Résumé : From the PNCR, GAP MPs free to vote conscience on gay rights bill By Johann Earle Stabroek News June 11, 2003 The PNCR will allow its members to vote their conscience on the controversial Constitution (Amendment) Act of 2001 which seeks to prevent discrimination against persons on the basis of their sexual orientation and other grounds. A number of religious organisations are opposed to the passage of the bill because it includes sexual orientation as one of the grounds. They are concerned that it could lead to a legalisation of homosexual relations and demands for recognition of gay marriages among other things. PNCR Member of Parliament (MP) Vincent Alexander told a forum at the National Library on Saturday, that the Bill did not seek to legalise homosexuality, but to ensure that persons would not be discriminated against based on their sexual preferences. He was one of two parliamentarians who showed up - the other being PNCR member, Myrna Peterkin. The forum was organised by Students Against Sexual Orientation Discrimination (SASOD), a group comprising fifteen students from the University of Guyana which was formed about two weeks ago. Alexander expects the vote on the bill to come up before the National Assembly in a matter of months. Paul Hardy, Leader of the Guyana Action Party (GAP), told Stabroek News that his party would not be using the so-called parliamentary whip. He added that GAP took a decision that every member should vote according to his or her own conscience. “We have no right to deny the rights of others based on sexual orientation. [The Bill] will guarantee rights to the homosexual.” GAP is in Parliament as part of an alliance with the Working People’s Alliance. GAP/WPA has two MPs. The bill was met with rejection from some members of the religious community in 2001 and as a result of this, the President did not assent to it. In a statement on Monday, the Central Islamic Organisa-tion of Guyana (CIOG) said that it stood in firm opposition to the Bill. The CIOG says the general purpose of the bill may be commendable and that the organisation’s objection is not based on a willingness to promote discrimination. Rather, the CIOG said, it was based on the fact that specific legal protection on the basis of sexual orientation without definition or qualification gives tacit legitimacy to practices which are considered criminal in Islam. “It is foreseeable that such a legal nod of approval (subtle as it may be) of these practices may pave the way for greater social (or even legal) acceptability in the future which, from the perspective of all Muslims including those in Guyana, is an undesirable and sinful outcome,” the CIOG statement said. At Saturday’s event, Muslim teacher Moulana Mohamed Ali Zenjibari spoke of instances of abuse, discrimination and harsh penalties meted out to gay and lesbian persons in countries such as Iran and Saudi Arabia and noted that the Quran did not sanction such punishments for homosexual behaviour. President of the CIOG, Fazeel Ferouz told Stabroek News that a meeting to discuss a strategy with regards to the bill was planned for tomorrow with various religious groups. Stabroek News tried to get a comment on the issue from the PPP/C but to no avail. ROAR leader, Ravi Dev said that his party was now having discussions on the issue. ROAR feels that it is an important question which has to do with morality and should be discussed across the country. He added legislators had to be in tune with their constituents on the issue. SASOD is lobbying for the legislation through the sensitisation of MPs. Keimo Benjamin, a law student at UG, gave a presentation based on the jurisprudential aspects of the discussion on sexual orientation. He argued that morality should not be the only guiding principle on which to base the laws. Sexual activities between two consenting male adults in private could not be equated with a violation of a person’s rights, he said, making the point that the thrust of his presentation was not whether homosexuality was wrong, but whether it violated the rights of others. He said that the attitudes of some towards this subject were based on preconceived notions and prejudices. He cited studies to show that the suppression of certain perceived deviant sexual impulses in persons might do more harm than good. One Harvard University study of teens who said they were gay indicated that those teens were three times more likely to commit suicide. Vidyaratha Kissoon, of Help and Shelter, in his contribution on Saturday, expressed his displeasure at the low turnout at the forum and urged the parliamentarians who showed up to take the message to their colleagues. He noted that because of homophobia, the numerical minority was terrified of speaking out against instances of discrimination. Gays and lesbians in Guyana were subjected to ridicule and abuse, and walk the streets at night not looking for sex necessarily, but for the companionship of persons who empathise with them. During his presentation, Joel Simpson, another member of SASOD, outlined a number of changes made within national jurisdictions that had international implications. One such crucial change was South Africa’s 1996 adoption of a new constitution, making that country the first in the world to expressly include sexual orientation as a prohibited ground of discrimination. It was the first time a developing country had taken the lead with respect to the rights of sexual minorities. He also said that according to Douglas Sanders, a Canadian jurist, the rights of homosexual, bisexual or transsexual men and women had never been officially recognised by the United Nations, despite the fact that international laws on the issue began to emerge at the close of the Second World War. Simpson said that under Article 170 (5), as amended by Section 8 of the Constitution (Amendment) (No. 4) Act 2000, the President is required to assent to any bill which is returned by the National Assembly unaltered after a two-thirds majority within 90 days of its presentation to him. To the parliamentarians present, Simpson stressed that the onus was now on them to adequately represent their constituents which include lesbian, gay, bisexual and transsexual Guyanese. http://www.landofsixpeoples.com/news301/ns306115.htm and Vote on sexual orientation should be a matter of conscience - MP Alexander By Esther Elijah Guyana Chronicle June 8, 2003 PEOPLE’S National Congress (PNC/R) Member of Parliament Mr. Vincent Alexander, said the Opposition will vote on “conscience” when the piece of legislation on sexual orientation is again brought before the National Assembly. “With specific reference to my party, when this Bill gets back to the Parliament in the spirit of the arguments here, we will not use the `whip’. Our party will not say we have to vote for the provision (in the Sexual Orientation Bill). We will allow our members to vote as a matter of conscience,” he told participants gathered in the Conference Room of the National Library. “We feel this is a matter of conscience. You may end up with a collective position but you have to deal with us individually,” Alexander said at a poorly attended public consultation aimed at gaining support for sexual orientation to be considered a fundamental right in Guyana. Alexander, one of the main persons who sat on the Constitutional Reform Commission that addressed this controversial clause, said the legislation was not meant to legalise homosexual activities in Guyana. “It was intended to ensure that persons who have an orientation - a way of thinking - which may or may not lead to a certain activity, to not be discriminated against, in terms of their rights,” he explained. Alexander noted that very often, discussions on the sexual orientation provision in the Bill have led to seepages into other areas where debates centre on the “right to be homosexual.” “I am saying the Bill does not comment on that… However, law is peculiar, especially in a Common Law system. Once you venture out and change the law, very often you open other windows which we cannot definitively say exist or does not exist in advance,” he said. “The fear of some people is that the legislators might say one thing and the Courts will eventually say something else. While some people can’t argue against the law, per say, they will say this has opened a window of opportunity not meant to be opened. So, it is better to stay without a window than open it and then have a possibility of something you didn’t intend to happen - happening sometime in the future.” Alexander added: “I want to say I’ve found this activity to have been rich from the perspective of the amount of research which was done by student (speakers). Without any comment as to whether I agree with the arguments, I would wish that much more research on other issues be done by students, and that at the University (of Guyana) students would find it convenient to have forums on other issues, with the same depth of research for their own intellectual development.” Alexander and other Opposition M.P, Lurlene Nestor were the only three Parliamentarians in attendance at the session organised by the recently formed `Students Against Sexual Orientation Discrimination’ (SASOD), a group that has a membership of 15 mostly University of Guyana (UG) students from various faculties. SASOD was established two weeks ago. With the exception of members of the press, the consultation only managed to attract 11 persons, a handful of who were SASOD members. While congratulating the students for an “insightful” presentation, Nestor pointed out that whether or not she chooses to agree with their position is “another issue” and she is entitled to her “own view”. “The issue of sexual orientation is very `toucheous’ …while we agree with the human rights provisions and all that as a society, we must also revert to our own society. Some of the very critical questions that I would want to ask is whether or not at the society (level) we are ready for that kind of thing,” she remarked. “We cannot, at (any) time, ignore the religious groups in our society. If we look at statistics going back to 1992 from a survey done by the Bureau of Statistics, we would see that a small section of the Guyanese population might be considered as people who do not subscribe to a religious view. While the laws are not necessarily based on moral values, we must acknowledge the fact that we might want to revert to many of the cases that (concern) laws that protect public morality.” Nestor told the speakers at the consultation these were some of the issues that they needed to deal with. She highlighted, too, that what must be examined is the effects of same-sex marriages on society and how this issue must be tackled. “These are some of the things we should consider and I don’t think you dealt with that in the presentations,” Nestor stated, adding that the issues must be addressed “frontally.” “Do we think that with the coming to being of this Bill that there might be quite a number of challenges to the Constitution in relation to the same issue of a man marrying a man? What do we do at the society (level)? Do we recognise that?” were the questions directed at the five speakers at the session. Nestor continued: “There is some argument that says, `Oh the Bill does not promote homosexuality or does not encourage a man to marry (another) man, but if you look at Section (15) that talks about `non-discrimination’ then how can we not, with the passage of this Bill, allow a man not to marry (another) man.” According to Nestor, matters of this nature constitute some of the “inconsistencies” of the Bill. On the argument raised by presenters at the session on who determines what is morality, Nestor said in the concept of democracy it is the people who are the determinants based on a “line of thinking.” She also rebutted on grounds that put the spotlight on teachers who may have been caught “interfering” with their young students and who may subsequently be dismissed from their jobs. “Could you imagine such a person interfering with a boy below age 10 - and by virtue of the fact that the Bill is there, the judges (in the case) will have to use their discretion in terms of what happens. We will have more Constitutional changes and problems (arising with the passage of the Bill).” SASOD member and law student, Joel Simpson, in reply, said he doesn’t think any homosexual in Guyana wants to “run into a church and ask that people marry them or anything of that sort.” At one point likening the church to a “club”, Simpson claimed the church has the right to exclude whomever it wants. He further stated that in accordance with the Constitution, people of the same sex do not currently have the right to marry, and will also not be able to do such an act with the passage of the Bill. However, Simpson said it is possible that the law, with the passage of the Bill, would have to recognise same-sex domestic partnerships in relation to employment benefits, sharing of properties, etc. Simpson said he believes there should be a realm of “public” and “private” morality between consenting adults, and implied that the Bill did not fully give “rights” to homosexuals. But, Nestor interjected: “I am informing you further…that the Sexual Orientation provision has, in fact, in some way recognised the rights of homosexuals and we must accept that.” Meanwhile, there was no vocal Christian representative(s) at the consultation and apart from the two Opposition representatives none other participant gave comments or directed questions at the presenters. Other speakers in support of the sexual orientation clause were: Moulana Mohammed Ali Zenjiban, Assistant Director of the International Islamic College; Denuka Radzik from Red Thread, Keimo Benjamin, UG law student and Vidyartha Kissoon from Help & Shelter. The Sunday Chronicle has been reliably informed that the Georgetown Ministers Fellowship, representing groups of Christian leaders staunchly against sexual orientation as a right in Guyana, have recently prepared a detailed 16-page document outlining issues arising from research to further boost their argument against the inclusion of the clause. The document is yet to be made public. http://www.landofsixpeoples.com/news301/nc306083.htm

