Éditeur(s) : HAL CCSD
Résumé : The North Tehran Fault is located at the southernmost piedmont of Central Alborz, north of Iran. It stands out as a major active fault menacing directly the city of Tehran, a 12 million people metropolis, and would have been the source of several major historical earthquakes in the past. The fault zone extends up to 110km and corresponds mainly to a reverse fault mostly crossing the northern suburbs of the Tehran metropolis, although NTF in its eastern part is characterized more as a left lateral strike slip active fault. We carried out a paleoseismological study of the fault zone in order to determine whether the fault was activated during the Holocene, and to define the characteristics of its activity in terms of kinematics and magnitude. Here in this paper we present only a part of our paleoseismological investigations trench TE2. Observations fromtwo trenches dug across the North Tehran fault scarp reveal evidence for a maximum of six surface-rupturing events within the late quaternary. According to the empirical relationships among average displacement per event and Moment magnitude [25], we can estimate six events Mw~ 6.5 associated with these ruptures in TE2 trench.
Journal of Seismology and Earthquake Engineering

hal-00758375
https://hal.archives-ouvertes.fr/hal-00758375

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le présent document a pour objet d’évaluer les implications potentielles sur les économies des états de la Caraïbe et de celles des DFA (Guadeloupe, Martinique, Guyane) du volet commercial de l’accord de partenariat économique (APE) signé en octobre 2008 entre les pays du CARIFORUM et l’Union européenne. Deux modèles ont été utilisés à cet effet : un modèle d’équilibre général calculable (le modèle GTAP), appliqué aux économies du CARIFORUM, et un modèle de gravité appliqué à celles des DFA. Les simulations issues du modèle d’équilibre général calculable montrent que dans l’hypothèse d’une pleine réciprocité (sans droits ou quotas entre les deux partenaires), les résultats dans le cas des pays du CARIFORUM seraient contrastés. Ils seraient positifs pour certains pays et secteurs de production, et modestes pour d’autres. Ils se traduiraient par une baisse sensible des recettes douanières pour la plupart des pays et par une dégradation de la balance commerciale pour les plus vulnérables. Enfin, la croissance et le bien-être des habitants de cette zone subiraient une très légère augmentation (0,04%). Concernant les DFA, les résultats issus de l’application du modèle de gravité révèlent que ces régions ultrapériphériques de l’Europe combinent, en raison de la structure de leur économie, de celle de leurs coûts de production et surtout à cause des liens institutionnels et économiques très étroits qu’elles entretiennent avec la France et donc avec l’Europe un certain nombre de facteurs pénalisants, susceptibles d’entraver le potentiel de commerce qu’elles pourraient développer avec les pays ACP voisins dans le cadre de cet APE.
The present paper seeks to provide an assessment of the likely implications of the CARIFORUM-EU Economic Partnership Agreement (EPA) on economy of Caribbean states and French Caribbean Outermost Regions (FCORs). Two models are used for that a computable general equilibrium model (GTAP model), applied to CARIFORUM countries, and a gravity model framework applied to French Caribbean Outermost Regions. The main findings from application of the computable general equilibrium model can be outlined as follows in case of full reciprocity between the partners in merchandise trade, the results show that impacts are contrasted among the economies. The effects appear positive for some countries, sectors and negative for the others. Tariff reductions will translate into a decline in government revenue and a degradation of their balance of payments. The well-being of CARIFORUM households has improved very lightly (0.04%). On the other hands, the application of the gravity model framework reveals several barriers to regional trade between French Caribbean Outermost Regions and their neighbours, particularly their strong institutional and economic links with continental France, responsible for a high labour cost and a lack of autonomy with regard to international trade. The study also highlights that French language is an obstacle to trade across the Caribbean, due to the fact it is a minority in this region, as well as absence of FCORs in main economic and trade agreements of Caribbean. Finally the paper finds that there is high degree of similarity of exports among the countries and territories in the Caribbean.
Caraïbes

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6928
http://journals.openedition.org/etudescaribeennes/6928

