Discovery of extremely REY-rich mud in the western North Pacific Ocean

Abstract

ment of green technologies, including electric and hybrid vehicles, compact and long-life LED lights, and wind power generation, is required to shift human society toward sustainable growth. Rare-earth elements and yttrium, hereinafter together called REY, are essential elements for products with these advanced and green technologies, because of the magnetic and optical properties of REY that result from the characteristic configurations of electrons in these elements. With rising economic growth in

Statistic and Isotopic Characterization of Deep‐Sea Sediments in the Western North Pacific Ocean: Implications for Genesis of the Sediment Extremely Enriched in Rare Earth Elements

“…IC2 IC2 shows distinct positive loadings of CaO, P 2 O 5 , ΣREY, and Ce (Figure 3). The samples of the extremely (ΣREY + Ce > 5,000 ppm; Iijima et al, 2016) and highly (ΣREY + Ce = 2,000-5,000 ppm; Iijima et al, 2016) REY-rich muds have very high IC2 scores, whereas the other samples have near-zero or negative IC2 scores (Figures 2j and 2k). In the compositional space, the IC2 vector extends toward very high REY content (Figures 2b and 2c).…”

“…These piston cores were 15 m in length, and the sediment core samples recovered were generally 10 to 13 m long (Table 1). The detailed lithologies, bulk chemical compositions, and mineralogical features of these cores were Geochemistry, Geophysics, Geosystems reported in previous studies Iijima et al, 2016;Ohta et al, 2016;Takaya et al, 2018;Yasukawa et al, 2018), while here we summarize general information of the deep-sea sediments in the studied area.…”

“…In 2013, the research cruise KR13‐02, conducted by the Japan Agency of Marine‐Earth Science and Technology (JAMSTEC) and the University of Tokyo, collected deep‐sea sediment samples using piston corers from the Japanese exclusive economic zone (EEZ) around Minamitorishima Island (Figure ), the easternmost island of Japan, located ~1,900 km southeast of Tokyo, in the western North Pacific Ocean. Some of the sediments obtained by the cruise show the bulk ΣREY and ΣHREE contents over 5,000 and 930 ppm, respectively (Iijima et al, ). These ΣREY and ΣHREE concentrations are higher than those of any other sediment ever reported from the world ocean, and the ΣHREE content is up to ~20 times that of the Chinese ion‐absorption‐type ore deposits on land (Iijima et al, ).…”

Acoustic characterization of pelagic sediments using sub-bottom profiler data: Implications for the distribution of REY-rich mud in the Minamitorishima EEZ, western Pacific

“…In order to identify the sediment types corresponding to the T-type and L-type acoustic facies, we compared these acoustic facies with the lithological and geochemical features of sediment core samples (published in Fujinaga et al, 2016;Iijima et al, 2016). Excluding three very short (£3 m) cores (KR13-02 PC01, KR14-02 PC01 and PC03), we used the data from eleven piston cores from both T-type and L-type facies regions.…”

“…However, the extent of the REY-rich mud layer was poorly constrained due to poor core recovery (Kato et al, 2012). More recently, more than 10 piston cores have been obtained from this area, and chemical analyses of the new piston core samples have demonstrated the presence of REY-rich mud (including highly concentrated REY-rich mud reported by Iijima et al, 2016) less than 10 m below the seafloor (Fujinaga et al, 2016). Even today, however, wide-area distribution of the REY-rich mud in the entire region of the Minamitorishima EEZ remains uncertain.…”