Basaltic reservoirs in the Earth’s mantle transition zone
Journal Publication ResearchOnline@JCUAbstract
The formation and preservation of compositional heterogeneities inside the Earth affect mantle convection patterns globally and control the long-term evolution of geochemical reservoirs. However, the distribution, nature, and size of reservoirs in the Earth’s mantle are poorly constrained. Here, we invert measurements of travel times and amplitudes of seismic waves interacting with mineralogical phase transitions at 400–700-km depth to obtain global probabilistic maps of temperature and bulk composition. We find large basalt-rich pools (up to 60% basalt fraction) surrounding the Pacific Ocean, which we relate to the segregation of oceanic crust from slabs that have been subducted since the Mesozoic. Segregation of oceanic crust from initially cold and stiff slabs may be facilitated by the presence of a weak hydrated layer in the slab or by weakening upon mineralogical transition due to grain-size reduction.
Journal
Proceedings of the National Academy of Sciences of the United States of America
Publication Name
Proceedings of the National Academy of Sciences of the United States of America
Volume
119
ISBN/ISSN
1091-6490
Edition
N/A
Issue
48
Pages Count
7
Location
N/A
Publisher
National Academy of Sciences
Publisher Url
N/A
Publisher Location
N/A
Publish Date
N/A
Url
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Date
N/A
EISSN
N/A
DOI
10.1073/pnas.2209399119