Two types of adakites revealed by 238U-230Th disequilibrium from Daisen Volcano, southwestern Japan

Tokunaga, Saimi; Nakai, S.; Orihashi, Yuji

doi:10.2343/geochemj.1.0080

Cited by 9 publications

(7 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tokunaga et al . [] propose a relationship between Sr/Y and ( 238 U/ 230 Th) for Daisen dacites, observing that Karasugasen is characterized by higher Sr/Y and ( 238 U/ 230 Th) < 1, while Misen has somewhat lower Sr/Y and ( 238 U/ 230 Th) > 1. This relationship is less clear in our data set, but still consistent with our observations (Figure c).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Sediment‐enriched adakitic magmas from the Daisen volcanic field, Southwest Japan

Feineman

Moriguti

Yokoyama

et al. 2013

Geochem Geophys Geosyst

View full text Add to dashboard Cite

[1] The Quaternary Southwest Japan Arc is a product of subduction of the hot, young Philippine Sea Plate beneath the Eurasian Continental Plate. The magmas erupted from the Southwest Japan Arc belong to a category of magmas commonly referred to as ''adakites'' or ''adakitic magmas''. These magmas show trace element evidence for interaction with garnet at depth, and may be associated with partial melting of subducted altered oceanic crust. Also found throughout the southern Sea of Japan region are alkali basalts with little apparent connection to the subduction zone. We have determined major element, trace element, and Sr, Nd, Pb, and U-Th isotopic compositions for a bimodal suite of lavas erupted at the Daisen volcanic field in the Southwest Japan Arc. These magmas consist of mildly alkaline basalts and a calcalkaline intermediate suite, separated by a $10 wt.% silica gap. The intermediate magmas show trace element and isotopic evidence for interaction with garnet, consistent with partial melting of the hot, young ($20 Ma) Philippine Sea Plate. The Daisen intermediate magmas are distinct from other adakitic magmas in their radiogenic isotopic characteristics, consistent with a significant contribution ($25%) from subducted Nankai Trough sediments. Our data suggest that the basalts erupted at the Daisen volcanic field are not parental to the intermediate magmas, and contain a small contribution of EM1-like mantle common in Sea of Japan alkali basalts but not apparent in the Daisen intermediate magmas.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Tokunaga et al . [] attribute the U‐excess in Misen lavas to interaction of slab melt with fluid‐metasomatized mantle. Although some exchange with the mantle is probably inevitable, the very low MgO content (<3%) in the Misen lavas argues against extensive mantle interaction.…”

Section: Discussionmentioning

confidence: 99%

Sediment‐enriched adakitic magmas from the Daisen volcanic field, Southwest Japan

Feineman

Moriguti

Yokoyama

et al. 2013

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

“…Adakitic dacites so far had been detected only among the Miocene to Pleistocene eruptive products of the Bakening volcanic center in southern Kamchatka [52]. Adakites in the northern segment frequently display high MgO contents consistent with slab Mineral compositions determined by microprobe following methods described in [99]. Mg-number: 100 × Mg/ (Mg + Fe) (at.%).…”

Section: Cenozoic Kamchatka Arcmentioning

confidence: 93%

“…Petrographically, adakites are characterized by abundant amphibole megacrysts, phenocrysts and microphenocrysts (several populations are usually present reflecting multiple stages of crystal fractionation under hydrous crustal conditions) along with clinopyrox-ene (which frequently forms cores of zoned amphibole megacrysts and phenocrysts) and plagioclase [38,76,78,101]. It is important to emphasize that in some primitive (high-Mg) adakites, amphibole crystallizes during early stages of magmatic differentiation and is texturally and compositionally interpreted as a near-liquidus (at temperatures of 975-1050 • C and pressures up to 1.5 GPa) phase [38,52,76,81,99,100]. In some cases, adakites contain abundant crystal clots and cognate inclusions indicative of polybaric crustal fractionation of their parental melts [38,45,52,54,[100][101][102][103].…”

Section: Adakitesmentioning

confidence: 99%

See 1 more Smart Citation

Adakites, High-Nb Basalts and Copper–Gold Deposits in Magmatic Arcs and Collisional Orogens: An Overview

et al. 2022

View full text Add to dashboard Cite

Adakites are Y- and Yb-depleted, SiO2- and Sr-enriched rocks with elevated Sr/Y and La/Yb ratios originally thought to represent partial melts of subducted metabasalt, based on their association with the subduction of young (<25 Ma) and hot oceanic crust. Later, adakites were found in arc segments associated with oblique, slow and flat subduction, arc–transform intersections, collision zones and post-collisional extensional environments. New models of adakite petrogenesis include the melting of thickened and delaminated mafic lower crust, basalt underplating of the continental crust and high-pressure fractionation (amphibole ± garnet) of mantle-derived, hydrous mafic melts. In some cases, adakites are associated with Nb-enriched (10 ppm < Nb < 20 ppm) and high-Nb (Nb > 20 ppm) arc basalts in ancient and modern subduction zones (HNBs). Two types of HNBs are recognized on the basis of their geochemistry. Type I HNBs (Kamchatka, Honduras) share N-MORB-like isotopic and OIB-like trace element characteristics and most probably originate from adakite-contaminated mantle sources. Type II HNBs (Sulu arc, Jamaica) display high-field strength element enrichments in respect to island-arc basalts coupled with enriched, OIB-like isotopic signatures, suggesting derivation from asthenospheric mantle sources in arcs. Adakites and, to a lesser extent, HNBs are associated with Cu–Au porphyry and epithermal deposits in Cenozoic magmatic arcs (Kamchatka, Phlippines, Indonesia, Andean margin) and Paleozoic-Mesozoic (Central Asian and Tethyan) collisional orogens. This association is believed to be not just temporal and structural but also genetic due to the hydrous (common presence of amphibole and biotite), highly oxidized (>ΔFMQ > +2) and S-rich (anhydrite in modern Pinatubo and El Chichon adakite eruptions) nature of adakite magmas. Cretaceous adakites from the Stanovoy Suture Zone in Far East Russia contain Cu–Ag–Au and Cu–Zn–Mo–Ag alloys, native Au and Pt, cupriferous Ag in association witn barite and Ag-chloride. Stanovoy adakites also have systematically higher Au contents in comparison with volcanic arc magmas, suggesting that ore-forming hydrothermal fluids responsible for Cu–Au(Mo–Ag) porphyry and epithermal mineralization in upper crustal environments could have been exsolved from metal-saturated, H2O–S–Cl-rich adakite magmas. The interaction between depleted mantle peridotites and metal-rich adakites appears to be capable of producing (under a certain set of conditions) fertile sources for HNB melts connected with some epithermal Au (Porgera) and porphyry Cu–Au–Mo (Tibet, Iran) mineralized systems in modern and ancient subduction zones.

show abstract

REE Mineralogy and Resources

Hoshino

Sanematsu

Watanabe

2016

Handbook on the Physics and Chemistry of Rare Earths

View full text Add to dashboard Cite

Two types of adakites revealed by 238U-230Th disequilibrium from Daisen Volcano, southwestern Japan

Abstract: Daisen volcano is located on the Quaternary volcanic front in southwestern Japan.

Cited by 9 publications

References 43 publications

Sediment‐enriched adakitic magmas from the Daisen volcanic field, Southwest Japan

Sediment‐enriched adakitic magmas from the Daisen volcanic field, Southwest Japan

Adakites, High-Nb Basalts and Copper–Gold Deposits in Magmatic Arcs and Collisional Orogens: An Overview

REE Mineralogy and Resources

Contact Info

Product

Resources

About