Sediments at the top of Earth's core

被引:214
作者
Buffett, BA [1 ]
Garnero, EJ
Jeanloz, R
机构
[1] Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V6T 1Z4, Canada
[2] Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA
[3] Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA
关键词
D O I
10.1126/science.290.5495.1338
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Unusual physical properties at the core-mantle boundary have been inferred from seismic and geodetic observations in recent years. We show how both types of observations can be explained by a Layer of silicate sediments, which accumulate at the top of the core as Earth cools. Compaction of the sediments expels most of the Liquid iron but Leaves behind a small amount of core material, which is entrained in mantle convection and may account for the isotopic signatures of core material in some hot spot plumes. Extraction of Light elements from the Liquid core also enhances the vigor of convection in the core and may increase the power available to the geodynamo.
引用
收藏
页码:1338 / 1342
页数:5
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