Developing sediment geochronologies for high-latitude continental shelf deposits: a radiochemical approach

Harden, Stephen L.; DeMaster, David J.; Nittrouer, Charles A.

doi:10.1016/0025-3227(92)90009-7

Cited by 116 publications

(83 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…is in agreement with the MRE range of 750e1300 14 C years determined in other parts of the Southern Ocean (e.g. Gordon and Harkness, 1992;Harden et al, 1992;Berkman and Forman, 1996;Domack et al, 2005).…”

Section: Methodssupporting

confidence: 91%

“…With the exception of site GC359, the down-core variability of the d 13 C org values at each individual core site is 1.1& (Table 1), which is comparable or less than at core sites from other parts of the Antarctic shelf (e.g. Harden et al, 1992;Domack et al, 1998Domack et al, , 1999Domack et al, , 2001Licht and Andrews, 2002;Ó Cofaigh et al, 2005a;Pudsey et al, 2006;Hemer et al, 2007;McKay et al, 2008;Hillenbrand et al, 2010). The d 13 C org composition of marine particulate organic substance typically ranges from À18& to À27& (e.g.…”

Section: Ams 14 C Down-core Agesmentioning

confidence: 86%

“…The d 13 C org composition of marine particulate organic substance typically ranges from À18& to À27& (e.g. Harden et al, 1992;Meyers, 1997;Lamb et al, 2006;Smith et al, 2006). More depleted d 13 C org values down to À29.4& were reported for the organic material in sediments from the Ross Sea shelf Domack et al, 1999).…”

Section: Ams 14 C Down-core Agesmentioning

confidence: 99%

See 2 more Smart Citations

The sedimentary legacy of a palaeo-ice stream on the shelf of the southern Bellingshausen Sea: Clues to West Antarctic glacial history during the Late Quaternary

Hillenbrand

Larter

Dowdeswell

et al. 2010

Quaternary Science Reviews

View full text Add to dashboard Cite

a b s t r a c tA major trough ("Belgica Trough") eroded by a palaeo-ice stream crosses the continental shelf of the southern Bellingshausen Sea (West Antarctica) and is associated with a trough mouth fan ("Belgica TMF") on the adjacent continental slope. Previous marine geophysical and geological studies investigated the bathymetry and geomorphology of Belgica Trough and Belgica TMF, erosional and depositional processes associated with bedform formation, and the temporal and spatial changes in clay mineral provenance of subglacial and glaciomarine sediments.Here, we present multi-proxy data from sediment cores recovered from the shelf and uppermost slope in the southern Bellingshausen Sea and reconstruct the ice-sheet history since the last glacial maximum (LGM) in this poorly studied area of West Antarctica. We combined new data (physical properties, sedimentary structures, geochemical and grain-size data) with published data (shear strength, clay mineral assemblages) to refine a previous facies classification for the sediments. The multi-proxy approach allowed us to distinguish four main facies types and to assign them to the following depositional settings: 1) subglacial, 2) proximal grounding-line, 3) distal sub-ice shelf/sub-sea ice, and 4) seasonal open-marine. In the seasonal open-marine facies we found evidence for episodic currentinduced winnowing of near-seabed sediments on the middle to outer shelf and at the uppermost slope during the late Holocene.In addition, we obtained data on excess 210 Pb activity at three core sites and 44 AMS 14 C dates from the acid-insoluble fraction of organic matter (AIO) and calcareous (micro-) fossils, respectively, at 12 sites. These chronological data enabled us to reconstruct, for the first time, the timing of the last advance and retreat of the West Antarctic Ice Sheet (WAIS) and the Antarctic Peninsula Ice Sheet (APIS) in the southern Bellingshausen Sea. We used the down-core variability in sediment provenance inferred from clay mineral changes to identify the most reliable AIO 14 C ages for ice-sheet retreat. The palaeo-ice stream advanced through Belgica Trough after w36.0 corrected 14 C ka before present (B.P.). It retreated from the outer shelf at w25.5 ka B.P., the middle shelf at w19.8 ka B.P., the inner shelf in Eltanin Bay at w12.3 ka B.P., and the inner shelf in Ronne Entrance at w6.3 ka B.P. The retreat of the WAIS and APIS occurred slowly and stepwise, and may still be in progress. This dynamical ice-sheet behaviour has to be taken into account for the interpretation of recent and the prediction of future mass-balance changes in the study area. The glacial history of the southern Bellingshausen Sea is unique when compared to other regions in West Antarctica, but some open questions regarding its chronology need to be addressed by future work.

