357 research outputs found

    COCARDE: new view on old mounds – an international network of carbonate mound research

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    EGU2012-12550 Carbonate mounds are important contributors of life in different settings, from warm-water to cold-water environments, and throughout geological history. Research on modern cold-water coral carbonate mounds over the last decades made a major contribution to our overall understanding of these particular sedimentary systems. By looking to the modern carbonate mound community with cold-water corals as main framework builders, some fundamental questions could be addressed, until now not yet explored in fossil mound settings. The international network COCARDE (http://www.cocarde.eu) is a platform for exploring new insights in carbonate mound research of recent and ancient mound systems. The aim of the COCARDE network is to bring together scientific communities, studying Recent carbonate mounds in midslope environments in the present ocean and investigating fossil mounds spanning the whole Phanerozoic time, respectively. Scientific challenges in modern and ancient carbonate mound research got well defined during the ESF Magellan Workshop COCARDE in Fribourg, Switzerland (21.–24.01.2009). The Special Volume Cold-water Carbonate Reservoir systems in Deep Environments – COCARDE (Marine Geology, Vol. 282) was the major outcome of this meeting and highlights the diversity of Recent arbonate mound studies. The following first jointWorkshop and Field Seminar held in Oviedo, Spain (16.–20.09.2009) highlighted ongoing research from both Recent and fossil academic groups integrating the message from the industry. The field seminar focused on mounds from the Carboniferous platform of Asturias and Cantabria, already intensively visited by industrial and academic researchers. However, by comparing ancient, mixed carbonate-siliciclastic mound systems of Cantabria with the Recent ones in the Porcupine Seabight, striking similarities in their genesis and processes in mound development asked for an integrated drilling campaign to understand better the 3D internal mound build-up. The Oviedo Workshop and Field Seminar led to the submission of a White Paper on Carbonate Mound Drilling and the initiation of the ESF European Research Network Programme Cold-Water Carbonate Mounds in Shallow and Deep Time – The European Research Network (COCARDE-ERN) launched in June 2011. The second COCARDE Workshop and Field Seminar was held in Rabat, Morocco (24.–30.10.2011) and thematically focussed on carbonate mounds of(f) Morocco. The compact workshop invited students from Moroccan Universities to experience ongoing carbonate mound research in Recent and Ancient environments of Morocco. Two Round Tables discussed innovative approaches in carbonate mound research in Morocco (Recent vs. Ancient - offshore vs. onshore) and reviewed together with oil industry opportunities of international collaboration. The outcome of this workshop will lead into joint research projects, drilling campaigns on- and offshore, and expansion of COCARDE onto the African continent

    Biogeochemistry of carbonate mounds from the Pen Duick escarpment in the Gulf of Cadiz

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    In the Gulf of Cadiz, carbonate mounds build by cold-water corals were recently discovered on the Renard Ridge, a zone of active fluid flow and mud volcanism. Their sizes vary from 25 to more than 60 m high, at a depth of 520 m and they are aligned along the ridge axis. These mounds, located in the close vicinity of fluid flow markers such as carbonate crusts and mud volcanoes, provided a novel opportunity to study a possible fluid flow control on the mound processes and distribution. Previous geochemical studies on the southernmost mound of the ridge indeed showed that this mound was located on focused fluid flow compared to surrounding sediments, and we observed typical profiles of methane migration and anoxic oxidation (AOM) at 3,8 m below the sea floor within the mound. Such AOM occurrence imprinted a characteristic d13C signature (down to –21,9 %¸ Vs. PDB) and significantly contributes to the overall carbonate budget of the mound.During the recent R/V Maria S. Merian cruise (April-June 2006), we sampled by mean of a gravity corer six new structures likely to be cold-water carbonate mounds, along the Pen Duick escarpment and the Renard Ridge. Our aim was to determine if the geochemical profiles observed in the first mound could be generalized to all the mounds in this area.Each core yielded a full sequence of cold-water corals down to about 5 meters below the sea floor. Hence, the numerous knoll-like structures revealed by high-resolution bathymetry along the ridge are indeed carbonate mounds build by cold-water corals and the entire Ridge has been massively colonized by corals. No live reef-forming coral could be recovered from the cores, nor observed by towed video instruments. Then, fluid migration seems to be a common feature all along the ridge. However, important discrepancies were observed: methane concentrations are higher and sulfate gradients steeper on both side of the ridge, whereas the central part of the ridge seems less active in term of fluid migration. In this case, the sulfate to methane transition zone could not be reached using conventional gravity corer. In order to obtain the full biogeochemical picture of these mounds, the use of a long piston corer, or drilling devices, will be required.The reasons of the formation of massive reefs in this area are still unknown and are probably linked to locally enhanced hydrologic conditions. However, it is possible that cold-water coral could have benefited from the hard substrate and the topographic elevations provided by fluid related structures such as carbonate crusts, chimneys and clasts, as observed in several other locations in the Gulf of Cadiz

