Recursos de colección

PANGAEA - Publishing Network for Geoscientific & Environmental Data (831.629 recursos)

The information system PANGAEA is operated as an Open Access library aimed at archiving, publishing and distributing georeferenced data from earth system research. The system guarantees long-term availability of its content through a commitment of the operating institutions.

Citable datasets

Mostrando recursos 1 - 20 de 12.364

  1. Geochemistry of sediment core PRGL1-4

    Pasquier, Virgil; Sansjofre, Pierre; Rabineau, Marina; Revillon, Sidonie; Houghton, Jennifer; Fike, David A
    The sulfur biogeochemical cycle plays a key role in regulating Earth's surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (d34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth's surface environment, including the rise of atmospheric oxygen. Such inferences assume that individual d34S records reflect temporal changes in the global sulfur cycle; this assumption may be well grounded for sulfate-bearing minerals but is less well established for pyrite-based records. Here, we investigate alternative controls on the...

  2. Geochemistry of sapropel S1 deposits in sediment core AMC99-1

    Tesi, Tommaso; Asioli, Alessandra; Minisini, D; Maselli, Vittorio; Dalla Valle, Giacomo; Gamberi, Fabiano; Langone, Leonardo; Cattaneo, Antonio; Montagna, Paolo; Trincardi, Fabio
    The formation of Eastern Mediterranean sapropels has periodically occurred during intensification of northern hemisphere monsoon precipitation over North Africa. However, the large-scale response of the Eastern Mediterranean thermohaline circulation during these monsoon-fuelled freshening episodes is poorly constrained. Here, we investigate the formation of the youngest sapropel (S1) along an across-slope transect in the Adriatic Sea. Foraminifera-based oxygen index, redox-sensitive elements and biogeochemical parameters reveal - for the first time - that the Adriatic S1 was synchronous with the deposition of south-eastern Mediterranean S1 beds. Proxies of paleo thermohaline currents indicate that the bottom-hugging North Adriatic Dense Water (NAdDW) suddenly decreased...

  3. Dissolved inorganic carbon data from 2010 and 2013 at the Gulf of Tehuantepec

    Chapa-Balcorta, Cecilia; Hernández-Ayón, José Martín; Beier Emilio, Durazo Reginaldo; Alin, Simone; López-Pérez, Andrés
    Measurements of dissolved inorganic carbon of 27 stations at the Gulf of Tehuantepec, México. Samples were taken during cruises carried out by the Mexican Navy. Secretaría de Marina Armada de Mexico. Stations sampled in June, 2010 on board of RV Altair, 9 were sampled on April 2013 onbord of RV Altair and 9 on October-November 2013 onboard of RV Río Suchiate. Measurements were carried out using the coulometric method described in Johnson et al (1987).

  4. Geochemistry and stable oxygen record of sediment core PS009PC

    Hennekam, Rick; Jilbert, Tom; Schnetger, Bernhard; de Lange, Gert Jan
    We present high-resolution records for oxygen isotopes of the planktic foraminifer Globigerinoides ruber (?18Oruber) and bulk sediment inorganic geochemistry for Holocene-age sediments from the southeast Mediterranean. Our ?18Oruber record appears to be dominated by Nile discharge rather than basin-scale salinity/temperature changes. Nile discharge was enhanced in the early to middle Holocene relative to today. The timing of the long-term maximum in Nile discharge during the early Holocene corresponds to the timing of maximum intensity of the Indian Ocean-influenced Southwest Indian summer monsoon (SIM). This coincidence suggests a major influence of an Indian Ocean moisture source on Nile discharge in the...

  5. Dissolved inorganic carbon, temperature and salinity measurement in the Gulf of Tehuantepec

    Chapa-Balcorta, Cecilia; Hernández-Ayón, José Martín; Beier Emilio, Durazo Reginaldo; Alin, Simone; López-Pérez, Andrés
    Temperature (C°), practical salinity and pressure (dB) data recorded at the Gulf of Tehuantepec during three sampling cruises carried out by the Secretaría de Marina Armada de Mexico. Measurements of dissolved inorganic carbon or 27 stations at the Gulf of Tehuantepec, México.