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cette étude originale a vocation à montrer comment un mysticisme authentique s’est formé au fil des siècles en Guadeloupe. Les Antilles sont composées de nombreuses ethnies, aux origines très diversifiées. En Guadeloupe, la société s’est constituée à partir de deux vagues de migrations, qui ont formé une société pluri-ethnique et pluri-culturelle. Ces vagues de migrations se sont inscrites dans un double processus de mondialisation, l’un historique, figé dans le temps, l’autre dynamique, encore effectif de nos jours. La confrontation et la cohabitation de ces ethnies et de ces cultures ont conduit à l’avènement de pratiques mystiques authentiquement guadeloupéennes. Ainsi, le mysticisme est devenu partie prenante de la culture guadeloupéenne, culture encore en construction, qui n’a pas encore soudé en un syncrétisme franc les pratiques des différentes communautés ; chaque individu choisissant, en fonction de ses nécessités, de se référer ou d’appliquer telle ou telle pratique mystique.
This study shows how an authentic mysticism arose in Guadeloupe. The West Indies are made up of many ethnic groups. In Guadeloupe, the society has been constituted by two waves of migrations; so far this society has been pluri-ethnic and pluri-cultural. Those waves reveal a two dimension globalization: the first is historical, likely to be identified in our history, the second is dynamic and is still expanding nowadays. The cohabitation of these ethnic groups and these cultures has led to the creation of an authentic Guadeloupean mysticism. Thus mysticism is important in the Guadeloupean culture. However there has not been syncretism between all the mysticisms of every ethnic group; and every one can choose the mysticism they want, and change whenever they want.
Guadeloupe

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5940
http://journals.openedition.org/etudescaribeennes/5940

Éditeur(s) : Public Library Science
Résumé : The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB) models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel–environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy). Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration) completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to different populations and sites.
Plos One (1932-6203) (Public Library Science), 2014-10 , Vol. 9 , N. 10 , P. 1-13

Droits : 2014 Picoche et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
http://archimer.ifremer.fr/doc/00218/32895/31380.pdf
http://archimer.ifremer.fr/doc/00218/32895/31381.pdf
http://archimer.ifremer.fr/doc/00218/32895/31382.pdf
http://archimer.ifremer.fr/doc/00218/32895/31383.pdf
http://archimer.ifremer.fr/doc/00218/32895/31384.pdf

Éditeur(s) : HAL CCSD Optical Society Optical Society - SOA Publishing
Résumé : International audience
We show that the canonical single frequency sarcomeric SHG intensity pattern (SHG-IP) of control muscles is converted to double frequency sarcomeric SHG-IP in preserved mdx mouse gastrocnemius muscles in the vicinity of necrotic fibers. These double frequency sarcomeric SHG-IPs are often spatially correlated to double frequency sarcomeric two-photon excitation fluorescence (TPEF) emitted from Z-line and I-bands and to one centered spot SHG angular intensity pattern (SHG-AIP) suggesting that these patterns are signature of myofibrillar misalignement. This latter is confirmed with transmission electron microscopy (TEM). Moreover, a good spatial correlation between SHG signature of myofibrillar misalignment and triad reduction is established. Theoretical simulation of sarcomeric SHG-IP is used to demonstrate the correlation between change of SHG-IP and -AIP and myofibrillar misalignment. The extreme sensitivity of SHG microscopy to reveal the submicrometric organization of A-band thick filaments is highlighted. This report is a first step toward future studies aimed at establishing live SHG signature of myofibrillar misalignment involving excitation contraction defects due to muscle damage and disease.
ISSN: 2156-7085

hal-00952823
https://hal.archives-ouvertes.fr/hal-00952823
https://hal.archives-ouvertes.fr/hal-00952823/document
https://hal.archives-ouvertes.fr/hal-00952823/file/boe-5-3-858_002.pdf
DOI : 10.1364/BOE.5.000858

