Geochronological studies of deep sea sediments by the ionium/thorium method

Goldberg, Edward D.; Koide, Minoru

doi:10.1016/0016-7037(62)90112-6

Cited by 436 publications

(129 citation statements)

References 17 publications

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“…Considering the amount of scatter in these data, it appears that the difference in sedimentation rates between cores 33 and 638 is not significant, but that core 3 does show a slightly lower sedimentation rate than the other two cores. The average of these values (0.95 mm/103 yr) is in agreement with the average value of 1.0 mm/103 yr found by Goldberg and Koide [1] for sediments in the North Pacific (19°N, 178°W). However, it is likely that bioturbation extends down to depths as great as 20 cm in this region, according to Bowen et al [9].…”

Section: Isotopic Profilessupporting

confidence: 91%

“…The 23°Th/232Th ratios were determined at the Scripps Institution of Oceanography on dried sediment samples using standard methods [1]. Percent sedimentary organic carbon (SOC) was determined on dried sediment using a HewlettPackard CHN Analyser.…”

Section: Methodsmentioning

confidence: 99%

“…Sedimentation rates determined using the 23°Th/232Th method were reported by Goldberg and Koide [1] for several locations in the Pacific. Significant variations were found in these red clay sediments (0.4-1.6 mm/10 3 yr), and appeared to be a function of distance from the continents.…”

Section: Introductionmentioning

confidence: 99%

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Variability of natural and bomb-produced radionuclide distributions in abyssal red clay sediments

Druffel

Williams

Livingston

et al. 1984

Earth and Planetary Science Letters

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Section: Isotopic Profilessupporting

confidence: 91%

Section: Methodsmentioning

confidence: 99%

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Variability of natural and bomb-produced radionuclide distributions in abyssal red clay sediments

Druffel

Williams

Livingston

et al. 1984

Earth and Planetary Science Letters

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“…The main processes governing excess 210 Pb profiles are sediment accumulation, radioactive decay, and particle mixing (Goldberg and Koide, 1962). Dividing the 210 Pb profile into a two-layer profile, a surface mixed layer extending to some depth in the sediment profile above a zone of no mixing, allows the sedimentation rate to be calculated in the region of limited mixing via:…”

Section: Core Collectionmentioning

confidence: 99%

Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level

Horton

Corbett

Culver

et al. 2006

Estuarine, Coastal and Shelf Science

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. (2006). Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level . Retrieved from http://repository.upenn.edu/ees_papers/46Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level AbstractWe collected modern diatom samples from Currituck Barrier Island, Oregon Inlet and Pea Island marshes, Outer Banks, North Carolina, USA, which have different salinity regimes due to their varying distances from a major barrier island inlet. Multivariate analyses separate the saltmarsh diatom assemblages into distinct elevational zones, dominated by differing abundances of polyhalobous, mesohalobous and oligohalobous taxa, suggesting that the distribution of saltmarsh diatoms is a direct function of elevation, with the most important controlling factors being the duration and frequency of subaerial exposure.We developed the first diatom-based transfer function for the east coast of North America to reconstruct former sea levels based upon the relationship between diatom assemblage and elevation. Results imply that this is possible to a precision of ±0.08 m, superior to most similar studies from temperate, mid-latitude environments. The transfer function is used to construct a relative sea-level curve from fossil assemblages from Salvo, North Carolina. These results suggest a sea-level rise of 0.7 m over the last c. 150 years, at an average of c. 3.7 mm year −1 . This is consistent with existing sea-level data, and illustrates the utility of the transfer function approach. AbstractWe collected modern diatom samples from Currituck Barrier Island, Oregon Inlet and Pea Island marshes, Outer Banks, North Carolina, USA, which have different salinity regimes due to their varying distances from a major barrier island inlet. Multivariate analyses separate the saltmarsh diatom assemblages into distinct elevational zones, dominated by differing abundances of polyhalobous, mesohalobous and oligohalobous taxa, suggesting that the distribution of saltmarsh diatoms is a direct function of elevation, with the most important controlling factors being the duration and frequency of subaerial exposure.We developed the first diatom-based transfer function for the east coast of North America to reconstruct former sea levels based upon the relationship between diatom assemblage and elevation.Results imply that this is possible to a precision of ± 0.08m, superior to most similar studies from temperate, mid-latitude environments. The transfer function is used to construct a relative sea-level curve from fossil assemblages from Salvo, North Carolina. These results suggest a sea-level rise of 0.7m sea-level rise over the last c. 150 years, at an average of c. 3.7 mm yr -1 . This is consistent with existing sea-level data, and illustrates the utility of the transfer function approach.

