Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere
Abstract The Archean Superior craton was formed by the assemblage of continental and oceanic terranes at ∼2.6 Ga. The craton is surrounded by multiple Proterozoic mobile belts, including the Paleoproterozoic Trans‐Hudson Orogen which brought together the Superior and Rae/Hearne cratons at ∼1.9–1.8 G...
Published in: | Geochemistry, Geophysics, Geosystems |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2024
|
Subjects: | |
Online Access: | https://doi.org/10.1029/2024GC011454 https://doaj.org/article/03971704169c485cae91e57aecc6fe91 |
id |
ftdoajarticles:oai:doaj.org/article:03971704169c485cae91e57aecc6fe91 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:03971704169c485cae91e57aecc6fe91 2024-09-15T18:11:06+00:00 Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere Riddhi Dave Fiona Darbyshire Juan Carlos Afonso I. Fomin 2024-06-01T00:00:00Z https://doi.org/10.1029/2024GC011454 https://doaj.org/article/03971704169c485cae91e57aecc6fe91 EN eng Wiley https://doi.org/10.1029/2024GC011454 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2024GC011454 https://doaj.org/article/03971704169c485cae91e57aecc6fe91 Geochemistry, Geophysics, Geosystems, Vol 25, Iss 6, Pp n/a-n/a (2024) lithosphere tomography continental cratons thermochemical structure Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2024 ftdoajarticles https://doi.org/10.1029/2024GC011454 2024-08-05T17:48:55Z Abstract The Archean Superior craton was formed by the assemblage of continental and oceanic terranes at ∼2.6 Ga. The craton is surrounded by multiple Proterozoic mobile belts, including the Paleoproterozoic Trans‐Hudson Orogen which brought together the Superior and Rae/Hearne cratons at ∼1.9–1.8 Ga. Despite numerous studies on Precambrian lithospheric formation and evolution, the deep thermochemical structure of the Superior craton and its surroundings remains poorly understood. Here we investigate the upper mantle beneath the region from the surface to 400 km depth by jointly inverting Rayleigh wave phase velocity dispersion data, elevation, geoid height and surface heat flow, using a probabilistic inversion to obtain a (pseudo‐)3D model of composition, density and temperature. The lithospheric structure is dominated by thick cratonic roots (>300 km) beneath the eastern and western arms of the Superior craton, with a chemically depleted signature (Mg# > 92.5), consistent with independent results from mantle xenoliths. Beneath the surrounding Proterozoic and Phanerozoic orogens, the Mid‐continent Rift and Hudson Strait, we observe a relatively thinner lithosphere and more fertile composition, indicating that these regions have undergone lithospheric modification and erosion. Our model supports the hypothesis that the core of the Superior craton is well‐preserved and has evaded lithospheric destruction and refertilization. We propose three factors playing a critical role in the craton's stability: (a) the presence of a mid‐lithospheric discontinuity, (b) the correct isopycnic conditions to sustain a strength contrast between the craton and the surrounding mantle, and (c) the presence of weaker mobile belts around the craton. Article in Journal/Newspaper Hudson Strait Directory of Open Access Journals: DOAJ Articles Geochemistry, Geophysics, Geosystems 25 6 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
lithosphere tomography continental cratons thermochemical structure Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
lithosphere tomography continental cratons thermochemical structure Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Riddhi Dave Fiona Darbyshire Juan Carlos Afonso I. Fomin Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
topic_facet |
lithosphere tomography continental cratons thermochemical structure Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract The Archean Superior craton was formed by the assemblage of continental and oceanic terranes at ∼2.6 Ga. The craton is surrounded by multiple Proterozoic mobile belts, including the Paleoproterozoic Trans‐Hudson Orogen which brought together the Superior and Rae/Hearne cratons at ∼1.9–1.8 Ga. Despite numerous studies on Precambrian lithospheric formation and evolution, the deep thermochemical structure of the Superior craton and its surroundings remains poorly understood. Here we investigate the upper mantle beneath the region from the surface to 400 km depth by jointly inverting Rayleigh wave phase velocity dispersion data, elevation, geoid height and surface heat flow, using a probabilistic inversion to obtain a (pseudo‐)3D model of composition, density and temperature. The lithospheric structure is dominated by thick cratonic roots (>300 km) beneath the eastern and western arms of the Superior craton, with a chemically depleted signature (Mg# > 92.5), consistent with independent results from mantle xenoliths. Beneath the surrounding Proterozoic and Phanerozoic orogens, the Mid‐continent Rift and Hudson Strait, we observe a relatively thinner lithosphere and more fertile composition, indicating that these regions have undergone lithospheric modification and erosion. Our model supports the hypothesis that the core of the Superior craton is well‐preserved and has evaded lithospheric destruction and refertilization. We propose three factors playing a critical role in the craton's stability: (a) the presence of a mid‐lithospheric discontinuity, (b) the correct isopycnic conditions to sustain a strength contrast between the craton and the surrounding mantle, and (c) the presence of weaker mobile belts around the craton. |
format |
Article in Journal/Newspaper |
author |
Riddhi Dave Fiona Darbyshire Juan Carlos Afonso I. Fomin |
author_facet |
Riddhi Dave Fiona Darbyshire Juan Carlos Afonso I. Fomin |
author_sort |
Riddhi Dave |
title |
Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
title_short |
Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
title_full |
Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
title_fullStr |
Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
title_full_unstemmed |
Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere |
title_sort |
thermochemical structure of the superior craton and environs: implications for the evolution and preservation of cratonic lithosphere |
publisher |
Wiley |
publishDate |
2024 |
url |
https://doi.org/10.1029/2024GC011454 https://doaj.org/article/03971704169c485cae91e57aecc6fe91 |
genre |
Hudson Strait |
genre_facet |
Hudson Strait |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 25, Iss 6, Pp n/a-n/a (2024) |
op_relation |
https://doi.org/10.1029/2024GC011454 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2024GC011454 https://doaj.org/article/03971704169c485cae91e57aecc6fe91 |
op_doi |
https://doi.org/10.1029/2024GC011454 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
25 |
container_issue |
6 |
_version_ |
1810448707428024320 |