Article
Engineering, Marine
Linzhang Wang, Zhigang Zeng
Summary: The ferromanganese deposit is a marine mineral resource rich in Mn, Fe, Co, Ni, and Cu. Its growth process is influenced by the guyot environment and seawater geochemical characteristics. Studying the texture morphology, microstructure, mineralogical features, and geochemical features of the ferromanganese crusts deposits is important for understanding their formation process and properties.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Hikari Hino, Akira Usui
Summary: Selected hydrogenetic ferromanganese crusts from various NW Pacific seamounts were analyzed at a microstratigraphic scale. The study revealed spatial compositional variation, with high levels of Co and Ni present in the crusts. The study also identified trends such as the lower phosphatized layer forming only on the Pacific Plate, increasing Co/Mn ratio with younger age, and an increase of detrital quartz and plagioclase since approximately 5 Ma. These findings provide insights into the influence of oceanographic and tectonic conditions on the composition of ferromanganese crusts.
Article
Geochemistry & Geophysics
Junming Zhou, Shengxiong Yang, Jingya Cao, Yutian Deng, Zhenquan Wei, Yuanheng Li, Dongmei Tian, Guang Hu
Summary: Ferromanganese crusts are potential marine deposits for high-tech metals and proxies for the oceanic paleoenvironment. Phosphatization during their growth causes the remobilization of elements and minerals. Rare earth elements plus yttrium (REY), important critical metals in Fe-Mn crusts, are influenced by phosphatization processes which remain uncertain. Multiple microanalysis methods were used to analyze the textures, structures, and REY geochemistry of an Fe-Mn crust sample. The phosphatized and non-phosphatized layers, as well as the presence of carbonate-rich fluorapatite (CFA) veins, display distinctly different REY patterns.
Article
Geosciences, Multidisciplinary
Mariana Benites, Javier Gonzalez, James Hein, Egidio Marino, Jesus Reyes, Christian Millo, Luigi Jovane
Summary: A study of deep-water ferromanganese crusts from Rio Grande Rise (RGR) revealed that the upper crusts are older, thicker, and phosphatized, while the lower crusts are younger, thinner, and non-phosphatized. These deep-water crusts mainly consist of vernadite and goethite with minor amounts of manganeseates and aluminosilicates. The upper crusts have high contents of hydrogenetic metals but lack calcite and phosphate minerals. The contents of certain elements decrease with water depth due to biological productivity, while others increase due to entrained detrital material.
Article
Geochemistry & Geophysics
Keishiro Azami, Naoto Hirano, Jun-Ichi Kimura, Qing Chang, Hirochika Sumino, Shiki Machida, Kazutaka Yasukawa, Yasuhiro Kato
Summary: This study analyzes the Sr isotope ratios of ferromanganese crusts using laser ablation inductively coupled plasma multiple-collector mass spectrometry. The results show that the Sr isotope ratios in the crusts collected from off Minamitorishima Island are similar to present-day seawater, while the crusts collected from off northeast Japan exhibit a wide variation. The variation suggests detrital influx contributions from both the NE Japan arc and aeolian dust from China. The study also proposes that the high-resolution Sr isotope analysis improves the burial history of Fe-Mn nodules.
Article
Geosciences, Multidisciplinary
Mariana Benites, James R. Hein, Kira Mizell, Luigi Jovane
Summary: Marine phosphorites at the summit of Rio Grande Rise in the Southwest Atlantic Ocean originated during the Miocene and occasionally during the Quaternary, mainly through the cementation of carbonate sediments. The intensity of phosphatization depended on factors like porosity/permeability and abundance of fine calcite material, and was linked to a transition to a more dynamic circulation system in the South Atlantic Ocean. The cessation of phosphatization at RGR was due to a rapidly cooling and dry climate during the Miocene-Pliocene transition.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Geochemistry & Geophysics
Yuanzhi Qi, Hiroyuki Matsuzaki, Takeyasu Yamagata, Hisao Nagai
Summary: This study investigated the concentrations of stable and radioiodine in seawater samples collected in the subarctic Pacific Ocean. The results showed large variations in the distributions of iodide and iodate concentrations with depth and geographical location. The study also revealed that anthropogenic 129I from atmospheric deposition is the dominant source of 129I in the subarctic Pacific Ocean.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geology
Zhengkun Li, Zhengxing Guo, Dengfeng Li, Xiaoming Sun, Yu Fu, Gaowen He
Summary: This study investigates the mineralogical and geochemical compositions of a seafloor ferromanganese sample and its carbonate substrate rocks. It reveals the presence of Mn-rich nuclei surrounded by a Fe-rich reaction interface in the hydrothermal ferromanganese sample. The phosphatized bedrock shows high metal content due to the partial replacement of calcite by apatite.
