Article
Geochemistry & Geophysics
Alessio Sanfilippo, Vincent J. M. Salters, Sergey Y. Sokolov, Alexander A. Peyve, Andreas Stracke
Summary: The upper mantle is a mixture of refractory and recycled crustal domains, with the recycled portions dominating the composition of surface basalts. Hf isotope ratios may provide hints for melting of refractory source materials in basalts, allowing the identification of depleted mantle materials. Basalts from the Arctic Atlantic show high Hf isotope ratios, suggesting a highly depleted asthenospheric mantle source beneath this region.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Hongda Hao, Ian H. Campbell, Richard J. Arculus, Michael R. Perfit
Summary: The study reveals that most primitive mid-ocean ridge basalts have low platinum-group element content, which may be due to changes in sulfur saturation during ascent from the mantle to the ridge magma chamber. Sulfide saturation status can be determined by changes in Pd content, and frequent small replenishments in the magma chamber help maintain sulfide saturation status.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
S. Brown Krein, Z. J. Molitor, T. L. Grove
Summary: The study presents a new algorithm, RevPet, to infer mantle melting conditions based on evolved basalts that have experienced multiphase fractional crystallization. Results show that the average apparent mantle potential temperature of basaltic glasses is around 1322 degrees C with melting pressures of 13 kbars. Variations in ambient MOR T-P are observed, with the estimate that it is generally homogeneous around 1350-1400 degrees C, except near hotspots where T-P can reach approximately 1600 degrees C.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Haibo Ma, Li-Juan Xu, Ji Shen, Sheng-Ao Liu, Shuguang Li
Summary: This study presents the first chromium stable isotopic data of mid-ocean ridge basalts (MORBs) from different ocean ridges and explores the correlation between chromium isotopes, oxygen fugacity, and crystallization.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Yidi Hong, Tao Wu, Chunfeng Li, Xuegang Chen, Jianggu Lu, Haiou Gu, Rong Xu
Summary: Mid-Ocean Ridge Basalts (MORBs) from the South China Sea (SCS) have attracted attention from geologists, but their petrogenesis is still disputed. Heterogeneous Mg isotopes in MORBs suggest olivine enrichment and contribution from lower continental crust. The study proposes that the role of the Hainan mantle plume in the opening and spreading of the SCS may be insignificant.
Article
Geochemistry & Geophysics
Adina E. Pusok, Richard F. Katz, Dave A. May, Yuan Li
Summary: Geophysical observations at mid-ocean ridges show asymmetry in indicators of magma production and non-monotonic variations in lithosphere-asthenosphere boundary depth. Models incorporating melting-induced buoyancy effects can explain these observations.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Pu Sun, Yaoling Niu, Shuo Chen, Pengyuan Guo, Meng Duan, Yanhong Chen, Hongmei Gong, Yuanyuan Xiao, Xiaohong Wang
Summary: Copper isotope fractionation during magmatic processes has been observed for the first time, with significant fractionation occurring during magma differentiation. The study also found that the fractionation of copper isotopes in magma differentiation is influenced by the redox state and sulfide segregation.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
David W. Graham, Peter J. Michael
Summary: Basalts erupted within intra-transform spreading centers can be valuable probes of geochemical components in Earth's upper mantle, providing constraints on the proportions of mantle carbon that are juvenile vs. tectonically recycled. Different isotopic compositions of basalts from GTF and EPR suggest they are derived from two different mantle source compositions.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Pengyuan Guo, Yaoling Niu, Pu Sun, Junjie Zhang, Shuo Chen, Meng Duan, Hongmei Gong, Xiaohong Wang
Summary: The study provides new Sr-Nd-Hf isotopic data on mid-ocean ridge basalts from the Oceanographer and Hayes fracture zones at the Mid-Atlantic Ridge to constrain the nature and origin of upper mantle heterogeneity. The data illustrate that the mantle sources of these lavas comprise three components, including ADM, E-type I, and E-type II components, which explain the contrast in crustal thickness, ridge morphology, and mantle Bouguer anomalies between the two ridge segments.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
E. K. A. Brett, J. Prytulak, M. Rehkamper, S. J. Hammond, C. Chauvel, A. Stracke, M. Willbold
Summary: The study reveals significant variations in thallium isotopic compositions in ocean island basalts, with widespread depletion in thallium concentration. The Tl concentration in OIB mantle sources may be influenced by subduction processes, leading to discrepancies between thallium isotopic compositions and radiogenic isotopic compositions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Q. Ahmad, M. Wille, C. Rosca, J. Labidi, T. Schmid, K. Mezger, S. Konig
Summary: Under modern oxidising Earth surface conditions, dehydrated subducted slabs show light Mo isotope compositions reflecting redox-dependent aqueous mobility of isotopically heavy Mo associated with slab dehydration. The correlation between Mo isotope values and radiogenic Sr and Nd isotopes suggests the recycling of Proterozoic sediments during anoxic deep sea sedimentation.
GEOCHEMICAL PERSPECTIVES LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Tran Danh Hung, Ting Yang, Ba Manh Le, Youqiang Yu, Mei Xue, Baohua Liu, Chenguang Liu, Jian Wang, Mohan Pan, Phan Thien Huong, Fang Liu, Jason P. Morgan
Summary: The study of crustal thickness and Vp/Vs ratios near an extinct mid-ocean ridge in the South China Sea reveals that as spreading ceased, the oceanic crust abruptly thinned and shifted to an ultraslow accretion style. Abnormally high Vp/Vs ratios indicate the presence of serpentine, suggesting the formation of normal faults and the enhancement of serpentinization along the ridge axis.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
K. J. Walowski, L. A. Kirstein, J. C. M. De Hoog, T. Elliott, I. P. Savov, R. E. Jones
Summary: The study presents the largest and most precise boron isotope dataset from ocean island basalt glasses and olivine-hosted melt inclusions, revealing the characteristics of volatile elements in the mantle and the processes generating different mantle reservoirs. It suggests that the deep mantle is becoming increasingly depleted in boron over time and highlights the decoupling of boron isotopes from radiogenic isotopes, providing a new perspective on volatile recycling.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
T. E. Johnson, L. J. Morrissey, A. A. Nemchin, N. J. Gardiner, J. F. Snape
Summary: Despite decades of research on the formation and evolution of the Moon, many questions still remain unanswered. Recent thermodynamic models have provided detailed constraints on the compositional, mineralogical, and density structure of the lunar interior, laying the foundation for future research on the origin and evolution of the Moon.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Nina Soager, Paul Martin Holm, Gabriela Isabel Massaferro, Miguel Haller, Marie Katrine Traun
Summary: The study revises the interpretation of mantle sources of volcanism in Patagonia, Argentina, based on an extensive literature dataset. It suggests that the Patagonian basalts were formed by metasomatism of the local lithospheric mantle by carbonatitic melts from the South Atlantic asthenosphere, indicating a young HIMU source.