气候变化领域集成服务门户(CCPortal): Stacked Magma Lenses Beneath Mid-Ocean Ridges: Insights From New Seismic Observations and Synthesis With Prior Geophysical and Geologic Findings

CCPortal

DOI	10.1029/2020JB021434
	Stacked Magma Lenses Beneath Mid-Ocean Ridges: Insights From New Seismic Observations and Synthesis With Prior Geophysical and Geologic Findings
	Carbotte S.M.; Marjanović M.; Arnulf A.F.; Nedimović M.R.; Canales J.P.; Arnoux G.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	Recent multi-channel seismic studies of fast spreading and hot-spot influenced mid-ocean ridges reveal magma bodies located beneath the mid-crustal Axial Magma Lens (AML), embedded within the underlying crustal mush zone. We here present new seismic images from the Juan de Fuca Ridge that show reflections interpreted to be from vertically stacked magma lenses in a number of locations beneath this intermediate-spreading ridge. The brightest reflections are beneath Northern Symmetric segment, from ∼46°42′-52′N and Split Seamount, where a small magma body at local Moho depths is also detected, inferred to be a source reservoir for the stacked magma lenses in the crust above. The imaged magma bodies are sub-horizontal, extend continuously for along-axis lengths of ∼1–8 km, with the shallowest located at depths of ∼100–1,200 m below the AML, and are similar to sub-AML bodies found at the East Pacific Rise. At both ridges, stacked sill-like lenses are detected beneath only a small fraction of the ridge length examined and are inferred to mark local sites of higher melt flux and active replenishment from depth. The imaged magma lenses are focused in the upper part of the lower crust, which coincides with the most melt rich part of the crystal mush zone detected in other geophysical studies and where sub-vertical fabrics are observed in geologic exposures of oceanic crust. We infer that the multi-level magma accumulations are ephemeral and may result from porous flow and mush compaction, and that they can be tapped and drained during dike intrusion and eruption events. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Juan de Fuca Ridge; magmatic system; mid-ocean ridge; mush; seismic imaging; stacked magma sills
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187200
作者单位	Department of Marine Geology and Geophysics, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France; Jackson School, Institute for Geophysics, University of Texas at Austin, Austin, TX, United States; Department of Earth and Environmental Sciences, Dalhousie University, Halifax, NS, Canada; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Department of Earth Sciences, University of Oregon, Eugene, OR, United States
推荐引用方式 GB/T 7714	Carbotte S.M.,Marjanović M.,Arnulf A.F.,et al. Stacked Magma Lenses Beneath Mid-Ocean Ridges: Insights From New Seismic Observations and Synthesis With Prior Geophysical and Geologic Findings[J],2021,126(4).
APA	Carbotte S.M.,Marjanović M.,Arnulf A.F.,Nedimović M.R.,Canales J.P.,&Arnoux G.M..(2021).Stacked Magma Lenses Beneath Mid-Ocean Ridges: Insights From New Seismic Observations and Synthesis With Prior Geophysical and Geologic Findings.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Carbotte S.M.,et al."Stacked Magma Lenses Beneath Mid-Ocean Ridges: Insights From New Seismic Observations and Synthesis With Prior Geophysical and Geologic Findings".Journal of Geophysical Research: Solid Earth 126.4(2021).