  6. Geochemistry of porewater and sediments of calcite in porous media

    Baumann, Joachim
    Ein grosse Teil! ca. 10 - 15%, der Sedimentgesteine der Erdkruste wird von Karbonaten im wesentlichen Kalkstein und Dolomit, aufgebaut (FAIRBRIDGE et al. 1967). Lösungs- und Fällungsreaktione von Kalziumkarbonat spielen schon bei deren Genese (Frühdiagenese) (WALTE & MORSE 1985) und verstärkt bei der Verwitterung eine zentrale Rolle. Die chemische Wechselwirkung zwischen Karbonatgesteinen und Wasser beeinflusst deren Porosität und Permeabilität und damit wesentliche hydrodynamische Eigenschaften (HANSHAW & BACK 1979) und bestimmt weitgehend den Chemismus der Sicker- und Grundwasser.

  7. Seawater carboante chemistry and copper toxicity in the green tide alga Ulva prolifera in laboratory experiment

    Gao, Guang; Liu, Yameng; Li, Xinshu; Feng, Zhihua; Xu, Zhiguang; Wu, Hongyan; Xu, Juntian; Yang, Yan
    Cu is considered to be toxic to macroalgae at higher levels. Ocean acidification can also alter the physiological performances of macroalgae. However, little is known regarding the interactive effects of Cu and ocean acidification on macroalgae. In this study, a green tide macroalga, Ulva prolifera, was cultured at the conditions of three levels of Cu (control, 0.5 µM, and 2 µM) and pCO2 (ambient, 1000 µatm, and 1400 µatm) to investigate the responses of U. prolifera to interaction of Cu exposure and ocean acidification. The relative growth rate of thalli decreased with the rise of Cu for all pCO2 conditions...

  8. Annotated record of the detailed examination of Mn deposits from DSDP Leg 84 (Holes 565 and 568)

    von Huene, Roland; Aubouin, Jean
    The Middle America Trench was first drilled in 1979 during Leg 66 off Oaxaca, Mexico and Leg 67 off Guatemala as part of a broad effort to study the mechanics of plate subduction and continental accretion and erosion. Leg 84 was recommended by the JOIDES Advisory Panels specifically to further examine the tectonic and gas-hydrate problems which had been revealed in the previous survey.

  9. Annotated record of the detailed examination of Mn deposits from DSDP Leg 82 (Holes 556, 558, 559, 562, 563, 564)

    Bougault, Henri; Cande, Steven C
    One of the most important geologic discoveries of the 1960s was the remarkable uniformity of the basalts produced at mid-ocean ridges. These basalts have a markedly different tholeiitic composition compared to the alkalic basalts from ocean islands. But very little is known about temporal variations in the composition of basalts derived from one or several mantle sources associated with both normal and anomalously shallow sections of the mid-ocean ridges. The strategy for drilling on DSDP Leg 82 was to set up a broad grid encompassing all possible drilling sites west and southwest of the present Azores Triple Junction in order...

  10. Organic-walled dinoflagellate cyst analysis of sediment core GeoB8331-4 and from surface sediment samples off western South Africa

    Zhao, Xueqin; Dupont, Lydie M; Schefuß, Enno; Bouimetarhan, Ilham; Wefer, Gerold
    Atmospheric and oceanographic interactions between the Atlantic and Indian Oceans influence upwelling in the southern Benguela upwelling system. In order to obtain a better knowledge of paleoceanographic and paleoenvironmental changes in the southern Benguela region during the Holocene, 12 marine surface sediment samples and one gravity core GeoB8331-4 from the Namaqualand mudbelt off the west coast of South Africa have been studied for organic-walled dinoflagellate cysts in high temporal resolution. The results are compared with pollen and geochemical records from the same samples. Our study emphasizes significantly distinct histories in upwelling intensity as well as the influence of fluvial input...

