start-ver=1.4
cd-journal=joma
no-vol=53
cd-vols=
no-issue=18
article-no=
start-page=e2026GL123823
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260926
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Hydrogen-Bond Symmetrization in Hydrous Aluminous Silica Enhances Deep-Mantle Water Cycle
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=(Al, H)-bearing CaCl2-type SiO2 serves as a key water carrier in Earth's deep-water cycle. Evolution of hydrogen-bond symmetrization in this phase was measured up to 62 GPa and 800 K by synchrotron infrared and Raman spectroscopy, and X-ray diffraction. It undergoes symmetrization at ?30 GPa and 300 K, while elevated temperature to 800 K lowers the onset pressure to ?12 GPa. This implies that the symmetrized phase will form directly near the base of the transition zone in (Al, H)-rich subducted slabs, and deeper in (Al, H)-poor slabs via transformation from stishovite. More importantly, this symmetrization state stiffens the crystal lattice and immobilizes hydrogen within the structure, enhancing water retention and preventing hydrogen loss during subduction to the lower mantle. Our findings suggest that this phase acts as an important deep-water reservoir capable of transporting water to the lower mantle, thereby linking the deep-water cycle from Earth's surface to core-mantle boundary.
en-copyright=
kn-copyright=

en-aut-name=ZhaoChaoshuai
en-aut-sei=Zhao
en-aut-mei=Chaoshuai
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=MaoZhu
en-aut-sei=Mao
en-aut-mei=Zhu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=YuYingxin
en-aut-sei=Yu
en-aut-mei=Yingxin
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=SunNingyu
en-aut-sei=Sun
en-aut-mei=Ningyu
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=FuYunhua
en-aut-sei=Fu
en-aut-mei=Yunhua
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=ZhangJianbo
en-aut-sei=Zhang
en-aut-mei=Jianbo
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=LiermannHanns]Peter
en-aut-sei=Liermann
en-aut-mei=Hanns]Peter
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

en-aut-name=TaoRenbiao
en-aut-sei=Tao
en-aut-mei=Renbiao
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=8
ORCID=

en-aut-name=IshiiTakayuki
en-aut-sei=Ishii
en-aut-mei=Takayuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=9
ORCID=

affil-num=1
en-affil=State Key Laboratory of Precision Geodesy, University of Science and Technology of China
kn-affil=

affil-num=2
en-affil=State Key Laboratory of Precision Geodesy, University of Science and Technology of China
kn-affil=

affil-num=3
en-affil=Department of Earth Sciences, University of Oxford
kn-affil=

affil-num=4
en-affil=State Key Laboratory of Precision Geodesy, University of Science and Technology of China
kn-affil=

affil-num=5
en-affil=SKLab]DeepMinE, MOEKLab]OBCE, School of Earth and Space Sciences, Peking University
kn-affil=

affil-num=6
en-affil=Center for High]Pressure Science and Technology Advance Research
kn-affil=

affil-num=7
en-affil=Deutsches Elektronen]Synchrotron DESY
kn-affil=

affil-num=8
en-affil=Center for High]Pressure Science and Technology Advance Research
kn-affil=

affil-num=9
en-affil=Institute for Planetary Materials, Okayama University
kn-affil=
en-keyword=hydrogen-bond symmetrization
kn-keyword=hydrogen-bond symmetrization
en-keyword=(Al,H)-bearing CaCl2-type SiO2
kn-keyword=(Al,H)-bearing CaCl2-type SiO2
en-keyword=deep-water cycle
kn-keyword=deep-water cycle
en-keyword=high temperature and high pressure
kn-keyword=high temperature and high pressure
END