A5101641024- Paleontology and Stratigraphy of Fossils
- Geological and Geophysical Studies
- Geology and Paleoclimatology Research
- Geochemistry and Elemental Analysis
- Geological and Geochemical Analysis
- Atmospheric and Environmental Gas Dynamics
- Ocean Acidification Effects and Responses
- Hydrocarbon exploration and reservoir analysis
- Marine and environmental studies
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Geomagnetism and Paleomagnetism Studies
- Maritime and Coastal Archaeology
- Archaeological and Geological Studies
- Archaeology and ancient environmental studies
- Oceanographic and Atmospheric Processes
- Methane Hydrates and Related Phenomena
- Paleontology and Evolutionary Biology
Japan Agency for Marine-Earth Science and Technology
2023-2025
University of Tsukuba
2024-2025
The University of Tokyo
2020-2023
Abstract During the mid-Cretaceous, Earth experienced several environmental perturbations, including an extremely warm climate and Oceanic Anoxic Events (OAEs). Submarine volcanic episodes associated with formation of large igneous provinces (LIPs) may have triggered these perturbations. The osmium isotopic ratio ( 187 Os/ 188 Os) is a suitable proxy for tracing hydrothermal activity LIPs formation, but Os data from mid-Cretaceous are limited to short time intervals. Here we provide...
Abstract The Cretaceous Period was marked by the formation of numerous large igneous provinces (LIPs), several which were associated with geologically rapid climate, environmental and biosphere perturbations, including early Aptian latest Cenomanian oceanic anoxic events (OAEs 1a 2, respectively). In most cases, magmatic CO 2 emissions are thought to have been major driver climate degradation. This work summarizes relationships between LIPs focusing on how volcanism caused warming during OAE...
Abstract 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 cause-effect relationship remains insufficiently understood. Here, we present a Pb-Os-C isotope dataset for tracking OJN volcanism across sedimentary sequence containing OAE1a record central Pacific. Lead isotopic evidence strongly supports deposition of OJN-sourced ash layers at this site after paired seawater δ 13 C...
The Aptian-Albian boundary is marked by one of the major oceanic perturbations during Cretaceous, called Oceanic Anoxic Event (OAE) 1b. Extensive volcanic episodes at Southern Kerguelen Plateau has been suggested as trigger OAE1b, but compelling evidence remains lacking. Here, we reconstructed temporal variations marine Os isotopic ratios across in Tethyan and Pacific pelagic sedimentary records to elucidate causal links between biotic turnover, episodes. Our new show two negative spikes...
The volcanic episodes forming Ontong Java Nui (OJN) likely caused late Barremian to mid-Aptian paleoenvironmental perturbations, the most substantial of which was early Aptian oceanic anoxic event (OAE) 1a (120 million years ago). However, recent estimates on younger OJN eruption ages cast doubt link between volcanism and OAE1a. Here, we further demonstrate synchroneity OAE1a by refining chronology Pacific volcanogenic sedimentary records Magellan Rise, nearby OJN, with detailed osmium...
Abstract The early to mid-Aptian was punctuated by episodic phases of organic-carbon burial in various oceanographic settings, which are possibly related massive volcanism associated with the emplacement Ontong Java, Manihiki, and Hikurangi oceanic plateaus southwestern Pacific Ocean, inferred have formed a single plateau called Java Nui. Sedimentary osmium (Os) isotopic compositions one best proxies for determining timing voluminous submarine volcanic episodes. However, available Os records...
The Carnian Pluvial Episode (CPE) was a short interval of extreme rainfall in the Late Triassic that caused significant changes marine ecosystems. Global warming induced by Wrangellia volcanism is thought to have resulted oceanic anoxia during CPE, but global extent, duration, and severity anoxia, its effects on major taxa, remain unclear. To address this, we examined an equatorial record conditions Panthalassa Ocean focusing Os isotope data, redox conditions, conodont radiolarian...
During the Cretaceous, several massive volcanic episodes led to significant environmental perturbations, including oceanic anoxic events (OAEs). The eruption forming Ontong Java Nui (ca. 120 Ma) in western Pacific Ocean is recognized as largest event on Earth and thought have caused 1a (OAE1a). Although metal emissions from this volcanism are believed played a crucial role triggering Aptian anoxia, no direct evidence has been reported so far. Here, we showed that iron-bearing minerals...
Abstract The Turonian age (~ 90–94 Ma) was the hottest geological interval in Cretaceous and also marked by K3 event, a pronounced enrichment of 3 He pelagic sediments (i.e., massive input extraterrestrial materials). Here, we present Os isotopic ( 187 Os/ 188 Os) platinum group element (PGE) data from sedimentary records. After sharp unradiogenic shift during end-Cenomanian oceanic anoxic event 2, ratios declined continuously throughout Turonian, which could be ascribed to formations...
Abstract The 405‐kyr eccentricity cycle is a consistent orbital parameter throughout the Phanerozoic that associated with long‐term variations in global continental weathering. However, lack of reliable geological evidence has hampered understanding relation between and weathering during Cretaceous. Os isotopic ratios ( 187 Os/ 188 Os) sedimentary record reflect balance radiogenic derived from unradiogenic sources (e.g., hydrothermal activity, mafic rocks, extraterrestrial sources). This...
<title>Abstract</title> The Archean Earth was characterized by a persistent weakly reducing atmosphere, while accumulated geological records suggest occurrence of transient atmospheric oxygenation events—whiff oxygen—during the late Archean, precise nature and causes which remain elusive. We used biogeochemical model to propose eruption large igneous provinces (LIPs) as plausible mechanistic explanation for events in atmosphere. Here we show that dynamics induced LIP eruptions could have...
<p>Figs. S1–S4 and Table S1.</p>
<p>Figs. S1–S4 and Table S1.</p>
Conodonts are tooth-like apparatuses of extinct marine animals and their geochemical composition is a key tool in reconstructions paleo-marine environmental conditions. Previous studies focused on conodont fossils with weak thermal maturation from shallow-marine sedimentary rocks. However, the features pelagic deep-sea rocks, which suitable for paleo-environmental conditions Panthalassa, poorly understood. This study presents data Triassic rocks Inuyama area, central Japan examines potential...