Article
Geosciences, Multidisciplinary
S. Thoram, W. W. Sager, K. Gaastra, S. M. Tikoo, C. Carvallo, A. Avery, Arianna V. Del Gaudio, Y. Huang, K. Hoernle, T. W. Hoefig, R. Bhutani, D. M. Buchs, C. Class, Y. Dai, G. Dalla Valle, S. Fielding, S. Han, D. E. Heaton, S. Homrighausen, Y. Kubota, C. -f. Li, W. R. Nelson, E. Petrou, K. E. Potter, S. Pujatti, J. Scholpp, J. W. Shervais, M. Tshiningayamwe, X. J. Wang, M. Widdowson
Summary: Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by seafloor spreading-type volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge. Magnetic data and inversion techniques were used to determine the crustal magnetization and reveal linear polarity zones, supporting the formation by seafloor spreading over approximately 4 million years. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 provide further evidence for this magnetic interpretation. The presence of deep rift valleys and the split of anomaly C33r into negative bands suggest a plate reorganization and the involvement of a westward ridge jump in the formation of VB.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Fucong Xu, Shaoping Lu, Chen Cai, Han Chen, Shaozhe Dong
Summary: By using the P-wave coda autocorrelation method and hydrophone waveform data from an ocean bottom seismometer (OBS) deployed on Tamu Massif, we were able to gain new insights into the structure of the oceanic crust for Tamu Massif. Our results suggest the presence of a layer in the shallow oceanic crust consisting of alternating eruptions of dense, higher velocity massive lava and sparse, lower velocity pillow lava flows, which generate reflection signals that were observed in our autocorrelation results.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Multidisciplinary Sciences
Nico Augustin, Froukje M. van der Zwan, Colin W. Devey, Bryndis Brandsdottir
Summary: Based on earthquake data, vertical gravity gradient data and high-resolution bathymetry, the research indicates that the Red Sea is a mature ocean basin where continuous seafloor spreading began along its entire length around 13 million years ago.
NATURE COMMUNICATIONS
(2021)
Article
Geology
Zhengyi Zhang, Dongdong Dong, Weidong Sun, Guangxu Zhang, Yongliang Bai
Summary: The study investigates the rift activity and volcanic effects on the crust in Caroline Ridge, presenting a typical case of plateau evolution. Rifts and seamount eruptions are shown to deform the strata, with lava flows and sedimentary layers being faulted by normal fault sets. The formation of Caroline Ridge is proposed to be caused by lateral extension of subaerial lava flows from hotspot magmatism, with initial rifting occurring during the Early-Middle Miocene.
INTERNATIONAL GEOLOGY REVIEW
(2021)
Article
Geochemistry & Geophysics
Florent Szitkar, Laurent Gernigon, Anna Lim, Marco Broenner
Summary: We used regional magnetic and local multibeam bathymetric data to investigate a prominent high in the Norwegian-Greenland Sea. The magnetization distribution and magnetic gradients suggest a basaltic environment, ruling out the possibility of an Oceanic Core Complex. Instead, we propose that this high is a basaltic hill and the depth asymmetry is likely caused by seafloor subsidence triggered by sediment accumulation from the Bear Island Fan.