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“…This implies either that seasonal varying sediment accumulation rates are considerably higher than the long-term net accumulation rate and/or that these radionuclides are transported to deeper layers by mixing processes. Assuming a constant delivery of these natural radionuclides and steady-state accumulation (Boudreau 1986), eddy-diffusion-type mixing coefficients (D b ;Goldberg & Koide 1962) for bulk sediment mixing were estimated to be 6 to 52 cm 2 yr -1 based on 7 Be. Clifton et al (1995) reported sediment mixing coefficients for intertidal sediments of the Tamar estuary of 1.8 to 108 cm 2 yr -1 based on 7 Be, and of 8 to 43 cm 2 yr -1 based on 210 Pb; these are consistent with our data.…”

Section: Mixing Processes In Sedimentmentioning

confidence: 99%

Role of physical and biological processes in sediment dynamics of a tidal flat in Westerschelde Estuary, SW Netherlands

Widdows

Blauw²,

Heip

et al. 2004

Mar. Ecol. Prog. Ser.

110

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This article synthesises a series of studies concerned with physical, chemical and biological processes involved in sediment dynamics (sedimentation, erosion and mixing) of the Molenplaat tidal flat in the Westerschelde (SW Netherlands). Total sediment accretion rate on the flat (sand to muddy sand) was estimated to be ~2 cm yr -1 , based on 210 Pb and 137 Cs profiles. 7 Be showed maximum activity in the surface sediments during summer, reflecting accretion of fine silt at this time of year, and total vertical mixing of sediment to be in the order of 50 cm 2 yr -1 . The extent to which different physical and biological processes (tidal currents, air exposure, bio-stabilisation, biodeposition and bioturbation) contributed towards sediment dynamics was estimated. A sediment transport model based on physical factors estimated sedimentation rates of 1.2 cm yr -1 , but did not account for tidal or seasonal variation in suspended particulate matter (SPM), wind or effects of spring-neap tidal cycles. When the model was run with an increased critical bed shear stress due to the microphytobenthos, net sedimentation rates increased 2-fold. These higher rates were in closer agreement with the rates derived from the depth profiles of radionuclides for the central region of the tidal flat (2.0 to 2.4 cm yr -1 ). Therefore a significant part of the sedimentation rate (~50%) may be explained by spatial-temporal changes in biological processes, including 'bio-stabilisation' by microphytobenthos, together with the enhanced biodeposition of silt by suspension feeders, and offset by processes of 'bio-destabilisation' by grazers and bioturbators. In the centre of the tidal flat there was a shift from high sediment stability in spring-summer 1996 to low sediment stability in autumn 1997, quantified by a significant reduction in critical erosion velocity of 0.12 to 0.15 m s -1 , and accompanied by a 30-to 50-fold increase in sediment erosion rate. The change was associated with a shift from a tidal flat dominated by benthic diatoms and a low biomass of bioturbating clams (Macoma balthica), to a more erodable sediment with a lower microphytobenthos density and a higher biomass of M. balthica. Vertical mixing of sediment and organic matter, studied using a variety of tracers, was rapid and enhanced by advective water flow at sandy sites and by burrowing polychaetes and bivalves at silty sites. The sediment dynamics and biogeochemistry of tidal flats is dependent on the complex interactions between physical, chemical and biological processes/properties, which include tidal currents, river flows, storm waves, air exposure, dehydration in summer, ice-scour in winter, sediment properties (grain size and composition, organic content, nutrient content, redox balance), stabilisation by biota (algal biofilms, mussel beds, salt marsh) and destabilisation by biota (bioturbating bivalves, scouring around clumps of animals and plants). To date, there have been very few multi-disciplinary studies providing an integrated view of the sedim...

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Geochronological studies of deep sea sediments by the ionium/thorium method

Cited by 436 publications

References 17 publications

Variability of natural and bomb-produced radionuclide distributions in abyssal red clay sediments

Variability of natural and bomb-produced radionuclide distributions in abyssal red clay sediments

Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level

Role of physical and biological processes in sediment dynamics of a tidal flat in Westerschelde Estuary, SW Netherlands

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