References of "Fagel, Nathalie"
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See detailGeoarchaeology of the ancient city of Utica (Tunisia) and evolution of the Medjerda delta's palaeoenvironment
Pleuger, Elisa ULg; Goiran, Jean-Philippe; Delile, Hugo et al

Conference (2014, March 05)

The Phoenician Utica remains today largely unknown, as well as the role that the ancient city held in the Phoenician expansion in the western Mediterranean. Aristotle and Pliny the Elder mentioned Utica ... [more ▼]

The Phoenician Utica remains today largely unknown, as well as the role that the ancient city held in the Phoenician expansion in the western Mediterranean. Aristotle and Pliny the Elder mentioned Utica as a maritime and port city and evaluate its origin around the 11th c. BC.. However, in the present state of research, no archaeological evidence goes back beyond the 7th c. BC.. Today, the ancient port city is located in the heart of the Medjerda delta, 10 km inland. Although the Utica site has been the subject of archaeological excavations since the 19th c., the location of port infrastructures, dating from Phoenician and Roman periods, remains unknown. Based on this observation, our research focuses on two main issues: Where are the port infrastructures of Utica? Why the city, formerly a seaport city, is today located 10 km from the coast? The location and the study of port infrastructures will bring primordial elements of response to the question of the city founding. The study of river paleoenvironments of the Medjerda delta during the Holocene aim to a better understanding of the nature of the settlement, as well as the function of the city of Utica. This study will also assess the impact of the ancient city on the environment and understand how the city has adapted to the mobility of this Mediterranean delta. Furthermore, the study of sedimentary processes causing the filling of the harbour basin will lead to speculate about the causes of the abandonment of the structures and more generally the decline of the city in favor of the city of Carthage. It will also detect if natural or anthropogenic factors have influenced this deltaic progradation over the centuries. This project proposes an interdisciplinary reflection to understand the Medejerda delta landscape changes during the Holocene. It starts from an archaeological problem and proposes the contribution of geoarchaeology to the understanding of the relationship between ancient societies and their environment. A major originality of this project lies in the multidisciplinary approach, which aim to provide an evolutive image of the landscapes of the Medjerda watershed, and to precise the sedimentary record considering control variables such as climate and anthropogenic pressure. The study of fluvial palaeoenvironments and sedimentary processes will be carried out through the mechanical extraction of cores (~10 m deep) to reach the early Holocene. Selected sediment samples will then be studied in laboratory, using different and complementary approaches. Particle size analysis and quartz morphoscopy will help to clarify the processes involved in the successive phases of deposits associated with different sedimentary environments. It will be supplemented by a series of sedimentological (magnetic susceptibility, mineralogy, organic and inorganic geochemistry) and biological analyses (pollen, ostracods) to reconstruct the evolution of the landscape over the last millennia. This reconstruction will be related to climate changes during the Holocene. The combination of mineralogical and geochemical approaches will help to identify the origin of clay minerals to determine their source regions and to highlight contamination by human activities. The influence of anthropogenic factors will be confirmed by analysing lead isotopes. Meanwhile, a series of radiocarbon dating will be conducted to establish the chrono-stratigraphic framework of the different evolution phases of the delta. More generally, this project focuses on the importance of knowledge of the past to understand and grasp the consequences of the human impact on the environment, more specifically on the deltaic environments. [less ▲]

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See detailMineralogical and geotechnical characterization of clays from Northern Morocco for their potential use in ceramic industry
El Ouahabi, Meriam ULg; Daoudi, Lahcen; Fagel, Nathalie ULg

in Clay Minerals (2014), 49

This study focuses on the mineralogical and geotechnical characterization of Northern Morocco clays (i.e., from Tangier and Tetouan areas) and further comparison with main clay ores used in national ... [more ▼]

This study focuses on the mineralogical and geotechnical characterization of Northern Morocco clays (i.e., from Tangier and Tetouan areas) and further comparison with main clay ores used in national ceramic (i.e., from Meknes, Fes, Salé and Safi regions). Sampled clays were analyzed by X-ray diffraction on bulk and clay (< 2 µm) fractions to identify the mineralogical assemblages of the clay outcrops. Further analyses were conducted to determine the particle size distribution (laser diffraction particle analyser), the total organic matter content (from LossOnIgnition measurements) and the Atterberg limits of the raw clays. The aims of this study were first to investigate the spatial variability of the clay samples and second to evaluate their potential application as raw materials in ceramic industry. Tetouan and Tangier clays are characterized by diversified mineralogical assemblages (in particular a variable proportion of clay, quartz and calcite) in regard with Meknes, Fes, Salé and Safi clays (high clay content, quartz and calcite). The clay fraction of Tetouan and Tangier samples is dominated by illite and kaolinite with variable contribution of chlorite, smectite and/or vermiculite. Illite is the dominant phase in Meknes, Fes, Safi and Salé clays, but is associated with kaolinite. There is no direct relationship between the mineral assemblage composition and the lithology of the series. The studied clays materials consist generally in fine particles with medium to high plasticity and low organic matter content. Taking into account mineralogy, grain-size distribution and plasticity those clays seem to be suitable as raw material for the growing Morocco ceramic industry. [less ▲]