    The early diagenetic and PETROphysical behaviour of recent cold-water CARbonate mounds in Deep Environments (PETROCARDE)

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    Sub-recent cold-water carbonate mounds localized in deeper slope settings on the Atlantic continental margins cannot be any longer neglected in the study of carbonate systems. They clearly play a major role in the dynamics of mixed siliciclastic-carbonate and/or carbonate-dominated continental slopes. Carbonate accumulation rates of cold-water carbonate mounds are about 4 to 12 % of the carbonate accumulation rates of tropical shallow-water reefs but exceed the carbonate accumulation rates of their slope settings by a factor of 4 to 12 (Titschack et al.,2009). These findings emphasize the importance of these carbonate factories as carbonate niches on the continental margins. The primary environmental architecture of such carbonate bodies is well-characterized. However, despite proven evidences of early diagenesis overprinting the primary environmental record (e.g. aragonite dissolution) (Foubert & Henriet, 2009), the extent of early diagenetic and biogeochemical processes shaping the petrophysical nature of mounds is until now not yet fully understood.Understanding (1) the functioning of a carbonate mound as biogeochemical reactor triggering early diagenetic processes and (2) the impact of early diagenesis on the petrophysical behaviour of a carbonate mound in space and through time are necessary (vital) for the reliable prediction of potential late diagenetic processes. Approaching the fossil carbonate mound record, through a profound study of recent carbonate bodies is innovative and will help to better understand processes observed in the fossil mound world (such as cementation, brecciation, fracturing, etc. . . ).In this study, the 155-m high Challenger mound (Porcupine Seabight, SW of Ireland), drilled during IODP Expedition 307 aboard the R/V Joides Resolution (Foubert & Henriet, 2009), and mounds from the Gulf of Cadiz (Moroccan margin) will be discussed in terms of early diagenetic processes and petrophysical behaviour. Early differential diagenesis overprints the primary environmental signals in Challenger mound, with extensive coral dissolution and the genesis of small-scaled semi-lithified layers in the Ca-rich intervals. The low cementation rates compared to the extensive dissolution patterns can be explained by an open-system diagenetic model. Moreover, Pirlet et al. (2009) emphasizes the occurrence of gypsum and dolomite in another mound system (Mound Perseverance) in Porcupine Seabight, which might be also related with fluid oxidation events in a semi-open diagenetic system. Along the Moroccan margins, fluid seepage and fluxes in pore water transport affect the development of mound structures, enhancing extensive cold-water coral dissolution and precipitation of diagenetic minerals such as dolomite, calcite, pyrite, etc. (Foubert et al., 2008). Recent carbonate mounds provide indeed an excellent opportunity to study early diagenetic processes in carbonate systems without the complications of burial and/or later meteoric diagenesis

