Zooming in on Heinrich layers

Grousset, F.; Cortijo, Elsa; Huon, Sylvain; Herve, Laurence; Richter, Thomas; Burdloff, Didier; Duprat, J.; Weber, O.

doi:10.1029/2000pa000559

Cited by 136 publications

(130 citation statements)

References 63 publications

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“…In fact, higher nutrient levels during iceberg discharges, enhancing primary productivity, have already been suggested (Sancetta, 1992). However, we have no micropaleontological evidence for such an increase, at least for core SU 90-09 (Grousset et al, 2001;Huon et al, 2002).…”

Section: Nature Of the Authigenic P Phasementioning

confidence: 44%

“…According to the magnetic susceptibility and IRD records (Fig. 3), HL 4 is characterized by a rather broad peak shape, whereas HL 5 is narrower (Grousset et al, 2001). The distribution of IRD in the sediment is not limited to the interval defined by foraminifer minima and IRD maxima (Heinrich, 1988;Bond et al, 1992), but is more widespread Authigenic P e 10 mL 1mol/L Na-acetate buffered to pH 4 with acetic acid (5 hr), 10 mL 1mol/L MgCl 2 (2 hr), 10 mL 1mol/L MgCl 2 (2 hr), 10 mL H 2 O (2 hr)…”

Section: Resultsmentioning

confidence: 99%

“…The down-core variations in the concentrations of different P phases within the fine-grained fraction for the Holocene and glacial sediments are displayed in Figures 2 and 3, together with low-field magnetic susceptibility values (Grousset et al, 2001), IRD content, fine-sized TOC concentrations, and ␦ 13 C values (Huon et al, 2002). According to the magnetic susceptibility and IRD records (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…3. Plots of down-core variations of (a) magnetic susceptibility and ice-rafted debris (IRD) (Ͼ150 m) content (Grousset et al, 2001); (b) total organic carbon (TOC) content and (c) ␦ 13 C of organic carbon of the Ͻ50-m fraction (Huon et al, 2002); (d) total phosphorus; (e) ferric Fe and Fe-bound P; (f) authigenic P; (g) detrital P; and (h) organic-bound P for the fine-sized fraction of samples from core SU 90-09 (130 to 200 cm depth). The 144.0-to 153.5-cm and 187.0-to 193.5-cm intervals represent the Heinrich events 4 and 5, respectively (Huon et al, 2002).…”

Section: Resultsmentioning

confidence: 99%

“…1; Grousset et al, 2001;Huon et al, 2002). Stratigraphic correlation with reference core SU90-08 (43°31'N, 30°24'W) and the down-core position of HLs 1 to 5 were performed using accelerator mass spectrometry 14 C ages on Neogloboquadrina pachyderma s. shells, coarse lithic grain (Ͼ150 m) counts under binocular, low-field magnetic susceptibility, and gray-scale reflectance records (methods described in Grousset et al, 1993;Cortijo et al, 1995;Grousset et al, 2001).…”

Section: Methodsmentioning

confidence: 99%

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Dysaerobic conditions during Heinrich events 4 and 5: Evidence from phosphorus distribution in a North Atlantic deep-sea core

Tamburini

Huon

Steinmann

et al. 2002

Geochimica et Cosmochimica Acta

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Abstract-Reactive phosphorus undergoes diagenetic transformation once transferred into marine sediments. The degree of regeneration and redistribution of phosphorus depends on early diagenetic and environmental conditions, which may be linked to larger scale phenomena, such as bottom water circulation, water column ventilation, and organic carbon flux. Phosphorus phases of the Ͻ50-m-sized fraction of deep-sea sediments from core SU 90-09 (North Atlantic, 43°31'N, 30°24'W, 3375 m below sea level) have been analyzed using a sequential extraction technique (SEDEX method) to reconstruct phosphorus geochemistry during Heinrich events 4 and 5. Comparison with Holocene samples from the same site indicates that postdeposition diagenetic transformation has not affected phosphorus distribution in the deep part of the sediments. Total and reactive phosphorus average 0.40 Ϯ 0.04 mg/g and 0.30 Ϯ 0.05 mg/g, respectively, and are comparable to values found in analog deep-sea environments in the North Atlantic. Detrital phosphorus, the phase linked to igneous-and metamorphic-derived material, sharply increases during Heinrich events and covaries with the ice-rafted debris record, whereas authigenic and Fe-bound phosphorus phases, both influenced by redox conditions, decrease or even disappear. These findings suggest that during the deposition of Heinrich layers (HLs), environmental parameters hampered the precipitation of these phases. Large freshwater discharges in relation to iceberg surges may have provoked a temporary stratification of the water column. Accordingly, dysaerobic conditions in the sediments may have fostered the loss of dissolved phosphorus from the sediments to the water column, in a direct and rapid response to the changed conditions. Decreasing trends in organic matter elemental ratios (total organic carbon/organic phosphorus) and Rock-Eval oxygen index values, along with the presence of partly authigenic dolomite and ankerite within HLs, also support this assumption.

