Two types of gabbroic xenoliths from rhyolite dominated Niijima volcano, northern part of Izu-Bonin arc: petrological and geochemical constraints

Arakawa, Yoji; Endo, Daisuke; Ikehata, Kei; Oshika, Junya; Shinmura, Taro; Mori, Yasushi

doi:10.1515/geo-2017-0001

Cited by 3 publications

(4 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Correlation diagrams of N-MORB normalized trace element ratios for the samples from Izu arc islands and knolls (Arakawa et al, 2017(Arakawa et al, , 2019Fukuda et al, 2008;Ishizuka et al, 2008;Kimura et al, 2010;Kuritani et al, 2018;Nakano et al, 1997;Oiwa et al, 2023;Tamura et al, 2007;Yokoyama et al, 2003, this study). Trace element abundances of N-MORB were taken from Sun and McDonough (1989).…”

Section: Figmentioning

confidence: 53%

“…Niijima (filled : this study / open : Arakawa et al, 2017Arakawa et al, , 2019Fukuda et al, 2008;Kimura et al, 2010;Koyaguchi, 1986) red triangles: Kozushima (filled: this study / open: Isshiki, 1982Taniguchi et al, 1990;Yamashita et al, 2005), light green crosses: Teishi knoll (Fukuda et al, 2008), gray circles: Miyakejima (Freymuth et al, 2016b;Fukuda et al, 2008;Yokoyama et al, 2003), indigo blue circles: Hachijojima and nearby seamount chains (Ishizuka et al, 2008;Nakano et al, 1997;Oiwa et al, 2023), gray squares: Izu-Torishima (Tamura et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Volcanic products on Niijima contain various types of xenoliths, including volcanic xenoliths and enclaves (basaltic to andesitic composition) in rhyolitic pyroclastic flow deposits and lavas (e.g., Arakawa et al, 2019;Isshiki, 1987;Koyaguchi, 1986). At Niijima, plutonic xenoliths (e.g., diorite, tonalite, and gabbro) in basaltic pyroclastic flow deposits and rhyolitic units have been reported (e.g., Arakawa et al, 2017), which are considered to be the cumulates of basaltic and andesitic magmas. In contrast, Koyaguchi (1986) suggested that the basaltic enclaves at Niijima originated from a basaltic magma that was active contemporaneously with the host rhyolite.…”

Section: Xenoliths In Felsic Lavas From the N-izu Arcmentioning

confidence: 99%

“…Correlation diagram of major element abundance (as oxide) of the Niijima and Kozushima basaltic samples (SiO2 < 53%). Literature data are from Arakawa et al, (2017), Fukuda et al (2008, Isshiki (1982Isshiki ( , 1987, Kimura et al (2010), Koyaguchi, (1986, Taniguchi et al (1990), andYamashita et al (2005). values in Izu sediments are from Freymuth et al (2015).…”

Section: Figmentioning

confidence: 99%

See 3 more Smart Citations

Molybdenum isotopic compositions in volcanic rocks from Northern Izu arc (Izu-Oshima, Niijima, and Kozushima)

Tamura,

Yokoyama,

Kuritani

et al. 2024

Geochem. J.

View full text Add to dashboard Cite

Variations in Mo isotopic ratios (δ 98/95 Mo values) in volcanic arc lavas reflect various processes occurring beneath island arcs, including slab dehydration, mantle melting, and crystal fractionation, making this tracer important in recent geochemistry. Previous studies of Mo isotopes have focused primarily on samples from the volcanic front (VF) of oceanic island arcs, and only a limited number of studies have been conducted on volcanoes in the rear arc (RA) regions. To better understand the behavior of Mo isotopes in subduction zones, we focused on the Northern Izu (N-Izu) arc and determined major and trace element abundances and δ 98/95 Mo values in basaltic samples from one VF (Izu-Oshima) and two RA (Niijima and Kozushima) islands. The N-Izu basalts are characterized by relatively uniform Zr/Hf ratios with systematic decrease in Ba/Th and increase in Ce/Mo ratios with increasing depth of the Wadati-Benioff zone, indicating a gradual decrease in the contribution of aqueous fluids from the subducting slab to a chemically homogeneous mantle wedge.Similarly, the δ 98/95 Mo values in the N-Izu basalts decrease with increasing slab depth from Izu Oshima (+0.11 ± 0.09‰) to Niijima (-0.14 ± 0.05‰) and Kozushima (-0.20 ± 0.21‰). The most straightforward interpretation for the elevated δ 98/95 Mo values in the N-Izu VF basalts is the contribution of slab-derived aqueous fluid enriched in heavy Mo isotopes to the source mantle of the VF volcanoes, due to the presence of residual minerals in the slab in which light Mo isotopes are preferentially distributed. In contrast, the low δ 98/95 Mo values in the RA basalts, which are as low as the mean MORB value (-0.18‰), suggest that the slab-derived fluid in the RA region is depleted in heavy Mo isotopes as a result of the continuous loss of heavy Mo isotopes via slab dehydration in the VF region, while other possibilities, including the incorporation of slab melts containing sedimentary components, cannot be ruled out.

show abstract

Section: Figmentioning

confidence: 53%

Section: Discussionmentioning

confidence: 99%

Section: Xenoliths In Felsic Lavas From the N-izu Arcmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

See 2 more Smart Citations

Molybdenum isotopic compositions in volcanic rocks from Northern Izu arc (Izu-Oshima, Niijima, and Kozushima)

Tamura,

Yokoyama,

Kuritani

et al. 2024

Geochem. J.

