2013 Fiscal Year Final Research Report
Genesis of arc magmas: how many primary magmas exist in an arc volcano?
| Project/Area Number |
23340166
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Petrology/Mineralogy/Science of ore deposit
|
|---|
| Research Institution | Japan Agency for Marine-Earth Science and Technology |
|---|
Principal Investigator |
TAMURA Yoshihiko 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, チームリーダー (40293336)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ISHIZUKA Osamu 独立行政法人産業技術総合研究所, 地質情報研究部門, 主任研究員 (90356444)
NICHOLS Alexander 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, 研究員 (00470120)
KIMURA Jun-ichi 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, チームリーダー (30241730)
|
|---|
| Project Period (FY) |
2011-04-01 – 2014-03-31
|
| Keywords | primary magma / arc volcano / subduction zone / basalt / mantle wedge / carbonatite / sediment melt / immiscible |
|---|
| Research Abstract |
We recovered and studied primitive basalt lavas from Pagan Volcano, Mariana Oceanic arc, and our findings have been attributed to each of the three parts of the subduction factory, which we describe as Mission Immiscible, Mission Invisible and Mission Inevitable, respectively. Mission Immiscible involves the subduction components, derived from the subducting slab below the volcanic front at the depth of 100 km, which consist of hydrous carbonate melt (carbonatite) and silicate melt (sediment melt). Mission Invisible involves the highly depleted residual mantle wedge of the subduction zone, composed of phlogopite-bearing dunite and harzburgite, which depletes Nb, Ta, Zr and Hf, and fractionates Nb from Ta, and Zr from Hf in arc magmas. Mission Inevitable describes the assimilation of arc magmas when they evolve; inevitable even in an oceanic arc.
|