Article
Geochemistry & Geophysics
Oke Okwokwo, Neil C. Mitchell, Wen Shi, I. C. F. Stewart, A. Y. Izzeldin
Summary: This study derives crustal magnetization for a constant-thickness source layer within the uppermost basement by inverting aeromagnetic anomalies. The results show that the low amplitudes of off-axis magnetic anomalies are mainly due to the greater depth of basement, which is depressed by isostatic loading by evaporites. However, magnetizations are still significant even where the basement lies several kilometers under the evaporites, suggesting that magnetizations have not been greatly affected by alteration under the evaporites. Additionally, prominent magnetization peaks are found on both tectonic plates, coinciding with a basement low that marks the transition to continental crust closer to the coasts. There is also an abrupt change from low-frequency anomalies off-axis to high-frequency anomalies towards the present axis, potentially indicating the stage at which buried spreading centers became exposed.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Yanming Huang, William W. Sager, Jinchang Zhang, Masako Tominaga, John Greene, Masao Nakanishi
Summary: Shatsky Rise oceanic plateau was formed during a period of frequent geomagnetic polarity reversals, with reconstruction of its tectonic evolution using magnetic anomalies. The study found that linear magnetic anomalies are ubiquitous in the region, suggesting that these volcanic edifices may have formed through spreading similar to mid-ocean ridges.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
J. A. Karson, L. A. Chutas, N. W. Hayman, R. N. Hey, A. J. Horst, S. D. Hurst, E. M. Klein, D. F. Naar, R. J. Varga
Summary: A tectonic window into the oceanic crust at the southern East Pacific Rise reveals a layered structure of basaltic lavas, sheeted dikes, and gabbroic rocks. The structure suggests fast crustal accretion and the formation of a thick lava unit due to subsidence beneath the spreading center. Tectonic and intrusive processes also modify the thickness of upper crustal rock units during accretion.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Environmental Sciences
Lucia Seoane, Guillaume Ramillien, Benjamin Beirens, Jose Darrozes, Didier Rouxel, Thierry Schmitt, Corinne Salauen, Frederic Frappart
Summary: In this study, an iterative Extended Kalman Filter approach was used to recover the topographic heights of an undersea volcanic mount using gravity measurements at sea surface. The method showed good accuracy in estimating the topography, especially when regional compensation was considered. However, larger discrepancies were found in the seamount flanks due to missing high-resolution information.
Article
Geochemistry & Geophysics
J. B. Russell, J. B. Gaherty, H. F. Mark, G. Hirth, L. N. Hansen, D. Lizarralde, J. A. Collins, R. L. Evans
Summary: Seismic anisotropy produced by aligned olivine in oceanic lithosphere provides insights into mid-ocean ridge dynamics. In this study, an in situ elastic tensor for oceanic lithosphere is estimated using observational data from the NoMelt experiment. The study compares the elastic model with petrofabric data to infer crystallographic orientations and strain accumulation in the lithosphere. The results reveal significant strain accumulation in the shallow mantle and provide evidence for a specific type of olivine lattice-preferred orientation.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Peng Yang, Qiang-tai Huang, Kai-Jun Zhang, Argyrios Kapsiotis, Hao Zheng, Tou-Ping Peng, Renjie Zhou, Qing-Kun Yang, Wen-xing Luo, Bin Xia
Summary: This paper reports the coexistence of large-scale mid-ocean ridge basalt (MORB)-like and enormous ocean island basalt (OIB)-type rocks in the Dongco ophiolitic rocks of the Bangong-Nujiang Suture Zone. The MORB-like rocks have tholeiitic geochemical characteristics and are derived from a depleted mantle source, while the OIB-type rocks have alkaline characteristics and are derived from an enriched mantle source representing remnants of a Meso-Tethyan oceanic plateau.
Article
Geosciences, Multidisciplinary
Baolu Sun, Boris J. P. Kaus, Jianfeng Yang, Gang Lu, Xinxin Wang, Kun Wang, Liang Zhao
Summary: Studying the accretion process of oceanic plateaus reveals that larger and lighter oceanic plateaus are favorable for subduction polarity reversal. Model results suggest that the collision of oceanic plateaus with overriding plates could lead to the breakoff of existing slabs and the subsequent sinking of the overriding plates, promoting subduction polarity reversal.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Shaza Haidar, Jacques Deverchere, David Graindorge, Mohamed Arab, Mourad Medaouri, Frauke Klingelhoefer
Summary: This study presents a new seismo-stratigraphic interpretation of the Eastern Algero-Balearic Basin (EABB) based on seismic data and magnetic anomalies. The results suggest that seafloor spreading in the EABB occurred during the Langhian-Serravallian times, with a half-spreading rate of 3.7 cm/yr for 2.45 Myr. The study also proposes a revised kinematic model for the Algero-Balearic domain, highlighting three stages of its evolution.
