.9 mm on MRI. The dural sac width was 13.7 +/- 1.8 mm, and the spinal cord diameter was 7.8 +/- 0.7 mm. Interobserver agreement was 0.701-0.927 and intraobserver agreement was 0.681-0.937. AADI values obtained on MDCT are significantly lower than those obtained on plain radiography or MRI. PADI values obtained on plain radiography are significantly higher than those obtained on MDCT or MRI. The dural sac width is most closely correlated with PADI values on MDCT. PADI seems to be easier to measure, more relevant, and clinically useful than AADI.

Anterior atlantodental and posterior atlantodental intervals on plain radiography, multidetector CT, and MRI

International Nuclear Information System (INIS)

Cha, Seung Woo; Ryu, Jeong Ah; Park, Dong Woo; Yoon, Ki Bo; Lee, Seung Hun; Joo, Kyung Bin

2015-01-01

To determine the normal values of the anterior atlantodental interval (AADI) and posterior atlantodental interval (PADI) on plain radiography, multidetector CT (MDCT) and MRI, as well as the dural sac width and spinal cord diameter at the atlantoaxial joint level on MRI. In total, 60 subjects underwent plain radiography, MRI and MDCT. We obtained values for AADI and PADI on plain radiography, MDCT, and MRI, and for dural sac width and spinal cord diameter on MRI. Two radiologists independently measured each value and a consensus was reached. The average AADI was 1.5 +/- 0.5 mm on plain radiography, 1.4 +/- 0.3 mm on MDCT, and 1.6 +/- 0.5 mm on MRI. The average PADI was 20.6 +/- 2.4 mm on plain radiography, 18.0 +/- 2.1 mm on MDCT, and 17.7 +/- 1.9 mm on MRI. The dural sac width was 13.7 +/- 1.8 mm, and the spinal cord diameter was 7.8 +/- 0.7 mm. Interobserver agreement was 0.701-0.927 and intraobserver agreement was 0.681-0.937. AADI values obtained on MDCT are significantly lower than those obtained on plain radiography or MRI. PADI values obtained on plain radiography are significantly higher than those obtained on MDCT or MRI. The dural sac width is most closely correlated with PADI values on MDCT. PADI seems to be easier to measure, more relevant, and clinically useful than AADI.

The sedimentological changes caused by human impact at the artificial channel of Medjerda-River (Coastal zone of Medjerda, Tunisia)

Science.gov (United States)

Benmoussa, Thouraya; Amrouni, Oula; Dezileau, Laurent; Mahé, Gil; Abdeljaouad, Saâdi

2018-04-01

Recent sedimentary and morphological changes at the new mouth of Medjerda-River (Gulf of Tunis) are investigated using a multiproxy approach of sediment cores complited by 210Pbex and 137Cs method dating. The subject of the study is to focus on surveying the sedimentary evolution of Medjerda-Raoued Delta caused by the human intervention in the management of the main tributaries of the Medjerda-River (artificial channel of Henchir Tobias). Sediment cores (CEM-1 and CEM-3) were subjected to both multiproxy approaches (Grain size, geochemical analysis and dating radiometric 210Pbex and 137Cs). The sedimentological analysis of the new deltaic deposits shows a progradation sequence with the silt and clay deposits on the historic sandy substratum. The mean grain size evolution on the old beach profile shows a decreasing trend from backshore (CEM-3) to nearshore (CEM-1). The geochemical results show varying concentrations of chemical elements such as Fe, K, Rb, Nb, Cr, Ti, Ba, Ca, Sr, Zr, V, and potentially toxic metal trace elements such as Pb, Zn and the As. The Principal component Analysis (PCA) applied in the geochemical elements evolution confirms the marine origin of the sand deposits in the basic layers of the two cores. The chronological method (210Pbex and 137Cs) affirms that the first fluvial deposits were set up only after 1950. The sedimentological and geochemical result confirm the actual unless of coarser fluvial supplies under the human activities leading the negative coastal sediment balance and the shoreline retreat as well.

550 years in sedimentological record from a varved type lake (Bolătău, Bukovina, NE Romania - changing storm frequency and climate fluctuation

Directory of Open Access Journals (Sweden)

Alexandra NEMETH

2014-11-01

Full Text Available In the present paper we introduce lake Bolătău, located in Obcina Feredeului, Eastern Carpathians (Romania, with seasonally controlled sedimentation and significant potential for generating precipitation sensitive proxy record. Two sediment cores were compared against each other in order to achieve a better understanding of the lateral discontinuity of observed microfacies and an accurate interpretation of the sedimentological data.

Tobacco branding, plain packaging, pictorial warnings, and symbolic consumption.

