The lithospheric thickness control on the compositional variation of continental intraplate basalts: A demonstration using the Cenozoic basalts and clinopyroxene megacrysts from eastern China

Sun, P.; Niu, Yaoling; Guo, P.Y.; Duan, M.; Wang, X.H.; Gong, H.M.; Xiao, Y.Y.

doi:10.1029/2019jb019315

The lithospheric thickness control on the compositional variation of continental intraplate basalts: A demonstration using the Cenozoic basalts and clinopyroxene megacrysts from eastern China

Sun, P.; Niu, Yaoling; Guo, P.Y.; Duan, M.; Wang, X.H.; Gong, H.M.; Xiao, Y.Y.

Authors

P. Sun

Yaoling Niu

P.Y. Guo

M. Duan

X.H. Wang

H.M. Gong

Y.Y. Xiao

Abstract

Studies on intra‐plate ocean island basalts have demonstrated the control of lithosphere thickness on the extent of melting and pressure of melt extraction (i.e., the lid‐effect). However, whether lithosphere thickness also controls the composition of within‐continent basalts remains unclear. Here we test this hypothesis by studying the Cenozoic basalts containing clinopyroxene megacrysts from 10 localities throughout eastern continental China with a north‐south spatial coverage in excess of 2500 km. Indeed, the geochemical parameters (e.g., abundances and ratios of major and trace elements) correlate well with the depth of the lithosphere‐asthenosphere boundary (LAB) calculated using the clinopyroxene barometry, showing significant lithospheric thickness control on basalt compositions. These observations offer further evidence for melt pooling (a melt rich layer) close beneath the LAB as a “stable magma reservoir” for crystallizing compositionally uniform clinopyroxene megacrysts to be carried by subsequent pulses of melt transport and eruption.

Citation

Sun, P., Niu, Y., Guo, P., Duan, M., Wang, X., Gong, H., & Xiao, Y. (2020). The lithospheric thickness control on the compositional variation of continental intraplate basalts: A demonstration using the Cenozoic basalts and clinopyroxene megacrysts from eastern China. Journal of Geophysical Research, 125(3), Article e2019JB019315. https://doi.org/10.1029/2019jb019315

Journal Article Type	Article
Acceptance Date	Mar 2, 2020
Online Publication Date	Mar 13, 2020
Publication Date	Mar 31, 2020
Deposit Date	Mar 3, 2020
Publicly Available Date	Sep 13, 2020
Journal	Journal of Geophysical Research
Print ISSN	0148-0227
Publisher	Wiley
Peer Reviewed	Peer Reviewed
Volume	125
Issue	3
Article Number	e2019JB019315
DOI	https://doi.org/10.1029/2019jb019315

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Copyright Statement
Sun, P., Niu, Yaoling, Guo, P.Y., Duan, M., Wang, X.H., Gong, H.M. & Xiao, Y.Y. (2020). The lithospheric thickness control on the compositional variation of continental intraplate basalts: A demonstration using the Cenozoic basalts and clinopyroxene megacrysts from eastern China. Journal of Geophysical Research 125(3): e2019JB019315. 10.1029/2019JB019315. To view the published open abstract, go to https://doi.org/ and enter the DOI.