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See detailSTUDY OF ENVIRONMENTAL CONTAMINATION OVER THE HISTORICAL PERIOD: TRACE ELEMENT AND LEAD ISOTOPIC SIGNATURE IN COASTAL SEDIMENTS FROM CAP CORSICA (FRANCE)
Fontaine, François ULg; lefebvre, lucie; Vranken, François et al

Poster (2014, February)

The Mediterranean coasts have been characterised by intense maritime commercial exchanges since Antiquity. Archeological researches reveal that Cape Corsica (France) may have been an ancient Roman harbor ... [more ▼]

The Mediterranean coasts have been characterised by intense maritime commercial exchanges since Antiquity. Archeological researches reveal that Cape Corsica (France) may have been an ancient Roman harbor. The purpose of this study is first to highlight an anthropogenic contamination due to Roman activities using trace element concentration. Second we aim to identify the contamination sources through Pb isotope composition. Radiocarbon ages performed on macroremains in coastal sediments from Cala Francese (cores CF10-II and CF10-III) allow the localisation of the Roman Period in the sedimentary columns. In core CF 10-II, two major shifts of trace element concentration (such as Pb, Cu, Zn, As and Sb) have been measured at 60-80 and 140-160 cm, corresponding respectively to the Industrial Revolution and to the Roman Period. The same tendency of the Pb concentration is observed in core CF10-III. In this core, the Roman Period is localised between 80 and 140 cm. A major shift in Pb isotopic composition is observed in both core at 140 cm in CF10-II and 60 cm in CD10-III, with a decrease of 206Pb/207Pb ratios and 208Pb/206Pb ratios. All the Pb isotopic ratios match with Pb Roman time signatures from Greece and Spain. Such significant changes in trace metal content and in Pb isotopic signature of sediments are consistent with Human perturbations of the environment during the Roman and Industrial periods. The Pb isotopic signatures measured in Cala Francese are in the same range as those located in other sites of Cape Corsica, indicating a regional contamination. [less ▲]

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See detailA 3400 year lacustrine paleoseismic record from the North Anatolian Fault, Turkey: Implications for bimodal recurrence behavior
Avsar, Ulas; Hubert, Aurelia ULg; De Batist, Marc et al

in Geophysical Research Letters (2014), 41(2), 377-384

High-resolution physical, geochemical, and geochronological analyses on the sedimentary sequence of Yeniçağa Lake, located in a fault-bounded basin along the North Anatolian Fault, reveal fingerprints of ... [more ▼]

High-resolution physical, geochemical, and geochronological analyses on the sedimentary sequence of Yeniçağa Lake, located in a fault-bounded basin along the North Anatolian Fault, reveal fingerprints of paleoearthquakes. A robust sediment chronology, spanning the last 3400 years, is constructed by radiocarbon dating and time-stratigraphical correlation with the precisely dated Sofular Cave speleothem record. Yeniçağa sedimentary sequence contains 11 seismically induced event deposits characterized by siliciclastic-enriched intervals. Some of the event deposits are also associated with implications of sudden lake deepening, which may be related to coseismic subsidence. The paleoearthquake series having an average recurrence interval of ca. 260 years are interrupted by two possible seismic gaps of ca. 420 and 540 years. [less ▲]

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See detailMineralogical, Physicochemical Properties of smectite clays from Bana (Western Cameroon) and Preliminary test as Potential oil bleaching earth
Mache, Jacques Richard; Signing, P.; Mbey, J.A. et al

in Applied Clay Science (2014)

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See detailPalaeogeographic controls on palygorskite occurrence in Maastrichtian-Palaeogene sediments of the Western High Atlas and Meseta basins (Morocco)
Knidiri, A.; Daoudi, Lachen; El Ouahabi, Meriam ULg et al

in Clay Minerals (2014), 49

The Maastrichtian-Palaeogene series of the Western High Atlas and Meseta Basins in Morocco are particularly rich in palygorskite. The present work is aimed at clarifying the genesis of palygorskite from ... [more ▼]

