کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6429146 1634753 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Interconnection of ferro-periclase controls subducted slab morphology at the top of the lower mantle
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Interconnection of ferro-periclase controls subducted slab morphology at the top of the lower mantle
چکیده انگلیسی


- An interconnectivity of ferro-periclase in post-spinel rock were examined.
- The interconnection can be maintained in subducted slab for geological time scale.
- The viscosity reduction of the slab due to the interconnection is expected.

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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 403, 1 October 2014, Pages 352-357
نویسندگان
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