Blog
About

  • Record: found
  • Abstract: found
  • Article: found
Is Open Access

Data report: grain size distribution of unconsolidated sands offshore Shimokita Peninsula, Japan (IODP Site C0020): Expedition 337

,

Proceedings of the IODP

Integrated Ocean Drilling Program

Read this article at

ScienceOpenPublisher
Bookmark
      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

      Abstract

      We report particle size analyses measured from 28 unconsolidated sand samples recovered during Integrated Ocean Drilling Program Expedition 337 from Hole C0020A. These samples span from 1277 to 2002 meters below seafloor (mbsf) across two lithostratigraphic units that record a transition from a nearshore estuarine/intertidal to an offshore hemipelagic paleoenvironment. Most recovered lithologies, including coarse-grained lithologies, are semiconsolidated to consolidated; however, some intervals of sand are unconsolidated and suitable for particle size analysis. Bulk sand samples were measured using a laser diffraction particle size analyzer. All samples fall within the range of sand to silty sand, with silty sand more abundant deeper than 1925 mbsf. Samples contain 49%–97% sand, 3%–42% silt, and 0%–13% clay. Median grain diameter ranges from 55 to 405 µm. Clay and silt content in these sands reach a minimum at ~1500 mbsf and then increase below 1925 mbsf in a coal-bearing unit containing shale, siltstone, sandstone, and unconsolidated sand.

      Related collections

      Most cited references 21

      • Record: found
      • Abstract: not found
      • Article: not found

      A Scale of Grade and Class Terms for Clastic Sediments

        Bookmark
        • Record: found
        • Abstract: not found
        • Article: not found

        Variability of deltaic processes in terms of sediment supply, with particular emphasis on grain size

          Bookmark
          • Record: found
          • Abstract: found
          • Article: not found

          DEEP BIOSPHERE. Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floor.

          Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.
            Bookmark

            Author and article information

            Journal
            10.2204/iodp.proc.337.2013
            Proceedings of the IODP
            Integrated Ocean Drilling Program
            1930-1014
            11 December 2017
            10.2204/iodp.proc.337.203.2017

            This work is licensed under a Creative Commons Attribution 4.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

            Product
            Self URI (journal page): http://publications.iodp.org/

            Comments

            Comment on this article