In this section
@inbook{Davies:2015:10.1007/978-3-319-15627-9,
author = {Davies, DR and Goes, S and Lau, HCP},
booktitle = {The Earth’s Heterogeneous Mantle: a geophysical, geodynamical, geochemical perspective},
doi = {10.1007/978-3-319-15627-9},
editor = {Khan and Deschamps},
pages = {441--477},
publisher = {Springer},
title = {Thermally dominated deep mantle LLSVPs: A review},
url = {http://dx.doi.org/10.1007/978-3-319-15627-9},
year = {2015}
}
TY - CHAP
AB - The two large low shear-wave velocity provinces (LLSVPs) that dominate lower-mantle structure may hold key information on Earth’s thermal and chemical evolution. It is generally accepted that these provinces are hotter than background mantle and are likely the main source of mantle plumes. Increasingly, it is also proposed that they hold a dense (primitive and/or recycled) compositional com- ponent. The principle evidence that LLSVPs may represent thermo-chemical ‘piles’ comes from seismic constraints, including: (i) their long-wavelength nature; (ii) sharp gradients in shear-wave velocity at their margins; (iii) non-Gaussian distributions of deep mantle shear-wave velocity anomalies; (iv) anti-correlated shear-wave and bulk-sound velocity anomalies (and elevated ratios between shear- and compressional-wave velocity anomalies); (v) anti-correlated shear-wave and density anomalies; and (vi) 1-D/radial profiles of seismic velocity that deviate from those expected for an isochemical, well-mixed mantle. In addition, it has been proposed that hotspots and the reconstructed eruption sites of large ig- neous provinces correlate in location with LLSVP margins. In this paper, we review recent results which indicate that the majority of these constraints do not require thermo-chemical piles: they are equally well (or poorly) explained by thermal heterogeneity alone. Our analyses and conclusions are largely based on comparisons between imaged seismic structure and synthetic seismic structures from a set of thermal and thermo-chemical mantle convection models, which are constrained by ∼ 300 Myr of plate motion histories. Modelled physical structure (temperature, pressure and composition) is converted into seismic velocities via a thermodynamic approach that accounts for elastic, anelastic and phase con- tributions and, subsequently, a tomographic resolution filter is applied to account for the damping and geographic bias inherent to seismic imaging. Our re
AU - Davies,DR
AU - Goes,S
AU - Lau,HCP
DO - 10.1007/978-3-319-15627-9
EP - 477
PB - Springer
PY - 2015///
SP - 441
TI - Thermally dominated deep mantle LLSVPs: A review
T1 - The Earth’s Heterogeneous Mantle: a geophysical, geodynamical, geochemical perspective
UR - http://dx.doi.org/10.1007/978-3-319-15627-9
UR - http://www.springer.com/gb/book/9783319156262
UR - https://link.springer.com/chapter/10.1007%2F978-3-319-15627-9_14
UR - http://hdl.handle.net/10044/1/91120
ER -