Droits : All rights reserved by the source institution.
http://ufdc.ufl.edu/AA00014700/00001

Éditeur(s) : Université de Brest
Résumé : The channel-lobe transition zone has been studied in two turbiditic systems: the Amazon channel-mouth lobe complex at the termination of the last eight channel-levee systems and the Neochannel termination, the last active channel of the Petit-Rhone turbidite system. - In the two cases, the internal geometry and stacking pattern of the deposits show a significant control of the configuration (size and shape) of the receiving basins, their morphology (gradients and subtle gradient changes), and their degree of confinement. - The Amazon and Petit-Rhone systems, with lobes built after the Last Glacial Maximum and the ensuing sea-level rise, evidence the major impact of external forcings (climatic events and eustatic variations) that induce variations in sediment fluxes delivered to the deep basin and therefore exert a control on channel-mouth lobes construction. The channel-mouth lobes of the Amazon and Petit-Rhone systems, even if they are located at great distances from the river mouths, at the termination of the turbidite systems and in areas characterised by subtle morphological variations, are both constrained by combined internal (accommodation and compensation) and external factors (post-glacial deconnection between the fluvial system and the deep basin).
La zone de transition chenal-levées/lobes a été étudiée dans 2 systèmes turbiditiques : le complexe de lobes à la terminaison des 8 derniers chenaux de l'éventail de l'Amazone et la terminaison du Néochenal, dernier chenal de l'éventail du Petit-Rhône. - Dans les deux cas, l'agencement des dépôts et leur évolution dans l'espace et le temps révèlent un fort contrôle de la configuration des réceptacles (taille et forme), de la morphologie des fonds (pentes et taux de changement des pentes) et du degré de confinement. - Les systèmes de l'Amazone et du Petit-Rhône, dont les lobes se sont construits à partir du Dernier Maximum Glaciaire et lors de la remontée du niveau marin qui a suivi, ont en outre permis de souligner l'impact majeur, sur la mise en place des lobes terminaux, de certains forçages externes (événements climatiques et variations eustatiques), qui déterminent les variations des flux sédimentaires arrivant au bassin. Ainsi, bien que situés à des distances considérables des sources fluviatiles et dans des zones distales où les variations de relief sont très ténues, les lobes terminaux de ces deux grands systèmes turbiditiques se sont révélés contraints à la fois par des processus internes (processus de compensation) et par des processus externes (déconnexion post-glaciaire du fleuve et du bassin).

