analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented.

Ocean circulation may have undergone reductions and reinvigorations in the past closely tied to regional climate changes. Measurements of 231Pa/230Th ratios in a sediment core from the Bermuda Rise have been interpreted as evidence that the Atlantic Meridional Overturning Circulation (AMOC) was weakened or completely eliminated during a period of catastrophic iceberg discharges (Heinrich‐Event 1, H1). Here we present new data from the Bermuda Rise that show further 231Pa/230Th peaks during Heinrich‐2 (H2) and Heinrich‐3 (H3). Additionally, a tight correlation between diatom abundances (biogenic silica) and 231Pa/230Th is discovered in this core. Our results redirect the interpretation of 231Pa/230Th from the Bermuda Rise as a proxy for ocean circulation towards a proxy that reacts highly sensitive to changes of particle composition and water mass properties.

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Starting material SC1 was the same as used by Brey et al. (1990Brey et al. ( , 2008. It consists of remixed olivine, orthopyroxene, clinopyroxene, and spinel originally separated from spinel lherzolite sample SC1 (Jagoutz et al., 1979) and ground to 520 mm. SC1 is a proxy for a fertile mantle composition and is similar to MixKLB-1 studied by and . The compositions of the minerals are listed inTable 1 together with the original bulk composition and that of the mineral mix. The latter was determined by electron microprobe analysis (EMPA) from a glass bead prepared from 20 mg SC1 blended with 20 mg high-purity SiO 2 , which was added to avoid the formation of quench crystals. Trace elements were analysed in this glass by LA ICP MS.Three experiments were carried out with mixture CL1, a composition estimated to be a melt in equilibrium with magnesite-bearing harzburgite at 6 GPa and 14008C (Table 1). This mixture was prepared from pure chemical reagents [SiO

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