Éditeur(s) : HAL CCSD Elsevier
Résumé : In order to address the question of the processes involved during shear zone nucleation, we present a petro-structural analysis of millimetre-scale shear zones within the Roffna rhyolite (Suretta nappe, Eastern central Alps). Field and microscopic evidences show that ductile deformation is localized along discrete fractures that represent the initial stage of shear zone nucleation. During incipient brittle deformation, a syn-kinematic metamorphic assemblage of white mica + biotite + epidote + quartz precipitated at ca. 8.5 ± 1 kbar and 480 ± 50 °C that represent the metamorphic peak conditions of the nappe stacking in the continental accretionary wedge during Tertiary Alpine subduction. The brittle to ductile transition is characterized by the formation of two types of small quartz grains. The Qtz-IIa type is produced by sub-grain rotation. The Qtz-IIb type has a distinct CPO such that the orientation of c-axis is perpendicular to the shear fracture and basal and rhombhoedric slip systems are activated. These Qtz-IIb grains can either be formed by recrystallization of Qtz-IIa or by precipitation from a fluid phase. The shear zone widening stage is characterized by a switch to diffusion creep and grain boundary sliding deformation mechanisms. During the progressive evolution from brittle nucleation to ductile widening of the shear zone, fluid–rock interactions play a critical role, through chemical mass-transfer, metasomatic reactions and switch in deformation mechanisms.
ISSN: 0191-8141

hal-01355954
https://hal.archives-ouvertes.fr/hal-01355954
DOI : 10.1016/j.jsg.2016.02.015

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
A dense, local network of 30 geodetic markers covering a 50 × 60 km2 area in the southwestern European Alps (Briançon region) has been temporarily surveyed in 1996, 2006 and 2011 by GPS. The aim is to measure the current deformation in this seismically active area. The study zone is characterized by a majority of extensional and dextral focal mechanisms, along north–south to N160 oriented faults. The combined analysis of the three measurement campaigns over 15 years and up to 16 years of permanent GPS data from the French RENAG network now enables to assess horizontal velocities below 1 mm/year within the local network. The long observation interval and the redundancy of the dense campaign network measurement help to constrain a significant local deformation pattern in the Briançon region, yielding an average E–W extension of 16 ± 11 nanostrain/year. We compare the geodetic deformation field to the seismic deformation rate cumulated over 37 years, and obtain good coherencies both in amplitude and direction. Moreover, the horizontal deformation localized in the Briançon region represents a major part of the Adriatic-European relative plate motion. However, the average uplift of the network in an extensional setting needs the presence of buoyancy forces in addition to plate tectonics.
ISSN: 0264-3707

hal-01119724
https://hal.archives-ouvertes.fr/hal-01119724
DOI : 10.1016/j.jog.2015.02.001

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This study aimed to identify factors associated with virological response (VR) to raltegravir (RAL)-containing regimens in 468 treatment-experienced but integrase inhibitor-naive HIV-1 patients receiving a RAL-containing regimen. VR was defined at Month 6 (M6) as HIV-1 RNA viral load (VL) <50 copies/mL. The impacts on VR of baseline integrase mutations, VL, CD4 count, genotypic sensitivity score for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors, and the number of new antiretrovirals used for the first time associated with RAL were investigated. For patients with VL >50 copies/mL at M6, integrase mutations selected were characterised. Median baseline VL was 4.2 log(10)copies/mL (IQR 3.3-4.9 log(10) copies/mL) and CD4 count was 219 cells/mm(3) (IQR 96-368 cells/mm(3)). At M6, 71% of patients were responders. In multivariate analysis, baseline VL and CD4 count and ≥ 2 new antiretrovirals among darunavir, etravirine, maraviroc and enfuvirtide were associated with VR to RAL. Neither HIV-1 subtype nor baseline integrase polymorphisms were associated with VR to RAL. Among 63 failing patients at M6, selection of ≥ 1 change in the integrase gene was observed in 49 (77.8%), and 27/63 (42.9%) were considered as RAL-associated resistance mutations. Factors independently associated with the occurrence of ≥ 1 RAL-associated resistance mutation were VL at failure >3 log(10) and having no new drugs associated with RAL. RAL showed great potency in treatment-experienced patients. The number of new drugs associated with RAL was an important factor associated with VR. HIV-1 subtype and baseline integrase polymorphisms do not influence the RAL VR.
ISSN: 0924-8579

hal-00875083
https://hal.archives-ouvertes.fr/hal-00875083
DOI : 10.1016/j.ijantimicag.2013.02.016
PUBMED : 23562640

