TY - JOUR
T1 - Identifying volatile mantle trend with the water–fluorine–cerium systematics of basaltic glass
AU - Shimizu, Kenji
AU - Ito, Motoo
AU - Chang, Qing
AU - Miyazaki, Takashi
AU - Ueki, Kenta
AU - Toyama, Chiaki
AU - Senda, Ryoko
AU - Vaglarov, Bogdan S.
AU - Ishikawa, Tsuyoshi
AU - Kimura, Jun Ichi
N1 - Funding Information:
We thank the curation staff at GANSEKI (Geochemistry and Archives of Ocean Floor Rocks on Networks for Solid Earth Knowledge Integration in JAMSTEC) and the curation staff of IODP (International Ocean Discovery Program) for providing the samples. We also thank T. Ushikubo, H. Iwamori, and T. Hanyu for discussions, and M. Takeda, W. Zhang, and H. Higuchi for analytical support. This study was supported by the JSPS (Japan Society for the Promotion of Science) KAKENHI Grant Nos. JP15H03751 , JP18H01320 , and JP25610160 to K.S., JP26287142 to M.I., JP15H02148 , JP16H01123 , and JP18H04372 to J.I.K. and, in part, by the JSPS Strategic Fund for Strengthening Leading-Edge Research and Development.
PY - 2019/9/20
Y1 - 2019/9/20
N2 - The lithophile elements and isotopic compositions of oceanic basalts suggest they derive from different mantle components. We present new analytical results of un-degassed deep-marine basaltic glasses from various regions, and we find strong linear correlations of R2 ≥ 0.997 between H2O and F as well as H2O and Ce, for which we propose mantle trends. The mantle trends represent global variations of mantle components, ranging from a depleted dry peridotite of mid-ocean ridge basalt (MORB) (DMM, depleted MORB source mantle: H2O = 100 ppm; H2O/Ce = 200; H2O/F = 10) to a hydrous peridotite of Hawaiian ocean island basalt (OIB) of deep mantle origin (FOZO, focal zone: H2O = 750 ppm; H2O/Ce = 200; H2O/F = 18.5). Accordingly, we defined the correlation as a volatile DMM–FOZO trend. Based on our findings, we report novel H2O–F–Ce systematics to discriminate the degree of water depletion in the source mantle and the rehydration of the mantle with recycled surface water through oceanic plate subduction. Using this method, most OIBs are distinguished clearly from the DMM–FOZO trend, and we find that the water in their sources originates from recycled water derived from the hydrated oceanic crust and sediment after various degrees of dehydration (75–95%) in subduction zones.
AB - The lithophile elements and isotopic compositions of oceanic basalts suggest they derive from different mantle components. We present new analytical results of un-degassed deep-marine basaltic glasses from various regions, and we find strong linear correlations of R2 ≥ 0.997 between H2O and F as well as H2O and Ce, for which we propose mantle trends. The mantle trends represent global variations of mantle components, ranging from a depleted dry peridotite of mid-ocean ridge basalt (MORB) (DMM, depleted MORB source mantle: H2O = 100 ppm; H2O/Ce = 200; H2O/F = 10) to a hydrous peridotite of Hawaiian ocean island basalt (OIB) of deep mantle origin (FOZO, focal zone: H2O = 750 ppm; H2O/Ce = 200; H2O/F = 18.5). Accordingly, we defined the correlation as a volatile DMM–FOZO trend. Based on our findings, we report novel H2O–F–Ce systematics to discriminate the degree of water depletion in the source mantle and the rehydration of the mantle with recycled surface water through oceanic plate subduction. Using this method, most OIBs are distinguished clearly from the DMM–FOZO trend, and we find that the water in their sources originates from recycled water derived from the hydrated oceanic crust and sediment after various degrees of dehydration (75–95%) in subduction zones.
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U2 - 10.1016/j.chemgeo.2019.06.014
DO - 10.1016/j.chemgeo.2019.06.014
M3 - Article
AN - SCOPUS:85070321341
VL - 522
SP - 283
EP - 294
JO - Chemical Geology
JF - Chemical Geology
SN - 0009-2541
ER -