ALBERT

Description: Data derived from Core SG-1b (coordinates: 38°21'9.46'' N, 92°16'24.72'' E) which was drilled within the framework of a Sino-German cooperation project in 2008. Attached Excel spreadsheet contains to data sets: 1. Data: Depth, Age, Sedimentation Rate and ln(Rb/Sr) ratio 2. Age model: Depth, Age Abstract: To contribute to a better understanding of Neogene climate evolution in Central Asia, we here present the first orbitally tuned time scale for a drillcore record from the Qaidam Basin (NE Tibetan Plateau) that consists of lacustrine sediments and spans the late Pliocene to early Pleistocene (~3.3 to 2.1 Ma). Our tuning of Core SG-1b is based on the ln(Rb/Sr) ratio derived from XRF core scanning and grain-size distribution data that trace wet-dry climate alternations predominantly paced by orbital obliquity. Based on our ln(Rb/Sr) record, obliquity-precession interferences persisted during the mid-Pliocene warm period, but disappeared during the early Pleistocene. This could indicate that over the course of the late Pliocene a low-latitude-derived climate modulator gained an increasingly prominent role in shaping the environment of the Qaidam paleolake. At the same time, the consistent presence of the precession signal during the early Pleistocene hampers a refinement of the entire tuning on precession time scales. The inferred changes in sedimentation rate from the late Pliocene to the early Pleistocene indicate a long-term decrease in sediment supply into the Qaidam paleolake. This finding is in line with the previously proposed notion of a long-term aridification trend across the Plio-Pleistocene transition in Central Asia.

Description: Bulk-rock carbon isotopes (d13C), redox-sensitive trace elements and carbonate content measured in the Bodudd section in Gotland, Sweden. The age of the section is Ludfordian (Ludlow, Silurian) and it was deposited on a tropical carbonate platform. Funded by Deutsche Forschungsgemeinschaft project JA 2718/3-1.

Description: These are the supplementary datasets for the manuscript: Drury, A.J., Liebrand, D., Westerhold, T., Beddow, H., Hodell, D., Rohlfs, N., Wilkens, R.H., Lourens, L., 'History of South Atlantic carbonate deposition since the Oligocene (30-0 Ma)', in final preparation for submission Climate of the Past

Description: Sediment properties of a 223-m-long drill core from the Ejina basin, NW China, for reconstructing the palaeoenvironmental history of a part of the Gobi Desert. The sediment study is part of the Q-TiP project (Quaternary Tipping Points of Lake Systems in the Arid Zone of Central Asia) in the frame of the CAME II program (BMBF funded).

Description: This dataset includes planktic foraminifera (Globigerinoides ruber sensu-stricto) stable oxygen isotope and Mg/Ca data from IODP Expedition 353, Sites U1446 and U1448 across Marine Isotope Stage 5 (140-70 ka). Additionally, included is a time-series of annual change in precipitation as emulated by PaleoPGEM across 6 large-scale low-latitude regions throughout Marine Isotope Stage 5 (140-70 Ka).

Description: We compiled modern and fossil relative abundance of coccolithophore species Florisphaera profunda from published and unpublished datasets, along with ocean environmental variable data from satellite remote sensing and physical measurements. The database includes relative abundances of F. profunda in sediment trap (n = 26) and core-top (n = 1258), and sediment core samples (n = 104). Downcore data covers the Last Glacial Maximum (n = 94, 24-19 ka) or the Mid-to-Late Holocene (n = 77, 〈6 ka). This database allows studying modern and past biogeography of F. profunda as a response to changing ocean and climate conditions, “Quantitative reconstruction of primary productivity in low latitudes during the last glacial maximum and the mid-to-late Holocene from a global Florisphaera. profunda calibration dataset” (Hernández-Almeida et al., 2018).

Description: This dataset presents the XRF core-scanning record from International Ocean Discovery Program (IODP) Site U1478 off the Limpopo River mouth (Mozambique Channel, SW Indian Ocean) spanning the past c. 4 Ma. Site U1478 was drilled in the northernmost Natal Valley, on the Inharrime Terrace (25°49.26′ S; 34°46.16′ E) at a water depth of 488 m below sea level. The XRF core scanning of the ~257-m-long splice for Site U1478 was carried out using an Itrax Core Scanner at Lamont-Doherty Earth Observatory Core Repository, Columbia University (USA). In total, 239 sections (archive halves) were scanned at a voltage of 30 kV and a tube current of 55 mA using a Cr tube and employing an exposure time of 2 seconds. Measurement spacing was set at 2 mm, with downcore and crosscore slit sizes set at 2 mm and 2 cm, respectively. The individual element counts were normalized using the ratio of raw total counts of a given element to the total counts of all processed elements for the respective measurement position. To eliminate non-linear matrix effects and constant-sum constraints, log ratios were applied on the elemental ratios. The age model of Site U1478 is based on cyclostratigraphic analysis of the XRF-based log(Ti/Ca) record and its tuning to ice-volume, precession and eccentricity cycles.

