ALBERT

Description: The dataset comprises X-ray fluorescence (XRF) measurements of the elements Barium, Iron and Titanium of gravity core SO264-45-2, which was recovered from Jimmu Seamount (46.5632°N 169.601211°E) from 2425 m water depth during R/V SONNE cruise SO264 (SONNE-EMPEROR) in August 2018. XRF measurements comprise the upper 3.44 m of the core thereby covering the past ~650 ka BP and were carried out on an Avaatech XRF core scanner at the Alfred‐Wegener‐Institute Bremerhaven (AWI). Each segment was scanned at a 1 cm resolution. Here the barium/titanium (Ba/Ti) record is used as proxy for changes in paleoproductivity (biogenic barium) and the iron (Fe) record as proxy for relative changes in terrigenous input.

Description: Stable carbon (δ13C) and oxygen isotope (δ18O) measurements were performed on the benthic foraminiferal species C. wullerstorfi and Uvigeringa spp. as well as on the planktic foraminiferal species G. bulloides and N. pachyderma. Additionally Mg/Ca-measurements were performed on the two planktic species. The foraminiferal specimens were selected from gravity core SO264-45-2, which was recovered from Jimmu Seamount (46.5632°N 169.601211°E) from 2425 m water depth during R/V SONNE cruise SO264 (SONNE-EMPEROR) in August 2018. Sampling and analytical studies were carried out from 0-3.44 m core depth at 2 cm spatial resolution. This interval covers the past ~650 ka BP. The isotope analyses were performed on a Thermo Scientific MAT 253 mass spectrometer with an automated Kiel IV carbonate preparation device. Trace metal analyses were performed on a VARIAN 720-ES Axial ICP-OES, a simultaneous, axial-viewing inductively coupled plasma - optical emission spectrometer coupled to a VARIAN SPS3 sample preparation system. Both systems were operated at GEOMAR. The proxy data provide stratigraphical information and were used to calculate water temperature and the ice volume-corrected δ18O of seawater. Contaminant phases of the trace metal analyses were added (Al/Ca, Fe/Ca, Mn/Ca in mmol/mol).

Description: The sediment deposited in the Arctic Ocean is transported by sea ice and icebergs, which are controlled by the Arctic surface circulations. Several cores from the central Arctic, the Lomonosov Ridge north of Greenland and the Morris Jesup Rise contain a distinct grayish, ice rafted debris (IRD)-rich, layer with some specific features: a sharp lower boundary, relatively low content of manganese, and a lack of bioturbation. Heavy minerals from these layers were analyzed primarily by Electron Probe X-Ray Microanalyzer (EPMA) and Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS) to establish the prominent provenance areas. The provenance variations can show the paleo-distribution and transport pathways of sea ice and icebergs and even indicate the origin of some abrupt glacial events. Initial results suggest that the majority of the grains in the gray layer originated from a limited area near the Putorana Basalt Plateau. We therefore hypothesize that this gray layer is related to an abrupt ice dammed lake drainage from northern Siberia, tentatively dated to around the boundary between MIS 4 and 3 based on all available chronostratigraphic data points and the correlation of distinct geochemical and sedimentological features: variation in Mn, bulk density, bioturbation and abundance of planktonic and benthic foraminifera; including published data and measured data in this study.

Description: Thirty marine sediment cores were collected from the subarctic Northwest Pacific (cruise SO264 with R/V SONNE in 2018), the central Drake Passage (cruise PS97 with RV Polarstern in 2016), the Pacific sector of the Southern Ocean (cruise PS75 in 2009/2010) and the Okhotsk Sea (cruise KOMEX I and KOMEX II with R/V Akademik Lavrentyev in 1998 and cruise SO178 in 2004). The cover area is mainly spreading over the high- to mid-latitude Northwest Pacific (37°N-52°N) and the Pacific sector of the Southern Ocean (53°S-63°S), with a water depth coverage from 1211 m to 4853 m. These cores are dominated by pelagic sediments and mainly consist of calcareous and siliceous ooze and non-carbonaceous fine-grained sediments. The drilling locates at the pelagic ocean rather than the nearby area to the shore to avoid too much influence of coastal erosion and fluvial input. The age range of the majority of the sediments spans from Holocene to mid-Pleistocene. All XRF-scanning measurements were carried out with an Avaatech XRF core scanner at the AWI in Bremerhaven. The X-ray excitation scanning settings were 10 kV at 150 mA with no filter for a count time of 10 s, and a rhodium target X-ray tube was deployed. The sample distance was 10 mm, with a 10x12 mm slit size. The presented XRF data are the raw spectra instead of processed elemental profiles. The samples for bulk chemistry measurements were weighed before and after freeze-drying, homogenized and measured for TC and TOC by a CNS-analyzer (Elementar vario EL III) and a carbon/sulfur analyzer (Eltra CS-800) in the laboratories at AWI in Bremerhaven. The CaCO3 content was then calculated from TC and TOC. The high-resolution (10 mm) quantified TOC and CaCO3 contents are products of machine learning applications using the XRF data. The process please refers to the related publication.