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This content will become publicly available on November 27, 2026

Title: Elasticity of davemaoite as a primary contributor to lower-mantle heterogeneities
Geophysical detection of subducted mid–ocean ridge basalt (MORB) in the lower mantle is hindered by uncertainties in the elasticity of Fe,Al,Mg,Ti–bearing davemaoite, a key MORB component. Using Brillouin spectroscopy and x-ray diffraction, we determined the elasticity of a Ca0.906(1)Fe2+0.027(1)Fe3+0.042(1)Mg0.033(1)Al0.072(1)Ti0.020(1)Si0.912(1)O3davemaoite up to 113 gigapascals and 2294 K. We found that it exhibited a shear wave velocity 10 to 20% slower than end-member davemaoite, making it the slowest phase among major lower-mantle minerals. Our models show that MORB, containing 20 to 25 volume percent davemaoite, potentially contributes to large low-shear-velocity provinces (LLSVPs), whereas a cumulate layer enriched in davemaoite crystallized from basal magma ocean may comprise ultralow-velocity zones (ULVZs). Davemaoite’s ability to host incompatible and heat-producing elements possibly links LLSVPs and ULVZs to mantle plume initiation and geochemical signatures of ocean island basalts.  more » « less
Award ID(s):
2240506
PAR ID:
10657854
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Publisher / Repository:
AAAS
Date Published:
Journal Name:
Science
Volume:
390
Issue:
6776
ISSN:
0036-8075
Page Range / eLocation ID:
935 to 939
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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