Geochemistry of rare earth elements in two-color core sediments from the Korea Deep Ocean Study (KODOS)-90 site, NE equatorial Pacific.

Distribution of Rare Earth Elements and Yttrium in Sediments From the Clarion‐Clipperton Fracture Zone, Northeastern Pacific Ocean

“…Ce/Ce* gradually decrease with increasing ∑REY (Figure 5e), suggestive of an enhanced signature of bioapatite (Ce/Ce* < 0.1; Liao, Sun, Li, et al., 2019). The role of (bio)apatite as a primary REY host is consistent with studies from elsewhere in the CCFZ (Jung, Choi, et al., 1998; Paul, Volz, et al., 2019; Ren et al., 2015; Sa et al., 2018) and other oceans such as the western North Pacific, South Pacific, and Indian oceans (e.g., Fujinaga et al., 2016; Yasukawa et al., 2014; Zhou et al., 2021).…”

“…The CCFZ is located to the west of the East Pacific Rise (EPR), a fast‐spreading mid‐ocean ridge with active hydrothermal venting. While several studies have previously investigated REY host in CCFZ sediments (Jung, Choi, et al., 1998; Paul, Volz, et al., 2019; Ren et al., 2015; Sa et al., 2018), the information was gathered mostly from the northwestern part of the CCFZ, where the influence of hydrothermal plumes might be relatively weak because of its distant location from the EPR. In this paper, we evaluate the relative importance of above‐mentioned phases as REY hosts based on the analyses of seven sediment cores from a polymetallic nodule field in the southeastern part of the CCFZ (∼132°W, 10.5°N).…”

Characteristics of Seafloor Morphology and Ferromanganese Nodule Occurrence in the Korea Deep-sea Environmental Study (KODES) Area, NE Equatorial Pacific

“…Siliceous sediments are mostly composed of siliceous fossil fragments, clay minerals (mostly authigenic Fe-rich smectite and terrigeneous illite), plagioclase, and micronodules (MOMAF, 1996). However, white-colored and highly consolidated calcareous sediments (mainly ooze) are also found in the northern part of the study area (stations 9, 10, 11, and 21) (Jung et al, 1997). The carbonate compensation depth (CCD) in the study area reaches about 4500 m because of limited supply of biogenic carbonate from oligotrophic surface water column in the study area and because of strong bottom currents (Seibold and Berger, 1996).…”

“…Siliceous sediments are dominant in the northern part of the study area while calcareous sediments are in the southern part (Horn, Horn, and Delach, 1973). Dominant surface sediment in the study area is siliceous clay, with red Morphology and Nodules in NE Equatorial PaciWc 169 clay veneering most of the sediment surface (Jung et al, 1997). Siliceous sediments are mostly composed of siliceous fossil fragments, clay minerals (mostly authigenic Fe-rich smectite and terrigeneous illite), plagioclase, and micronodules (MOMAF, 1996).…”

“…White calcareous sediments are occasionally outcropped (2nd and 12th zones). Calcareous sediments were sampled many times in this study area (Jung et al, 1997), and calcareous sediments coated on the sled of the DSC were usually found after the DSC bumped against the rugged sea¯oor or cliOE s. Moving traces of benthic animals are rare in these B-type zones.…”