气候变化领域集成服务门户(CCPortal): The spreading rate dependence of the distribution of axial magma lenses along mid-ocean ridges

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DOI	10.1073/pnas.2214048120
	The spreading rate dependence of the distribution of axial magma lenses along mid-ocean ridges
	Liu, Zhonglan; Buck, W. Roger
发表日期	2023
ISSN	0027-8424
EISSN	1091-6490
卷号	120 期号:1 页码:8
英文摘要	Seismically imaged axial melt lenses (AMLs) are seen almost everywhere along the axis of fast-spreading ridges but at only a few localized segment centers on slow-spreading ridges. Standard models assuming that AMLs form when melt percolating upward pools where freezing produces an impermeable cap do not explain this fundamental observation. To tackle this long-standing problem, we combine a crustal density model and a thermal model with a recent mechanical model for sill formation. The mechanical model predicts that AMLs form below the axial lithosphere but only if the average density of the axial brittle lithosphere is not greater than the magma density. For standard thermal models, crustal density structures inferred from seismic velocity data and normal crustal thicknesses, AMLs are found to be stable along all of a ridge segment for spreading rates greater than about 50 mm/y. To explain slow-spreading observations, we assume that a share of the melt produced by the mantle upwelling all along a segment is focused to the segment center. Some of this melt partially crystallizes, releasing latent heat, before the evolved magma flows along the axis to build the crust away from the segment center. This extra heat, beyond what is supplied by the magma that builds the crust near the segment center, results in the lithosphere thin enough for stable melt lenses at the segment center. Our results are consistent with observations and offer a quantitative explanation of the marked difference in the distribution of AMLs along fast-versus slow-spreading centers.
英文关键词	plate spreading centers; magmatism; tectonics; axial magma lens
学科领域	Multidisciplinary Sciences
语种	英语
WOS研究方向	Science & Technology - Other Topics
WOS记录号	WOS:000932082200003
来源期刊	PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273943
作者单位	Jilin University; Ministry of Natural Resources of the People's Republic of China; Columbia University
推荐引用方式 GB/T 7714	Liu, Zhonglan,Buck, W. Roger. The spreading rate dependence of the distribution of axial magma lenses along mid-ocean ridges[J],2023,120(1):8.
APA	Liu, Zhonglan,&Buck, W. Roger.(2023).The spreading rate dependence of the distribution of axial magma lenses along mid-ocean ridges.PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,120(1),8.
MLA	Liu, Zhonglan,et al."The spreading rate dependence of the distribution of axial magma lenses along mid-ocean ridges".PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 120.1(2023):8.