Benthic foraminifera and sediment grain size variability at intermediate water depths in the Northeast Atlantic during the late Pliocene–early Pleistocene

Austin, William E. N.; Evans, James R.

doi:10.1016/s0025-3227(00)00097-9

Cited by 16 publications

(9 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Amplitudes of glacial‐to‐interglacial shifts in magnetic susceptibility remained constant (100–1000 10 −5 SI units) from 3.1 to 2.5 Ma. This finding suggests that late Pliocene magnetic susceptibility variations at Site 984 were hardly correlated with variations in IRD but rather with changes in bottom current velocity [ Austin and Evans , 2000], as first proposed by Kissel et al [1999] for the late Pleistocene.…”

Section: Resultsmentioning

confidence: 86%

“…The magnetic susceptibility at Site 984 during the late Pliocene potentially records bottom current velocity changes, with interglacial lows in magnetic susceptibility corresponding to high velocity and improved carbonate preservation [ Austin and Evans , 2000; see also Kissel et al , 1999]. The 1‐cm sampling resolution [ Jansen et al , 1996] may provide the best insights into submillennial‐scale climate variability much better than any other parameter measured in this core.…”

Section: Methods and Core Locationmentioning

confidence: 99%

See 1 more Smart Citation

Late Pliocene millennial‐scale climate variability in the northern North Atlantic prior to and after the onset of Northern Hemisphere glaciation

2006

View full text Add to dashboard Cite

Sediments recovered at Ocean Drilling Program Site 984 on the Reykjanes Ridge provided multicentennial‐scale records of late Pliocene climate change over the onset of Northern Hemisphere glaciation (NHG), 2.95–2.82 Ma. Short‐term climate variations prior to and after the onset of continent‐wide glaciation were compared to test the hypothesis of whether Dansgaard‐Oeschger (DO) cycles may have been triggered by continental ice breakouts. During two selected interglacial stages prior to and after NHG (G15 and G1), climate variability resembled that found in the Holocene and the mid‐Pliocene warm period. In contrast, DO‐like periodicities of 1470, 2900, and 4400 years indeed only occurred in glacial stages after the onset of NHG (G14, G6, and 104) but not in stage G20 prior to the onset. These results suggest a causal link between DO cycles and the late Pliocene onset of major NHG and ice breakouts in the North Atlantic.

show abstract

Section: Resultsmentioning

confidence: 86%

Section: Methods and Core Locationmentioning

confidence: 99%

Late Pliocene millennial‐scale climate variability in the northern North Atlantic prior to and after the onset of Northern Hemisphere glaciation

2006

View full text Add to dashboard Cite

show abstract

“… Austin and Evans [2000] data from ODP Site 984 south of Iceland (MIS 77–79 and 103): mean sortable silt size (10–63 μ m) (by laser) versus IRD (noncarbonate% >125 μ m). Due to the laser shape effect the SS% is high in these records; nevertheless, there is little correlation between IRD and (r = 0.028 or, without two very high IRD values, r = 0.366).…”

Section: Problemsmentioning

confidence: 99%

Size sorting in marine muds: Processes, pitfalls, and prospects for paleoflow‐speed proxies

McCave

Hall

2006

Geochem Geophys Geosyst

301

309

View full text Add to dashboard Cite

[1] The basis for, and use of, fine grain size parameters for inference of paleoflow speeds is reviewed here. The basis resides in data on deposited sediment taken in conjunction with flow speed measurements in the field, experimental data on suspended sediment transport and deposition, and theoretical treatments of the generation of size distributions of deposits from suspension controlled by particle settling velocity and flow speed. In the deep sea, sorting events occur under resuspension/deposition events in benthic storms. At flow speeds below 10-15 cm s À1 , size in the noncohesive ''sortable silt'' (10-63 mm) range is controlled by selective deposition, whereas above that range, removal of finer material by winnowing also plays a role. The best particle size instruments to measure a flow speed-related grain size employ the settling velocity method, while laser diffraction sizers can yield misleading results because of particle shape effects. Potential problems, including source effects, downslope supply on continental margins, spatial variability of flow over bedforms, and influence of ice-rafted detritus, are examined. A number of studies using the sortable silt flow speed proxy are reviewed, and inverse modeling of grain size distributions is examined. Outstanding problems are that corroboration is sparse because almost no studies have yet used the full range of proxies for flow rate and water mass identification and that the sortable silt mean size is not yet properly calibrated in terms of flow speed.