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-6796.pdf
http://archimer.ifremer.fr/doc/00000/6796/

Éditeur(s) : INRA : Institut National de la Recherche Agronomique Université des Antilles. Service commun de la documentation University of Suriname
Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS
Description : Many rural areas in Suriname are lacking information on technology from extension agents from the government extension agency, and research institutes. Communication and informal voices of farmers are shared by media. As part of a baseline study conducted for the sixth operational strategic plan of the Small Grants Programme in Suriname, four communities were selected: Moengo, Pokigron, Nickerie, Sipaliwini and Para. The purpose of this study was to collect data from communities regarding problems related to climate change, agricultural innovation and landscape management. This qualitative study was done through the focus group method. Eight focus group meetings were organized and consisted of 8-15 participants each. The key questions were extracted from the SEPLS method (Socio-ecological Production Landscapes and Seascapes). The data was analyzed through the SWOT method. Based on the results, the communities have a good level of awareness about management of their landscapes. Improvement of agriculture management will be possible by access to innovative and new knowledge developed in and outside the community. Climate change is an important issue that the community already is aware of, they developed their own local strategy in resilience to this issue. Beaucoup de zones rurales au Surinam manquent d'information sur la technologie des agents de vulgarisation de l'agence d'extension de gouvernement, et des instituts de recherche. La communication et les voix informelles des agriculteurs sont partagées par media. En tant qu'élément d'une étude de ligne de base entreprise pour le sixième plan stratégique opérationnel du petit programme de concessions au Surinam, les quatre communautés ont été sélectionnées : Moengo, Pokigron, Nickerie, Sipaliwini et paragraphe. Le but de cette étude était de rassembler des données de communautés concernant des problèmes liés au changement climatique, à l'innovation agricole et à la gestion de paysage. Cette étude qualitative a été faite par la méthode de groupe cible. Huit réunions de groupe cible ont été organisées et se sont composées de 8-15 participants chacun. Les questions clé ont été extraites à partir de la méthode de SEPLS (des paysages et des paysages marins Socio-écologiques de production). Les données ont été analysées par la méthode de BÛCHEUR. Basé sur les résultats, les communautés ont un bon niveau de conscience au sujet de la gestion de leurs paysages. L'amélioration de la gestion d'agriculture sera possible par l'accès aux connaissances innovatrices et nouvelles développées à l'intérieur et à l'extérieur de la communauté. Le changement climatique est une question importante que la communauté a pris en compte et développé sa propre stratégie locale dans la résilience.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16256
V16256

Éditeur(s) : Springer
Résumé : The Golo Margin in eastern Corsica is dissected by four canyons and two gullies which fed turbidite systems. Study of the dispersal of surficial sediments and flow dynamic in the Golo system is based on Kullenberg and interface cores interpreted in relation to a previously published seismic dataset. Cores were described in detail and interpreted within a sedimentary and stratigraphic framework. During the last 42,000 years, gravity processes which occurred in the large systems with a canyon source were mainly slide-induced, differentiated turbulent surges and hyperpycnal flows. Processes occurring in the small system with a gully source are mainly hyperconcentrated and concentrated flows. Deposits from the Corsican Margin can intercalate with products of processes triggered on the Pianosa Ridge located in the eastern part of the basin. During relative sea-level lowstands or during periods of rapid or high-amplitude sea-level fall, only large canyons (South and North Golo) are supplied by carbonate-rich hyperconcentrated and concentrated flows which are channelled in incised valleys on the shelf. During periods of slow or low-amplitude sea-level fall and during sea-level rise, sediments are trapped on a shelf delta and intensely winnowed by shelf hydrodynamic processes. Sand-rich hyperconcentrated and concentrated flows occur. All the systems fed by a canyon are active simultaneously. Gullies form and are active only during periods of sea-level rise. During relative highstands of sea level (Holocene), all the system is draped by hemipelagic sediments. Relative sea-level changes and canyon location relative to river mouths have a strong influence on the nature of sediment input, and the initiation and type of gravity flows which, in turn, control morphology and geometry.
Geo-Marine Letters (0276-0460) (Springer), 2006-12 , Vol. 26 , N. 6 , P. 373-395

