Terrigene Partikeltransporte als Abbild spätquartärer Tiefen- und Bodenwasserzirkulation im Südatlantik und angrenzendem Südpolarmeer
The South Atlantic plays a profound role in global thermohaline abyssal circulation as it forms the pathway for the major deep water masses, the North Atlantic Deep Water, the Circumpolar Deep Water, and the Antarctic Bottom Water. These water masses are fed into the Southern Ocean and are distributed to other world oceans via the Antarctic Circumpolar Current.Down-core fluctuations of kaolinite/chlorite ratios in late Quaternary sediment cores of the South Atlantic indicate a less southward advection of northern-source deep water (kaolinite supply) into the Antarctic Circumpolar Current during glacial times in respect to interglacials. In turn, southern-source deep and bottom water masses (chlorite supply) show a greater extension during cold periods.Past changes in current strength of southern-source bottom water outflow show no coherent pattern in both the western South Atlantic and the adjoining Weddell Sea, as inferred from silt grain size proxies. Maximal current velocities occurred either during interglacials, interglacial-glacial transitions, or glacial-interglacial transitions, however, not unequivocally during glacial periods anywhere.The more extensive advection of southern-source water masses is not consistent with a less or similar vigorous southern-source bottom water flow during glacial periods and may be only explained by a strongly reduced northern-source deep water production at the same time.