Katsuhiko Suzuki

Japan Agency for Marine-Earth Science Technology | JAMSTEC · Submarine Resources Research Center

During the Cretaceous, several massive volcanic episodes led to significant environmental perturbations, including oceanic anoxic events (OAEs). The volcanic eruption forming Ontong Java Nui (ca. 120 Ma) in the western Pacific Ocean is recognized as the largest volcanic event on Earth and is thought to have caused oceanic anoxic event 1a (OAE1a). A...

The volcanic episode that formed Ontong Java Nui (OJN) in the western Pacific ~ 120 million-year-ago is thought to have triggered Oceanic Anoxic Event (OAE) 1a, yet the cause-effect relationship remains insufficiently understood. Here, we present a Pb-Os-C isotope dataset for tracking OJN volcanism across a sedimentary sequence containing OAE1a rec...

Osaka Bay adjacent to the Kyoto–Osaka–Kobe metropolitan area was affected by severe metal pollution during the twentieth century; yet little is known about the trace metal sources and pre-industrial human activities. We have determined the elemental concentrations and zinc stable isotope ratios (δ66Zn) in bulk sediments and the trace metal concentr...

Commonly biotite occurs as a minor rock-forming mineral in a wide range of felsic to intermediate intrusive rocks. It can record the physicochemical conditions of the parent magma due to its complex crystal structure that allows multiple site substitutions of a wide range of elements. Geochemical studies of whole rocks and biotite (using EPMA and L...

This study reports total nitrogen (TN), carbon (TC) and organic carbon (TOC) contents, as well as stable isotopic ratios (δ15NTN, δ13CTC and δ13Corg), from marine, stream and lacustrine geological reference materials (JMs‐1, JMs‐2, SBC‐1, SCo‐2, JSd‐3, JSd‐4 and JLk‐1), which can be classified into two types; modern surface, and ancient, sediments....

The catchment of Lake Biwa, the largest freshwater lake in Japan, has experienced rapid urbanization and industrialization in the second half of the 20th century; yet little is known about the historical trend of metal pollution. We analyzed the elemental concentrations and zinc stable isotope ratios (δ66Zn) in a sediment core from the Northern bas...

Nickel (Ni), copper (Cu), and zinc (Zn) are commonly used in human activities and pollute aquatic environments including rivers and oceans. Recently, Ni, Cu, and Zn isotope ratios have been measured to identify their sources and cycles in environments. We precisely determined the Ni, Cu, and Zn isotope ratios in rain, snow, and rime collected from...

Recent geochemical data suggest the occurrence of an O2 overshoot during the mid-Paleoproterozoic (~2.3–2.0 Ga). This O2 overshoot appears to be consistent with carbon isotope records that suggest high burial rates of organic carbon during that period, the so-called Lomagundi Event. However, little is known about the changes in the ocean redox cond...

Molybdenum isotopic compositions (δ98/95Mo) of Archean and Paleoproterozoic Fe- and Mn-rich sedimentary rocks have been used to investigate local accumulations of O2 in an O2-lean ocean. Previous studies interpret that these δ98/95Mo values would be a representation of the global minimum for δ98/95Mo of contemporaneous seawater and would, therefore...

Redox-sensitive metallic elements, Mn and Fe, are oxidized in deep sea waters and form abundant ferromanganese crusts and nodules on the world’s ocean floors at ultraslow rates of growth. This process of oxidation and the mechanism of precipitation are yet unknown. In this paper, the results of the first successful, long-term, on-site experiment of...

Chalcophile elements are enriched in the Cretaceous−Paleogene (KPg) boundary clays from Stevns Klint, Denmark. As the concentrations of Cu, Ag, and Pb among several chalcophile elements such as Cu, Zn, Ga, As, Ag, and Pb are correlated with those of Ir, we suggest that these elements were supplied to the oceans by processes related to the end-Creta...

