DOI: 10.1038/ngeo1925
论文题名: A mantle magma reservoir beneath an incipient mid-ocean ridge in Afar, Ethiopia
作者: Desissa M. ; Johnson N.E. ; Whaler K.A. ; Hautot S. ; Fisseha S. ; Dawes G.J.K.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 10 起始页码: 861
结束页码: 865
语种: 英语
Scopus关键词: buoyancy
; continental breakup
; electrical conductivity
; magma chamber
; magnetotelluric method
; mid-ocean ridge
; rifting
; strain analysis
; upper mantle
; Afar
; Ethiopia
英文摘要: Shallow magma reservoirs exist in the crust beneath volcanoes and mid-ocean ridges, yet there are no reports of extensive magma bodies within the uppermost mantle. Indeed the buoyancy of magma should cause it to intrude into the crust, preventing it from ponding in the mantle below. The Dabbahu magmatic segment in Afar, Ethiopia, marks the late stages of continental rifting. This segment has been active since 2005 and has experienced repeated magma intrusions. Here we use magnetotelluric data to image magma bodies beneath it. We identify a 30-km-wide region of very high electrical conductivity that reaches down to about 35 km depth. We interpret this region as a large volume of magma of at least 500 km 3 that extends well into the mantle and contains about 13% melt fraction. The magma volume is orders of magnitude larger than that intruded during a typical rifting episode, implying that the magma reservoir persists for several tens of thousands of years. This is in marked contrast to the situation beneath mid-ocean ridges, where melt supply is thought to be episodic. Large magma reservoirs within the mantle may therefore be responsible for the localization of strain that accompanies the final stages of continental break-up. © 2013 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106683
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, United Kingdom; Imagir, IUEM, 29280 Plouzané, France; Institute of Geophysics, Space Sciences and Astronomy, Addis Ababa University, Addis Ababa, Ethiopia
Recommended Citation:
Desissa M.,Johnson N.E.,Whaler K.A.,et al. A mantle magma reservoir beneath an incipient mid-ocean ridge in Afar, Ethiopia[J]. Nature Geoscience,2013-01-01,6(10)