    COCARDE: A research platform for a new look to ancient mounds

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    Carbonate mounds are important contributors of life in different settings, from warm-water to cold-water environments, and throughout geological history. Research on modern carbonate mounds over the last years made a major contribution to our overall understanding of these particular sedimentary systems. By looking to the modern carbonate mound community, some fundamental questions could be addressed, until now not yet explored in fossil mound settings.The international network COCARDE (Cold-Water Carbonate Reservoir Systems in Deep Environment) is a platform for exploring new insights in cold- and warm-water carbonate mound research of recent and ancient mound systems (http://www.cocarde.eu). One aim of the COCARDE network is to bring scientific communities together, to study recent carbonate mounds in midslope environments in the present ocean, and to investigate fossil mounds spanning the whole Phanerozoic time.Scientific challenges on modern and ancient carbonate mound systems got already well defined during two dedicated workshops of the COCARDE network: 1) the ESF Magellan COCARDEWorkshop in Fribourg, Switzerland, January 21-24, 2009, and 2) the ESF MiCROSYSTEMS – FWO COCARDE Flanders – ESF CHECREEF Workshop and Field Seminar, Oviedo, Spain, September 16–20, 2009.The wide spectrum of disciplines in geosciences and biology are summarized in the following five topics for the carbonate mound research: i) Palaeoenvironment; ii) The Microbial Filter; iii) Petrophysical Characterization; iv) Connectivity and Compartmentalization – the Fluid System; v) Advancing our Insight in Phanerozoic Reef Systems– the Slope Niche. One of the most important outcomes of these meetings was the identification of the need for combined research efforts on fossil and modern carbonate settings to provide the baseline reference standard for a better understanding of these exceptional systems and their potential as hydrocarbon reservoirs

    Deep-water oyster cliffs at La Chapelle Bank (Celtic Margin)

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    The maiden voyage of Ghent University’s ROV GENESIS on-board R/V Belgica (13-20 June 2006) has succeeded in contributing to several objectives of the EU-projects HERMES and EURODOM, as well as of the ESF Euromargins project MoundForce. After several trials in the Bay of Douarnenez, GENESIS made its first deep-water survey dives off the Banc de la Chapelle, on the Celtic margin, down to 700 m. The French canyon system near the Banc de la Chapelle offered a perfect location for rigorous trials of GENESIS: reported cold-water coral finds, rugged topography and hydrodynamics in a setting linking the shelf seas to the deep marine realm. The area was first surveyed using R/V Belgica’s multibeam echosounder, imaging deep canyons and thalweg channels between prominent spurs where corals had been reported. High resolution seismic sparker lines provided a geological context and linked in to the existing seismostratigraphy.Two successful dives revealed a sandy-muddy seabed with curious bedforms and erosion exposing consolidated sedimentary sequences, often cut by vertical cliffs up to 10m high. At the base of the cliffs, fallen blocks provided settlement sites for sessile organisms whilst the cliffs and protruding banks revealed dense communities of unidentified giant ostreidae (probably Neopycnodonte sp) forming 3D assemblage with occasional cold-water coral colonies (Lophelia pertusa). Though deep-water ‘oyster banks’ of Neopyncodonte cochlear had already been reported in the Bay of Biscay by ..Le Danois (1948) based on dredges, these dramatic seascapes had remained largely hidden to the human eye up to now

    A comparative study of the recent history of Thérèse and Challenger mound, two cold-water coral carbonate mounds in the Belgica Mound province, Porcupine Seabight, SW of Ireland