Science.gov (United States)

Hoek, Janet; Gendall, Philip; Gifford, Heather; Pirikahu, Gill; McCool, Judith; Pene, Gina; Edwards, Richard; Thomson, George

2012-05-01

We use brand association and symbolic consumption theory to explore how plain cigarette packaging would influence the identities young adults cocreate with tobacco products. Group discussions and in-depth interviews with 86 young adult smokers and nonsmokers investigated how participants perceive tobacco branding and plain cigarette packaging with larger health warnings. We examined the transcript data using thematic analysis and explored how removing tobacco branding and replacing this with larger warnings would affect the symbolic status of tobacco brands and their social connotations. Smokers used tobacco brand imagery to define their social attributes and standing, and their connection with specific groups. Plain cigarette packaging usurped this process by undermining aspirational connotations and exposing tobacco products as toxic. Replacing tobacco branding with larger health warnings diminishes the cachet brand insignia creates, weakens the social benefits brands confer on users, and represents a potentially powerful policy measure.

41 CFR 102-2.140 - What elements of plain language appear in the FMR?

Science.gov (United States)

2010-07-01

... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What elements of plain language appear in the FMR? 102-2.140 Section 102-2.140 Public Contracts and Property Management Federal...

Carpal pseudoerosions: a plain X-ray interpretation pitfall

Energy Technology Data Exchange (ETDEWEB)

Wawer, Richard [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Budzik, Jean Francois [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires; Demondion, Xavier [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; CHRU Lille (France). Lab. d' Anatomie; Forzy, Gerard [Univ. Catholique de Lille, Lomme (France). Lab. de Biologie; Cotten, Anne [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires

2014-10-15

To examine in detail images of pseudoerosion of the wrist and hand on plain radiographs. The study was conducted with 28 cadaver wrists. During a single imaging session three techniques - plain radiography, tomosynthesis, and computed tomography - were used to visualize the wrist and hand specimens. For each technique, 20 radio-ulno-carpo-metacarpal sites known to present bone erosions in rheumatoid arthritis were analyzed by two radiologists using a standard system to score the cortical bone: normal, pseudoerosion, true erosion, or other pathology. Cohen's concordance analysis was performed to determine inter-observer and intra-observer (for the senior radiologist) agreement by site and by technique. Serial sections of two cadaver specimens were examined to determine the anatomical correlation of the pseudoerosions. On the plain radiographs, the radiologists scored many images as pseudoerosion (7.3 %), particularly in the distal ulnar portion of the capitate, the distal radial portion of the hamate, the proximal ulnar portion of the base of the third metacarpal, the proximal radial portion of the base of the fourth metacarpal, the distal ulnar portion of the hamate, and the proximal portion of the base of the fifth metacarpal. The computed tomography scan revealed that none of these doubtful images corresponded to true erosions. The anatomical correlation study showed that these images could probably be attributed to ligament insertions, thinner lamina, and enhanced cortical bone transparency. Knowledge of the anatomical carpal localizations where pseudoerosions commonly occur is a necessary prerequisite for analysis of plain radiographs performed to diagnose or monitor rheumatoid arthritis. (orig.)

An appraisal of plain language in the South African banking sector

African Journals Online (AJOL)

combination of approaches to plain language, but no testing is done on real consumers. ... language' definition in relation to other definitions of plain language, before the findings ... minimal experience as a consumer of the relevant goods or services, could be ..... The legal practitioner agreed by mentioning that marketing.

49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing box: Journal lubrication... Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system...) Metal parts contacting the journal; or (e) Is— (1) Missing; or (2) Not in contact with the journal. ...

The role of plain radiographs in the diagnosis of chronic maxillary ...

African Journals Online (AJOL)

Background: Computed tomography is currently the gold standard for the diagnosis of chronic rhinosinusitis. However, this facility is not readily available in many developing countries. Thus, plain sinus radiography is still widely in use in our practice. Objectives: To assess the diagnostic value of plain radiographs in adult ...

Impact of value-driven scenarios on the geomorphology and ecology of lower Rhine floodplains under a changing climate

NARCIS (Netherlands)

Straatsma, M.W.; Schipper, A.; Perk, M. van der; Brink, N.G. van den; Leuven, R.S.E.W.; Middelkoop, H.

2011-01-01

In the future, the bio-geomorphological functioning of lowland floodplains is likely to be altered at an increasing pace. Together with increasing socio-economic demands, climatic changes are expected to increase the pressures on lowland rivers in developed countries. To cope with

Sedimentology and Rock Magnetism of Bailey River Peat Cores, Sudbury Area: Preliminary Results

Science.gov (United States)

Yurtseven, A.; Cioppa, M. T.; Dean, K.