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
The processes active in the deep crust above an oceanic subduction zone during its evolution have been constrained through a detailed geochemical study (major and trace elements and Sr, Nd and Pb isotopes) of representative samples through an 30 km thick exhumed crustal section of the Cretaceous Kohistan oceanic island arc (Northern Pakistan). The use of both trace elements and radiogenic isotopes reveals two distinct geochemical suites (suites A and B) within the JijalPatanKiruKamila (JPKK) complex. Suite A is characterized by a progressive enrichment in Pb-207 and a decrease in Nd-143/Nd-144 with increasing La-N/Sm-N. Suite B has higher Pb-207/Pb-204 and lower Nd-143/Nd-144 ratios with approximately constant La-N/Sm-N. By combining trace elements with different partitioning behaviour it is demonstrated that there is an increasing contribution of the subduction component in the magmas with time. It is also possible to distinguish a slab component imprint carried by aqueous fluids from one corresponding to sediment melts. Intrusive granites are abundant in the upper levels of the JPKK section. All were generated at the arc root level (Jijal crustal section) during dehydration-melting of hornblende-rich plutonic rocks. A three-stage geodynamic model is proposed for the evolution of the arc over a period of 30 Myr. The first stage (117105 Ma) starts with the onset of subduction, which was followed by the building of the volcanic arc. The second stage (10599 Ma to 9691 Ma) corresponds to a major igneous event, which was characterized by abundant magma underplating and granulite-facies metamorphism at the arc base. Recycling of the residualcumulative lower crust into the convective asthenospheric mantle was efficient during this stage, and was probably related to thermo-mechanical erosion of the base of the crust. The last stage (9585 Ma) corresponds to a period of low magmatic activity, which marked the end of the intra-oceanic subduction. This is related to the formation of a cold blanket above the slab surface as a result of thermo-mechanical erosion of the cold walls of the subduction zone (i.e. the upper part of the slab and the base of the overriding plate), and corner flow dragging the cold material into the zone of melt generation. Ultimately, a voluminous magmatic pulse occurred around 85 Ma (forming the Chilas complex), before arccontinent collision.
ISSN: 0022-3530

hal-00420068
https://hal.archives-ouvertes.fr/hal-00420068
DOI : 10.1093/petrology/egp010

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Ovarian failure (OF) is considered premature if it occurs before the age of 40. This study investigates the genetic aetiology underlying OF in women under the age of 40 years. Methods: We conducted an experimental prospective study performing all genome microarrays in 60 patients younger than 40 years presenting an OF revealed by a decrease of circulating Anti-Mullerian Hormone (AMH) and leading to an oocyte donation program. Results: We identified nine significant copy number variations (CNVs) including candidate genes potentially implicated in reproductive function. These genes are principally involved in cell division and chromosome segregation (SYCE1, CLASP1, CENP-A, CDC16), in ciliary development and/or function (RSPH1, KIF24), are linked with known gonadal genes or expressed in female genital tract (CSMD1, SEMA6D, KIAA1324). Conclusions: Our data strengthen the idea that microarrays should be used in combination with karyotype for aetiological assessment of patients with OF. This analysis may have a therapeutic impact as the identification of new molecular actors for gonadal development or ovarian physiology is useful for the prediction of an ovarian reserve decline and makes possible preventive fertility preservation.
ISSN: 1757-2215

hal-01390979
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390979
DOI : 10.1186/s13048-016-0272-5
PUBMED : 27716277

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : Climate models predict a range of changes in tropical forest regions, including increased average temperatures, decreased total precipitation, reduced soil moisture and alterations in seasonal climate variations. These changes are directly related to the increase in anthropogenic greenhouse gas concentrations, primarily CO2. Assessing seasonal forest growth responses to climate is of utmost importance because woody tissues, produced by photosynthesis from atmospheric CO2, water and light, constitute the main component of carbon sequestration in the forest ecosystem. In this paper, we combine intra-annual tree growth measurements from published tree growth data and the corresponding monthly climate data for 25 pan-tropical forest sites. This meta-analysis is designed to find the shared climate drivers of tree growth and their relative importance across pan-tropical forests in order to improve carbon uptake models in a global change context. Tree growth reveals significant intra-annual seasonality at seasonally dry sites or in wet tropical forests. Of the overall variation in tree growth, 28.7% was explained by the site effect, i.e. the tree growth average per site. The best predictive model included four climate variables: precipitation, solar radiation (estimated with extrasolar radiation reaching the atmosphere), temperature amplitude and relative soil water content. This model explained more than 50% of the tree growth variations across tropical forests. Precipitation and solar radiation are the main seasonal drivers of tree growth, causing 19.8% and 16.3% of the tree growth variations. Both have a significant positive association with tree growth. These findings suggest that forest productivity due to tropical tree growth will be reduced in the future if climate extremes, such as droughts, become more frequent.
ISSN: 1932-6203