Droits : 2006 Springer
http://archimer.ifremer.fr/doc/2006/publication-3594.pdf
DOI:10.1007/s00367-006-0045-z
http://archimer.ifremer.fr/doc/00000/3594/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le changement climatique et le développement durable du tourisme représentent des enjeux majeurs pour l’avenir du tourisme dans plusieurs régions du monde, notamment aux Antilles françaises. Aussi, la présente étude se propose d’analyser et d’évaluer les effets économiques de la variation climatique sur le secteur touristique à la Guadeloupe et à la Martinique, pour quatre raisons essentielles : (a) le secteur du tourisme et les petites économies insulaires qui en dépendent, comme celles de la Guadeloupe et de la Martinique, sont fortement sensibles à la variabilité et au changement du climat. (b) la vulnérabilité intrinsèque de ces petites destinations et de leurs infrastructures à l’élévation du niveau de la mer et aux évènements climatiques extrêmes (cyclones, inondations, sécheresse), (c) la haute dépendance de l’industrie touristique régionale à l’utilisation des énergies fossiles, (d) enfin, en raison du fait qu’aucune évaluation économique chiffrée n’a été produite à ce jour sur les effets économiques de la la variation climatique sur le secteur touristique à la Guadeloupe et à la Martinique. Par conséquent, il importe de cerner dans ces deux régions les conséquences possibles de ce changement au plan touristique et d’envisager le cas échéant des stratégies d’adaptation et d’atténuation. Ce faisant, cette étude se fixe quatre objectifs principaux : (a) examiner les facteurs qui influencent la demande et l’offre de tourisme aux Antilles Françaises ; (b) effectuer à l’aide d’un modèle de demande touristique, l’impact économique de ces facteurs sur le nombre d’arrivées ainsi que sur la dépense touristique dans ces régions ; (c) évaluer et projeter en termes de coût, les effets du changement climatique sur l’activité touristique ; et (d) proposer aux autorités locales, des stratégies d’adaptation et d’atténuation face au défi du changement climatique.L’évaluation de ces différents effets est abordée ici à l’aide d’un modèle structurel de base (MSB) et d’un modèle structurel général (MSG), inspirés tous deux des travaux de Harvey (1990) pour capter à l’aide d’un indice climato-touristique, les éléments du climat qui impactent l’activité touristique. Cet indice synthétique est calculé en se basant sur les données climatiques du passé selon deux scénarios climatiques proposés par le groupe d’experts intergouvernemental sur l’évolution du climat (GIEC) – un scénario pessimiste A2, et un scénario optimiste B2-. Les résultats issus de l’application de ces modèles montrent que les caractéristiques climato-touristiques de la Guadeloupe et de la Martinique subiront vraisemblablement un déclin à long terme, et devraient au plan économique impacter négativement le secteur touristique de ces destinations, se traduisant par des pertes à la fois d’attractivité et de chiffre d’affaires du secteur. Les pertes subies par le tourisme en raison du changement climatique s’élèveraient à l’horizon 2100, et selon le scénario A2, à 45 millions d’euros à la Guadeloupe soit 0,7% de son PIB 2004, et à 60 millions d’euros à la Martinique soit 0,8% de son PIB 2004.
Climate change and the tourism sustainable development are important challenges for tourism future trends of many countries, including the French West Indies. Therefore, this study provides an evaluation of the likely economic effects of climate change on tourism sector in Guadeloupe and Martinique, and identifies four reasons why these countries should be concerned about the potential effects of climate change on tourism: (a) Guadeloupe and Martinique are island destinations very sensitive to climate change; (b) their intrinsic vulnerability and their infrastructure to sea level rise and extreme climatic events (e.g. hurricanes and floods); (c) the high dependence of their tourist industry on carbon-based fuels; and (d) up to date, no economic evaluation of climate change on tourism sector in Guadeloupe and Martinique is provided. Therefore, this study attempted to quantify the likely effects of the changes in the climatic factors on the economy of the French West Indies. There are four main objectives in this study. The first is to examine the factors that influence the demand and supply tourism in Guadeloupe and Martinique. The second is to forecast the impact of climate change to tourism arrivals until 2050 under two scenarios from the intergovernmental panel on climate change (IPCC) – A2: pessimistic scenario and B2: optimistic scenario-. Third is to evaluate and forecast the cost of climate change to the tourism sector until 2100. The fourth is to recommend to authorities the adaptation and mitigation strategies that can be undertaken by the tourism sector to French West Indies to address climate change.Following Harvey (1990), a Basic Structural Model (BSM) and a General structural Model (GSM), are employed to model tourist arrivals to Martinique. A tourism climatic index (TCI) conceptualized by Mieczkowski (1985) is used in this model to capture the elements of climate that impact on a destination’s experience. The results suggest that under both scenarios, the island’s key tourism climatic features will probably decline, and therefore, negatively impact on the destination experience of visitors. Tourism losses due to climate change are projected in 2100 to 45 millions euros in Guadeloupe, or 0.7% of its GDP, and to 60 millions euros in Martinique, or 0,8% of its GDP.
Guadeloupe
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6750
http://journals.openedition.org/etudescaribeennes/6750

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Detection and attribution of human influence on sea level rise are important topics that have not yet been explored in depth. We question whether the sea level changes (SLC) over the past century were natural in origin. SLC exhibit power law long-term correlations. By estimating Hurst exponent through Detrended Fluctuation Analysis and by applying statistics of Lennartz and Bunde [2009], we search the lower bounds of statistically significant external sea level trends in longest tidal records worldwide. We provide statistical evidences that the observed SLC, at global and regional scales, is beyond its natural internal variability. The minimum anthropogenic sea level trend (MASLT) contributes to the observed sea level rise more than 50% in New York, Baltimore, San Diego, Marseille, and Mumbai. A MASLT is about 1 mm/yr in global sea level reconstructions that is more than half of the total observed sea level trend during the XXth century.
ISSN: 0094-8276

hal-01336190
https://hal.archives-ouvertes.fr/hal-01336190
https://hal.archives-ouvertes.fr/hal-01336190/document
https://hal.archives-ouvertes.fr/hal-01336190/file/BECKER2014a.pdf
DOI : 10.1002/2014GL061027

Éditeur(s) : HAL CCSD Wiley
Résumé : SUBSURF
International audience
Similarity of form between subaerial and submarine landscapes affected by erosion could suggest similarities in the process of erosion, such as by runoff and sedimentary flows, respectively. On the other hand, if aspects of form vary, its characteristics may be used to identify the environmental origin of erosion. Towards these goals, this contribution addresses the morphology of submarine volcanoes (seamounts) with widely differing histories of erosion. One set from the Pacific Ocean never exposed above sea level includes Cretaceous-age seamounts near Hawai'i (including Apu'upu'u Seamount), two seamounts of < 3 Ma in age near a mid-ocean ridge and the 11-4 Ma Jasper Seamount. These seamounts are all isolated from continents and hence from any erosion associated with mass wasting of unstable terrigenous deposits. In such isolated submarine environments, surfaces erode slowly from in situ weathering, mass wasting and scouring by sedimentary flows initiated by slope failure in pelagic or bedrock materials. The Pacific seamounts are compared with Valencia Seamount in the western Mediterranean, exposed subaerially for 100-400 k.y. during the Messinian Salinity Crisis before 5 Ma. Multibeam and deeply towed sidescan sonar data of Valencia Seamount reveal features typical of subaerial erosion of volcanic islands, such as canyons and relatively uneroded sectors (planezes) between them. Using a simple topographical reconstruction, the apparent erosion depth typically reaches 100 m within canyons and up to 180 m in places. Whereas the younger Pacific seamounts do not show these erosional features, the much older Cretaceous seamounts do have channels, which in one example suggests up to 200 m of incision. Both Valencia and Apu'upu'u seamounts have channel longitudinal profiles that are steep and typically linear to concave upwards. The erosion depth of Apu'upu'u Seamount is significant, despite the seamount's persistent submarine environment, because of its greater age, steeper flanks and greater contributing areas to channels compared with Valencia Seamount. These results illustrate that the channel morphology resulting from submarine erosion can become similar to that produced by subaerial erosion given sufficient time.
ISSN: 0950-091X

hal-00411425
https://hal.archives-ouvertes.fr/hal-00411425
DOI : 10.1111/j.1365-2117.2008.00355.x