Éditeur(s) : HAL CCSD
Actes du 38ème Congres Groupe Français des pesticides
Brest, France

hal-00672031
https://hal.archives-ouvertes.fr/hal-00672031

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
The impact of stratospheric ozone on the tropospheric general circulation of theSouthern Hemisphere (SH) is examined with a set of chemistry‐climate models participatingin the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐ClimateModel Validation project phase 2 (CCMVal‐2). Model integrations of both the past andfuture climates reveal the crucial role of stratospheric ozone in driving SH circulationchange: stronger ozone depletion in late spring generally leads to greater polewarddisplacement and intensification of the tropospheric midlatitude jet, and greater expansion ofthe SH Hadley cell in the summer. These circulation changes are systematic as polewarddisplacement of the jet is typically accompanied by intensification of the jet and expansion ofthe Hadley cell. Overall results are compared with coupled models participating in theIntergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), andpossible mechanisms are discussed. While the tropospheric circulation response appearsquasi‐linearly related to stratospheric ozone changes, the quantitative response to a givenforcing varies considerably from one model to another. This scatter partly results fromdifferences in model climatology. It is shown that poleward intensification of the westerly jetis generally stronger in models whose climatological jet is biased toward lower latitudes.This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.
ISSN: 2169-897X

hal-00337060
https://hal.archives-ouvertes.fr/hal-00337060
https://hal.archives-ouvertes.fr/hal-00337060/document
https://hal.archives-ouvertes.fr/hal-00337060/file/Bock_et_al-2008-Journalsur Geophysical_Research__Solid_Earth_%281978-2012%29.pdf
DOI : 10.1029/2008JD010327

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The investigation of deformation rates on a mountain piedmont can provide key information for improving our understanding of the overall dynamics of a mountain range. Here, we estimate the shortening rate absorbed by a Quaternary emergent detachment fold on the southeastern piedmont of the Tianshan (China). Our work is primarily based on new 10Be cosmogenic exposure dating of deformed alluvial surfaces. The method we have developed combines depth profiling with sampling of surface cobbles, thereby allowing exposure time, erosion rate and inheritance to be simultaneously constrained. The exposure ages of the uppermost uplifted alluvial surfaces are around 140±17 ka140±17 ka, 130±9 ka130±9 ka and 47±9 ka47±9 ka, from west to east. A terrace lying below the 140 ka surface is dated at 65±5 ka65±5 ka. The ages of the uplifted and folded alluvial surfaces were then combined with estimates of shortening obtained using two distinct methods: (1) the excess area method, where sedimentation rates, extracted from magnetostratigraphic studies, are used to determine the amount of sedimentation after the abandonment of the river; and (2) a folding model derived from sandbox experiments. The late Pleistocene shortening rates are shown to be between 0.4±0.1 mm/yr0.4±0.1 mm/yr and 0.8±0.5 mm/yr0.8±0.5 mm/yr on the western part of the fold and 2.1±0.4 mm/yr2.1±0.4 mm/yr along its central part. The central part of the frontal Yakeng anticline therefore accommodates up to 25% of the total shortening currently absorbed across the whole Eastern Tianshan range (8 mm/yr). However, this situation seems to have prevailed for only the last 150 ka, as the shortening rate absorbed by this nascent fold was previously ten times slower. While the initiation of folding of the Yakeng anticline can be traced back to 5.5 Ma ago, the basinward migration of the active deformation front onto the Yakeng fold is a relatively recent phenomenon and appears to be diachronous from west to east, probably in relation to the tectonic activity of the folds in the hinterland.
ISSN: 0012-821X

hal-01306997
https://hal.archives-ouvertes.fr/hal-01306997
DOI : 10.1016/j.epsl.2015.11.041