Article
Geosciences, Multidisciplinary
Junhui Yu, Pin Yan, Yan Qiu, Matthias Delescluse, Wenkai Huang, Yanlin Wang
Summary: This study reveals the crustal structure variations in the East Sub-basin of the South China Sea, showing an increase in magmatic budget during early spreading stage and a decrease during late spreading stage. The findings suggest slow seafloor spreading during the last spreading stage and limited or negligible magma contribution from the Hainan mantle plume.
Article
Geosciences, Multidisciplinary
Santiago Leon, Gaspar Monsalve, Camilo Bustamante
Summary: Quantifying topographic growth at convergent margins is crucial for understanding the link between tectonic processes and landscape evolution. Using calibrations based on trace elements of arc-related magmatic rocks, we estimated crustal thickening and surface uplift of the northern Colombian Andes during the early Andean orogeny.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Masako Tominaga, Estefania Ortiz, Joshua Franz Einsle, Noah Francis Ryoichi Vento, Matthew O. Schrenk, Iris Buisman, Isra S. Ezad, Dawn Cardace
Summary: This study utilized a novel approach combining multi-scale quantitative rock magnetic analyses and nano-resolution geochemical imaging analyses to investigate mineral weathering within a serpentinite formation in California. The findings revealed a new mode of magnetite production in serpentinites, highlighting the potential of magnetite abundance as a proxy for water-rock interaction in mantle peridotite and serpentinite.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Correction
Geosciences, Multidisciplinary
A. Beinlich, T. John, J. C. Vrijmoed, M. Tominaga, T. Magna, Y. Y. Podladchikov
Summary: The paper has been corrected and the correction has been published at the specified link.
Article
Geochemistry & Geophysics
Masako Tominaga, Maurice A. Tivey, William W. Sager
Summary: The study establishes a revised GPTS for the Middle to Late Jurassic, revealing the rapid onset of the Mesozoic Dipole Low from M42 through M39 and subsequent gradual recovery in field strength into the Cenozoic. Coherency between short-wavelength anomalies in the Japanese and Hawaiian lineation magnetic anomaly sequences implies a regionally coherent field during this period of rapid geomagnetic reversals. The identification of a zone of difficult-to-correlate anomalies in both sequences suggests the presence of a core similar to the JQZ crust bounded by M39-M41 isochrons.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Yanming Huang, William W. Sager, Jinchang Zhang, Masako Tominaga, John Greene, Masao Nakanishi
Summary: Shatsky Rise oceanic plateau was formed during a period of frequent geomagnetic polarity reversals, with reconstruction of its tectonic evolution using magnetic anomalies. The study found that linear magnetic anomalies are ubiquitous in the region, suggesting that these volcanic edifices may have formed through spreading similar to mid-ocean ridges.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
William W. Sager, Sriharsha Thoram, Daniel W. Engfer, Anthony A. P. Koppers, Cornelia Class
Summary: The study of Rio Grande Rise and Walvis Ridge in the South Atlantic revealed a complex tectonic history during the Late Cretaceous, involving the formation of a microplate surrounded by igneous massifs. This challenges simple hot spot models for the evolution of these large igneous provinces.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Anne M. Trehu, Masako Tominaga, Mitch Lyle, Kathy Davenport, Benjamin J. Phrampus, Jules Favorito, Edward Zhang, Brandi L. Lenz, Srisharan Shreedharan, Subbarao Yelisetti
Summary: New seismic reflection data collected and processed as part of early career scientist training at sea and in classroom projects provide new insights into anomalous subduction behavior and mass wasting along the south-central Cascadia Subduction Zone (CSZ) and fill gaps in seismic coverage of the region.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
E. Contreras, P. Jimenez Garcia, W. W. Sager, S. Thoram, K. Hoernle, R. Sarralde, H. Zhou
Summary: This study developed a bathymetric map of Valdivia Bank using various data sets, revealing previously unknown geological features and demonstrating ongoing geological activities in oceanic plateaus.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
S. Thoram, W. W. Sager, W. Reed, M. Nakanishi, J. Zhang
Summary: This paper presents an improved high-resolution bathymetry map for southern Shatsky Rise and provides important insights on its evolution. The map reveals the distribution of secondary volcanic cones, the segmentation pattern of Tamu Massif, and the presence of numerous escarpments. The results suggest that spreading ridges largely controlled the evolution of Shatsky Rise during its active volcanic phase.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Brendan T. Philip, Evan A. Solomon, Deborah S. Kelley, Anne M. Trehu, Theresa L. Whorley, Emily Roland, Masako Tominaga, Robert W. Collier
Summary: Pythia's Oasis is a newly discovered seafloor seep on the Central Oregon segment of the Cascadia Subduction Zone, emitting highly altered fluids similar to 9 degrees C above the background temperature. The unique chemistry of the seep fluids includes extreme enrichment of boron and lithium and depletion of chloride, potassium, and magnesium. The fluids, sourced from pore water compaction and mineral dehydration reactions, have minimum source temperatures of 150 degrees to 250 degrees C, indicating the source near the plate boundary offshore Central Oregon. The high fluid flow rates are likely driven by extreme overpressures along the plate boundary, with potential regulation by vertical faults such as the Alvin Canyon Fault in Central Cascadia.
