| DOI: | 10.1016/j.epsl.2018.05.001
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| Scopus记录号: | 2-s2.0-85048703001
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| 论文题名: | Oblique seafloor spreading across intermediate and superfast spreading centers |
| 作者: | Zhang T.; Gordon R.G.; Wang C.
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| 刊名: | Earth and Planetary Science Letters
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| ISSN: | 0012821X
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| 出版年: | 2018
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| 卷: | 495 | | 起始页码: | 146
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| 结束页码: | 156
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| 语种: | 英语
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| 英文关键词: | fluid-filled cracks
; intermediate seafloor spreading
; mantle plumes
; oblique seafloor spreading
; orthogonal seafloor spreading
; superfast seafloor spreading
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| Scopus关键词: | Thermal plumes
; East Pacific Rise
; Fluid filled crack
; Mantle plume
; Pacific plates
; Plate boundaries
; Seafloor spreading
; Spreading rate
; Tectonic stress
; Tectonics
; Cocos plate
; mantle plume
; Nazca plate
; overpressure
; plate boundary
; plate tectonics
; seafloor spreading
; spreading center
; East Pacific Rise
; Pacific Ocean
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| 英文摘要: | We show that oblique seafloor spreading occurs in several regions where obliquity, α, was not recognized before. These include the slow spreading centers of the Red Sea (α≈20°), intermediate spreading centers of the Cocos–Nazca plate boundary between 91°W and 94°W (α≈9°), and superfast spreading centers of the East Pacific Rise at the Nazca–Pacific plate boundary between 29°S and 32°S (α≈10°) and perhaps between ≈16°S and ≈22°S (α≈4°). Thus, oblique spreading occurs across slow, intermediate, and superfast spreading centers, but not across fast spreading centers. Across intermediate and superfast spreading centers, oblique spreading does not occur in staircase-mode plate geometries, but does occur in oblique-mode plate geometries. Across slow and intermediate spreading centers, obliquity tends to decrease with increasing spreading rate, while across fast and superfast spreading centers it tends to increase with increasing spreading rate. Oblique spreading at intermediate and superfast spreading centers may be related to magma overpressure or to unusual directions of remote tectonic stress or to ongoing plate boundary reorganizations or to some combination of these. Using prior methods, we estimate the ratio of overpressure to remote tectonic stress for several spreading centers. In particular we show along a segment of the Cocos–Pacific plate boundary that magma overpressure is only one-fourth as large as remote tectonic stress, consistent with a prior inference from other observations. The highest obliquity occurs along ridge segments lying 200 km to 1500 km from a mantle plume, but not all ridge segments near plumes spread obliquely. For one set of estimates of plume fluxes, the rate of plume flux delivered to ridges correlates positively and significantly with spreading rate. © 2018 Elsevier B.V. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/109833
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| Appears in Collections: | 影响、适应和脆弱性
气候变化事实与影响
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作者单位: | Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX 77005, United States
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| Recommended Citation: | |
Zhang T.,Gordon R.G.,Wang C.. Oblique seafloor spreading across intermediate and superfast spreading centers[J]. Earth and Planetary Science Letters,2018-01-01,495
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