show abstract

“…The colder surface water would have restrained the abundance of microplankton in the glacial periods and resulted in the lowering of bioproductivity. In addition, the bottom water could be warmer as a result of reduced NADW production (Bond et al, 1997;Bianchi and McCave, 1999) and drifted MUCW (Austin and Evans, 2000;White, 2007) during glacial times (Fig. 5A).…”

Section: Caco 3 Contentmentioning

confidence: 99%

Pleistocene geochemical stratigraphy of the borehole 1317E (IODP Expedition 307) in Porcupine Seabight, SW of Ireland: applications to palaeoceanography and palaeoclimate of the coral mound development

Takashima

Kano

et al. 2011

J Quaternary Science

View full text Add to dashboard Cite

Stable isotopes and element compositions of the fine-grained matrix were measured for IODP Expedition 307 Hole U1317E drilled from the summit of Challenger Mound in Porcupine Seabight, northeast Atlantic, to explore the palaeoceanographic and palaeoclimatic background to development of the deep-water coral mound. The 155 m long mound section was divided into two units by an unconformity at 23.6 mbsf: Unit M1 (2.6-1.7 Ma) and Unit M2 (1.0-0.5 Ma). Results from 519 specimens show a difference in d 13 C value between Unit M1 (À0.6% to À5.0%) and Unit M2 (À1.0% to 1.0%), but such a distinct difference was not seen in d 18 O values (1.0%-2.5%), CaCO 3 content (40-60 wt%), Sr/Ca ratio (2.0-8.0 mmol mol À1 ), and Mg/Ca ratio (10.0-20.0 mmol mol À1 ) through the mound. Positive d 18 O and negative d 13 C shifts at the mound base are consistent with the oceanographic changes in the northeast Atlantic at the beginning of the Quaternary. The positive d 13 C regression in Unit M2 suggests a linkage to the mid Pleistocene intensified glaciation in the Northern Hemisphere. Warm Mediterranean Upper Core Water of Mediterranean Outflow Water, Eastern North Atlantic Water and cold Labrador Sea Water of North Atlantic Deep Water are key oceanographic features that cause spikes and shifts in stable isotope and element composition. However, the stable isotope values of the sediment matrix could not primarily record the glacial-interglacial eustatic/temperature change, but indirectly indicate current regimes of the intermediate oceanic layer where the coral mound grew. Similarly, elemental ratios and CaCO 3 content may not represent the productivity and temperature of surface sea water, respectively, but superpose the fractions from both surface and bottom water. It is concluded that palaeoceanographic change coupled to the Pleistocene glacial/interglacial cycles is a key control on the geochemical stratigraphy of the matrix sediments of the carbonate mound developed in Porcupine Seabight.

show abstract

Benthic foraminifera and sediment grain size variability at intermediate water depths in the Northeast Atlantic during the late Pliocene–early Pleistocene

Cited by 16 publications

References 34 publications

Late Pliocene millennial‐scale climate variability in the northern North Atlantic prior to and after the onset of Northern Hemisphere glaciation

Late Pliocene millennial‐scale climate variability in the northern North Atlantic prior to and after the onset of Northern Hemisphere glaciation

Size sorting in marine muds: Processes, pitfalls, and prospects for paleoflow‐speed proxies

Pleistocene geochemical stratigraphy of the borehole 1317E (IODP Expedition 307) in Porcupine Seabight, SW of Ireland: applications to palaeoceanography and palaeoclimate of the coral mound development

Contact Info

Product

Resources

About