hal-01268529
https://hal.archives-ouvertes.fr/hal-01268529
https://hal.archives-ouvertes.fr/hal-01268529/document
https://hal.archives-ouvertes.fr/hal-01268529/file/journal.pone.0092337.PDF
DOI : 10.1371/journal.pone.0092337

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Tilt fluctuations can potentially reflect the response of hydrosystems to important rainfall. In this context, long baseline tiltmeters have been installed in an underground tunnel penetrating the Fontaine de Vaucluse karst to study the medium deformation related to solicitations exerted by water infiltrating the hydrosystem. The instruments monitor the tilt as well as its spatial variation. Northward tilts reaching a 1 μrad amplitude are observed consecutively to rainfalls. The tilt amplitude is highly correlated with the Fontaine de Vaucluse outlet flow fluctuations. The measured tilt signal is also relatively homogeneous over a 150 m length. Different types of structure likely to produce such observations are tested in order to identify their location with respect to the tiltmeters, their dimension as well as the amount of water level variation in the structure. Following rainfalls, the infiltration of water modifies the pore pressure, inducing a medium deformation. The hypothesis of an homogeneous surface loading on the Vaucluse plateau is first refuted since the related tilt is much lower than the one measured. The water supplied by rainfalls has to accumulate in discontinuities in order to generate a higher tilt. So, the deformation related to a pressure exerted on a fracture filled by water is assessed. A first study reveals the interest of the tilt homogeneity information that constrains strongly the fracture properties. Thus, the fracture must be located at a distance more than a few hundreds metres from the tiltmeters in order to produce a tilt homogeneous in space. If the fracture is initially dry, it must also be filled on a height higher than 150 m consecutive to a rainfall in order to generate a tilt amplitude in the same magnitude as the one measured. Then, we explore the influence of water level variations on the tilt produced by a fracture located at the interface between the saturated and unsaturated zones, which are thereby permanently flooded. Since several parameters of that model satisfactorily explain the field observations, we discuss how simultaneous geodetical observations could provide complementary information that would further constrain the geometry of the structure at the origin of the medium deformation.
ISSN: 0956-540X

insu-01408482
https://hal-insu.archives-ouvertes.fr/insu-01408482
https://hal-insu.archives-ouvertes.fr/insu-01408482/document
https://hal-insu.archives-ouvertes.fr/insu-01408482/file/Lesparre-2017.pdf
DOI : 10.1093/gji/ggw446

Éditeur(s) : HAL CCSD
Résumé : Prelimary version - 13 pages.
International audience
A new approach to the algebra G_{τ} of temperate nonlinear generalized functions is proposed, in which G_{τ} is based on the space O_{M} endowed with is natural topology in contrary to previous constructions. Thus, this construction fits perfectly in the general scheme of construction of Colombeau type algebras and reveals better properties of G_{τ}. This is illustrated by the natural introduction of a regularity theory in G_{τ}, of the Fourier transform, with the definition of G_{O_{C}′}, the space of rapidly generalized distributions which is the Fourier image of G_{τ}.
Publ. Inst.Math. (Beograd) (N.S.)

hal-00201458
https://hal.archives-ouvertes.fr/hal-00201458
https://hal.archives-ouvertes.fr/hal-00201458/document
https://hal.archives-ouvertes.fr/hal-00201458/file/NewGOMdec29WithAdditions.pdf
ARXIV : 0801.0074