Pelagic cherts preserved in accretionary complexes represent former seafloor sediment that can retain geochemical evidence of paleoceanographic conditions that predate the oldest extant oceanic crust. The ratio of Os isotopes in seawater, in particular, is of wide interest as a source of insight into notable geologic events such as oceanic anoxic e...

The Proterozoic Bryah and Yerrida basins of Western Australia contain important base and precious metal deposits. Here we present microtextural data, trace element and S isotope analyses of massive sulphide mineralisation hosted in Palaeoproterozoic subvolcanic rocks (dolerite) recently discovered at Red Bore. The small-scale high-grade mineralisat...

Unusual mafic rock fragments deposited in Plio-Pleistocene-aged marine sediments were recorded at Integrated Ocean Drilling Program (IODP) Site U1359, in Wilkes Land, East Antarctica. These fragments were identified from sediment layers deposited between c. 3 and 1.2 Ma, indicating a sustained supply during this time interval. Clinopyroxenes in the...

To examine environmental changes in the biosphere during the Triassic-Jurassic transition, with a particular focus on the global carbon cycle related to Central Atlantic Magmatic Provinces (CAMP) volcanism in the mid-Panthalassa, we established stratigraphic δ 13 C org variations using Rhaetian (Late Triassic) to Hettangian (Early Jurassic) shales...

We performed X-ray adsorption fine structure (XAFS) analyses of Y, Ce, Fe, and P for rare earth elements and yttrium-rich muds (REY-rich muds) from the two regions of the Pacific Ocean: the eastern South Pacific and the central North Pacific. Yttrium K-edge XAFS revealed that calcium phosphate (apatite) is the common host of REY even in the hydroth...

This paper presents an analytical technique to determine the concentrations of Te and Se, and the stable isotope composition of Te. The outlined analytical protocol combines Se single-spike and Te double-spike methods to determine the Se and Te concentrations using the isotope dilution method and mass dependent fractionation of Te isotopes using th...

By presenting benthic foraminifera isotope profiles and bulk geochemical composition of core sediments, we offer a mutiproxy reconstruction of the central Okhotsk Sea oceanography between ∼130 to and ∼115 kyr, related to the marine isotopic stage 5e (MIS 5e). Sediments from the site MR0604-PC7A have been compared with paleo- sea surface temperature...

Platinum-group elements (PGEs) are one of the key tracers to reveal early differentiation processes of the Earth due to their preferential distribution into the metallic core. Meanwhile, informative evidence for early differentiation has been greatly disturbed through metasomatic PGE disturbance, which has been demonstrated through a number of PGE...

The South China Sea is the largest marginal basin in the world, and is located in the confluence of three major tectonic plates (Pacific-Philippine Sea, Indo-Australia, Eurasia). Its tectonic history and evolution throughout the Cenozoic has been the subject of much discussion with regards to its mechanism, timing, and relationship to neighboring g...

Whale carcasses (whale falls) deposited on the deep seafloor are associated with a distinctive biotic community. A fossil whale bone recovered from São Paulo Ridge, South Atlantic Ocean, during cruise YK13–04 Leg 1 of R/V Yokosuka was covered by a ferromanganese (Fe–Mn) crust approximately 9 mm thick. Here, we report an age constraint for this foss...

We determined highly siderophile element (HSE: Os, Ir, Ru, Pt, Pd, and Re) concentrations and ¹⁸⁷Os/¹⁸⁸Os ratios for ultramafic rocks distributed over the Eoarchean gneiss complex of the Saglek-Hebron area in northern Labrador, Canada in order to constrain to what extent variations in HSE abundances are recorded in Early Archean mantle that have we...

Biogenic manganese oxides (BioMnOx) can be applied for the effective removal and recovery of trace metals from wastewater because of their high adsorption capacity. Although a freshwater continuous-flow system for a nitrifier-based Mn-oxidizing microbial community for producing BioMnOx has been developed so far, a seawater continuous-flow bioreacto...

Deep-sea hydrothermal vents discharge abundant reductive energy into oxidative seawater. Herein, we demonstrated that in situ measurements of redox potentials on the surfaces of active hydrothermal mineral deposits were more negative than the surrounding seawater potential, driving electrical current generation. We also demonstrated that negative p...

