Geochemical systematics of Northeastern Lau basin affected by fertile plume

Title
Geochemical systematics of Northeastern Lau basin affected by fertile plume
Author(s)
우현동; 장윤득; 명보라; 김종욱; 김정훈
KIOST Author(s)
Kim, Jonguk(김종욱)
Alternative Author(s)
김종욱
Publication Year
2015-12-14
Abstract
Lau basin is located in the South Pacific Ocean, forming a triangle shaped oceanic rift basin. It has been made by the collision between the Indian-Australian and Pacific plate, and is producing the specific kind of basalt characterized by intermediate chemistry between the MORB and the IAB. In particular, there is a tear along the northern boundary of the basin, by which the fertile plume can inflow to the mantle wedge beneath the basin. We conducted the petrological study intended to the Back-Arc Basin Basalt in the North Lau basin. There are a total 23 samples from the Fonualei Rift and Spreading Center (FRSC) and 9 samples from the Northeast Lau Spreading Center (NELSC) that were collected. In the spider diagram for trace elements, there is successive change from the Tofua arc through FRSC to NELSC, while the Samoa Island has a different pattern. This tendency presents itself in the diagram for Rare-earth elements as well. The fertility enhances from south to north, having more distinct variations in NELSC compared with FRSC. The degree of melting calculated by fractionation-corrected Na and Fe contents has no significant range in accordance with the assumption that the fertility variations are caused by the melt input, not a degree of melting. Isotope modeling by end-members used in previous studies in this area indicates that NELSC has a 10% more intense influence than FRSC in regards to the fertile plume, itseintermediate chemistry between the MORB and the IAB. In particular, there is a tear along the northern boundary of the basin, by which the fertile plume can inflow to the mantle wedge beneath the basin. We conducted the petrological study intended to the Back-Arc Basin Basalt in the North Lau basin. There are a total 23 samples from the Fonualei Rift and Spreading Center (FRSC) and 9 samples from the Northeast Lau Spreading Center (NELSC) that were collected. In the spider diagram for trace elements, there is successive change from the Tofua arc through FRSC to NELSC, while the Samoa Island has a different pattern. This tendency presents itself in the diagram for Rare-earth elements as well. The fertility enhances from south to north, having more distinct variations in NELSC compared with FRSC. The degree of melting calculated by fractionation-corrected Na and Fe contents has no significant range in accordance with the assumption that the fertility variations are caused by the melt input, not a degree of melting. Isotope modeling by end-members used in previous studies in this area indicates that NELSC has a 10% more intense influence than FRSC in regards to the fertile plume, itse
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/24984
Bibliographic Citation
AGU Fall Meeting, pp.1, 2015
Publisher
American Geophysical Union
Type
Conference
Language
English
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