Results 1 to 10 of about 4,939,312 (268)
Coupled deep-mantle carbon-water cycle: Evidence from lower-mantle diamonds [PDF]
The Innovation, 2021 Diamonds form in a variety of environments between subducted crust, lithospheric and deep mantle. Recently, deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered.
Wenzhong Wang +6 more
doaj +2 more sources
Depletion of davemaoite in Earth’s ambient lower mantle [PDF]
Nature CommunicationsThe mineralogy of the Earth’s lower mantle is fundamental to understanding the planet’s formation, composition, evolution, and dynamics. However, uncertainties in the elastic properties and phase transitions of CaSiO₃ davemaoite—the third most abundant ...
Ming Hao +3 more
doaj +2 more sources
Probing recycled carbonate in the lower mantle. [PDF]
Natl Sci Rev, 2022 Whether surficial carbonates can be carried into the Earth's lower mantle is key to global deep carbon cycles but remains poorly understood. New clues from magnesium and zinc isotopic systematics on rocks from deep-rooted mantle plumes are presented and discussed in this Perspective.
Chen LH, Wang XJ, Liu SA.
europepmc +3 more sources
Geophysical evidence of a nearly dry bridgmanite in the Earth’s lower mantle [PDF]
Nature CommunicationsWater in Earth’s mantle plays a crucial role in shaping geological and geochemical processes. While previous electrical conductivity measurements on major mantle minerals have constrained water content in the Earth’s mantle down to the mantle transition ...
Yoshiyuki Okuda +7 more
doaj +2 more sources
Persistence of davemaoite at lower-mantle conditions. [PDF]
Nat GeosciAbstract The lower mantle occupies over half of Earth’s volume, and accordingly, its mineralogy is crucial in determining the structure and dynamics of Earth. Davemaoite, the calcium silicate perovskite, was believed to coexist with bridgmanite in the lower mantle and is considered essential for understanding the chemical evolution and ...
Wang L, Miyajima N, Wang F, Katsura T.
europepmc +3 more sources
Carbonate-Metal Reactions in the Lower Mantle. [PDF]
ACS Earth Space ChemCarbonates are important carbon-bearing phases in the mantle. While their role in upper mantle petrologic processes has been well studied, their effect on phase relations, melting, and transport properties in the lower mantle is less understood. The stability of carbonates in the mantle depends on a host of factors, including pressure, temperature ...
Davis AH +4 more
europepmc +4 more sources
Review of seismic velocity anomalies in the lower mantle
地球与行星物理论评, 2023 The lower mantle accounts for more than 50% of the total volume of the Earth, and influences the evolution of the Earth. Early studies showed that the lower mantle is relatively homogeneous, but since the 1970s, seismic tomography revealed the velocity ...
Yutong Shi +4 more
doaj +1 more source
Geophysical Research Letters, 2022 We report on the observation of a diffracted P‐wave (Pdiff) along the core of Mars from a distant impact that has been recorded by the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission.
C. Durán +7 more
doaj +1 more source
Pangea and the Lower Mantle [PDF]
Tectonics, 2019 AbstractWe show that the peripheral Pangea subduction zone closely followed a polar great circle. We relate it to the band of faster‐than‐average velocities in lowermost mantle. Both structures have an axis of symmetry in the equatorial plane. Assuming geologically long‐term stationarity of the deep mantle structure, we propose to use the axis of ...
Xavier Le Pichon +2 more
openaire +1 more source
Shallow Lower Mantle Viscosity Modulates the Pattern of Mantle Structure
Geochemistry, Geophysics, Geosystems, 2020 Tomographic images of Earth's mantle reveal that structure, even at the largest spatial scales, does not remain correlated across all mantle depths.
Lourenço D. L., Rudolph M. L.
doaj +1 more source