A powerful preconcentration system, Cascade preconcentration and separation system, is based on the combination of two and more different types of the chemical preconcentration and separation techniques. This system can drastically enhance the sensitivity and performance of analytical instruments. In the present work, the online solid-phase extract...

Deep-sea hydrothermal vents discharge abundant reductive energy into oxidative seawater. Herein, we demonstrated that in situ measurements of redox potentials on the surfaces of active hydrothermal mineral deposits were more negative than the surrounding seawater potential, driving electrical current generation. We also demonstrated that negative p...

Electricity generation is observed from sub-seafloor hydrothermal fluids. In their Communication (DOI: 10.1002/anie.201701768), M. Yamamoto et al. show widespread and distant electron transfer from sub-seafloor hydrothermal fluids to the seafloor by way of electrically conductive massive hydrothermal mineral deposits.

Die Erzeugung von Elektrizität in hydrothermalen Strömen unter dem Meeresboden beschreiben M. Yamamoto et al. in ihrer Zuschrift (DOI: 10.1002/ange.201701768). Die Ergebnisse belegen einen ausgedehnten und weiträumigen Elektronentransfer aus diesen hydrothermalen Strömen zum Meeresboden über elektrisch leitfähige massive Mineralablagerungen.

Introduction: The paleontological record clearly reveals that impacts of large extra–terrestrial bodies may cause ecosystem devastation at a global scale [1], whereas smaller impacts have more local consequences depending on their size, impact angle and composition of the target rocks [2]. Approximately 190 impact structures are currently confirmed...

Introduction: The paleontological record clearly reveals that impacts of large extra-terrestrial bodies may cause ecosystem devastation at a global scale [1, 2]. Approximately 200 impact structures are currently confirmed on Earth and each year a small number is added to this list but only nine verified impact craters have been detected on the Sout...

Introduction: The geological and paleontological record have revealed that impacts of large extraterrestrial bodies may cause ecosystem devastation at a global scale [1], whereas smaller impacts have more regional consequences depending on their size, impact angle and composition of the target rocks [2]. Approximately 200 impact structures are curr...

Stable isotope ratios of nickel, copper, and zinc are powerful tools for elucidating the biogeochemical cycling of trace metals in the ocean. However, analytical difficulties have impeded isotopic studies of these metals. We present a simple and rapid method for simultaneous analysis of Ni, Cu, and Zn isotope ratios in seawater using NOBIAS Chelate...

Deep-sea ferromanganese crusts are found ubiquitously on the surface of seamounts of the world’s oceans. Considering the wide distribution of the crusts, archaeal and bacterial communities on these crusts potentially play a significant role in biogeochemical cycling between oceans and seamounts; however little is known about phylogenetic diversity,...

Photos of the crust samples collected from the Takuyo-Daigo Seamount, Ryusei Seamount, and Daito Ridge. Surface and section surface of each sample, left and right in each photo. Some samples had bumpy surfaces. The basement rocks were basalts or limestones. (PDF)

Phylogenetic trees of 16S rRNA gene OTUs. Trees for (A) Alphaproteobacteria; (B) Betaproteobacteria and Deltaproteobacteria; (C) Gammaproteobacteria; (D) Acidobacteria, Gemmatimonadetes, and Cyanobacteria; (E) Actinobacteria, Bacteroidetes, and Chlorobi; (F) Caldithrix, Chlamydiae, Firmicutes, Verrucomicrobia, Nitrospinae, and Nitrospirae; (G) Chlo...

Rarefaction curves for amoA gene clone libraries. Red, green, and blue lines are for the crusts, sediments, and seawater, respectively. (PDF)

List of bacterial amoA clones for each OTU. (XLSX)

List of archaeal amoA clones for each OTU. (XLSX)

Phylogenetic trees of amoA gene OTUs. Trees for (A) bacterial and (B) archaeal amoA genes are shown. OTUs in brown and purple indicate those from oceanic basalts from a previous study and from crusts in the present study, respectively. Numbers in parentheses following the OTU name indicate the numbers of clones from the crust libraries (red), the s...