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Section: Nature Of the Authigenic P Phasementioning

confidence: 44%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Dysaerobic conditions during Heinrich events 4 and 5: Evidence from phosphorus distribution in a North Atlantic deep-sea core

Tamburini

Huon

Steinmann

et al. 2002

Geochimica et Cosmochimica Acta

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Bivalve shell horizons in seafloor pockmarks of the last glacial‐interglacial transition: a thousand years of methane emissions in the Arctic Ocean

Ambrose

Panieri

Schneider

et al. 2015

Geochem Geophys Geosyst

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We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (∼1200 m water depth) and western Svalbard (79°00′ N, 06°55′ W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at 250–400 cm deep in the cores. The carbon isotope composition of inorganic (δ13C from −13.02‰ to +2.36‰) and organic (δ13C from −29.28‰ to −21.33‰) shell material and a two‐end member mixing model indicate that these taxa derived between 8% and 43% of their nutrition from chemosynthetic bacteria. In addition, negative δ13C values for planktonic foraminifera (−6.7‰ to −3.1‰), concretions identified as methane‐derived authigenic carbonates, and pyrite‐encrusted fossil worm tubes at the shell horizons indicate a sustained paleo‐methane seep environment. Combining sedimentation rates with 14C ages for bivalve material from the shell horizons, we estimate the horizons persisted for about 1000 years between approximately 17,707 and 16,680 years B.P. (corrected). The seepage event over a 1000 year time interval was most likely associated with regional stress‐related faulting and the subsequent release of overpressurized fluids.

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Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a paleobenchmark for models of marine ice sheet deglaciation

Patton

Andreassen

Bjarnadóttir

et al. 2015

Reviews of Geophysics

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Our understanding of processes relating to the retreat of marine‐based ice sheets, such as the West Antarctic Ice Sheet and tidewater‐terminating glaciers in Greenland today, is still limited. In particular, the role of ice stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, a marine‐based ice sheet has waxed and waned over the Barents Sea continental shelf, characterized by a number of ice streams that extended to the shelf edge and subsequently collapsed during periods of climate and ocean warming. Increasing availability of offshore and onshore geophysical data over the last decade has significantly enhanced our knowledge of the pattern and timing of retreat of this Barents Sea ice sheet (BSIS), particularly so from its Late Weichselian maximum extent. We present a review of existing geophysical constraints that detail the dynamic evolution of the BSIS through the last glacial cycle, providing numerical modelers and geophysical workers with a benchmark data set with which to tune ice sheet reconstructions and explore ice sheet sensitivities and drivers of dynamic behavior. Although constraining data are generally spatially sporadic across the Barents and Kara Seas, behaviors such as ice sheet thinning, major ice divide migration, asynchronous and rapid flow switching, and ice stream collapses are all evident. Further investigation into the drivers and mechanisms of such dynamics within this unique paleo‐analogue is seen as a key priority for advancing our understanding of marine‐based ice sheet deglaciations, both in the deep past and in the short‐term future.

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Zooming in on Heinrich layers

Cited by 136 publications

References 63 publications

Dysaerobic conditions during Heinrich events 4 and 5: Evidence from phosphorus distribution in a North Atlantic deep-sea core

Dysaerobic conditions during Heinrich events 4 and 5: Evidence from phosphorus distribution in a North Atlantic deep-sea core

Bivalve shell horizons in seafloor pockmarks of the last glacial‐interglacial transition: a thousand years of methane emissions in the Arctic Ocean

Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a paleobenchmark for models of marine ice sheet deglaciation

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