Results 21 to 30 of about 9,158 (119)

Geochemical Constraints on the Structure of the Earth's Deep Mantle and the Origin of the LLSVPs

Geochemistry, Geophysics, Geosystems, 2021
Geophysical analysis of the Earth's lower mantle has revealed the presence of two superstructures characterized by low shear wave velocities on the core‐mantle boundary.
Matthew Gleeson, Caroline Soderman, Simon Matthews, Sanne Cottaar, Sally Gibson   +4 more
doaj   +1 more source

Low‐Degree Melt Metasomatic Origin of Global Upper Mantle Fe Isotope Fractionation

Geophysical Research Letters, 2023
The upper mantle is heterogeneous in Fe isotope compositions, but the origin of the heterogeneity needs understanding. Recent studies on oceanic basalts demonstrate that the upper mantle Fe isotope heterogeneity results from low‐degree melt metasomatism.
Pengyuan Guo, Yaoling Niu, Pu Sun, Shuo Chen, Yanhong Chen, Meng Duan, Xiaohong Wang, Hongmei Gong   +7 more
doaj   +1 more source

Tomography of core-mantle boundary and lowermost mantle coupled by geodynamics: joint models of shear and compressional velocity

Annals of Geophysics, 2015
We conduct joint tomographic inversions of P and S travel time observations to obtain models of delta v_P  and delta v_S in the entire mantle. We adopt a recently published method which takes into account the geodynamic coupling between mantle ...
Gaia Soldati, Lapo Boschi, Steve Della Mora, Alessandro M. Forte   +3 more
doaj   +1 more source

Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas

Scientific Reports, 2021
Two-thirds of the Earth is covered by mid-ocean ridge basalts, which form along a network of divergent plate margins. Basalts along these margins display a chemical diversity, which is consequent to a complex interplay of partial mantle melting in the ...
Marianne Richter, Oliver Nebel, Martin Schwindinger, Yona Nebel-Jacobsen, Henry J. B. Dick   +4 more
doaj   +1 more source

Global observations of reflectors in the mid-mantle with implications for mantle structure and dynamics

Nature Communications, 2018
The Earth’s mantle undergoes changes as temperature and pressure increase with depth. Here, the authors present a global interrogation of reflectors in the Earth’s mid-mantle revealing a significant variation in their properties, with widespread ...
Lauren Waszek, Nicholas C. Schmerr, Maxim D. Ballmer   +2 more
doaj   +1 more source

Dense hydrous silica carrying water to the deep Earth and promotion of oxygen fugacity heterogeneity

Matter and Radiation at Extremes, 2022
Water has remarkable effects on the properties of mantle rocks, but, owing to the high temperatures in the mantle, uncertainties remain about how and how much water is transported into the deep Earth.
Yanhao Lin, Ho-Kwang Mao
doaj   +1 more source

Mantle Hg isotopic heterogeneity and evidence of oceanic Hg recycling into the mantle

Nature Communications, 2022
This work demonstrates distinct mass-independent mercury isotope fractionation in global basalts, which suggests mantle Hg isotope heterogeneity and reveals large-scale translithospheric Hg recycling via plate tectonics.
Runsheng Yin, Di Chen, Xin Pan, Changzhou Deng, Liemeng Chen, Xieyan Song, Songyue Yu, Chuanwei Zhu, Xun Wei, Yue Xu, Xinbin Feng, Joel D. Blum, Bernd Lehmann   +12 more
doaj   +1 more source

Long‐Lived Source Heterogeneities in the Galapagos Mantle Plume

Geochemistry, Geophysics, Geosystems, 2018
Mantle plume‐derived melts provide a unique glimpse into the chemical heterogeneity of the deep mantle. However, the exact processes involved in forming and sampling lower mantle heterogeneities remain unresolved and thus, require further investigation ...
Esteban Gazel, Jarek Trela, Michael Bizimis, Alexander Sobolev, Valentina Batanova, Cornelia Class, Brian Jicha   +6 more
doaj   +1 more source

pyMelt: An extensible Python engine for mantle melting calculations

Volcanica, 2022
Modelling the melting of Earth’s mantle is crucial for understanding the distribution of volcanic activity on Earth and for testing models of mantle convection and mantle lithological heterogeneity.
Simon Matthews, Kevin Wong, Matthew Gleeson   +2 more
doaj   +1 more source

Assessment of the effect of three-dimensional mantle density heterogeneity on Earth rotation in tidal frequencies

Geodesy and Geodynamics, 2016
In this paper, we report the assessment of the effect of the three-dimensional (3D) density heterogeneity in the mantle on Earth orientation parameters (EOP) (i.e., the polar motion, or PM, and the length of day, or LOD) in the tidal frequencies.
Lanbo Liu, Benjamin F. Chao, Wenke Sun, Weijia Kuang   +3 more
doaj   +1 more source