Results of qPCR. (XLSX)

Summary of PCR clone libraries. (XLSX)

p values by p-test (lower) and UniFrac significance test (upper) between two samples. (XLSX)

Environmental clones with 97% or higher similarity with OTUa646 or OTUamoAA01. (XLSX)

Water depth dependence on temperature (red), salinity (blue), and dissolved oxygen concentration (green) in the sampling regions, the Takuyo-Daigo Seamount, Ryusei Seamount, and Daito Ridge. The depths for the sample collections are indicated with lines and the sample IDs. (PDF)

Comparison of Chao1 species richness estimates, Shannon diversity index, and rarefaction curves among the sample types. Data for the crusts (red), sediments (green), and seawater samples (blue) are shown. Box plots are used for the Chao1 species richness estimates and Shannon diversity index. *, p <0.001; **, p <0.01. (PDF)

Venn diagrams showing numbers of unique and shared OTUs of 16S rRNA genes. (A) Among habitat types, (B) among regions for the crust samples, and (C) among water depths for the crust samples of the Takuyo-Daigo Seamount. Numbers in circles and in parentheses are the numbers of OTUs. The names and taxonomic affiliations of the common OTUs among them...

List of 16S rRNA gene clones for each OTU. (XLSX)

The neodymium (Nd) isotopic composition of the surface layers of eleven ferromanganese crust samples collected from the Takuyo-Daigo Seamount (northwest Pacific Ocean) was determined. This is the first systematic study of the Nd isotopic composition of ferromanganese crusts collected by remotely operated vehicles (ROVs) from a single seamount over...

Geochemical tools such as the chemical and isotopic compositions of the samples with a wide range of ages have revealed the chemical evolution of the Earth. A model of the very early history of the earth with accumulation of the planetesimal, the giant impact, core segregation and late veneer has been proposed based on siderophile element abundance...

Sub-bottom profiling was conducted in the Japanese Exclusive Economic Zone (EEZ) around Minamitorishima Island, western Pacific Ocean, to investigate the features and distribution of mud rich in rare earth elements and yttrium (REY-rich mud). Based on the echogram records, we distinguished three acoustic facies: opaque (O), transparent (T), and lay...

We report detailed lithological and chemical characteristics of deep-sea sediments, including rare-earth elements and yttrium-rich mud (REY-rich mud), in the Japanese Exclusive Economic Zone (EEZ) around Minamitorishima Island. Three research cruises obtained fourteen sediment cores collected by piston coring. Based on the visual descriptions and g...

We have discovered deep-sea mud that is extremely enriched in rare-earth elements and yttrium (together called REY) in the Japanese Exclusive Economic Zone around Minamitorishima Island, in the western North Pacific Ocean. The maximum total REY concentration reaches approximately 7000 ppm, which is much higher than that reported for conventional RE...

We report major element and trace element compositions of ferromanganese crusts (Fe-Mn crusts) on Takuyo Daigo Seamount, northwestern Pacific Ocean. Highly enriched elements in these crusts, such as Co (6500 ppm), Ni (4000 ppm), Mo (520 ppm), Te (39 ppm), W (92 ppm), Pt (0.19 ppm), and rare earth elements (REEs; Sigma REE = 1700 ppm), exhibit stron...

Seven piston cores were collected from the seafloor similar to 250 km south of Minamitorishima Island in the western North Pacific Ocean during the cruise KR13-02 of R/V Kairei; in some portions of cores PC04 and PC05, the total contents of rare-earth elements and yttrium (Sigma REY) exceeded 4,000 ppm. Microscopic observations showed that the high...

Hydrogenous ferromanganese (Fe-Mn) crusts can provide records of long-term environmental changes during the Cenozoic. To understand the paleoceanographic conditions in the southwestern Atlantic Ocean, we investigated depth profiles of major- and trace-element concentrations as well as Os and Pb isotopic compositions in a Fe-Mn crust collected from...