  11. Geochemistry on Mn-nodules from Leg81

    Jehanno, Celestine; Lallier-Verges, Elisabeth; Bonnot-Courtois, Chantal; Desprairies, Alain; Bijon, J; Rivière, Marc
    ree types of concretions were recovered during Leg 81 from Holes 552A, 553A, and 554A, located on the west margin of the Rockall Plateau. In the sedimentary section, these concretions are located at the level of major unconformities, in condensed sequences representing a period from early Eocene to Miocene. This study is a detailed mineralogical and geochemical investigation that permits comparison among the three holes and between the fossil Leg 81 concretions and recent polymetallic nodules found on the ocean floor.

  12. Analysis of Mn-depositis from the Briançon area, France

    Bourbon, Maurice
    This text offers a general introduction to the geological history of the North-Tethys Platform from the Malm to the Lower Eocene periods. It is followed by three parts: a sedimentology development, a geochemical study and a part devoted to the reconstitution of the environment and the sedimentation rates, the subsidence, the depth and the morphology of the seabed and therefore the paleogeography of the Briançonnais domain. The last two chapters deal, one with the evolution of the Briançonnais domain in the context of events affecting Western Tethys and the Central Atlantic, and the other with two sedimentation models deduced from...

  13. Coccolithophore assemblage and palaeoproductivity proxies at sediment core PS75/059-2

    Saavedra-Pellitero, Mariem; Baumann, Karl-Heinz; Ullermann, Johannes; Lamy, Frank
    This work aims to provide new insights into environmental conditions during late Pleistocene Marine Isotope Stage 11 (MIS 11) in the Southern Ocean. We generated a multi-proxy coccolithophore dataset based on sediment core PS75/059-2. This core was retrieved at the western flank of the southern East Pacific Rise crest at ~3600 m water depth. Coccolithophore assemblage counts indicated that the coccolith fraction (CF; <20 µm) during MIS 11 was dominated by Gephyrocapsa caribbeanica and subsequently by small Gephyrocapsa. Coccolith accumulation rates, CF Sr/Ca data and temperature-corrected CF Sr/Ca records were consistent and showed a steep increase in coccolithophore productivity as...

  14. Observation of manganese deposits in the Kane Fractue Zone of the Mid-Atlantic Ridge

    Karson, Jeffrey A; Rona, Peter A
    Seven Alvin dives (14 km total) and numerous deep-towed camera traverses using ANGUS and NOAA camera systems provide dense coverage of a 12-km2 portion of the eastern wall of the Mid-Atlantic Ridge in the TAG area (26°N lat.). These data, in conjunction with recent Soviet Mir submersible data, provide important constraints on the tectonic, magmatic, and hydrothermal history of this spreading center segment. Active hydrothermal venting occurs near the junction of the median valley floor and eastern median valley wall and appears to be tectonically controlled by the intersection of major fault zones. An east-west fault-line scarp interpreted as an...

  15. Trace elements in recent ans glacial sediments of the North Atlantic

    Willamowski, Claudia
    Benthic Cd/Ca and d13C-records along sediment cores from the northern North Atlantic and the Portuguese and Moroccan continental margins are used to trace water mass distribution patterns during the last glacial with special emphasis on glacial meltwater events (,Heinrich' events). Along the western Iberian continental margin andin the Gulf of Cadiz, water column profiles of cadmium, calcium and phosphate are combined to retrieve a regional Cd:P-correlation which represents tracer patterns in Mediterranean Outflow Water (MOW). Benthic Cd/Ca-ratios of surface-sediment samples are used to determine modern distribution coefficients ((Cd/Ca)foraminifera:(Cd/Ca)sea water) which, in turn, are used to infer water column paleo-cadmium (Cdw)...

