In:
Solid Earth, Copernicus GmbH, Vol. 11, No. 1 ( 2020-01-07), p. 23-36
Abstract:
Abstract. We present geochemical and 40Ar∕39Ar age data
for a peridotite xenolith-bearing basalt dredged from the Seifu Seamount (SSM
basalt) in the northeast Tsushima Basin, southwest Sea of Japan. An
40Ar∕39Ar plateau age of 8.33±0.15 Ma (2σ) was
obtained for the SSM basalt, indicating that it erupted shortly after the
termination of back-arc spreading in the Sea of Japan. The SSM basalt is a
high-K to shoshonitic alkali basalt that is characterized by light rare
earth element enrichment. The trace element features of the basalt are
similar to those of ocean island basalt, although the Yb content is much
higher, indicating formation by the low-degree partial melting of spinel
peridotite. The Nd, Sr, and Pb isotopic compositions of the SSM basalt
differ from those of back-arc basin basalts in the Sea of Japan. The Sr–Nd
isotopic composition of the SSM basalt suggests its source was depleted
mid-ocean ridge mantle containing an enriched mantle (EM1) component. The SSM basalt was
formed in a post-back-arc extension setting by the low-degree partial melting of
an upwelling asthenosphere that had previously been associated with the main
phase of back-arc magmatism.
Type of Medium:
Online Resource
ISSN:
1869-9529
DOI:
10.5194/se-11-23-2020
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2020
detail.hit.zdb_id:
2545676-3
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