During Integrated Ocean Drilling Program (IODP) Expedition 329, a deep-sea ferromanganese nodule and surrounding sediment were collected from the South Pacific Gyre, the most oligotrophic oceanic environment on earth. Using a combination of cryo-sectioning and fluorescence-based cell counting techniques, we determined that the microbial cell densit...

Boninite is a volcanic rock derived from shallow melting of highly depleted hydrous mantle, fluxed with water from subducted slabs. The eruption of boninite early in the history of the Izu-Bonin-Mariana (IBM) arc (~ 48–45 Ma), suggests generation by melting of upper mantle material that was relatively unmodified by subducted components. Thus, the b...

Serpentinization of Al-depleted and Al-undepleted komatiites (and olivine for comparison) was experimentally characterized under high-temperature and high-pressure conditions of 300 °C and 500 bar to evaluate the H 2 generation potential in komatiite-hosted hydrothermal systems in the early Earth. From the results, the steady-state H 2 concentratio...

Hydrogen generated in hydrothermal and fault systems has recently received considerable attention as a potential energy source for hydrogen-based microbial activity such as methanogenesis. Laboratory experiments that have reproduced conditions for the serpentinization of ultramafic rocks such as peridotite and komatiite have clarified the chemical...

To assess the effects of microbes on the exchange of Cu, Zn, and P between seafloor massive sulfide (SMS) deposits and seawater, we monitored the variation of the concentrations of Cu, Zn, and P in the artificial seawater of reaction systems that did or did not also include slabs and microbes originating from an SMS sample at 4ºC for 71 days. Disso...

It has been suggested that Saturn's moon Enceladus possesses a subsurface ocean. The recent discovery of silica nanoparticles derived from Enceladus shows the presence of ongoing hydrothermal reactions in the interior. Here, we report results from detailed laboratory experiments to constrain the reaction conditions. To sustain the formation of sili...

Supplementary Figures 1-6, Supplementary Tables 1-4, Supplementary Note 1 and Supplementary References

The 3.4-Ga Strelley Pool Formation (SPF) at the informally named 'Waterfall Locality' in the Goldsworthy greenstone belt of the Pilbara Craton, Western Australia, provides deeper insights into ancient, shallow subaqueous to possibly subaerial ecosystems. Outcrops at this locality contain a thin (<3 m) unit of carbonaceous and non-carbonaceous chert...

Os isotope compositions in ferromanganese crusts (Fe-Mn crusts) have been used for the dating of model ages from present to the Late Cretaceous. This dating method assumes that the Fe-Mn crusts preserve a paleo-seawater Os isotope composition at the timing of Fe-Mn crust deposition. However, available Os isotope data are limited to dredged samples...

During the Integrated Ocean Drilling Program (IODP), a total of 41.54 m of basement rock, consolidated volcaniclastic sediment, was recovered beneath a thin sediment cover. The drilled site is at the eastern end of the crestal area of Bowers Ridge, a north and westward sweeping offshoot of the Aleutian Arc into the Bering Sea. The volcanic sequence...

Detection of sodium-salt-rich ice grains emitted from the plume of the Saturnian moon Enceladus suggests that the grains formed as frozen droplets from a liquid water reservoir that is, or has been, in contact with rock. Gravitational field measurements suggest a regional south polar subsurface ocean of about 10 kilometres thickness located beneath...

We present a simplified method for simultaneous determinations of fluorine (F), chlorine (Cl), and sulfur (S) contents and isotopic abundances in rock samples. After using pyrohydrolysis to extract F, Cl, and S from a sample and transfer it into a sodium hydroxide (NaOH) solution, concentrations of F, Cl, and S as sulfate are measured by ion chroma...

The Louisville Seamount Chain (LSC) is, besides the Hawaiian-Emperor Chain, one of the longest-lived hotspot traces. We report here the first Re-Os isotope and pla