Éditeur(s) : HAL CCSD
Résumé : International audience
This communication reports on a field experiment carried out on a microtidal beach in Camargue, France. The analysis is built on the initial work presented by Sous et al. (2016) on swash-groundwater dynamics. The analysis of a cross-shore network of buried pressure sensors allows to monitor the watertable dynamics over the full 2013-2014 winter season. The pressure head gradients are observed to be primarily seaward, forced by a higher level at the landward boundary. The groundwater flux is driven by the relative fluctuations of Still Water Level and inland elevations. Rain and tides have a little effect. A nearly isolated groundwater circulation is driven by wave activity below the swash zone whatever the overall watertable gradient. Estimations of beach groundwater discharge over the Gulf of Beauduc reveal the importance of beach groundwater in the exchanges between coastal aquifer and open sea.
Coastal Dynamics 2017
Helsingor, Denmark

hal-01562908
https://hal.archives-ouvertes.fr/hal-01562908

Éditeur(s) : HAL CCSD European Geosciences Union
Résumé : International audience
The exchanges of carbon, water and energy between the atmosphere and the Amazon basin have global implications for the current and future climate. Here, the global atmospheric inversion system of the Monitoring of Atmospheric Composition and Climate (MACC) service is used to study the seasonal and interannual variations of biogenic CO 2 fluxes in Amazonia during the period 2002–2010. The system assimilated surface measurements of atmospheric CO 2 mole fractions made at more than 100 sites over the globe into an atmospheric transport model. The present study adds measurements from four surface stations located in tropical South America, a region poorly covered by CO 2 observations. The estimates of net ecosystem exchange (NEE) optimized by the inversion are compared to an independent estimate of NEE upscaled from eddy-covariance flux measurements in Amazonia. They are also qualitatively evaluated against reports on the seasonal and interannual variations of the land sink in South America from the scientific literature. We attempt at assessing the impact on NEE of the strong droughts in 2005 and 2010 (due to severe and longer-than-usual dry seasons) and the extreme rainfall conditions registered in 2009. The spatial variations of the seasonal and in-terannual variability of optimized NEE are also investigated. While the inversion supports the assumption of strong spatial heterogeneity of these variations, the results reveal critical limitations of the coarse-resolution transport model, the surface observation network in South America during the recent years and the present knowledge of modelling uncertainties in South America that prevent our inversion from capturing the seasonal patterns of fluxes across Amazonia. However, some patterns from the inversion seem consistent with the anomaly of moisture conditions in 2009.
ISSN: 1680-7316

hal-01557375
https://hal.univ-lorraine.fr/hal-01557375
https://hal.univ-lorraine.fr/hal-01557375/document
https://hal.univ-lorraine.fr/hal-01557375/file/acp-15-8423-2015.pdf
DOI : 10.5194/acp-15-8423-2015-supplement

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Multiproxy analyses were performed on core MS27PT recovered in hemipelagic sediments deposited on the Nile margin in order to reconstruct Nile River palaeohydrological fluctuations during the last 100,000 years. The strontium and neodymium isotope composition of the terrigenous fraction and the major element distribution reveal large and abrupt changes in source, oscillating between a dominant aeolian Saharan contribution during arid periods and a dominant Nile River contribution during pluvial periods. Iron content shows a strong correlation with strontium and neodymium isotopes. This allows the use of a high-resolution continuous Fe record as a proxy of Blue Nile sediment input over the last 100,000 years. The detailed Fe record, with approximately 10 years resolution during pluvial periods, is consistent with subtropical African records of well-dated lake level fluctuations and thus constitutes a first continuous high resolution record of the East African monsoon regime intensity over Ethiopia.;The detailed Fe record shows the two main known pluvial periods attributed to strengthening of the African monsoon over Ethiopia, the Nabtian period from 14 to 8 ka cal BP and the Saharan period from 98 to 72 ka BR For the first time, the last glacial period (Marine Isotope Stage (MIS) 2,3 and 4) is documented with a continuous record showing large oscillations between high and low East African palaeo-monsoon regimes.;The end of the Nabtian period occurred at 8 ka in core MS27PT, i.e. much earlier than on the East Equatorial African region where it ended around 5.5 ka. We interpret this as evidence that the southward shift of the rain belt occurred 3000 years earlier over the Eastern Ethiopian Highland and propose that the gradual southward migration of the rain belt was associated with highly variable intensity and longer rainy seasons from 8 to 5 ka. During the last glacial period, two wet periods are present around 60-50 ka BP and 38-30 ka BP. These two humid periods are in phase with the rise of atmospheric CH4 concentrations suggesting that wetland tropical African area was one of the sources of the atmospheric CH4 during the MIS 3. During the Last Glacial Maximum and MIS 4, high Saharan aeolian influxes in phase with records of aeolian dust deposited in East Antarctica are documented. This study highlights the importance of reconstructions of monsoon rainfall fluctuation at high temporal resolution to better understand the link between low- and high-latitude climate variability at millennial timescales.
ISSN: 0277-3791