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
The Tian Shan Mountains constitute central Asia's longest and highest mountain range. Understanding their Cenozoic uplift history thus bears on mountain building processes in general, and on how deformation has occurred under the influence of the India-Asia collision in particular. In order to help decipher the uplift history of the Tian Shan, we collected 970 samples for magnetostratigraphic analysis along a 4571-m-thick section at the Jingou River (Xinjiang Province, China). Stepwise alternating field and thermal demagnetization isolate a linear magnetization component that is interpreted as primary. From this component, a magnetostratigraphic column composed of 67 polarity chrons are correlated with the reference geomagnetic polarity timescale between ~1 Ma and ~23.6 Ma, with some uncertainty below ~21 Ma. This correlation places precise temporal control on the Neogene stratigraphy of the southern Junggar Basin and provides evidence for two significant stepwise increases in sediment accumulation rate at ~16–15 Ma and ~11–10 Ma. Rock magnetic parameters also undergo important changes at ~16–15 Ma and ~11–10 Ma that correlate with changes in sedimentary depositional environments. Together with previous work, we conclude that growth history of the modern Tian Shan Mountains includes two pulses of uplift and erosion at ~16–15 Ma and ~11–10 Ma. Middle to upper Tertiary rocks around the Tian Shan record very young (<~5 Ma) counterclockwise paleomagnetic rotations, on the order of 15° to 20°, which are interpreted as because of strain partitioning with a component of sinistral shear that localized rotations in the piedmont.
ISSN: 0278-7407

insu-00376345
https://hal-insu.archives-ouvertes.fr/insu-00376345
https://hal-insu.archives-ouvertes.fr/insu-00376345/document
https://hal-insu.archives-ouvertes.fr/insu-00376345/file/2007TC002137.pdf
DOI : 10.1029/2007TC002137

Éditeur(s) : HAL CCSD Elsevier Elsevier Masson
Résumé : New field and micropalaeontological investigations have been conducted in four of the Pliocene rias of the internal zone of the Rif in Morocco, on the southern margin of the Alboran Sea. We found that marine sediments outcropping in these rias were deposited mainly during the Early Zanclean, between 5.04 and 3.8 Ma. After a transgressive episode that led to the deposition of terrestrial to marine conglomerates, dark clays deposited first at shallow palaeo-depths and then at bathyal palaeo-depths. The rias were then infilled with a shallowing upward succession comprising marine clays and sandstone and, locally, terrestrial sediments that indicate their final emersion. No Gilbert-deltas were observed in these rias. The presence of transgressive deposits at the bottom of the rias, also identified in other basins of the external zone of the Rif, and the absence of Gilbert deltas question a catastrophic reflooding after the Messinian Salinity Crisis in this area.
ISSN: 1631-0713

hal-01115243
https://hal.archives-ouvertes.fr/hal-01115243
DOI : 10.1016/j.crte.2014.03.002

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
ISSN: 0002-9262

hal-01010674
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01010674
DOI : 10.1093/aje/kwt315
PUBMED : 24401564

Éditeur(s) : HAL CCSD Elsevier
Résumé : An integrated magneto-biostratigraphic study, based on calcareous nannofossils and foraminifers, together with the radiometric dating of a volcaniclastic layer found in several outcrops, was carried out on the hemipelagic deposits of the Lindos Bay Formation (LBF) at six localities on the island of Rhodes (Greece). Our highly refined chronostratigraphic framework indicates that the lower and upper lithostratigraphic boundaries of the LBF are diachronous. Associated with the 40Ar/39Ar age determination of 1.85 ± 0.08 Ma for the volcaniclastic layer, our data show that among the investigated outcrops, the Lindos Bay type locality section provides the longest record (1.1 Ma) of the LBF. Hemipelagic deposition occurred continuously from the late Gelasian (∼1.9 Ma) to the late Calabrian (∼0.8 Ma), i.e., from Chrons C2n (Olduvai) to C1r.1r (Matuyama) and from nannofossil Zones CNPL7 to CNPL10. This long record, together with the hemipelagic nature of the deposits, make the Lindos Bay type locality section a unique element in the eastern Mediterranean region, allowing future comparisons with other early Quaternary deep-sea sections available in the central and western Mediterranean regions.
ISSN: 0033-5894

