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doi:10.14379/iodp.sp.382.2018

Cited by 5 publications

(5 citation statements)

References 189 publications

(247 reference statements)

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“…These IRD distribution patterns have been recently investigated since they provide valuable information on the past variability of the Antarctic ice shield (Weber et al, 2018). IRD deposits have been frequently reported for both glacial and interglacial periods off Antarctica, in the Scotia Sea and across the southernmost South Atlantic (Ciesielski et al, 1982;Conolly & Ewing, 1965;Diekmann et al, 2000Diekmann et al, , 2003Hodell et al, 2001;Noble et al, 2012;Teitler et al, 2010;Weber et al, 2014).…”

Section: Local Versus Remote Provenance Of Cobbles and Pebblesmentioning

confidence: 99%

“…They may drop down from melting sea ice or be reworked from a parent glaciomarine deposit. Dropstones and ice-rafted debris (IRD) in marine sediments have been largely studied because they provide valuable information on ice sheet growth and decay dynamics as well as global sea-level variability and oceanographic change (Weber et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

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Dropstones in the Mar del Plata Canyon Area (SW Atlantic): Evidence for Provenance, Transport, Distribution, and Oceanographic Implications

Bozzano

Cerredo

Remesal

et al. 2021

Geochem Geophys Geosyst

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A variety of gravel-to cobble-sized rocks, recovered from the Mar del Plata (MdP) Canyon area (Western South Atlantic at 38°S) and interpreted as ice-rafted debris, represent the first evidence that large icebergs have floated in the Falkland (Malvinas) Current from the southern polar high latitudes far northward. Detailed petrographic analyses identified the Antarctic Peninsula, sub-Antarctic islands in the Scotia Sea, and Tierra del Fuego as plausible source areas. The drift process could have started as early as at the beginning of the last deglaciation, according to an age obtained from a cold-water coral fragment associated with one of the dropstones. At the end of the Last Glacial Maximum, large icebergs have been supplied to the Antarctic Circumpolar Current, captured by those ocean current branches that circumvent the Falkland (Malvinas) Islands and entered the Argentine Margin. When the iceberg fleets approached the Brazil-Falkland (Malvinas) Confluence Zone with its steep latitudinal temperature gradient, the icebergs got oceanographically trapped and melted off rapidly. The sediment load sinking down to the seafloor formed a dropstone blanket particularly where the MdP Canyon had incised into the continental slope. Here, mass-flow processes, induced by local slope instability, and along-slope sediment resorting, due to the erosional effects of strong and persistent contouritic bottom currents, favored local enrichment in dropstones in the form of a loose, coarse sediment drape inside morphological depressions. The bottom current velocity would be locally strong enough to rework this sediment, leaving coarse rafted debris as a lag deposit. Plain Language Summary Icebergs can transport sand-to cobble-sized sediment while drifting with the ocean currents over large distances away from the high latitudes. When seawater temperature forces the ice to melt, this "ice-rafted debris" will sink down as "dropstones" to the seabed. Offshore dropstone deposits are common in polar regions but rarely found in lower latitudes because icebergs barely survive if the ocean water is not extremely cold. We found evidence of dropstone deposits along the Argentine Margin at the relatively low latitude of 38°S. They rest inside morphological seafloor depressions at the continental slope in association with the Mar del Plata Canyon. Here, also the oceanic Brazil-Falkland (Malvinas) Confluence Zone is located, which acts as a barrier for northward drifting icebergs. The presence of icebergs in the Argentine Sea was already known; we, however, describe the first finding of rocks that clearly had originated from the Antarctic Peninsula, sub-Antarctic islands in the Scotia Sea, and Tierra del Fuego, the southern tip of the South American continent. These dropstones are often found together with fragments of cold-water corals, suggesting that the imported rocks have locally served as hard substrate for coral colonies to establish.

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Section: Local Versus Remote Provenance Of Cobbles and Pebblesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dropstones in the Mar del Plata Canyon Area (SW Atlantic): Evidence for Provenance, Transport, Distribution, and Oceanographic Implications

Bozzano

Cerredo

Remesal

et al. 2021

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

“…The combination of robust biomagnetostratigraphy and highresolution records of MS, GRA, NGR, and b* is used to assign glacial and interglacial periods, providing a strong time-stratigraphic framework for this site. Furthermore, MS, a presumed dust proxy at the sites from Iceberg Alley (Weber et al, 2012(Weber et al, , 2018 shows distinct 100 ky peaks representing glacial periods that can be correlated in great detail with the dust record of Antarctic ice cores (e.g., to the EPICA Dome C record of Lambert et al [2008]) over the last 800 ky.…”

Section: Principal Resultsmentioning

confidence: 87%

“…The operations plan for Expedition 382 laid out in the Scientific Prospectus (Weber et al, 2018) considered the maximum amount of possible coring if no hazards occurred. However, operating east of the Drake Passage in the center of Iceberg Alley and near the Antarctic sea ice edge involves a number of potential hazards, in particular icebergs and bad weather.…”

Section: Operational Considerations Related To the Science Objectivesmentioning

confidence: 99%

“…The scientific objectives of Expedition 382 center around four thematic investigations of the late Neogene: the ice mass loss history of the AIS, the regional atmospheric circulation and dust transport, the flow of deep water through the Drake Passage, and the AAIW transport beneath the Subantarctic Front. Based on a preliminary analysis of the core material and data collected during the expedition, we assess the nine specific objectives that were formulated in the Scientific Prospectus (Weber et al, 2018).…”

Section: Preliminary Assessment Of Scientific Objectivesmentioning

confidence: 99%

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