hal-00496481
https://hal.archives-ouvertes.fr/hal-00496481
DOI : 10.1016/j.quascirev.2010.02.006

Éditeur(s) : HAL CCSD
Résumé :   Diffusion du document : INRA Antilles-Guyane, SDAR/ERIST, Domaine Duclos, F97170 Petitt-Bourg (Guadeloupe) Diplôme : DEA
il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION
ln French Guiana, the mangrove covers almost ail the coastline. It results original because of a dynamic influenced by the system of the amazon muds' dispersion. The coastline's variations are important and the mangrove growing there constitutes various facies. To understand the structure and dynamic of this forest, a test-site has been selected at the Kaw river's estuary. Field measurements of structure parameters permited to identify 3 major types of mangrove forests with different developement stages. Relations between the measured parameters show the facies'dynamic with a self-thinning phnomenon then a gap regeneration. Correlations between structure parameters and corresponding spectral parameters extracted from an IKONOS image have been tested. The use of texture indexes are discussed. Then, a classification of the image reveals the spatial distribution of the facies Parallely, the constitution of a temporal series from 1950 to 2001, base on various remote sensed datas, shows the evolution of the coastline and the associated mangrove. During this period, succeed accretion phases (1950-1981; 1991-2001) and erosion phase (1981-1991). A theorical ages map of the forest stands are also established. Relating with the facies map, it explains the complex evolution of limited Rhizophora zones. A comparison with Sinnamary test-site is made and futurs researches considered.
En Guyane française, la mangrove couvre l'essentiel du littoral. Elle tire son originalité d'une dynamique influencée par le système de dispersion des boues amazoniennes. Les variations de la ligne de côte sont alors importantes et les mangroves s'y développant constituent des faciès variés. Pour mieux comprendre la structure et la dynamique de ces mangroves, un site atelier a été choisi au niveau de l'estuaire de la rivière de Kaw. Les mesures sur le terrain de paramètres de structure des peuplements permettent d'identifier 3 grands types de forêt avec différents stades de développement. Des relations entre les différents paramètres mesurés mettent en évidence la dynamique de ces faciès, basée sur un phénomène d'auto-éclaircie puis une régénération par chablis. Un essai de corrélation entre paramètres de structure et paramètres spectraux correspondant sur une image IKONOS a été faite. L'apport des indices de texture est discuté. Une classification de l'image montre la distribution spatiale des faciès. Parallèlement, la reconstitution d'une série temporelle de 1950 à 2001 à partir de données de télédétection variées permet de suivre l'évolution de la côte et de la mangrove associée. Pendant cette période se succèdent phases d'accrétion (1950-1981 ; 1991-2001) et phase d'érosion (1981-1991). Une carte des âges théoriques des peuplements est également établie. Mise en relation avec la carte des faciès, elle explique notamment l'évolution complexe des zones limitées de mangrove à Rhizophora. Une comparaison avec le site de Sinnamary est faite et de futures recherches envisagées.
https://hal.archives-ouvertes.fr/hal-01189238

