气候变化领域集成服务门户(CCPortal): The Water-Saturated Solidus and Second Critical Endpoint of Peridotite: Implications for Magma Genesis Within the Mantle Wedge

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DOI	10.1029/2020JB019452
	The Water-Saturated Solidus and Second Critical Endpoint of Peridotite: Implications for Magma Genesis Within the Mantle Wedge
	Wang J.; Takahashi E.; Xiong X.; Chen L.; Li L.; Suzuki T.; Walter M.J.
发表日期	2020
ISSN	21699313
卷号	125 期号:8
英文摘要	The “wet” silicate solidus of mantle peridotite defines the initial melting temperature of Earth's mantle under water-saturated conditions and the second critical endpoint (SCEP) marks the high P-T end of the wet solidus. However, the location of the wet solidus has remained an outstanding issue for over 50 years and the position of the SCEP is hotly debated. Published wet solidi show a difference of 200–600°C at a given pressure while reported SCEPs range from <4 to >6 GPa. Using a large-volume multianvil apparatus, we investigated the water-saturated melting behavior of a fertile peridotite at 3–6 GPa, 950–1200°C, and obtained well-preserved quenched materials. On the basis of textures and compositions of the quenched materials, we bracket the wet solidus to between 950°C and 1000°C at 3 GPa and the SCEP between 3 and 4 GPa. Combining our experimental results with seismologic and petrologic observations, we propose that the lithosphere-asthenosphere boundary in subduction zones should be constrained by the wet solidus and emphasize the role of a deep hydrous partial-melting zone (DHPMZ) on magma genesis within the mantle wedge. We suggest that the DHPMZ is a source of hydrous melts to the primary melting zone in the mantle wedge and that the position of the volcanic front and its magma production rate may largely be controlled by melting and melt segregation processes within the DHPMZ. Our experimental results also suggest that high-magnesian magmas (e.g., boninite, picrite, and komatiite) could be formed at conditions representative of subduction zones. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	magma genesis; peridotite; second critical endpoint; subduction zones; water-saturated solidus
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/187724
作者单位	High Pressure Center, State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, CAS, Guangzhou, China; Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo, Japan; Now at Research Institute of Earthquake and Volcano Geology, Geological Survey of Japan, Tsukuba, Japan; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, United States
推荐引用方式 GB/T 7714	Wang J.,Takahashi E.,Xiong X.,et al. The Water-Saturated Solidus and Second Critical Endpoint of Peridotite: Implications for Magma Genesis Within the Mantle Wedge[J],2020,125(8).
APA	Wang J..,Takahashi E..,Xiong X..,Chen L..,Li L..,...&Walter M.J..(2020).The Water-Saturated Solidus and Second Critical Endpoint of Peridotite: Implications for Magma Genesis Within the Mantle Wedge.Journal of Geophysical Research: Solid Earth,125(8).
MLA	Wang J.,et al."The Water-Saturated Solidus and Second Critical Endpoint of Peridotite: Implications for Magma Genesis Within the Mantle Wedge".Journal of Geophysical Research: Solid Earth 125.8(2020).