Description: Seven different labs XRF scanned the same seven marine sediment sections. Additionally, four labs XRF scanned pellets that had known compositions determined by ICP-ES and ICP-MS. These datasets contain the XRF scanning results of the seven sediment section and four pellets. The seven 1.5 m core sections of marine sediment core used in this study were drilled during Integrated Ocean Drilling Program (IODP) Expedition 346 at Site U1424 in the Japan Basin (40°11.39'N, 138°13.90'E, 2808 m water depth) and Site U1425 on the Yamato Rise (39°29.43' N, 134°26.55' E, 1909 m water depth). The sections selected (Hole U1424C Sections 1H4, 2H5, 3H5 and Hole U1425C Sections 2H3, 2H4, and 2H6, and 3H6) cover a range of sediment compositions. U-channels extracted continuous marine sediment approximately 1 cm thick from the center of each split core section. One lab scanned sections from different holes at the same sites (U1424A, U1425B, and U1425D) that were stratigraphically aligned with the sections listed above. Over the course of four years (2014 to 2017), the set of seven u-channels was shipped around the world to seven labs with XRF scanners including, in no particular order, the Kochi Core Center at Kochi University (Japan), IODP Core Repository at Texas A&M University (U.S.A.), Nanjing Normal University (China), Rosenstiel School of Marine and Atmospheric Science at the University of Miami (U.S.A.), ETH Zurich (Switzerland), Woods Hole Oceanographic Institution (U.S.A.), and the Royal Netherlands Institute of Sea Research (The Netherlands). We intentionally do not identify which lab generated which scans, as many of the variables (e.g., X-ray tube aging, detector aging, and/or dehydration of the core material) could affect any instrument at various times or be exacerbated during the transit between labs. Instead, we label the XRF scans #1-#7 in the order in which they were scanned. The lead investigators overseeing the XRF scanning in these labs were shipboard participants on IODP Expedition 346 and are among the authors of this paper. The only instructions to each lab were "to XRF scan the seven sediment sections at 1mm or 2mm resolution using the approach and elements typical for paleoceanographic research performed in your lab." To emulate variations in the XRF results that have been previously published, these simple guidelines were intentionally broad and general to determine the degree of intercomparability between the labs amongst all the different settings and nuances of XRF scanning. The labs used various types and different generations of XRF scanning instruments (4 Avaatech Core Scanners, 2 ITRAX Core Scanners, and 1 Geotek Core Scanning Logger) with different X-ray sources (Rhodium, Molybdenum). Three of the labs scanned the cores at two or three excitation energies (e.g., 10 kV, 30 kV, and 50 kV). Each lab reported a different suite of elements, but all included Ca, Fe, K, Mn, Si, Sr, Ti, and Zr. Six labs also reported Al, Br, Cr, Cu, Ni, Pb, Rb, S, and Zn and five labs reported and Ba, Cl, Ga, Mo, V, and Y. In addition to the seven core sediment sections, we freeze-dried and powdered four discrete samples that were pressed into disc-shaped pellets about 2 cm in diameter from nearby Core MD01-2407 on the Oki Ridge (37°04'N, 134°42'E, 932m water depth). The four samples have a similar matrix to the seven sediment sections scanned in this study. The four samples from Core MD01-2407 covered a range of sediment types (calcareous, siliceous, light-, and dark-colored; Kido et al., 2007) that span the dynamic range of at least Fe and Ca element cps scanned for this study. A set of four pellets was sent to four of the seven labs (1 ITRAX and 3 Avaatech) involved in the study to be scanned using the same instrument parameters they used on the sediment sections. Three labs used the same instrument and parameters used for the sediment section, but the fourth lab replaced the X-ray tube in between scanning the pellets and sediment sections. The major and trace element concentrations of the pellets were also analyzed by inductively coupled plasma (ICP)-optical emission spectrometry (OES) and ICP-mass spectrometry (MS) in the Analytical Geochemistry Facilities at Boston University, Boston, MA, USA. The ICP analyses had ~2% precision and a standard reference material analyzed as an unknown alongside the samples was accurate within precision.

Description: Palynology data and analysis for branched glycerol dialkyl glycerol tetraethers (brGDGTs) from Point Margaret (Southern Australia), respectively, were used to estimate the mean annual air temparature during the Paleocene-Eocene Thermal Maximum.

Description: Global climate cooled from the early Eocene hothouse (~52-50 Ma) to the latest Eocene (~34 Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum-Antarctic gateways, which affected both surface- and deep-ocean circulation. The Tasmanian Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasmanian Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on both the physico-chemical properties of the water masses and the path of surface-ocean currents. The extent to which climate and tectonics have influenced the distribution and composition of surface currents and thus fossil assemblages has, however, remained unclear. In particular, the contribution of climate change to oceanographic changes, superimposed on long-term and gradual changes induced by tectonics, is still poorly understood. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend, the Middle Eocene Climatic Optimum (MECO; ~40 Ma). This 500-thousand-year-long phase of global warming was unrelated to regional tectonism, and thus provides a test case to investigate the ocean's physiochemical response to climate change alone. We reconstruct changes in surface-water circulation and temperature in and around the Tasmanian Gateway during the MECO through new palynological and organic geochemical records from the central Tasmanian Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia) and the Hampden Beach section (New Zealand). Our results confirm that dinocyst communities track specific surface-ocean currents, yet the variability within the communities can be driven by superimposed temperature change. Together with published results from the east of the Tasmanian Gateway, our new results suggest a shift in surface-ocean circulation during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasmanian Gateway area, pollen assemblages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints we suggest that a regional southeast Australian transgression might have been coincident with the MECO.