hal-01467764
https://hal.archives-ouvertes.fr/hal-01467764
DOI : 10.1016/j.yqres.2016.05.002

Éditeur(s) : HAL CCSD
Résumé : International audience
This work presents a synthesis of the present-day knowledge on both emerged and submerged carbonate platforms of the Guadeloupe archipelago. Onshore and offshore data acquired during the KaShallow project are presented. Since the early Zanclean, some isolated platforms developed onto a Jurassic to Tortonian basement which displayed reliefs inherited from a major extensional tectonic episode dated from −8 to −5 Ma. Marie-Galante, Grande Terre and the southern shelf of Grande-Terre show strong similarities with Zanclean to Gelasian red-algal facies upward changing into early Calabrian coral facies. A major erosional unconformity (SB2) was recognized and allows to distinguish two early Calabrian formations (Calcaires à Agaricia Formation and Calcaires à Acropora Formation). The final emersion of these platforms is late Calabrian. The La Désirade platform displays Zanclean to early Piacenzian red-algal facies upward changing into coral facies. This platform emerged as soon as in the late Piacenzian. The island subsided again in relation with later extensional tectonic episode and early Calabrian reef platform then unconformably deposited. The Colombie bank deposits comprise Pliocene basinal deposits overlain by late Calabrian coral reefs. The Flandre bank might have emerged synchronously with La Désirade but was drowned only in the late Pleistocene-Holocene interval. Four extensional tectonic episodes have been identified in the late Miocene-Recent interval. Their effects depend on the location of the platforms within the fore-arc.
Bulletin Société Géologique de France

insu-00816463
https://hal-insu.archives-ouvertes.fr/insu-00816463
DOI : 10.2113/gssgfbull.184.1-2.99

Éditeur(s) : HAL CCSD
International conference on Environmental Epidemiology and Exposure ISEE/ISEA
Paris, France

hal-00697382
https://hal.archives-ouvertes.fr/hal-00697382

Éditeur(s) : HAL CCSD
Résumé : International audience
Acromyrmex octospinosus (Reich), est une fourmi champignonniste qui vit dans un nid souterrain en symbiose avec un champignon du genre Leucoagrinus. Elle est la seule espèce du genre Acromyrmex recensée en Guadeloupe et est appelée " Fourmi manioc". C'est une espèce invasive; découverte en 1954, dans une seule localité, elle est présente dans presque toute la totalité de l'île. Fourmi défoliatrice, elle s'attaque à de nombreuses cultures (vivrières, fruitières,....) et actuellement, elle représente un danger pour certaines espèces patrimoniales et des essences forestières. L'objectif du projet est de proposer des solutions de lutte efficaces mais respectueuses de la santé et de l'environnement et qui s'intègrent dans un schéma de développent durable de la Guadeloupe.
UIEIS-SF

hal-00684225
https://hal.archives-ouvertes.fr/hal-00684225

Éditeur(s) : HAL CCSD International Union Against Tuberculosis and Lung Disease
Résumé : International audience
ISSN: 1027-3719

inserm-00864941
http://www.hal.inserm.fr/inserm-00864941
DOI : 10.5588/ijtld.12.0051
PUBMED : 22762431

