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  • 1
    In: Paleoceanography, Hoboken, NJ : Wiley, 1986, 24(2009), 1944-9186
    In: volume:24
    In: year:2009
    In: extent:14
    Description / Table of Contents: The intratest variation in the chemical composition of Globorotalia scitula and G. inflata recovered from a sediment trap sample collected at 3000 m in the North Atlantic in early spring has been investigated using laser ablation inductively coupled plasmamass spectrometry and electron microprobe. Mg/Ca, Li/Ca, B/Ca, Mn/Ca, and Ba/Ca vary by up to a factor of 10 through the test walls. Water column properties, including temperature and salinity, are well documented at the trap site, and the observed variations are too large to be explained by vertical migration of the foraminifera. However, changes in calcite precipitation rate, crystal structure, or the chemical composition of the internal calcification reservoir also cannot, by themselves, fully account for the pattern of intratest variability. Nevertheless, the average Mg/Ca for each chamber generally produces a Mg/Ca temperature that matches that measured in the water column. The exception is small, morphologically distinct G. inflata tests that have anomalously high Mg/Ca.
    Type of Medium: Online Resource
    Pages: 14 , Ill., graph. Darst
    ISSN: 1944-9186
    Language: English
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  • 2
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    In:  Supplement to: James, Rachael H; Rudnicki, Mark D; Palmer, Martin R (1999): The alkali element and boron geochemistry of the Escanaba Trough sediment-hosted hydrothermal system. Earth and Planetary Science Letters, 171(1), 157-169, https://doi.org/10.1016/S0012-821X(99)00140-5
    Publication Date: 2024-01-09
    Description: A suite of conjugate pore fluid and sediment samples were collected during Leg 169 of the ODP from within the clastic sedimentary sequences which host massive sulphides at Central Hill, Escanaba Trough (ODP Site 1038). We report the alkali element and boron, and Li and B isotope data for these samples. Relative to a reference site (Site 1037) located outside the zone of high heat flow, pore fluids from Site 1038 show a wide variation in Cl (300-800 mM), and have far higher concentrations of Li (up to 6.2 mM), B (up to 9.7 mM), Cs (up to 5.0 mM), and Rb (up to 97 mM). We show that the pore fluids are derived from hydrothermal circulation that has extended into the basement oceanic crust, with input of the alkali elements and B as the rising hydrothermal fluids interact geochemically with the overlying clastic sediments. There is, however, no marked depletion of these elements in the conjugate sediments, suggesting that there has been advective transport of fluids away from the primary hydrothermal reaction site. This is supported by modelling of the Li and B isotope systematics of the pore fluids, which shows that they record extensive formation of secondary minerals during cooling of the fluids from ~350 to ~20ºC. Precipitation of metal-rich sulphides would have occurred prior to the formation of these minerals, thus, the pore fluid Li and B isotope data can place important constraints on the locus of sulphide deposition beneath the seafloor at Escanaba.
    Keywords: 169-1038A; 169-1038B; 169-1038C; 169-1038D; 169-1038F; 169-1038G; 169-1038H; 169-1038I; DRILL; Drilling/drill rig; Escanaba Trough, North Pacific Ocean; Joides Resolution; Leg169; Ocean Drilling Program; ODP
    Type: Dataset
    Format: application/zip, 2 datasets
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  • 3
    Publication Date: 2024-01-09
    Keywords: 169-1038A; 169-1038B; 169-1038C; 169-1038D; 169-1038F; 169-1038G; 169-1038H; 169-1038I; Caesium; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Escanaba Trough, North Pacific Ocean; Event label; Inductively coupled plasma - mass spectrometry (ICP-MS); Joides Resolution; Leg169; Mass spectrometer Finnigan MAT 262; Ocean Drilling Program; ODP; Rubidium; Sample code/label; δ11B; δ6Li
    Type: Dataset
    Format: text/tab-separated-values, 108 data points
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  • 4
    Publication Date: 2024-04-16
    Keywords: 169-1038A; 169-1038G; 169-1038H; 169-1038I; Caesium; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Escanaba Trough, North Pacific Ocean; Event label; Inductively coupled plasma atomic emission spectroscope (ICP-AES); Inductively coupled plasma - mass spectrometry (ICP-MS); Joides Resolution; Leg169; Lithium; Mass spectrometer Finnigan MAT 262; Ocean Drilling Program; ODP; Rubidium; Sample code/label; δ6Li
    Type: Dataset
    Format: text/tab-separated-values, 90 data points
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  • 5
    Publication Date: 2017-10-13
    Description: More than 250 plumes of gas bubbles have been discovered emanating from the seabed of the West Spitsbergen continental margin, in a depth range of 150– 400 m, at and above the present upper limit of the gas hydrate stability zone (GHSZ). Some of the plumes extend upward to within 50 m of the sea surface. The gas is predominantly methane. Warming of the northward-flowing West Spitsbergen current by 1° C over the last thirty years is likely to have increased the release of methane from the seabed by reducing the extent of the GHSZ, causing the liberation of methane from decomposing hydrate. If this process becomes widespread along Arctic contine ntal margins, tens of Teragrams of methane per year could be released into the ocean.
    Type: Article , PeerReviewed
    Format: text
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