Results 61 to 70 of about 3,317 (237)

Are mantle plumes adiabatic? [PDF]

Earth and Planetary Science Letters, 2001
Abstract The issue concerning the state of adiabaticity of mantle plumes has been examined in a cartesian two-dimensional box with an aspect-ratio of six. We have investigated in the quasi steady-state regime high Rayleigh number convection with both depth-dependent viscosity and thermal expansivity for both the Boussinesq and the extended Boussinesq
Ctirad Matyska, David A. Yuen
openaire   +1 more source

Queen Anne's Wardrobe: Fashion, Sartorial Politics, and the Representational Strategies of the Last Stuart Queen

Journal for Eighteenth-Century Studies, EarlyView.
Abstract The final Stuart monarch, Queen Anne, has often been overlooked in studies of visual and material culture, particularly of fashion and dress. This article is the first to undertake a qualitative and quantitative analysis of the wardrobe accounts of Queen Anne, situating her consumption within the context of the eighteenth‐century fashion ...
Sarah A. Bendall
wiley   +1 more source

Noble gases in the Cameroon line and the He, Ne, and Ar isotopic compositions of high mu (HIMU) mantle

, 1999
Ultramafic xenoliths, basaltic lavas, and CO2 gases from the Cameroon line volcanic chain provide the first characterization of combined He, Ne, and Ar isotopes in a high-time-integrated 238U/204Pb = μ (HIMU) magmatic system. Helium isotopic compositions
Alex N. Halliday, Barfod, Dan N., Dan N. Barfod, Halliday, AN, J. Godfrey Fitton, Barfod, D. N., Ballentine, Chris J., Fitton, J. G., Halliday, Alex, Barfod, DN, Fitton, J. Godfrey, Ballentine, C. J., Halliday, A. N., Chris J. Ballentine, Fitton, JG, Ballentine, CJ, Halliday, Alex N.   +16 more
core   +1 more source

Large volcanic eruptions are mostly sourced above mobile basal mantle structures

Communications Earth & Environment
Most deep mantle plumes rise from hot basal mantle structures, creating large volcanic eruptions at Earth’s surface. In previous studies, mantle plumes were the implicit process connecting volcanic eruptions to hot basal mantle structures.
Annalise Cucchiaro, Nicolas Flament, Maëlis Arnould, Noel Cressie   +3 more
doaj   +1 more source

Spectacle and Spy Stories: The 1954 Royal Commission on Espionage

Australian Journal of Politics &History, EarlyView.
ABSTRACT The Menzies government's 1954 royal commission, established to investigate Soviet espionage in Australia, is well known as the backdrop to the Labor Party split. It saw opposition leader H.V. Evatt's demise and ushered in an almost 20‐year period of Liberal Party governance.
Ebony Nilsson
wiley   +1 more source

Shear-induced material transfer across the core-mantle boundary aided by the post-perovskite phase transition

, 2005
We present a novel mechanical model for the extraction of outer core material upwards across the CMB into the mantle side region of D" and subsequent interaction with the post-perovskite (ppv) phase transition.
Brodholt, John, Petford, Nick; id_orcid, Petford, Nick, Rushmer, Tracy, Yuen, D., Stackhouse, Stephen, Yuen, Dave   +6 more
core   +1 more source

Long‐Lasting Volcanism of the Moon Aided by the Switch in Dominant Mechanisms of Magma Ascent: Role of Localized Radioactive Enrichment in a Numerical Model of Magmatism and Mantle Convection

Geophysical Research Letters
Significant volcanic activity continued for billions of years since 3.5–4 Gyr ago in the Procellarum KREEP Terrane (PKT) of the Moon, but not so significant outside the PKT.
Ken'yo U, Masanori Kameyama, Gaku Nishiyama, Takehiro Miyagoshi, Masaki Ogawa   +4 more
doaj   +1 more source

Resolving Micrometre‐Scale Zircon Growth in Silicic Systems by 7 μm LA‐MC‐ICP‐MS U‐Pb Dating: Linking Petrology and Geochronology in Silicic Volcanic and Granitic Rocks from Victoria, Australia

Geostandards and Geoanalytical Research, EarlyView.
Key Points 7 μm spot‐diameter LA‐MC‐ICP‐MS analyses yield accurate zircon U‐Pb ages. 1013 Ω amplifier resistors improve low‐signal Pb measurements. Saturn correction protocols minimise down‐hole fractionation effects. We present a systematic evaluation of high spatial‐resolution zircon U‐Pb dating using a Thermo Scientific Neoma multi‐collector ICP‐MS ...
Cristiano Lana, John D. Clemens
wiley   +1 more source

Mantle roots of the Emeishan plume: an evaluation based on teleseismic P-wave tomography [PDF]

Solid Earth, 2017
The voluminous magmatism associated with large igneous provinces (LIPs) is commonly correlated to upwelling plumes from the core–mantle boundary (CMB). Here we analyse seismic tomographic data from the Emeishan LIP in southwestern China.
C. He, M. Santosh, M. Santosh
doaj   +1 more source

Polymict melt‐bearing breccia dikes in the Morokweng impact structure formed by slip‐induced mechanical mixing of pseudotachylite and cataclasite along large‐displacement impact faults

Meteoritics &Planetary Science, EarlyView.
Abstract A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter‐ to meter‐wide clastic‐matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter‐ to centimeter ‐size ...
Roger L. Gibson, S'lindile S. Wela, Leonidas C. Vonopartis, Marco A. G. Andreoli   +3 more
wiley   +1 more source