Éditeur(s) : Elsevier
Résumé : The Okinawa Trough is a natural laboratory for the study of later Quaternary land-ocean interaction and paleoenvironmental changes. In this study we reconstruct the evolution of clay mineral assemblages in Core DGKS9604 retrieved from the central Okinawa Trough. Illite dominates the clay mineral compositions, with average contents above 60%. Clay mineral evolution since 28 ka is closely related to changes in sediment provenance and paleoenvironment. Sea level rise and the strength of the Kuroshio Current control the dispersal and deposition of clays on the East China Sea shelf and in the Okinawa Trough, and thus, determine the clay mineral compositions in the core sediments. During the late last glacial period (28.0-14.0 ka), the paleo-Changjiang River mouth was situated at the shelf edge close to the central Okinawa Trough and thus, together with the outer shelf, supplied large volumes of terrigenous sediments directly into the trough. From 14.0 to 8.4 ka influence from the Changjiang decreased while the mid-outer shelf of the East China Sea became the dominant sediment source to the central Okinawa Trough as sea level rose and the Changjiang river mouth migrated west. Strong sediment reworking and erosion at the shelf edge at 15-13 ka significantly increased the lateral transport of fine-grained shelf sediments to the central Okinawa Trough. Since ca. 8.4 ka clays from Taiwan have dominated the sediment flux to the site, coinciding with the re-entry of the Kuroshio Current into the trough. The increasing influence of the Changjiang-sourced sediments since 1.5 ka was probably related to the weakening of the Kuroshio Current and/or a higher river flux. (C) 2010 Elsevier B.V. All rights reserved.
Palaeogeography, Palaeoclimatology, Palaeoecology (0031-0182) (Elsevier), 2010-03 , Vol. 288 , N. 1-4 , P. 108-117

Droits : 2010 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00002/11367/7977.pdf
DOI:10.1016/j.palaeo.2010.01.040
http://archimer.ifremer.fr/doc/00002/11367/

Éditeur(s) : HAL CCSD Borntraeger Science Publishers
Résumé : This study characterizes the stratigraphical context as well as the palaeoenvironmental and sealevel trends during the Late Frasnian and Famennian in the Buschteich section (Thuringia, Germany). An integrated approach combines conodont biostratigraphy, chemostratigraphy based on carbon and oxygen isotopes, conodont biofacies analyses and investigations of the morphotypes of foraminifera that occur in the section was applied. Conodonts provided a fine-scale biostratigraphical framework. All the Famennian conodont biozones were identified, with the exception of the three lowest. The Frasnian – Famennian transition was further identified by a positive carbon isotope excursion. This continuous Famennian record is developed in a condensed limestone succession. The reddish Griotte facies, typical of strata of this period, were not documented. Black shales were not developed except for an interval of dark colored mud rocks corresponding to the Hangenberg event at the top of the section. The carbonate succession of Buschteich was deposited in an outer ramp environment, pelagic organisms are the dominant fauna. This is corroborated by the overall dominance of the deep-water conodont genus Palmatolepis. Microfacies, conodont biofacies and foramini fera indicated a deepening trend from the Lower crepida to the Lower rhomboidea Zone, followed by a shallowing trend from the Upper rhomboidea to the praesulcata Zone. This sequence overall matches the sea level reference curve for Euramerica. The timing of maximum water depth at Buschteich, as well as the general sea-level reference record, differs from the Col des Tribes (Montagne Noire, France). Differential uplift or overprinting of the long-term eustatic changes may be the cause of the discrepancy in the local sea-level records.
ISSN: 0078-0421

hal-01623111
https://hal.archives-ouvertes.fr/hal-01623111
DOI : 10.1127/nos/2016/0318

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Comme dans d’autres régions du monde, la croissance démographique et l’accentuation des activités côtières au Canada entraînent une dégradation continue des écosystèmes et de la biodiversité. L’aménagement côtier contribue essentiellement à la vulnérabilité et à la détérioration des littoraux. Ce constat concerne le littoral acadien du Nouveau-Brunswick. Au-delà de ces pressions démographiques et de l’urbanisation sur les zones littorales, l'élévation du niveau marin et l'augmentation des températures (effets du changement et des variations climatiques) provoquent des impacts vérifiables : l’intensité des ondes de tempêtes, la dégradation des sols par l’érosion, etc. Ainsi, l’adaptation au changement climatique constitue un enjeu de taille pour la province du Nouveau-Brunswick. C’est pourquoi cet article propose d’étudier les impacts de ces changements auprès de deux régions côtières du littoral acadien et d’apprendre des expériences de chacun pour renforcer leur résilience. La recherche souhaite s’inscrire dans une nouvelle forme d’engagement communautaire qui prend en compte des aspects de la « gouvernance », de l’« aménagement du territoire » et de la « cohésion sociale ». L’article tente d’avoir une meilleure compréhension de l’enchâssement des aspects économiques et sociétaux dans les enjeux environnementaux.
As in other parts of the world, demographic growth and an increased use of coastal zones in Canada lead to a degradation of coastal ecosystems and a loss of biodiversity. Coastal development contributes in large part to the vulnerability and deterioration of coastal zones. This is very clearly seen in the case of the Acadian coast of New Brunswick. In addition to stresses from demographic growth and urbanization, the coastal zone is affected by sea level rise, temperature increases and other impacts of climate change such as increased climate variability, which lead to measurable effects such as an increase in storm intensity or increased coastal erosion. Thus, adaptation to climate change constitutes a major challenge for the province of New Brunswick. It is in this context that we propose to analyze the impacts of climate change in two sites on the Acadian coast and to profit from both experiences in order to increase the resilience of the communities through mutual learning. The research undertaken here aims at contributing to a new form of community engagement that takes “governance”, “land use planning” and “social cohesion” into account. The article aims at a better understanding of the interplay of social and economic aspects in this environmental problem.
Canada
Nouveau-Brunswick

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6970
http://journals.openedition.org/etudescaribeennes/6970