View full text Add to dashboard Cite

show abstract

High-silica rhyolites of Niijima volcano in the northern Izu–Bonin arc, Japan: Petrological and geochemical constraints on magma generation and supply

Arakawa

Endo

Oshika

et al. 2019

Lithos

View full text Add to dashboard Cite

Chemical Differentiation by Mineralogical Buffering in Crustal Hot Zones

Blundy

2022

Journal of Petrology

View full text Add to dashboard Cite

Chemical diversity in convergent margin magmas is a product of igneous differentiation in crustal hot zones, vertically-extensive regions characterized by a low-volume (<20%) mobile melt phase dispersed in a crystal-rich mush. Chemical reaction between buoyant, percolating melts and the surrounding mush leads to chemical buffering by the local mineral assemblage. Where this assemblage has low thermodynamic variance (e.g. six mineral phases plus melt and H2O-CO2 fluid) the resultant multiply-saturated melts will show limited chemical variability. Plutonic xenoliths from many volcanic arcs, as well as exhumed arc crustal sections, testify to the ubiquity of low-variance, broadly gabbroic, mineral assemblages. Here I use the concept of multiple saturation to explore the chemical consequences of percolative reactive melt flow in crustal hot zones using data from published experimental studies on a wide variety of different starting materials. I show that the common, low-variance hornblende gabbronorite assemblage clinopyroxene-hornblende-orthopyroxene-magnetite-plagioclase-ilmenite (CHOMPI) coexists with fluid-saturated melt over a wide range of pressure (1 to 10 kb) temperature (800 to 1050 °C) and fluid composition (molar fraction H2O, XH2O, of 1.0 to 0.3). The CHOMPI stability field is bounded by: the appearance of garnet at high pressure, the hydrous haplogranite granite liquidus at low temperature, and amphibole breakdown at high temperature and low pressure. CHOMPI melts cover a wide compositional range (54 to 74 wt% SiO2; 4.4 to 0.1 wt% MgO) that can be parameterized in terms of five independent variables: pressure, temperature, fO2, molar CO2/H2O in the fluid and melt K2O content. The compositional diversity and broad stability field of CHOMPI-saturated melts makes them extremely common in the rock record. Parameterization of melt composition can be inverted to recover pressure (±1.3 kb), temperature (±16 °C) and fluid molar CO2/H2O (±0.43) of CHOMPI-saturated melts. If a natural magma composition can be shown to lie on or close to the CHOMPI saturation surface then the conditions under which a given melt was last in equilibrium with this hot zone mineral assemblage can be established. I apply this method of magma source thermobarometry and hygrometry to the most recent eruptions from fifteen Cascades arc volcanic centres. Calculated pressures range from 1.3 to 5.8 kb (5-21 km depth) with significant along-arc variation. Temperatures correlate with pressure, and match independent estimates of eruption temperatures from mineral thermometry with the exception of two eruptions where significant (≤100 °C) cooling occurred during pre-eruptive magma storage. Fluid XH2O is in the range 0.47 to 0.92, and inversely correlates with pressure. Mineralogical buffering of melt chemistry in hot zones is proposed as an important mechanism of chemical differentiation in volcanic arcs. Mineralogical buffering can operate at the low melt fractions observed in geophysical surveys of arc crust, providing an alternative to traditional concepts of assimilation-fractional crystallization and liquid lines of descent that operate most effectively in melt-rich systems.

show abstract

Two types of gabbroic xenoliths from rhyolite dominated Niijima volcano, northern part of Izu-Bonin arc: petrological and geochemical constraints

Cited by 3 publications

References 25 publications

Molybdenum isotopic compositions in volcanic rocks from Northern Izu arc (Izu-Oshima, Niijima, and Kozushima)

Molybdenum isotopic compositions in volcanic rocks from Northern Izu arc (Izu-Oshima, Niijima, and Kozushima)

High-silica rhyolites of Niijima volcano in the northern Izu–Bonin arc, Japan: Petrological and geochemical constraints on magma generation and supply

Chemical Differentiation by Mineralogical Buffering in Crustal Hot Zones

Contact Info

Product

Resources

About