  16. Atlantic ITCZ planktonic foraminifera RN/Gg, MAT subsurface temperature, Ti/Ca and EDP-XRF calibrate scanning data

    Portilho-Ramos, Rodrigo Costa; Chiessi, Cristiano Mazur; Zhang, Yancheng; Mulitza, Stefan; Kucera, Michal; Siccha, Michael; Prange, Matthias; Paul, André
    The modern state of the Atlantic meridional overturning circulation promotes a northerly maximum of tropical rainfall associated with the Intertropical Convergence Zone (ITCZ). For continental regions, abrupt millennial-scale meridional shifts of this rainbelt are well documented, but the behavior of its oceanic counterpart is unclear due the lack of a robust proxy and high temporal resolution records. Here we show that the Atlantic ITCZ leaves a distinct signature in planktonic foraminifera assemblages. We applied this proxy to investigate the history of the Atlantic ITCZ for the last 30,000 years based on two high temporal resolution records from the western Atlantic...

  17. Damage and protection cost curves for coastal flooding at the 600 largest coastal cities within Europe

    Prahl, Boris F; Boettle, Markus; Costa, Luis; Rybski, Diego; Kropp, Jürgen P
    Costs of coastal flooding and protection are essential information for risk assessment and natural hazards research, but there are few systematic attempts to quantify cost curves beyond the case study level. Here, we present a set of systematically derived damage and protection cost curves for the 600 largest (by area) European coastal cities. The city clusters were identified by an automated cluster algorithm from CORINE land cover 2012 data, following the Urban Morphological Zone (UMZ) definition. The data provides detailed cost curves for direct flood damages at flood heights between 0 and 12 m on a 0.5 m increment. Costs estimates...

  18. Interaction between glacial activity 2 and flood frequency in proglacial Lake Muzelle

    Fouinat, Laurent; Sabatier, Pierre; Poulenard, Jérôme; Etienne, David; Develle, Anne-Lise; Doyen, Elise; Malet, Emmanuel; Reyss, Jean-Louis; Sagot, Clotilde; Bonet, Richard; Arnaud, Fabien
    Local glacial fluctuations and flood occurrences were investigated in the sediment sequence of proglacial Lake Muzelle. Based on geochemical analysis and organic matter content established using loss on ignition and reflectance spectroscopy, we identified six periods of increased glacial activity over the last 1700 yr. Each is in accordance with records from reference glaciers in the Alps. A total of 255 graded layers were identified and interpreted as flood deposits. Most of these occurred during glacial advances such as the Little Ice Age period and exhibit thicker deposits characterized by an increase in the fine grain-size fraction. Fine sediment produced...

  19. Coccolithophore distribution in the Mediterranean Sea during spring 2011 (M84/3 cruise)

    Oviedo, Angela Maria; Ziveri, Patrizia; Álvarez, Marta; Tanhua, Toste
    The Mediterranean Sea is considered a "hot spot" for climate change, being characterized by oligotrophic to ultra-oligotrophic waters and rapidly increasing seasurface temperature and changing carbonate chemistry. Coccolithophores are considered a dominant phytoplankton group in these waters. As marine calcifying organisms they are expected to respond to the ongoing changes in seawater carbonate chemistry. We provide here a description of the springtime coccolithophore distribution in the Mediterranean Sea and relate this to a broad set of in situ-measured environmental variables. Samples were taken during the R/V Meteor (M84/3) oceanographic cruise in April 2011, between 0 and 100 m water depth...

  20. Analysis of ferromanganese deposits from the Northwestern Pacific seamounts

    Joshima, Masato; Usui, Akira
    Fine-scale dating is crucial to understanding the growth and environments of formation of marine manganese deposits. The paleomagnetic method of dating of manganese nodules and crusts has been attempted but with no success so far. We measured remanent magnetization (RM) on up to 75-mm-thick hydrogenetic crusts at intervals of 2.5 mm after mineralogical and chemical examination, careful separation, and alternative field demagnetization. Stable sharp RM and well-correlated polarity-change patterns between four samples made it possible to identify the Pliocene-Quaternary magnetic chrons in them. These data show that the three crusts have grown continuously at rates of 14-17 mm/m.y. since the...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.