Éditeur(s) : HAL CCSD
Résumé : During the course of their life cycle organisms are exposed to natural environment variations capable of inducing physiological, morphological and behaviour changes, thus a phenotypic plasticity. Phenotypic plasticity is the ability of a genotype to generate a new phenotype following exogeneous or endogeneous stress. Here, we investigated the phenotypic plasticity of the non-calcifying symbiotic cnidarian Anemonia viridis at multiple levels of structural complexity, in vivo and in vitro. In vivo, we determined the mechanisms behind the phenotypic plasticity under expected future climate change (i.e. ocean acidification and ocean warming). Our results show physiological changes in the inorganic carbon use of the sea anemone A. viridis exposed to high pCO2 during a long-term stress in natura or a short-term stress in controlled conditions. We then observed an equivalent decrease in carbonic anhydrase activity, a key enzyme of cnidarian carbon concentrating mechanisms. Also, we demonstrated that an increase in seawater temperature modified the response observed during a high pCO2 scenario. In vitro, we established a viable primary cell culture from regenerating tentacles of A. viridis. We determined the gastrodermal tissue origin of the cultivated cells and validated the use of this new tool to the in vitro study of stress response at the cellular level. The set-up of this powerful in vitro tool will open a multitude of perspectives for the study of cellular responses to exogeneous stress (as global change perturbations) and to endogeneous stress (as the symbiosis constraints experienced by symbiotic cnidarians)
Durant leur cycle de vie, les organismes sont exposés à des variations environnementales capables d'induire des changements physiologiques, morphologiques et comportementaux, résultant d’une plasticité phénotypique. La plasticité phénotypique est la capacité d'un génotype à générer un nouveau phénotype suite à un stress. Ici, nous avons étudié la plasticité phénotypique d’un Cnidaire symbiotique et non-calcifiant, l’anémone de mer Anemonia viridis, à de multiples niveaux de complexité structurale, in vivo et in vitro. In vivo, nous avons identifié les mécanismes sous-jacents de la plasticité phénotypique potentiellement induits par les futurs changements climatiques (acidification et réchauffement des océans). Nos résultats montrent des modifications dans l'utilisation du carbone inorganique par A. viridis exposée à une forte pCO2 lors d’un stress chronique in natura ou lors d’un stress court en conditions contrôlées. Nous avons ainsi observé une diminution des activités anhydrase carbonique, une enzyme clé des mécanismes de concentration du carbone chez les Cnidaires. Nous avons aussi démontré que l'augmentation concomittante de la température modifie la réponse observée lors d'une élévation seule de la pCO2. In vitro, nous avons établi une culture de cellules primaires viables issue de tentacules d’A. viridis en régénération. Nous avons déterminé l'origine gastrodermale des cellules cultivées et validé l'utilisation de ce nouvel outil pour l'étude de la réponse au stress au niveau cellulaire. Ce nouvel outil ouvre une multitude de perspectives pour l'étude des réponses cellulaires aux stress exogènes (changement climatique) et endogènes (contraintes dues à la symbiose)
https://tel.archives-ouvertes.fr/tel-01674220

Droits : info:eu-repo/semantics/OpenAccess
NNT : 2016AZUR4136
tel-01674220
https://tel.archives-ouvertes.fr/tel-01674220
https://tel.archives-ouvertes.fr/tel-01674220/document
https://tel.archives-ouvertes.fr/tel-01674220/file/2016AZUR4136.pdf

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : Late Jurassic platform carbonates of Languedoc (southern France) are deeply incised by Late Miocene canyons, allowing the observation of karst systems filled with sediments containing evidences of marine origin. Field and structural relationships as well as new biostratigraphic data (planktonic foraminifera and calcareous nannofossils) provide a Latest Cretaceous-Earliest Paleocene age for the major karstification and a Paleocene (Danian-Selandian) age for the sedimentary filling. The ≥ 350 m vertical extent of this karst system and its subsequent marine filling gives a minimum amplitude for the base-level variation responsible for the karstification and then the marine flooding events. The observations suggest that at least, two marine successive events occurred in the Late Danian then in Selandian time. The large amplitude of base level is not in agreement with eustatic sea-level change, and the rate of base-level change is too fast for tectonic uplift and subsidence within the tabular, poorly deformed studied area. We propose a model of a silled endoreic basin, which was dessiccated and karstified over hundreds of meters, when it was disconnected from the World Ocean, and later suddently transgressed by the Paleocene sea and the karst flooded, when the bounding sill was submerged. Such a model is similar, although with significant differences, with the later Messinian-Zanclean event that affected the Mediterranean realm.
EISSN: 1777-5817

hal-00767556
https://hal.archives-ouvertes.fr/hal-00767556
DOI : 10.2113/gssgfbull.183.5.425

Éditeur(s) : HAL CCSD
Résumé : Report
This activity combines tide gauge and geodetic data to determine the 20th century trends and patterns of relative and absolute sea level changes along the coastline of British Columbia. This information is then used to derive scenarios of relative sea-level rise in coastalcommunities for the 21st century. Particular emphasis is put on the Fraser River Delta and Greater Vancouver region. The projections of 21 st century sea-level rise are provided to provincial and municipal partners to inform local and regional land-use and planning policies.
https://hal.archives-ouvertes.fr/hal-00856631

hal-00856631
https://hal.archives-ouvertes.fr/hal-00856631

Éditeur(s) : HAL CCSD Blackwell Publishing
Résumé : International audience
Pliocene and Pleistocene deposits from Grande-Terre (Guadeloupe archipelago, French Lesser Antilles) provide a remarkable example of an isolated carbonate system built in an active margin setting, with sedimentation both controlled by rapid sea-level changes and tectonic movements. Based on new field, sedimentological and palaeontological analyses, these deposits have been organized into four sedimentary sequences (S1 to S4) separated by three subaerial erosion surfaces (SB0, SB1 and SB2). Sequences S1 and S2 ('Calcaires inférieurs à rhodolithes') deposited during the late Zanclean to early Gelasian (planktonic foraminiferal Zones PL2 to PL5) in low subsidence conditions, on a distally steepened ramp dipping eastward. Red algal-rich deposits, which dominate the western part of Grande-Terre, change to planktonic foraminifer-rich deposits eastward. Vertical movements of tens of metres were responsible for the formation of SB0 and SB1. Sequence S3 ('Formation volcano-sédimentaire', 'Calcaires supérieurs à rhodolithes' and 'Calcaires à Agaricia') was deposited during the late Piacenzian to early Calabrian (Zones PL5 to PT1a) on a distally steepened, red algal-dominated ramp that changes upward into a homoclinal, coral-dominated ramp. Deposition of Sequence S3 occurred during a eustatic cycle in quiet tectonic conditions. Its uppermost boundary, the major erosion surface SB2, is related to the Cala1 eustatic sea-level fall. Finally, Sequence S4 ('Calcaires à Acropora') probably formed during the Calabrian, developing as a coral-dominated platform during a eustatic cycle in quiet tectonic conditions. The final emergence of the island could then have occurred in late Calabrian times.
ISSN: 1469-3496

hal-00760906
https://hal.archives-ouvertes.fr/hal-00760906
DOI : 10.1111/j.1365-3091.2011.01311.x