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The interpretation of high-resolution 2D marine seismic profiles together with the analysis of sea-bottom cores allowed a stratigraphic and structural framework of the Provence continental shelf to be proposed. The integration of onshore and offshore stratigraphy, structure and geomorphology provided new insights into Messinian paleotopography and paleohydrography. A geological map of the offshore Provence continental shelf, isobath map of the base Plio-Quaternary surface are presented for the first time in this area. The base Plio-Quaternary surface is a polyphased unconformity that is composed of deep canyons developed by fluvial erosion during the Messinian event, and wave-cut surfaces formed during post-Messinian transgressions. The study evidenced a deep, E-W-trending canyon (Bandol canyon) connected to the head of the Cassidaigne canyon, and filled with up to 600 m-thick Plio-Quaternary deposits. The development of canyons on the Provence margin during the Messinian event was dominantly controlled by the lithology and structure of pre-Messinian formations. A map of the Messinian paleo-drainage network is proposed to explain the presence of deep canyons in the Eastern area and the lack of incision in the Western area. An underground karst drainage scheme is proposed, linked with the current submarine Port-Miou spring.
ISSN: 0264-8172

insu-01009592
https://hal-insu.archives-ouvertes.fr/insu-01009592
https://hal-insu.archives-ouvertes.fr/insu-01009592/document
https://hal-insu.archives-ouvertes.fr/insu-01009592/file/Mar-Pet-Tassy.pdf
DOI : 10.1016/j.marpetgeo.2014.05.001

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The parasitic life cycle of Leishmania includes an extracellular promastigote stage that occurs in the gut of the insect vector. During that period, the sucrose metabolism and more specifically the first glycosidase of this pathway are essential for growth and survival of the parasite. We investigated the expression of the invertase BfrA in the promastigote and amastigote stages of three parasite species representative of the three various clinical forms and of various geographical areas, namely Leishmania major, L. donovani and L. braziliensis. Thereafter, we cloned, overexpressed and biochemically characterized this invertase BfrA from L. major, heterologously expressed in both Escherichia coli and L. tarentolae. For all species, expression levels of BfrA mRNA were correlated to the time of the culture and the parasitic stage (promastigotes > amastigotes). BfrA exhibited no activity when expressed as a glycoprotein in L. tarentolae but proved to be an invertase when not glycosylated, yet owing low sequence homology with other invertases from the same family. Our data suggest that BfrA is an original invertase that is located inside the parasite. It is expressed in both parasitic stages, though to a higher extent in promastigotes. This work provides new insight into the parasite sucrose metabolism
ISSN: 0008-6215

hal-01187142
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187142
DOI : 10.1016/j.carres.2015.07.001
PUBMED : 26279524

Éditeur(s) : HAL CCSD
Résumé : 16 p.
National audience
The objective of this paper is to present an approach for experimenting territorial prospective analysis based on spatial modelling. This approach is carried out in the framework of the DESCARTES project which aims at developing a spatial simulation tool to support the design and analysis of different scenarios for land-use allocation in Reunion Island in terms of environmental services. The spatial modelling tool is composed of two complementary applications: (i) the Ocelet modelling language and its land dynamics simulation environment, and (ii) the Margouill@ platform. The first demonstrator, a model of farm land consumption by urbanization, was developed and presented during workshops in order to test the role of the spatial simulation tool in support of a collaborative innovation process among stakeholders, and to foster new research on social learning, spatial simulation of environmental services, and scale change issues.
L'objectif de cet article est de présenter une démarche de construction d'un exercice de prospective territoriale basé sur un outil de modélisation spatiale. Cette démarche est mise en œuvre dans le cadre du projet ANR DESCARTES dont l'objectif est de construire un outil de simulation cartographique pour analyser différents scénarios d'affectation de l'usage des sols à l'Ile de La Réunion, en termes de services environnementaux. La plateforme de simulation cartographique est composée de deux applications complémentaires (i) le langage de modélisation Ocelet et son environnement de simulation de paysages dynamiques, et (ii) la plateforme Margouill@. Le développement puis la présentation, en atelier, d'un premier démonstrateur sur la consommation des terres agricoles par l'urbanisation a permis de tester l'outil cartographique comme support d'un processus d'innovation collective entre les parties prenantes, et d'ouvrir de nouveaux champs de recherche sur l'analyse de la démarche par les apprentissages, la spatialisation et la simulation prospective des services écosystémiques, et la prise en compte du changement d'échelle.
Acte de la Conférence Internationale de Géomatique et d'Analyse Spatiale
Brest, France

