Abstract
The electrical conductivity of mantle rocks during phase transformation from ringwoodite to silicate perovskite and ferro-periclase was measured at 25 GPa and various temperatures ranging from 1300 to 1900 K. The electrical conductivity was high at the initial stage of annealing, suggesting that ferro-periclase forms interconnected layers in aggregates of silicate perovskite and ferro-periclase that are representative of lower mantle rock. At 1900 K the electrical conductivity quickly decreased and reached that of silicate perovskite, suggesting the cut-off of the interconnected ferro-periclase because of rounding of crystals. Below 1700 K, the high conductivity values were maintained for experimental duration. The interconnection of ferro-periclase, which has a lower viscosity than silicate perovskite, can be maintained in a cold descending slab over geological time scales (~1 My), indicating that a colder slab is less viscous than the warmer mantle surrounding it. The low-viscosity slab can be prevented from penetrating into the deeper part of the lower mantle by the high viscosities encountered at a depth of ~1000 km, referred to as the "viscosity hill", that cause stagnation at this depth as observed by seismic tomography.
| Original language | English |
|---|---|
| Pages (from-to) | 352-357 |
| Number of pages | 6 |
| Journal | Earth and Planetary Science Letters |
| Volume | 403 |
| DOIs | |
| Publication status | Published - Oct 1 2014 |
Fingerprint
Keywords
- Connectivity
- Ferro-periclase
- Subducting slab
- Viscosity
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
Cite this
Interconnection of ferro-periclase controls subducted slab morphology at the top of the lower mantle. / Yamazaki, Daisuke; Yoshino, Takashi; Nakakuki, Tomoeki.
In: Earth and Planetary Science Letters, Vol. 403, 01.10.2014, p. 352-357.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Interconnection of ferro-periclase controls subducted slab morphology at the top of the lower mantle
AU - Yamazaki, Daisuke
AU - Yoshino, Takashi
AU - Nakakuki, Tomoeki
PY - 2014/10/1
Y1 - 2014/10/1
N2 - The electrical conductivity of mantle rocks during phase transformation from ringwoodite to silicate perovskite and ferro-periclase was measured at 25 GPa and various temperatures ranging from 1300 to 1900 K. The electrical conductivity was high at the initial stage of annealing, suggesting that ferro-periclase forms interconnected layers in aggregates of silicate perovskite and ferro-periclase that are representative of lower mantle rock. At 1900 K the electrical conductivity quickly decreased and reached that of silicate perovskite, suggesting the cut-off of the interconnected ferro-periclase because of rounding of crystals. Below 1700 K, the high conductivity values were maintained for experimental duration. The interconnection of ferro-periclase, which has a lower viscosity than silicate perovskite, can be maintained in a cold descending slab over geological time scales (~1 My), indicating that a colder slab is less viscous than the warmer mantle surrounding it. The low-viscosity slab can be prevented from penetrating into the deeper part of the lower mantle by the high viscosities encountered at a depth of ~1000 km, referred to as the "viscosity hill", that cause stagnation at this depth as observed by seismic tomography.
AB - The electrical conductivity of mantle rocks during phase transformation from ringwoodite to silicate perovskite and ferro-periclase was measured at 25 GPa and various temperatures ranging from 1300 to 1900 K. The electrical conductivity was high at the initial stage of annealing, suggesting that ferro-periclase forms interconnected layers in aggregates of silicate perovskite and ferro-periclase that are representative of lower mantle rock. At 1900 K the electrical conductivity quickly decreased and reached that of silicate perovskite, suggesting the cut-off of the interconnected ferro-periclase because of rounding of crystals. Below 1700 K, the high conductivity values were maintained for experimental duration. The interconnection of ferro-periclase, which has a lower viscosity than silicate perovskite, can be maintained in a cold descending slab over geological time scales (~1 My), indicating that a colder slab is less viscous than the warmer mantle surrounding it. The low-viscosity slab can be prevented from penetrating into the deeper part of the lower mantle by the high viscosities encountered at a depth of ~1000 km, referred to as the "viscosity hill", that cause stagnation at this depth as observed by seismic tomography.
KW - Connectivity
KW - Ferro-periclase
KW - Subducting slab
KW - Viscosity
UR - http://www.scopus.com/inward/record.url?scp=84905248662&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84905248662&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2014.07.017
DO - 10.1016/j.epsl.2014.07.017
M3 - Article
AN - SCOPUS:84905248662
VL - 403
SP - 352
EP - 357
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
ER -