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : We present detailed biostratigraphy based on conodonts and palaeoenvironmental trends deduced from microfacies and conodont abundance through the Famennian (Late Devonian) at Col des Tribes (Montagne Noire, France). The succession is characterized by micritic limestones deposited in settings oscillating between mid to outer ramp. Facies contain poor fauna, widely dominated by nektonic organisms. This section is complete and one of the most conodont-rich for the Famennian of the north Gondwana-related area. The Upper Kellwasser event (Frasnian–Famennian boundary) and the Hangenberg (Devonian–Carboniferous boundary) have been lithologically identified. They are characterized by decimetre-thick black dysoxic to anoxic argillaceous sediments. The Condroz and annulata events, although not materialized by lithological changes, have been positioned due to the precise stratigraphy. The first event occurred during the deposition of condensed ferruginous facies (griotte limestones) and the second event during the deposition of micrites barren of benthic fauna. The combination of information from both facies and conodont biofacies changes allows a general sea-level curve through the entire Famennian for north Gondwana to be proposed for the first time. At Col des Tribes, the general trend is a slight deepening upwards from triangularis to trachytera zones, then a pronounced shallowing-upwards trend from upper trachytera to praesulcata zones. This curve correlates with the well-known reference curve from Euramerica concerning the late Famennian (trachytera to praesulcata Zones). There are some discrepancies in minor cycles which can be explained by tectonical phenomena at the onset of the edification of the Variscan belt in Europe.
ISSN: 0016-7568

hal-01115222
https://hal.archives-ouvertes.fr/hal-01115222
DOI : 10.1017/S0016756813000927

Éditeur(s) : HAL CCSD Universidad Complutense de Madrid
Résumé : Based on new seismological and recent faulting data, we analyze five main sectors in the western part of the Betic Cordillera from an active tectonic perspective: i. The northwestern frontal sector of the cordillera, including the Morón de la Frontera area, with shallow (< 15 km depth) seismogenic active NE-SW reverse and strike-slip faults that do not reach the surface. ii. The Teba area, in the External Zones, which is deformed by sparse N-S to NW-SE normal faults with associated wedges of Quaternary sediments and active strike-slip faults at intermediate crustal levels. iii. The Ronda Basin, representing the major Late Miocene intramontane basin of the western Betic Cordillera, is mainly deformed by NNE-SSW and WNW-ESE folds and locally by NW-SE normal faults. iv. The internal part of the orogen, which is characterized by shallow (<40 km) and intermediate (40 to 120 km depth) seismicity beneath Málaga and the Alborán Sea, ENE-WSW folding, relief uplift, river incision and scarce active faults with surface expression. v. The Spanish Atlantic coast, which coincides with the western end of the Betic orogen, where Pliocene to Quaternary shallowmarine sedimentary rocks are deformed by meso-scale NW-SE oriented normal faults and few ENE-WSW reverse faults. These data support the recent tectonic activity of the western Betic Cordillera determined by the NW-SE Eurasian-African convergence with variable features from the mountain front, characterized by shallow deformations, up to the Internal Zones that mainly undergo uplift and intermediate seismicity.
ISSN: 1698-6180

hal-00750359
https://hal.archives-ouvertes.fr/hal-00750359
DOI : 10.5209/rev_JIGE.2012.v38.n1.39211

Éditeur(s) : Elsevier
Résumé : In New Caledonia, the "syndrome 93," which results in mass mortalities of farmed shrimp Penaeus stylirostris, occurs during the transitional and the cold seasons. The transitional season is characterized by an important fall in the average water temperature from 28 to 19 degreesC in 2 weeks. Besides this marked temperature fall, there are also nyctemeral temperature changes of up to 7 degreesC in 12 h. The cold season is characterized by an average water temperature of 19 degreesC with extreme lows of 14 degreesC. The objective of this study was to determine the effect of temperature and its variations on the osmoregulatory capacity of juvenile (7-10 g average weight) and subadult (25 g average weight) shrimps subjected to conditions of different salinity. A reduction in temperature level resulted in a decreased osmoregulatory capacity (OC) (defined as the difference between the osmolality of the haemolymph and that of sea water) at low salinity (hyper-CO) and at high salinity (hypo-CO), respectively, below and above the isoosmotic point (26.2 ppt). In subadult shrimps, the hyper-CO was affected when temperature dropped from 26 to 22 degreesC. The hypo-CO was modified only when temperature decreased down to 15 degreesC. Furthermore, the sensitiveness of osmoregulation to temperature changes was dependent on the developmental stage of the shrimp. Subadults were more sensitive than juvenile animals. The value of the isoosmotic point, which did not depend on the shrimp developmental stage, increased when temperature decreased to 17 or 15 degreesC. Our results provide an additional explanation of the "syndrome 93" and display the unfavourable influence of marked temperature drop on shrimp health. Our research could provide a possibility of seeking a nutritional and/or genetic solution to improve the capacity of the shrimps to maintain their homeostasis within a rearing medium with fluctuating temperatures.
Aquaculture (0044-8486) (Elsevier), 2002-06 , Vol. 209 , N. 1-4 , P. 307-317

Droits : 2002 Elsevier Science B.V. All rights reserved
http://archimer.ifremer.fr/doc/2002/publication-395.pdf
DOI:10.1016/S0044-8486(01)00756-6
http://archimer.ifremer.fr/doc/00000/395/

