Descriptions of smear slides from the above given hole of International Ocean Discovery Program (IODP) Expedition 386 (Japan Trench Paleoseismology). The offshore phase of this expedition took place between 2021-04-13 and 2021-06-01 onboard Japanese R/V Kaimei from and to Yokosuka, Japan. This was followed by an onshore phase onboard D/V Chikyu between 2022-02-14 – 2022-03-15. During the offshore phase, smear slides were prepared from paleontology samples collected with a tip-cut syringe from section ends every 5 m. During the onshore phase, smear slides samples were collected every 2 m to complement visual core description observations and identify the composition of fine-grained sediment. The smear slides were prepared by putting a small amount of sediment on a glass slide mixed with distilled water. The slide was subsequently evaporated on a hot plate, and the dried sample was mounted in Norland Optical Adhesive 61 using ultraviolet light. Sediment grain size and composition were examined under a polarized light petrographic microscope (Zeiss Axio Imager A1m POL-1) with an ocular micrometer.For further methodological information see methods chapter in Strasser, M. et al., 2023 https://doi.org/10.14379/iodp.proc.386.102.2023

Data was submitted and proofread by Vera Barbara Bender, MARUM - Center for Marine Environmental Sciences (University Bremen) on behalf of ECORD Science Operator Data Management (https://www.ecord.org).