show abstract

Section: Methodssupporting

confidence: 91%

Section: Ams 14 C Down-core Agesmentioning

confidence: 86%

See 1 more Smart Citation

The sedimentary legacy of a palaeo-ice stream on the shelf of the southern Bellingshausen Sea: Clues to West Antarctic glacial history during the Late Quaternary

Hillenbrand

Larter

Dowdeswell

et al. 2010

Quaternary Science Reviews

View full text Add to dashboard Cite

show abstract

“…Despite this, the ages display a clear down-core pattern, indicating a linear and high sedimentation rate Bárcena et al ( , 2002 in agreement with the accumulation rates given in the literature. In this area radiocarbon dating yields anomalous old ages caused by two main effects: the large and regionally variable reservoir effect, which results in an age delay of 1200-1400 years, and the input of older eroded sediment that was re-deposited as a result of lateral transport, current winnowing, and mass-wasting processes (Stuiver et al, 1981 andHarden et al, 1992). Moreover, ice-rafting of fine particles from icebergs could also contribute to this effect.…”

Section: Methodsmentioning

confidence: 99%

Holocene neoglacial events in the Bransfield Strait (Antarctica). Palaeocenographic and paleoclimatic significance

Bárcena¹,

Fabrés²,

Isla³

et al. 2006

Sci. Mar.

View full text Add to dashboard Cite

SUMMARY: Geochemical analysis, micropalaeontological analysis and radiometric dating techniques were performed on four gravity cores, G-1, G-2, A-3 and A-6, recovered during the BIO Hesperides expeditions GEBRA-93 and FRUELA-96 from the Bransfield Strait (Antarctica). Moreover, in order to improve the sedimentation rate control we tentatively relate abundance variations in the sea-ice taxa group (SITG) to air temperature estimations based on Deuterium contents in Vostok ice-core. The results of diatom analyses were related to the sequence of neoglacial events that have occurred over the last three millennia. For these periods, a restricted communication between the Weddell, Bransfield and Bellingshausen seas has been proposed. The abundance patterns of diatom valves, resting spores (RS) of the diatom Chaetoceros and opal content agree with the high productivity values previously reported for the area. The significant reduction Chaetoceros RS towards the present is interpreted as a reduction in surface productivity. Trend differences between Chaetoceros RS and TOC contents are explained in terms of organic matter preservation. Diatom communities from the Bransfield Strait did not play an important role in the global CO 2 cycle during cold periods. Bio-and geochemical changes have overprinted high frequency cyclicity at about 200-300 yr, which might be related to the 200-yr solar cycle.Keywords: diatoms, geochemistry, neoglacial events, palaeoceanography, palaeocliomatology, Holocene, Bransfield Strait, Antarctica. RESUMEN: EVENTOS NEOGLACIALES DEL HOLOCENO EN EL ESTRECHO DE BRANSFIELD (ANTÁRTICA). SIGNIFICADO PALEOCEA-NOGRÁFICO Y PLAEOCLIMÁTICO. -Se han realizado análisis geoquímicos y micropaleontológicos, así como técnicas de datación radiométricas sobre cuatro testigos de gravedad (G-1, G2, A-3 y A-6) recuperados durante las campañas del BIO Hespérides Gebra-93 y Fruela-96 en el Estrecho de Bransfield (Antártida). Se han correlacionado las estimaciones de temperatura del aire, derivadas del contenido en Deuterio en el testigo de hielo Vostok, con la abundancia del grupo de taxones de mar helado (SITG). Los resultados obtenidos del análisis de diatomeas han sido relacionados con la secuencia de eventos neoglaciales que tuvieron lugar durante los últimos 3000 años. Se propone una restricción en la comunicación entre el Mar de Weddel, Estrecho de Bransfield y Mar de Bellingshausen durante los episodios neoglaciales. Los patrones de abundancia de valvas de diatomeas, esporas (RS) de Chaetoceros y el contenido en ópalo biogénico indican valores altos en productividad, previamente descritos para el área. La progresiva reducción en Chaetoceros (RS) hacia techo se ha interpretado como reducción en la productividad superficial. Las diferencias entre la abundancia de Chaetoceros (RS) y el contenido en carbono orgánico (TOC) puede deberse a diferencias en la preservación de la materia orgánica. Por otro lado, los datos analizados indican que las comunidades de diatomeas del estrecho de Bransfield no jugaron un papel dete...