hal-01189238
https://hal.archives-ouvertes.fr/hal-01189238
PRODINRA : 18075

Éditeur(s) : HAL CCSD
Résumé : International audience
The giant Imiter silver mine located at the northern edge of the West African craton in Morocco is assumed to be a late Neoproterozoic epithermal deposit mainly characterized by a hypogene paragenesis of Agrich sulphides and sulfosalts, and Ag-Hg alloys occuring preferentially in quartz-rich veins. The secondary enrichment zone at Imiter reaches a thickness of 50 to 150 m below ground surface. The upper levels, famous because of giant native silver crystals, grade up to 300 kg/t. Metallographic observations, SEM-EDS and XRD analyses reveal the presence of a quite complex secondary paragenesis made of acanthite, cinnabar, imiterite, perroudite, cerussite, mimetite, iron oxyhydroxides, synchisite and coronadite. Supergene alteration processes of the giant Imiter silver mine deposit consist of the remobilisation of the primary hypogene paragenesis by (i) deep and old basinal brines and (ii) downward infiltrations of surficial waters becoming progressively more reduced and F-enriched in response to fluid-rock interactions. Development of such a supergene mineralization strongly suggests prevalence of arid to semiarid conditions.
Let's talk ore deposits, proceeding of the eleventh biennial sga meeting
Antofagasta, Chile

hal-00601984
https://hal-brgm.archives-ouvertes.fr/hal-00601984
https://hal-brgm.archives-ouvertes.fr/hal-00601984/document
https://hal-brgm.archives-ouvertes.fr/hal-00601984/file/SGA2011_0234.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Signatures are one of the most accessible and prevailed ways of authenticating documents.Over the last many years, a large number of signature verication systems have been reported. Acommon assumption in nearly all of these system is that the signatures are available readily extractedfrom documents. In this paper we provide a detailed literature survey on the subject and arguethat pre-extracted signatures are not always available especially in forensic cases. Furthermore, wepresent a novel system of automatically extracting signatures from documents with the help ofhyper-spectral imaging. Initial experiments reveal that the proposed idea possess great potential toform a baseline signature extraction system above whom any signature verication system can beadjuncted for signature verication.
17th Biennial Conference of the International Graphonomics Society
Pointe-à-Pitre, Guadeloupe

hal-01165888
https://hal.univ-antilles.fr/hal-01165888
https://hal.univ-antilles.fr/hal-01165888/document
https://hal.univ-antilles.fr/hal-01165888/file/IGS_2015_submission_18.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The coastal sediments of Rhodes in the eastern Mediterranean have recorded transgression-regression cycles that took place during the early Pleistocene. The sedimentary deposits from the Kritika Member of the Rhodes Formation consist in conglomerates, sandstones, siltstones and clays deposited in brackish to shallow marine environments. Faunal associations are dominated by molluscs and reveal rapid ecological changes. Carbon and oxygen isotope ratios of aquatic skeletal carbonates show that these ecological changes were most likely driven by large salinity changes while water temperature remained rather constant at about 22.0 ± 1.5 °C. The tectonic activity of the island rather than glacio-eustatic variations of climatic origin is advocated to be responsible for the ecological and salinity changes and sea-level variations recorded in the sedimentary sequence.
ISSN: 0031-0182

hal-00767568
https://hal.archives-ouvertes.fr/hal-00767568
DOI : 10.1016/j.palaeo.2012.06.009

Éditeur(s) : Elsevier Sci Ltd
Résumé : A detailed morphological analysis of the outer shelf and continental slope of the Western Gulf of Lion is presented, based on swath bathymetry data together with sub-bottom profiles and high resolution seismic reflection profiles. These data reveal two main erosive features, of very different dimensions: the axial incision and the canyon's major valley. The height of axial incisions' flanks with respect to the canyon deepest point (the thalweg) ranges from 40 to 150 m. It creates a small axial erosive path within the canyon's major valley, which is typically bounded by flanks of more than 700 m in height. We interpret the axial incision observed in the sea floor as the imprint of turbidity currents that eroded the floor of canyons during phases of connection to rivers (hyperpycnal turbidity current). Such currents are most likely to have formed during the Last Glacial Maximum (LGM) as both proximity of the shoreline (due to the lowstand of sea level) and high detrital sediment supply (due to glacial abrasion upstream) increased the flow of sediments delivered to the canyon heads. Fossil axial incisions, observed in seismic lines, are related to equivalent conditions. The axial incision, however, has a key influence on canyon evolution as it triggers mass wasting of different sizes that affect the canyon's major valley (head and flanks). We interpret the geometry of the canyon's major valley as the result of recurrent activity of axial incisions. These periods of activity occurred during low sea levels at glacial maxima and show a cyclicity of 100,000 years for the last 400,000 years.
Marine And Petroleum Geology (0264-8172) (Elsevier Sci Ltd), 2005-06 , Vol. 22 , N. 6-7 , P. 805-826

