scholarly journals Hydrous and anhydrous melting experiments of an alkali basalt and a transitional tholeiite from the Oginosen volcano, Southwest Japan: The possible influence of melt depolymerization on Ca-Na partitioning between plagioclase and the melt

2012 ◽  
Vol 107 (1) ◽  
pp. 8-32 ◽  
Author(s):  
Ushio HONMA
Keyword(s):  
Alkali Basalt ◽  
Southwest Japan ◽  
Melting Experiments

scholarly journals Abyssal Peridotite as a Component of Forearc Mantle: Inference from a New Mantle Xenolith Suite of Bankawa in the Southwest Japan Arc

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 540 ◽  
Author(s):  
Shoji Arai ◽  
Akihiro Tamura ◽  
Makoto Miura ◽  
Kazuma Seike
Keyword(s):  
Alkali Basalt ◽  
Mantle Peridotite ◽  
Chromian Spinel ◽  
Abyssal Peridotite ◽  
Southwest Japan ◽  
Limited Sampling ◽  
Basalt Dike ◽  
Light Rare Earth Elements ◽  
Arc Magma ◽  
Forearc Mantle

Lithology and petrologic nature of the forearc mantle have been left unclear due to the very limited sampling to date. Here, we present petrological data on a forearc peridotite suite obtained as xenoliths in an alkali basalt dike (7.5 Ma) from the Bankawa area in the Southwest Japan arc for our better understanding of the forearc mantle. The host alkali basalt is of asthenosphere origin, and passed through a slab window with slight chemical modification by the slab-derived component. The Bankawa peridotite suite is comprised of lherzolites, which contain various amounts of secondary phlogopite and were metasomatized to various degrees. The least metasomatized lherzolite exhibits Fo91 of olivine, Cr/(Cr + Al) = 0.3 of chromian spinel, and depletion of middle to light rare-earth elements in clinopyroxene, and is overall similar to an abyssal lherzolite. It had originally formed at the proto-Pacific Ocean and then was trapped at a eastern margin of Eurasian continent by initiation of subduction. The forearc mantle peridotite formed as a residue of proto-arc magma formation is depleted harzburgite as represented by the peridotites obtained from the forearc seafloor, but can be less depleted abyssal peridotite if being devoid of partial melting or reaction with magmas after entrapment.

A new type of orthopyroxenite xenolith from Takashima, Southwest Japan: silica enrichment of the mantle by evolved alkali basalt

2006 ◽  
Vol 152 (3) ◽  
pp. 387-398 ◽  
Author(s):  
Shoji Arai ◽  
Yohei Shimizu ◽  
Tomoaki Morishita ◽  
Yoshito Ishida
Keyword(s):  
Alkali Basalt ◽  
Southwest Japan ◽  
New Type

scholarly journals A reply to the comments on "Garnet-bearing spinel harzburgite xenolith from Arato-yama alkali basalt, southwest Japan by Yamamoto et al.".

2001 ◽  
Vol 30 (4) ◽  
pp. 194-197
Author(s):  
Masatsugu YAMAMOTO ◽  
Shiho ABE ◽  
Hiromi ABE ◽  
Mitsuhiro YASUI ◽  
Tsutomu KISHI
Keyword(s):  
Alkali Basalt ◽  
Southwest Japan

scholarly journals Garnet-bearing spinel harzburgite xenolith from Arato-yama alkali basalt, southwest Japan.

1999 ◽  
Vol 94 (2) ◽  
pp. 46-56 ◽  
Author(s):  
Masatsugu YAMAMOTO ◽  
Shiho ABE ◽  
Hiromi ABE ◽  
Mitsuhiro YASUI ◽  
Tsutomu KISHI
Keyword(s):  
Alkali Basalt ◽  
Southwest Japan

Fluorine in igneous rocks and minerals with emphasis on ultrapotassic mafic and ultramafic magmas and their mantle source regions

1996 ◽  
Vol 60 (399) ◽  
pp. 243-257 ◽  
Author(s):  
A. D. Edgar ◽  
L. A. Pizzolato ◽  
J. Sheen
Keyword(s):  
Partial Melting ◽  
Mantle Source ◽  
Alkali Basalt ◽  
Mantle Xenoliths ◽  
Igneous Rocks ◽  
Positive Correlation ◽  
Source Regions ◽  
Melting Experiments ◽  
Melt Phase

AbstractIn reviewing the distribution of fluorine in igneous rocks it is clear that F abundance is related to alkalinity and to some extent to volatile contents. Two important F-bearing series are recognized: (1) the alkali basalt—ultrapotassic rocks in which F increases with increasing K2O and decreasing SiO2 contents; and (2) the alkali basalt—phonolite—rhyolite series with F showing positive correlation with both total alkalis and SiO2. Detailed studies of series (1) show that F abundance in ultrapotassic magmas (lamproite, kamafugite, lamprophyre) occurs in descending order in the sequence phlogopite>apatite>amphibole>glass. Fluorine contents in the same minerals from fresh and altered mantle xenoliths may be several orders of magnitude less than those in the host kamafugite. For many lamproites, F contents correlate with higher mg# suggesting that F is highest in the more primitive magmas.Experiments at mantle conditions (20 kbar, 900–1400°C) on simplified F-bearing mineral systems containing phlogopite, apatite, K-richterite, and melt show that F is generally a compatible element. Additionally, low F abundance in minerals from mantle xenoliths suggests that F may not be available in mantle source regions and hence is unlikely to partition into the melt phase on partial melting. Melting experiments on the compositions of F-free and F-bearing model phlogopite harzburgite indicate that even small variations in F content produce melts similar in composition to those of lamproite.

Characterization of groundwater based on δ2H, δ18O and Cl− concentration beneath the Osaka Plain, Southwest Japan

2019 ◽  
Vol 53 (4) ◽  
pp. 235-247
Author(s):  
Tsuyoshi Shintani ◽  
Harue Masuda ◽  
Kaori Okazaki ◽  
Emilie Even ◽  
Masahiko Ono ◽  
...  
Keyword(s):  
Southwest Japan
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