2023-06-16 ジョージア工科大学
◆Naifは、この発見の解釈について他の研究者と議論し、それを裏付ける証拠を集めるための調査を行いました。彼の研究チームは、地震反射データと海底掘削結果を組み合わせ、マントルのマグマの挿入を解析しました。彼らは、このマグマチャネルが広範で長期間にわたって存在し、ガラパゴスプルームから供給されたマグマによる火山活動の源となっていることを示唆しています。今後の研究により、他の海底地域でも同様のマグマ活動の発見が期待されます。
＜関連情報＞
- https://research.gatech.edu/scientists-unearth-20-million-years-hot-spot-magmatism-under-cocos-plate
- https://www.science.org/doi/10.1126/sciadv.add3761
遠位プルーム起源の長寿命メルトチャネルに供給されるエピソード型プレート内マグマティズム Episodic intraplate magmatism fed by a long-lived melt channel of distal plume origin
Samer Naif,Nathaniel C. Miller,Donna J. Shillington,Anne Bécel,Daniel Lizarralde,Dan Basset and Sidney R. Hemming
Science Advances Published:9 Jun 2023
DOI:https://doi.org/10.1126/sciadv.add3761
Abstract
In the past decade, marine geophysical observations have led to the discovery of thin channels at the base of oceanic plates with anomalous physical properties that indicate the presence of low-degree partial melts. However, mantle melts are buoyant and should migrate toward the surface. We show abundant observations of widespread intraplate magmatism on the Cocos Plate where a thin partial melt channel was imaged at the lithosphere-asthenosphere boundary. We combine existing geophysical, geochemical, and seafloor drilling results with seismic reflection data and radiometric dating of drill cores to constrain the origin, distribution, and timing of this magmatism. Our synthesis indicates that the sublithospheric channel is a regionally extensive (>100,000 km2) and long-lived feature that originated from the Galápagos Plume more than 20 Ma ago, supplying melt for multiple magmatic events and persisting today. Plume-fed melt channels may be widespread and long-lived sources for intraplate magmatism and mantle metasomatism.