cirad-00850243
http://hal.cirad.fr/cirad-00850243
http://hal.cirad.fr/cirad-00850243/document
http://hal.cirad.fr/cirad-00850243/file/SAGEO-Brest2013-version_finale.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The thermal evolution of sediments in the shallowest part of sedimentary basins is challenging to investigate as most of the geothermometers are at their application limits. This is typically the case of the Callovian-Oxfordian claystones at the eastern border of the Paris Basin. A recent 2000 m deep well penetrated the entire Jurassic and Triassic sedimentary series and permitted coring of sediments never reached by previous drilling in this part of the basin. Thanks to the use of several independent geothermometers (apatite fission track thermochronology, fluid inclusion microthermometry, clay mineralogy and sedimentary organic matter evolution) the burial history of the Mesozoic series has been reconstructed, modeled and calibrated using kinetic algorithms relevant to the various paleothermometers used. In addition to these conventional methods, an innovative approach was developed using the temperature-dependence of the magnetic mineral assemblage within clay-rich sediments ("MagEval"). Thermal modeling indicates that the Callovian-Oxfordian and the Lower Triassic experienced maximum burial temperatures of 50 +/- 5 C-circle and 90 +/- 10 C-circle respectively, i.e., about 25 C higher than present-day. This temperature offset implies the erosion of several hundred meters of sediments which, depending on the thermal flux and conductivity considered, most likely constituted Upper Cretaceous chalk deposits. Falling sea level resulted in the exposure and subsequent dismantling of the chalk cover at the beginning of Cenozoic times. The eastern border of the basin was then subjected to slow erosion and discrete tectonic deformation.
ISSN: 0264-8172

hal-01313142
https://hal.archives-ouvertes.fr/hal-01313142
DOI : 10.1016/j.marpetgeo.2013.08.019

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
New investigations in the Neogene Boudinar basin (Morocco) provide new information about the Messinian Salinity Crisis (MSC) and Zanclean reflooding in the southern part of the Alboran realm (westernmost Mediterranean). Based on a new field, sedimentological and palaeontological analyses, the age and the geometry of both the Messinian erosional surface (MES) and the overlying deposits have been determined. The MES is of late Messinian age and was emplaced in subaerial settings. In the Boudinar basin, a maximum of 200 m of Miocene sediments was eroded, including late Messinian gypsum blocks. The original geometry of the MES is preserved only when it is overlain by late Messinian continental deposits, conglomeratic alluvial fans or lacustrine marly sediments. These sediments are interpreted as indicators of the sea-level fall during the MSC. Elsewhere in the basin, the contact between late Messinian and early Pliocene deposits is a low-angle dipping, smooth surface that corresponds to the early Pliocene transgression surface that subsequently re-shaped the regressive MES. The early Pliocene deposits are characterized by: (i) their onlap onto either the basement of the Rif chain or the late Miocene deposits; (ii) lagoonal deposits at the base to offshore marls and sands at the top (earliest Pliocene; 5.33–5.04 Ma interval; foraminifer zone PL1); (iii) marine recovery occurring in the 5.32–5.26 Ma interval; and (iv) the change from lagoonal to offshore environments occurring within deposits tens of metres thick. This information indicates that at least the end of the reflooding period was progressive, not catastrophic as previously thought.
ISSN: 0037-0738

hal-01306672
https://hal.archives-ouvertes.fr/hal-01306672
DOI : 10.1016/j.sedgeo.2015.12.014

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
ISSN: 0954-4879

hal-00708866
https://hal.archives-ouvertes.fr/hal-00708866
DOI : 10.1111/j.1365-3121-2011-014-x