TY - JOUR
T1 - Viscosity jump in the lower mantle inferred from melting curves of ferropericlase
AU - Deng, Jie
AU - Lee, Kanani K.M.
N1 - Funding Information:
We thank Z. Du, M. Long, S. Karato and J. Korenaga for helpful discussions; M. Rooks and F. Camino for FIB help at YINQE at Yale University and CFN at Brookhaven National lab, respectively; Z. Jiang for SEM assistance; J. Girard for laser heating assistance; Z. Liu for assistance in the collection of optical spectra of ferropericlase. This work was supported by NSF (EAR-1321956, EAR-1551348). FIB use was supported by YINQE and NSF MRSEC DMR 1119826 and by the Center for Functional Nanomaterials, and National Synchrotron Light Source II at Brookhaven National Laboratory, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science under Contract No. DE-SC0012704. This research was also partially supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 1606856.
Funding Information:
We thank Z. Du, M. Long, S. Karato and J. Korenaga for helpful discussions; M. Rooks and F. Camino for FIB help at YINQE at Yale University and CFN at Brookhaven National lab, respectively; Z. Jiang for SEM assistance; J. Girard for laser heating assistance; Z. Liu for assistance in the collection of optical spectra of ferropericlase. This work was supported by NSF (EAR-1321956, EAR-1551348). FIB use was supported by YINQE and NSF MRSEC DMR 1119826 and by the Center for Functional Nanoma-terials, and National Synchrotron Light Source II at Brookhaven National Laboratory, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science under Contract No. DE-SC0012704. This research was also partially supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 1606856.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Convection provides the mechanism behind plate tectonics, which allows oceanic lithosphere to be subducted into the mantle as "slabs" and new rock to be generated by volcanism. Stagnation of subducting slabs and deflection of rising plumes in Earth's shallow lower mantle have been suggested to result from a viscosity increase at those depths. However, the mechanism for this increase remains elusive. Here, we examine the melting behavior in the MgO-FeO binary system at high pressures using the laser-heated diamond-anvil cell and show that the liquidus and solidus of (Mg x Fe1-x )O ferropericlase (x = ~0.52-0.98), exhibit a local maximum at ~40 GPa, likely caused by the spin transition of iron. We calculate the relative viscosity profiles of ferropericlase using homologous temperature scaling and find that viscosity increases 10-100 times from ~750 km to ~1000-1250 km, with a smaller decrease at deeper depths, pointing to a single mechanism for slab stagnation and plume deflection.
AB - Convection provides the mechanism behind plate tectonics, which allows oceanic lithosphere to be subducted into the mantle as "slabs" and new rock to be generated by volcanism. Stagnation of subducting slabs and deflection of rising plumes in Earth's shallow lower mantle have been suggested to result from a viscosity increase at those depths. However, the mechanism for this increase remains elusive. Here, we examine the melting behavior in the MgO-FeO binary system at high pressures using the laser-heated diamond-anvil cell and show that the liquidus and solidus of (Mg x Fe1-x )O ferropericlase (x = ~0.52-0.98), exhibit a local maximum at ~40 GPa, likely caused by the spin transition of iron. We calculate the relative viscosity profiles of ferropericlase using homologous temperature scaling and find that viscosity increases 10-100 times from ~750 km to ~1000-1250 km, with a smaller decrease at deeper depths, pointing to a single mechanism for slab stagnation and plume deflection.
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U2 - 10.1038/s41467-017-02263-z
DO - 10.1038/s41467-017-02263-z
M3 - Article
C2 - 29222478
AN - SCOPUS:85037605989
SN - 2041-1723
VL - 8
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 1997
ER -