2009-05-01

Magnetic measurements on peat can reveal atmospheric anthropogenic contamination. Two cores were collected from a marsh surrounding the Bailey River, 10 km north of Sudbury, Ontario, using a Russian peat borer. The BR1 core (1.4 m) was collected right at the river's edge, whereas the BR2 core (2.5 m) was collected about 50 m away from the river's edge, close to the edge of the marsh and near the forest. Significant sedimentological variation between the two cores was observed: core BR1 had several centimeter to decimeter scale fine to coarse grey sand layers at 0.14 m, 0.46 m and 0.87 m between thicker organic-rich (peat) zones, whereas core BR2 had only one 5 cm sand-rich layer at 0.94 m within the organic-rich material. The cores were subsampled at 2.5 cm intervals for laboratory magnetic analysis. Volume susceptibility was measured using a Bartington MS2B meter, and mass-specific susceptibility was then calculated. In core BR1, the sand layers had relatively higher susceptibility (13 x 10-8 m3/kg) , while the organic rich layers had very low susceptibility (0 - 2 x 10-8 m3/kg). In core BR2, which had little sand, the susceptibility variation was dominated by higher values near-surface (10 x 10-8 m3/kg), and very low susceptibility (0.3 x 10-8 m3/kg) below 0.3 m depth. Since the lithology in this core did not vary substantially, susceptibility variations may be controlled by anthropogenic deposition in the near-surface during the peak mining and smelting decades. These preliminary results suggest that any anthropogenic signal in core BR1 appears to be masked by the sedimentological variation. On pilot results from eight samples in core BR1, saturation isothermal remanence acquisition showed 95% saturation by 200 mT, and the S-ratios (0.3T/0.9T) were above 0.93, suggesting that magnetite is the major magnetization carrier. In core BR2, six out of eight samples showed similar results; however, two samples had slightly more higher coercivity minerals (90% saturation

Long-term Agroecosystem Research in the Northern Great Plains.

Science.gov (United States)

Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

2015-12-01

The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

The case for the plain packaging of tobacco products.

Science.gov (United States)

Freeman, Becky; Chapman, Simon; Rimmer, Matthew

2008-04-01

The Framework Convention on Tobacco Control (FCTC) requires nations that have ratified the convention to ban all tobacco advertising and promotion. In the face of these restrictions, tobacco packaging has become the key promotional vehicle for the tobacco industry to interest smokers and potential smokers in tobacco products. This paper reviews available research into the probable impact of mandatory plain packaging and internal tobacco industry statements about the importance of packs as promotional vehicles. It critiques legal objections raised by the industry about plain packaging violating laws and international trade agreements. Searches for available evidence were conducted within the internal tobacco industry documents through the online document archives; tobacco industry trade publications; research literature through the Medline and Business Source Premier databases; and grey literature including government documents, research reports and non-governmental organization papers via the Google internet search engine. Plain packaging of all tobacco products would remove a key remaining means for the industry to promote its products to billions of the world's smokers and future smokers. Governments have required large surface areas of tobacco packs to be used exclusively for health warnings without legal impediment or need to compensate tobacco companies. Requiring plain packaging is consistent with the intention to ban all tobacco promotions. There is no impediment in the FCTC to interpreting tobacco advertising and promotion to include tobacco packs.

Three-dimensional coastal geomorphology deformation modelling using differential synthetic aperture interferometry

Energy Technology Data Exchange (ETDEWEB)

Marghany, Maged [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia). Inst. for Science and Technology Geospatial (INSTeG)

2012-06-15

This work presents a new approach for three-dimensional (3D) coastal deformation simulation using differential synthetic aperture interferometry (DInSAR). In doing so, conventional InSAR procedures are implemented to three repeat passes of RADARSAT-1 SAR fine mode data (F1). Further, the DInSAR method is implemented with the phase unwrapping technique. Consequently, DInSAR is used to eliminate the phase decorrelation impact from the interferograms. The study shows the accurate performance of DInSAR with a root mean square error of 0.02 {+-} 0.21 m and 90% confidence intervals. In conclusion, the DInSAR technique produces an accurate 3D coastal geomorphology reconstruction. (orig.)

Geomorphological and morphometric analysis of the river basin of Salsa, south coast of the state of Paraiba / Brazil

International Nuclear Information System (INIS)

Barbosa, M.E.; Nascimento, J.; Furrier, M.

2010-01-01

This paper aims to extend the knowledge on the geomorphology of the river basin of Salsa , located in the municipality of Conde, State of Paraíba / Brazil . The research was to develop guiding object thematic maps related to morphometric aspects of the basin such as fluvial hierarchy , hypsometric and slope . After obtaining the morphometric data can assess the likely tectonic influences on the morphology of this basin. Literature searches , acquisition and analysis of cartographic data (satellite imagery , topographic and thematic maps), where with the help of software SPRING 5:03 , were made the thematic maps of the basin : For this research, the following milestones have been met. In addition, there have been two topographic profiles of the area through which it was possible to further analyze the geomorphological aspects and clinográficos watershed. Already in possession of the first results of this research it was observed with the analysis of charts and topographic profiles the high level of dissection Barriers Training and dissection of this discrepancy between the left and right margins . Barriers in Education, was observed indicative of tectonics from setbacks headwater quite different slots and obsequente towards the River Salsa (SN), which is discordant from the direction of the main waterways and Training Barriers own inclination is that WE . These findings are important because the geomorphological analysis of litoestatigráfica unit is of paramount importance for the understanding of the mechanisms governing the morphology of the northeast coast, mainly in relation to the mechanisms that govern the morphology of watersheds coast of Paraiba