Article
Geochemistry & Geophysics
Masako Tominaga, Andreas Beinlich, Eduardo A. Lima, Paiden Pruett, Noah R. Vento, Benjamin P. Weiss
Summary: In this study, we investigate in situ serpentinization and mineral carbonation processes in oceanic lithosphere using a combination of field magnetic measurements, rock magnetic analyses, microscopy, and phase mapping. Our results show a correlation between changes in magnetic signal strengths and the amount of alteration, providing insights into the mode of fluid flow and the composition that control the scale and extent of carbonation. This study highlights the potential use of magnetometry as a monitoring tool for the reaction progress from serpentinite to carbonate-bearing assemblages.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Multidisciplinary Sciences
M. L. G. Tejada, T. Sano, T. Hanyu, A. A. P. Koppers, M. Nakanishi, T. Miyazaki, A. Ishikawa, K. Tani, S. Shimizu, K. Shimizu, B. Vaglarov, Q. Chang
Summary: This study finds new evidence, such as the discovery of low-Ti basalts on the Ontong Java Plateau that match those on the Manihiki Plateau, and the identification of new age data that bridge the temporal gap between the Ontong Java Plateau and Hikurangi Plateau. These findings support the hypothesis of the Ontong Java Nui super oceanic plateau and provide insights into the tectonomagmatic evolution of the region.
SCIENTIFIC REPORTS
(2023)
Article
Geosciences, Multidisciplinary
Eunseo Choi, Masako Tominaga
Summary: We find that the ridge-parallel bathymetric profiles of fast- and intermediate-spreading seafloor are mostly upward concave, excluding the inward part of the seafloor within the fracture zone valley. The evolution of the bathymetric profiles formed at the Chile Rise shows rapid growth of the middle deflection followed by a steady state, which can be explained as the flexure of a thin elastic plate contracting thermally. Our model is consistent with recent observations that the oceanic lithosphere is cut open at fracture zone valleys, disproving the previous assumption of bending down of the ocean floor.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
S. Thoram, W. W. Sager, K. Gaastra, S. M. Tikoo, C. Carvallo, A. Avery, Arianna V. Del Gaudio, Y. Huang, K. Hoernle, T. W. Hoefig, R. Bhutani, D. M. Buchs, C. Class, Y. Dai, G. Dalla Valle, S. Fielding, S. Han, D. E. Heaton, S. Homrighausen, Y. Kubota, C. -f. Li, W. R. Nelson, E. Petrou, K. E. Potter, S. Pujatti, J. Scholpp, J. W. Shervais, M. Tshiningayamwe, X. J. Wang, M. Widdowson
Summary: Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by seafloor spreading-type volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge. Magnetic data and inversion techniques were used to determine the crustal magnetization and reveal linear polarity zones, supporting the formation by seafloor spreading over approximately 4 million years. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 provide further evidence for this magnetic interpretation. The presence of deep rift valleys and the split of anomaly C33r into negative bands suggest a plate reorganization and the involvement of a westward ridge jump in the formation of VB.
GEOPHYSICAL RESEARCH LETTERS
(2023)