TY - JOUR
T1 - Intraplate continental basalts over the past billion years track cooling of the mantle and the onset of modern plate tectonics
AU - Chen, Qian
AU - Liu, He
AU - Johnson, Tim
AU - Hartnady, Michael
AU - Kirkland, Christopher L.
AU - Lu, Yongjun
AU - Sun, Wei dong
N1 - Funding Information:
This study was supported by the National Natural Science Foundation of China (42073011). T.J. acknowledges support from Open fund GPMR201903 from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan. Y.L. publishes with the permission of the Executive Director, Geological Survey of Western Australia.
Funding Information:
This study was supported by the National Natural Science Foundation of China ( 42073011 ). T.J. acknowledges support from Open fund GPMR201903 from the State Key Laboratory of Geological Processes and Mineral Resources , China University of Geosciences, Wuhan . Y.L. publishes with the permission of the Executive Director, Geological Survey of Western Australia.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/11/1
Y1 - 2022/11/1
N2 - The temperature of the convecting mantle exerts a first-order control on the rheology, composition, and consequently, tectonic behavior of Earth's lithosphere. Although the mantle has likely been cooling since the Archaean eon, how mantle temperature has evolved thereafter is poorly understood. Here, we apply a statistical analysis to secular changes in the alkali index [AI = whole-rock (Na2O + K2O)2/(SiO2 − 35) as weight%] of global sodic intracontinental basalts, a proxy for the degree of mantle melting, to constrain the evolution of mantle potential temperature (TP) over the past billion years. Our results show that, during the early Neoproterozoic, TP remained relatively constant until the beginning of the Cryogenian (720 Ma), when mantle temperature dropped rapidly over the following ∼180 Ma. This remarkable episode of cooling records the onset of modern-style plate tectonics characterized by continuous deep subduction of the oceanic lithosphere, consistent with the widespread appearance of blueschists in the metamorphic rock record.
AB - The temperature of the convecting mantle exerts a first-order control on the rheology, composition, and consequently, tectonic behavior of Earth's lithosphere. Although the mantle has likely been cooling since the Archaean eon, how mantle temperature has evolved thereafter is poorly understood. Here, we apply a statistical analysis to secular changes in the alkali index [AI = whole-rock (Na2O + K2O)2/(SiO2 − 35) as weight%] of global sodic intracontinental basalts, a proxy for the degree of mantle melting, to constrain the evolution of mantle potential temperature (TP) over the past billion years. Our results show that, during the early Neoproterozoic, TP remained relatively constant until the beginning of the Cryogenian (720 Ma), when mantle temperature dropped rapidly over the following ∼180 Ma. This remarkable episode of cooling records the onset of modern-style plate tectonics characterized by continuous deep subduction of the oceanic lithosphere, consistent with the widespread appearance of blueschists in the metamorphic rock record.
KW - intracontinental basalts
KW - mantle cooling
KW - modern plate tectonics
KW - snowball Earth
UR - http://www.scopus.com/inward/record.url?scp=85138450805&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2022.117804
DO - 10.1016/j.epsl.2022.117804
M3 - Article
AN - SCOPUS:85138450805
SN - 0012-821X
VL - 597
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
M1 - 117804
ER -