show abstract

“…Most parts of the earth are now 10,000 to 18,000 years removed from the last major glacial episode (Schlesinger 1990), and 5 lands once covered by continental glaciers are now accumulating soil organic C at a rate possibly between 0.075 and 0.18 Gt of C year −1 (Harden et al, 1992). Hence, these soils may be sinks for CO2 within the atmospheric CO2 balance (Amundson 2001).…”

Section: Introductionmentioning

confidence: 99%

Uncovering biological soil crusts: Carbon content and structure of intact Arctic, Antarctic and alpine biological soil crusts

Jung¹,

Briegel-Williams²,

Simon³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. Arctic, Antarctic and alpine biological soil crusts (BSCs) are formed by adhesion of soil particles to exopolysaccharides (EPS), excreted by cyanobacterial and green algal communities, the pioneers and main producers in these habitats. These BSCs provide and influence many ecosystem services such as soil erodibility, soil formation and Nitrogen-(N) as well as carbon-(C) cycles. In cold environments degradation rates are low and BSCs increase continuously soil organic C, whereby these soils are considered as CO2 sinks. This work provides a novel, non-destructive and highly comparable method 15 to investigate intact BSCs with a focus on cyanobacteria and green algae and their contribution to soil organic C. A new terminology arose, based on confocal laser scanning microscopy (CLSM) 2D biomaps, dividing BSCs into a photosynthetic active layer (PAL), made of active photoautotrophic organisms and a photosynthetic inactive layer (PIL), harbouring remnants of cyanobacteria and green algae glued together by their remaining EPS. By the application of CLSM image analysis (CLSM-IA) to 3D biomaps, C coming from photosynthetic active organisms could be visualized as depth profiles with C peaks at 0.5 20 to 2 mm depth. Additionally, the CO2 sink character of these cold soil habitats dominated by BSCs could be highlighted, demonstrating that the first cm³ of soil is made of between 7 and 17 % total organic carbon, identified by loss on ignition.

show abstract

Developing sediment geochronologies for high-latitude continental shelf deposits: a radiochemical approach

Cited by 116 publications

References 45 publications

The sedimentary legacy of a palaeo-ice stream on the shelf of the southern Bellingshausen Sea: Clues to West Antarctic glacial history during the Late Quaternary

The sedimentary legacy of a palaeo-ice stream on the shelf of the southern Bellingshausen Sea: Clues to West Antarctic glacial history during the Late Quaternary

Holocene neoglacial events in the Bransfield Strait (Antarctica). Palaeocenographic and paleoclimatic significance

Uncovering biological soil crusts: Carbon content and structure of intact Arctic, Antarctic and alpine biological soil crusts

Contact Info

Product

Resources

About