The Maastrichtian-Palaeogene series of the Western High Atlas and Meseta Basins in Morocco are particularly rich in palygorskite. The present work is aimed at clarifying the genesis of palygorskite from the interbedded facies and gaining an understanding of their relationships with the depositional environment. The mineralogical characteristics of palygorskite from these series were studied by X-ray diffraction (XRD) and electron microscopy (SEM/TEM). The palygorskite content and microstructure show large geographical and stratigraphical variations in the deposits studied. The palygorskite occurrence is directly related to palaeobathymetry, since it is the dominant clay mineral in shallow marine and restricted environments. According to the morphology of palygorskite crystallites, four types of textures were distinguished. These types of palygorskite are polygenetic, formed by chemical precipitation, by the recrystallization of smectite clays or reworked by wind or water from sub-aerial environments. The difference between the two studied sub-basins with respect to palygorskite occurrence is attributed to the palaeomorphology of the hinterlands, to the tectonic differentiation and to the physical-chemical conditions of sea water. [less ▲]

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See detailSeismically-triggered organic-rich layers in recent sediments from lake Gollukoy (North Anatolian Fault, Turkey
Avşar, Ulaş; Hubert, Aurelia ULg; De Batist, Marc et al

in Quaternary Science Reviews (2014), 103

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See detailMineralogical and Physical Changes during Sintering of Plastic Red Clays from Sanaga Swampy Valley, Cameroon.
Nzeukou, Aubin; Traina, K.; Mjedo, E.R. et al

in International ceramique review (2014), 63(4), 186-192

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See detailLate Quaternary evolution of sediment provenances in the Central
Fagel, Nathalie ULg; Not, Christelle; Gueibe, Jonathan et al

in Quaternary Science Reviews (2014), 92

Mineral assemblage, trace element content and Nd and Pb isotope signatures were analysed on the fine fraction (<20 mm) of sedimentary records from the Northern Mendeleev Ridge in the Central Arctic Ocean ... [more ▼]

Mineral assemblage, trace element content and Nd and Pb isotope signatures were analysed on the fine fraction (<20 mm) of sedimentary records from the Northern Mendeleev Ridge in the Central Arctic Ocean. Our aimwas to identify the detrital particle provenance and to interpret the changes over the past w250 ka in the relative contribution of the different source-areas in relation to paleoenvironmental conditions. The clay mineral assemblage and the Nd and Pb isotope signatures depict systematic changes over the Late Quaternary. The bulk mineralogy exhibits increases in the relative contribution of carbonate minerals vs. silicates in interglacial/deglacial intervals. In glacial intervals, the mineral assemblage of the <20 mm fraction is characterised by an enrichment in kaolinite, counterbalanced by a decrease in illite. The Nd and Pb isotope signatures of <20 mm fraction are interpreted using a three end-member mixing model, involving crustal supplies from North America and Canada, from the Siberian margin and some from volcanic material. A compilation of geochemical signatures of geological terraines surrounding the Arctic Ocean allowed each end-member to be assigned a representative signature, averaging the signal of the eroded terraines. The Suspended Particulate Matter (SPM) of the MacKenzie River represents an average signature of the sedimentary supplies delivered from the North American platform and Canadian margin. The SPM of the Lena River reflects the mean sedimentary signature of the Siberian platform. The Okhotsh-Chukotka province from the Eastern border of Siberia is identified as the most probable volcanic source. Late Quaternary evolution of the estimated relative contribution of the three end-members confirms that the sediment provenances in the Central Arctic Ocean remain close to the current conditions during past interglacials/deglacials MIS1e3, MIS5/TII and MIS7/TIII. In contrast, glacial conditions (MIS4 and MIS6) record minimum supplies from the American margin, associated with increased volcanic contribution, to the Mendeleev Ridge core location suggesting a different sea-ice circulation associated with a low sea-level and reduced shelf area. [less ▲]

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See detailPotentiality of clay raw materials from northern Morocco in ceramic industry: Tetouan and Meknes areas
El Ouahabi, Meriam ULg; Daoudi, Lahcen; De Vleeschouwer, François et al

in Journal of Minerals and Materials Characterization and Engineering (2014)

This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical ... [more ▼]