ORE GEOLOGY REVIEWS
(2023)
Article
Environmental Sciences
Elise S. Droste, Alex R. Baker, Chan Yodle, Andrew Smith, Laurens Ganzeveld
Summary: Iodine plays a significant role in the radiative budget and oxidative capacity of the atmosphere, with a portion of it ending up in aerosols where it contributes to the destruction of ozone. Research on aerosol samples collected from various ocean regions showed a consistent proportion of different iodine species, with iodate reduction attributed to aerosol acidity and anthropogenic emissions. The data contributes to the understanding of aerosol iodine speciation and the complex composition of organic iodine in aerosols.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Geochemistry & Geophysics
Mark A. Kendrick, Michael A. W. Marks, Marguerite Godard
Summary: The concentrations of halogens in serpentinised olivine-rich lithologies in the lower oceanic crust are evaluated. It is found that serpentinites formed from seawater in the lower crust could significantly contribute to halogen subduction and have preserved seawater-like halogen signatures.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Multidisciplinary Sciences
Anya V. Hess, Alexandra Auderset, Yair Rosenthal, Kenneth G. Miller, Xiaoli Zhou, Daniel M. Sigman, Alfredo Martinez-Garcia
Summary: The oxygen content of the oceans has declined due to climate change, especially in oxygen-deficient zones. Climate warming simulations predict the expansion of these zones until at least 2100. The response of ocean oxygenation on longer timescales remains uncertain.
Review
Oceanography
Andrei Grischenko
Summary: The sessile benthic fauna on ferromanganese (Fe-Mn) crusts remains poorly known, and two new species and a new genus of cheilostome bryozoans have been discovered on Magellan Seamounts. The diversity of bryozoans associated with Fe-Mn crusts is relatively low, highlighting the need for further investigations.
PROGRESS IN OCEANOGRAPHY
(2022)
Article
Engineering, Ocean
Taku Kaji, Oak Yono, Kazuya Okada, Hikari Hino, Haruhisa Morozumi
Summary: This study developed a method to quantitatively estimate the distribution of ferromanganese crusts (FMCs) and thickness of the surface sediment (TSS) by determining the relationship between topographic features and backscatter intensity using statistical analyses. The results showed that FMCs and TSS could be quantitatively evaluated with high accuracies, providing valuable information for future mineral explorations.
MARINE GEORESOURCES & GEOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Liang Yi, Martin Medina-Elizalde, Liangcheng Tan, David B. Kemp, Yanzhen Li, Gunther Kletetschka, Qiang Xie, Huiqiang Yao, Huaiyu He, Chenglong Deng, James G. Ogg
Summary: We derived a record of abyssal ventilation spanning 4.7 million years and evaluated its linkage to Antarctic bottom water (AABW) formation by analyzing marine ferromanganese nodules from the eastern Pacific. Our findings showed a relative weakness in abyssal ventilation during the early Pliocene, with a persistent intensification from 3.4 million years ago. We identified seven episodes of AABW formation collapse since the late Pliocene, coinciding with key stages of Northern Hemisphere glaciation, indicating a possible link between the collapse events and global glaciation.
Review
Oceanography
Michael J. Miller, Madoka Shimizu, Jun Aoyama, Shun Watanabe, Mari Kuroki, Eric Feunteun, Takatoshi Higuchi, Aya Takeuchi, Yu-San Han, Pierre Sasal, Christine Dupuy, Donald Jellyman, Robert Schabetsberger, Shingo Kimura, Noritaka Mochioka, Tsuguo Otake, Katsumi Tsukamoto
Summary: The larvae of different types of eels mix together in the ocean surface layer, while juvenile anguillid eels and marine eels live in freshwater/estuarine habitats and diverse ocean environments respectively. The western South Pacific is a unique region for studying long-lived leptocephali due to the presence of different eel habitats, the South Equatorial Current, and countercurrents.
PROGRESS IN OCEANOGRAPHY
(2022)