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    During the Geomound-cruise with the R/V Marion Dufresne in 2001 gravity cores were recovered on the top of Thérèse mound (MD01-2463G) and Challenger mound (MD01-2451G). Both mounds are built up by cold-water corals (Lophelia pertusa sp. and Madrepora oculata sp.). This was confirmed by the IODP drilling (expedition 307) where Challenger mound was drilled to its base and cold-water corals were observed over the entire length of the mound.The gravity core (MD01-2463G), taken on top of Thérèse mound, was described and analyzed for its foraminiferal content and grainsize. A combination of these data with the results from previous studies (P-wave velocity, gamma density, magnetic susceptibility, X-ray imagery, U/Th-dating of corals and foraminifera (Frank et al., 2005, Foubert et al., 2006)), made it possible to distinguish different units, enabling a reconstruction of the evolution of the top of Thérèse mound.In a next step, the different zones in the core on top of Thérèse mound could be correlated with the sections identified in the gravity core recovered on top of Challenger mound (MD01-2451G) (Foubert et al., 2006). The mounds unveiled a comparable recent history, implying that their growth was controlled by the same parameters. Both cores revealed at least one discontinuity in the record, corresponding with a time hiatus of more than 200 ka. This discontinuity corresponds most likely to a change in hydrodynamic environment which prohibited further coral growth but erosional processes cannot be ruled out. The hiatus is in both cases covered with a layer of fine laminated sediments and dropstones. The origin of this detritic material is still unclear and will be further investigated using the Nd isotopic signature of the sediment as a tracer

    Perinatal mortality in Ireland. Annual report 2014.

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    ‌Perinatal mortality refers to the death of babies in the weeks before or after birth. Perinatal mortality includes stillbirths (babies born with no signs of life after 24 weeks of pregnancy or weighing at least 500 grams) and the deaths of babies within 28 days of being born. Perinatal mortality is an important indicator of the quality of obstetric and neonatal care. Measurement of the outcome of care is central to the development of safe and high quality healthcare services. In recent years, the National Perinatal Epidemiology Centre (NPEC) has worked with colleagues in developing an in-depth clinical audit of perinatal mortality. Smoking and substance use - page 2

    Biogeochemical evidence for anoxic oxidation of methane occurrences in the juvenile carbonate mounds from the Gulf of Cadiz

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    Carbonate mounds are conspicuous features of the European margins. Only fossil examples of these mounds were known when modern giant carbonate mounds were discovered in the S.-W. Irish margin. A decade of thorough studies in this area provided remarkable insight on mound processes and distribution. However, the question of the genesis and stabilization over geological times of these carbonate mounds remain wide open.Our work hypothesis is that moderate fluxes of low molecular hydrocarbons are oxidized and produces carbonates that may serve as cement for the mound stabilization. The recent discovery and mapping (R/V Belgica 2003, 2005) of the Pen Duick escarpment on the Moroccan margin (Gulf of Cadiz) by swath bathymetry shed light on new carbonate mounds associated with fluid migration markers such as pockmarks, carbonate crusts and mud volcanoes. Pore water biogeochemical profiles show that the sulphate to methane transition zone occurs at 3.5 meters below the sea floor within the mound, whereas the depth of no sulphate is much deeper in the surrounding sediments. At the same depth, carbonates are released with d13C values as low as -21 permil indicating a methane and possibly other light hydrocarbons origin. Hence anoxic oxidation of hydrocarbons, and subsequent carbonate production, may play a key role in the mound formation and/or stabilization. Interestingly, Lophelia coral rubbles were present all along the sediment column suggesting that this mound is a potential habitat for cold coral and associated communities

    Geosciences Roadmap for Research Infrastructures 2025–2028 by the Swiss Geosciences Community

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    This community roadmap presents an integrative approach including the most urgent infrastructure requests for the future development of geosciences in Switzerland. It recommends to strengthen the multidisciplinary nature of the geosciences by putting all activities under the roof of the Integrated Swiss Geosciences supported by four specific research infrastructure pillars. The roadmap represents the view of the Swiss scientific community in the field of geosciences and is a formal element of the process to elaborate the Swiss Roadmap for Research Infrastructures 2023. This bottom-up contribution to the identification and selection of important national and international research infrastructures has been coordinated by the Swiss Academy of Sciences (SCNAT) on a mandate by the State Secretariat for Education, Research and Innovation (SERI).ISSN:2297-1564ISSN:2297-157
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