This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical, thermal and firing characteristics. Textural properties were identified by specific surface area, cation exchange capacity (CEC) and bulk density (ρs). Chemical and thermal properties were assessed using XRF and TG/DTA techniques, respectively. Firing characteristics at temperatures from 800°C to 1100°C were determined by linear firing shrinkage, loss on weight and water absorption capacity. The Meknes clays are characterised by medium cation exchange capacity (CEC) and specific surface area (SSA) values due to their moderate smectite content. The Tetouan clays have medium to low CEC and medium SSA values. The main oxides in the clayey samples are SiO2 (35 – 54.3 wt.%), Al2O3 (20.6 – 43.9 wt.%), and Fe2O3 (9.7 – 22.4 wt.%). The amount of CaO in Meknes clays ranges from 8 to 12 wt.%, whereas CaO is only present in some Tetouan clay (TE4, TE7, TN4 and TN5). A significant densification of ceramic behaviour could be noticed for most of Tetouan clays at firing temperatures above 1000°C. Meknes clays show earlier densification from 800 °C. The chemical, textural and ceramic properties of Tetouan and Meknes clays indicate their suitability as raw materials for the production of structural ceramics. The high amount of Fe2O3 in all clays makes them inappropriate in fine ceramics. [less ▲]

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See detailBiological nitrate utilization in south Siberian lakes (Baikal and Hovsgol) during the last glacial period: the influence of climate changes on primary productivity
Watanabe Nara, F.; Watanabe, T.; Kakegawa, T. et al

in Quaternary Science Reviews (2014), 90

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See detailCharacterization of clay deposits of Nanga-Eboko (Central Cameroon): Suitability in the production of building materials
Nzeukou Nzeugang, A.; Medjo Eko, R.; Fagel, Nathalie ULg et al

in Clay Minerals (2013), 48(4), 655-662

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See detailHolocene dust record in a NW European peat bog: A multiproxy approach
Allan, Mohammed ULg; Le Roux, Gael; Verheyden, Sophie et al

Conference (2013, August 28)

Dust deposition in southern Belgium is estimated from the geochemical signature of an ombrotrophic bog. The analyses of Rare Earth Elements (REE) and lithogenic element concentrations as well as Nd ... [more ▼]

Dust deposition in southern Belgium is estimated from the geochemical signature of an ombrotrophic bog. The analyses of Rare Earth Elements (REE) and lithogenic element concentrations as well as Nd isotopes were performed by HR-ICP-MS and MC-ICP-MS respectively, in a  6 m peat section representing 5300 years, from 30 BC to 5300 BC dated by the 14C method. REE concentration variations in peat samples were used as a dust proxy and the Nd isotopes to trace the sources. Peat humification and testate amoebae were used to evaluate hydroclimatic conditions. The range of dust deposition varied from 0.03 to 4 g m-2 yr-1. The highest dust fluxes were observed from 800 to 600 BC, and from 3200 to 2800 BC and correspond to cold periods. The Nd values show large variability, between -5 and –13, identifying three major sources of dust: local soils, distal volcanic and desert particles. By comparing our results with the dust recorded in other peat bogs and ice cores from different latitudes, we evidence that the Misten peat is a valid archive for dust deposition. [less ▲]

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See detailOmbrotrophic peat records of mercury deposition in Europe
Le Roux, Gael; Enrico, Maxime; Allan, Mohammed ULg et al

Conference (2013, August 02)

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See detailSmectite clay from the Sabga deposit (Cameroon): mineralogical and physicochemical properties
Mache, Jacques Richard ULg; Nyoja, A.; Signing, P. et al

in Clay Minerals (2013), 48(48), 499-512

The physicochemical and mineralogical characterization of the < 250 µm particle-size fraction from six the clay-rich samples from the Sabga deposit (North-west, Cameroon) were carried out in order to ... [more ▼]

The physicochemical and mineralogical characterization of the < 250 µm particle-size fraction from six the clay-rich samples from the Sabga deposit (North-west, Cameroon) were carried out in order to evaluate their potential applications. Analyses revealed that the major clay mineral was dioctahedral smectite along with small amounts of kaolinite in three clay samples. Cristobalite, feldspars, ilmenite and heulandites were also found as accessory minerals. A Li-saturation test (Greene-Kelly test) revealed the montmorillonitic nature of the smectite component. The chemical composition of the bulk clays consists of (66-70%) SiO2, (13-16%) Al2O3 and (2-7%) Fe2O3. These clays present mineralogical (high montmorillonite content) and physico-chemical (cation exchange capacity (CEC): 38 to 46 meq/100g and specific surface areas ranging from 33 to 90 m2/g). These physical and chemical properties are fully compatible with potential uses in environmental applications. After some pretreatment (purification, chemical modification), these materials could also be used in refining edible oil as adsorbent, waste water treatment and wine technology. [less ▲]

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