Droits : 2005 Elsevier Ltd All rights reserved
http://archimer.ifremer.fr/doc/2005/publication-353.pdf
DOI:10.1016/j.marpetgeo.2005.03.011
http://archimer.ifremer.fr/doc/00000/353/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In fold and thrust belts drainage organization and patterns of sedimentation depend conceptually on the ability or not for preexisting reaches to incise uplifting thrust sheets. In this study we investigate experimentally the dynamics of drainage network in a wedge submitted to shortening and erosion. It allows us to reproduce and to monitor the interactions between tectonics, erosion and sedimentation during the development of up to five successive thrust sheets. In the experiments channels adjust to uplift rate by both increasing their slope and narrowing their channels as it is observed in nature. The series of experiments shows that the proportion of persistent preexisting transverse channels increases with the ratio of rainfall over shortening rates. The experiments confirm the view that the competition between discharge and tectonic uplift controls along-strike variations in sediment flux in sedimentary basins by controlling the drainage organization. If the transverse channels draining a wedge are not diverted, a line-source dispersal system develops in front of the active structure. If channels are diverted in the backlimb of the frontal structure it results in point-sourced depositional systems separated by areas fed only by small channels developing in the front of the wedge. Fans accumulated in front of the active structures reveal two stages of sedimentation, one of progradation, while the frontal structure is active and a second one of valley backfilling and thrust sealing during internal deformation of the wedge. The experiments also suggest that spatial variations in rock uplift rate along a thrust front may be evidenced by minimum-discharge variations of persistent transverse channels.
ISSN: 0040-1951

insu-01252482
https://hal-insu.archives-ouvertes.fr/insu-01252482
DOI : 10.1016/j.tecto.2015.09.007

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Gibraltar arc, spans a complex portion of the Africa-Eurasia plate boundary marked by slow oblique convergence and intermediate and deep focus seismicity. The seemingly contradictory observations of a young extensional marine basin surrounded by an arcuate fold-and-thrust belt, have led to competing geodynamic models (delamination and subduction). Geophysical data acquired in the past decade provide a test for these models and support a narrow east-dipping, subduction zone. Seismic refraction studies indicate oceanic crust below the western Gulf of Cadiz. Tomography of the upper mantle reveals a steep, east-dipping high P-wave velocity body, beneath Gibraltar. The anisotropic mantle fabric from SKS splitting shows arc-parallel "fast directions", consistent with toroidal flow around a narrow, westward retreating subducting slab. The accompanying WSW advance of the Rif-Betic mountain belt has constructed a thick pile of deformed sediments, an accretionary wedge, characterized by west-vergent thrust anticlines. Bathymetric swath‐mapping images an asymmetric embayment at the deformation front where a 2 km high basement ridge has collided. Subduction has slowed significantly since 5 Ma, but deformation of recent sediments and abundant mud volcanoes suggest ongoing activity in the accretionary wedge. Three possible origins for this deformation are discussed; gravitational spreading, overall NW-SE convergence between Africa and Iberia and finally a WSW tectonic push from slow, but ongoing roll-back subduction. In the absence of arc volcanism and shallow dipping thrust type earthquakes, evidence in favor of present-day subduction can only be indirect and remains the object of debate. Continued activity of the subduction offers a possible explanation for great (M > 8.5) earthquakes known to affect the area, like the famous 1755 Great Lisbon earthquake. Recent GPS studies show SW motion of stations in N Morocco at velocities of 3-6 mm/yr indicating the presence of an independent block, a "Rif-Betic-Alboran" microplate, situated between Iberia and Africa.
ISSN: 0040-1951

insu-00769762
https://hal-insu.archives-ouvertes.fr/insu-00769762
DOI : 10.1016/j.tecto.2012.08.038