Éditeur(s) : Elsevier Science Bv
Résumé : The modern Rhone delta in the Gulf of Lions (NW Mediterranean) is a typical wave-dominated delta that developed after the stabilization of relative sea level following the last deglacial sea-level rise. Similar to most other deltas worldwide, it displays several stacked parasequences and lobes that reflect the complex interaction between accommodation, sediment supply and autogenic processes on the architecture of a wave-dominated delta. The interpretation of a large set of newly acquired very high-resolution seismic and sedimentological data, well constrained by 14C dates, provides a refined three-dimensional image of the detailed architecture (seismic bounding surfaces, sedimentary facies) of the Rhone subaqueous delta, and allows us to propose a scenario for delta evolution during the last deglaciation and Holocene. The subaqueous delta consists of “parasequence-like” depositional wedges, a few meters to 20–30 m in thickness. These wedges first back-stepped inland toward the NW in response to combined global sea-level rise and overall westward oceanic circulation, at a time when sediment supply could not keep pace with rapid absolute (eustatic) sea-level rise. At the the Younger Dryas-Preboreal transition, more rapid sea-level rise led to the formation of a major flooding surface (equivalent to a wave ravinement surface). After stabilization of global sea level in the mid-Holocene, accommodation became the leading factor controlling delta architecture. An eastward shift of depocenters occurred, probably favoured by higher subsidence rate within the thick Messinian Rhone valley fill. The transition between transgressive (backstepping geometry) and regressive (prograding geometry) (para)sequences resulted in creation of a Maximum Flooding Surface (MFS) that differs from a “classical” MFS described in the literature. It consists of a coarse-grained interval incorporating reworked shoreface material within a silty clay matrix. This distinct lithofacies results from condensation/erosion, which appears as an important process even within supply-dominated deltaic systems, due to avulsion of distributaries. The age of the MFS varies along-strike between ca. 7.8-5.6 kyr cal. BP in relation to the position of depocenters and climatically-controlled sediment supply. The last rapid climate change of the Holocene, the Little Ice Age (1250–1850 AD), had a distinct stratigraphic influence on the architecture and lithofacies of the Rhone subaqueous delta through the progradation of two deltaic lobes. In response to changes in sediment supply linked to rapid climate changes (and to anthropic factors), the Rhone delta evolved from wave-dominated to fluvial dominated, and then wave dominated again.
Sedimentary Geology (0037-0738) (Elsevier Science Bv), 2014-05 , Vol. 305 , P. 35-53

Droits : 2014 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00179/29017/27445.pdf
DOI:10.1016/j.sedgeo.2014.02.004
http://archimer.ifremer.fr/doc/00179/29017/

Éditeur(s) : Elsevier
Résumé : Emplacement of post-glacial turbidites is commonly controlled by rapid changes in sea level or by seismicity. On the continental rise of the Gulf of Lions (Western Mediterranean), an aseismic area, we identified turbiditic beds deposited during the rising stage and highstand of sea level. Swath bathymetry, sediment cores, in situ Cone Penetrating Tests (CPTU), heavy mineral associations and radiocarbon dating determined the source, composition, distribution and age of the turbiditic beds. Turbidites are composed of homogeneous to positively graded silts to medium sand with quartz (up to 90%), shell debris and shelfal benthic faunas. Their distribution on the sea floor is very patchy and controlled by abundant inherited erosional bedforms. Their source is found in relict regressive sands at the outershelf. Their deposition occurred just after the onset of the post-glacial sea level rise and the concomitant sediment starvation of the Rhone deep sea turbiditic system until recently. Whilst canyons are fed with sand by strong seasonal hydro-sedimentary dynamics on the outershelf, the emplacement of post-glacial turbidites is not controlled by sea level changes but probably by the periodic flushing of the canyons. Our study revealed that this low energy aseismic margin undergoes significant transport of sand, down to the base of slope, during the sea-level rise and the Holocene highstand.
Marine Geology (0025-3227) (Elsevier), 2009-02 , Vol. 257 , N. 1-4 , P. 65-86

Droits : 2009 Published by Elsevier Ltd.
http://archimer.ifremer.fr/doc/2009/publication-6316.pdf
DOI:10.1016/j.margeo.2008.10.013
http://archimer.ifremer.fr/doc/00000/6316/

Éditeur(s) : Elsevier
Résumé : In situ microbialites occurring in reef rocks dredged between 80 and 130 in water depth on the modern fore-reef slopes of Tahiti and the Marquesas islands yield ages ranging from 17,100 2900 to 4410 2250 years BP, suggesting that they played a prominent role during the last deglacial sea level rise. Microbialites developed in both shallow and deep water depositional environments where they characterize various zones of the reef tracts (reef crests, upper reef slopes, deep fore-reef slopes), reflecting contrasting scenarios of microbialite development involving ''reefal microbialites'' in shallow-water settings and ''slope microbialites'' that formed in environments deeper than 1020 in and extending down to more than 100 m. Reefal microbialites correspond to a late stage of encrustation of the dead parts of coral colonies, or more commonly, of related encrusting organisms (red algae and foraminifers), thus forming surface crusts. Slope microbialites generally form the ultimate stage of a biological succession indicating a deepening sequence, whereby shallow water corals and associated encrusting organisms are replaced by deeper water assemblages of red algae and foraminifers before microbialite growth. The precipitation of phosphatic-iron-manganese crusts and the deposition of planktonic micritic limestones on the microbialites characterize a deepening-upward sequence. The widespread development of microbialites in reef sequences from the Last Deglaciation characterizes a period of environmental degradation consequential oil the rapid sea-level rise and abrupt climatic changes of that time. The reported biological succession reflects changes in water quality, and especially an increase in nutrients. In shallow-water settings, increased alkalinity and nutrient availability in interstitial waters were related to surface fluxes and terrestrial groundwater seepage while slope environments were exposed to continuous upwelling of nutrient-rich deeper waters during the last deglacial sea level rise. The age differences between corals and overlying slope microbialites range from 1600 to 8400 years, based on high-precision U-series age measurements of both corals and microbialites, and indicates that a significant time (several thousand years) elapsed between the development of the coralgal frameworks and the growth of slope microbialite crusts. Microbialites cannot be considered as part of the drowning event some 14,000 years ago that resulted in the demise of reef frameworks in the 90-110 m present depth range, but are Substantially younger. (c) 2006 Elsevier B.V. All rights reserved.
Sedimentary Geology (0037-0738) (Elsevier), 2006-03 , Vol. 185 , N. 3-4 , P. 277-295

Droits : 2006 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2006/publication-4204.pdf
DOI:10.1016/j.sedgeo.2005.12.018
http://archimer.ifremer.fr/doc/00000/4204/