Description: The dataset includes solid-phase geochemistry data of sediment cores from Site C0023 (Hole A) that was recovered during International Ocean Discovery Program (IODP) Expedition 370 in the Nankai Trough offshore Japan in the Pacific Ocean (Drilling vessel Chikyu). Site C0023 was established on 17 September 2016. Coring terminated on 3 November 2016. Stable carbon isotopes of total organic carbon measurement occurred on an EA-IRMS system after complete decalcification of homogenized sediment samples with 10% HCl. The δ13C-TOC values are expressed relative to VPDB (Vienna Pee Dee Belemnite).

Description: Hemipelagic sediments contained in 7 cc plastic cubes were analyzed for paleomagnetic and rock magnetic properties. Samples were collected from Hole C0023A drilled during International Ocean Discovery Program (IODP) Expedition 370, off Cape Muroto, Shikoku Island, Japan, which took place in 2016 (Heuer et al., 2017, https://doi.org/10.14379/iodp.proc.370.2017). A series of magnetic measurements were carried out at the Center for Advanced Marine Core Research, Kochi University, Japan. These analyses include magnetic susceptibility, natural remanent magnetization and its alternating field demagnetization, anhysteretic remanent magnetization, and isothermal remanent magnetization. Detailed rock magnetic measurements, which include hysteresis parameters, characterize magnetic mineral assemblages in terms of abundance, grain size, and composition. For further information on the methodology, please refer to “Read Me” document.

Description: The dataset includes rock magnetic end-member unmixing data of sediment cores from Site C0023 (Hole A) that was recovered during International Ocean Discovery Program (IODP) Expedition 370 in the Nankai Trough offshore Japan in the Pacific Ocean (Drilling vessel Chikyu). Site C0023 was established on 17 September 2016. Coring terminated on 3 November 2016. End-member modelling of isothermal remanent magnetization (IRM) acquisition curves were performed to characterize the iron mineralogy. IRM acquisition curves were measured using a Princeton Measurements Corporation Vibrating Sample Magnetometer (VSM). IRM was imparted stepwise (non-linearly) up to a maximum field of 1 T with an averaging time of 200 ms. Unmixing of IRM acquisition curves were performed using the web application MAX UnMix by Maxbauer et al. (2016). Mean coervity (Bh) is given in log10 B mT and dispersion parameter (DP) in log. EC is the extrapolated contribution to the total IRM.

Description: The dataset includes solid-phase geochemistry data of sediment cores from Site C0023 (Hole A) that was recovered during International Ocean Discovery Program (IODP) Expedition 370 in the Nankai Trough offshore Japan in the Pacific Ocean (Drilling vessel Chikyu). Site C0023 was established on 17 September 2016. Coring terminated on 3 November 2016. Algal lipid biomarker analysis was performed after Sturt et al. (2004) and HPLC-MS analyses after Becker et al. (2015). Biomarker concentrations are reported as the integrated peak area of the sum of all detected diols normalized to kg extracted sediment (PA/kg).

Description: The dataset includes solid-phase and porewater trace elements data of sediment cores from Site C0023 (Hole A) that was recovered during International Ocean Discovery Program (IODP) Expedition 370 in the Nankai Trough offshore Japan in the Pacific Ocean (Drilling vessel Chikyu). Site C0023 was established on 17 September 2016. Coring terminated on 3 November 2016. Solid-phase trace elements data include bulk molybdenum (Mo), uranium (U), vanadium (V), and rare earth elements (REEs) contents, and Mo isotopes. Trace element analyses were performed using a Thermo Fisher iCAPQ ICP-MS equipped with a ASX560 AutoSampler. Approximately 50 mg of each dry sediment powder was dissolved in Teflon bomb with the double-distilled concentrated HNO3-HF (1:1) mixture. The dissolution was maintained in an oven at 185°C for 3 days and then dried down to evaporate HF. The residues were re-dissolved with double-distilled concentrated HNO3 followed by the HNO3-H2O (1:1) mixture, and dried again. After that, the sample was dissolved in the final 3ml 2N HNO3 stock solution. Finally, the sample solution is diluted by 1000 times with 2.5% HNO3 and 10ppb Rh internal spikes. The standard GBW07316 was used as a reference. Internal spikes and external monitors were used to correct instrument drift mass bios. The ICP-MS procedure for trace element analyses is based on the protocol developed by Eggins et al. (1997, doi:10.1016/S0009-2541(96)00100-3). The Mo-isotope composition were analyzed by a Thermo-Fisher Scientific Neptune-Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) using the double-spike method. About 0.02-0.05g whole-rock powders were weighed and combined with appropriate amounts of a 97Mo-100Mo double spike within a pre-cleaned 15 mL PFA beaker. The sample was then dissolved using 1 mL HNO3 and 2 mL HF at 140 ℃ for 2 days before being dried at 120 ℃ and re-dissolved in 4 mL of a 1 M HCl-0.3 M HF mixture for column separation. Molybdenum was separated and purified using an N-benzoyl-N-phenyl hydroxylamine extraction chromatographic resin with the approaches outlined in Li et al. (2014, doi:10.1111/j.1751-908X.2013.00279.x). Pore water trace elements data include Mo, U, V, and nickel (Ni). The pore water was collected during IODP Expedition 370 as described in the Expedition 370 Methods by Heuer et al. (2017;doi:10.14379/iodp.proc.370.103.201). The trace elements were measured in untreated (original) in acidified pore-water samples. The inductively coupled plasma-mass spectrometry (ICP-MS, Element2, Thermo Fisher Scientific Inc.) is equipped with an ESI Apex-Q desolvating system to increase the sensitivity.

Description: This dataset comprises leached contents of different manganese and iron mineral phases from sediment cores, which were retrieved by a multiple corer (MUC) during RV SONNE expedition SO239 in 2015. During this cruise, different European contract areas for the exploration of polymetallic nodules in the area of the Clarion-Clipperton Zone (CCZ) were visited (BGR, IOM, GSR, IFREMER), which are currently being explored in light of potential future deep-sea mining. Furthermore, one of the protected Areas of Particular Environmental Interest (APEI), more precisely the APEI3 north of the CCZ, was visited. For the extraction of various manganese and iron minerals, the extraction schemes after Koschinsky et al. (2001) and Poulton and Canfield (2005) were combined. The leached mineral phases comprise (1) carbonate-associated Mn and Fe (Mncarb; Fecarb), (2) easily reducible/mobilizable Mn- and Fe(oxyhydr)oxides (Mnmobil; Femobil), (3) easily reducible Fe oxides, such as ferrihydrite and lepidocrocite (Feox1) and associated Mn oxides (Mnox1), (4) reducible Fe oxides, such as goethite and hematite (Feox2) and associated Mn oxides (Mnox2) and (5) magnetite (Femag) and associated Mn oxides (Mnmag). The dataset was produced in the laboratories of the Alfred Wegener Institute (AWI) Bremerhaven, Germany.

Description: This dataset comprises solid-phase bulk sediment manganese, iron and aluminum contents from sediment cores, which were retrieved by a multiple corer (MUC) during RV SONNE expedition SO239 in 2015. During this cruise, different European contract areas for the exploration of polymetallic nodules in the area of the Clarion-Clipperton Zone (CCZ) were visited (BGR, IOM, GSR, IFREMER), which are currently being explored in light of potential future deep-sea mining. Furthermore, one of the protected Areas of Particular Environmental Interest (APEI), more precisely the APEI3 north of the CCZ, was visited. The dataset was produced in the laboratories of the Alfred Wegener Institute (AWI) Bremerhaven, Germany.