U-Pb ages and trace element compositions of reddish, colorless, and detrital zircons in the Kumano Acidic Rocks in the Outer Zone of southwest Japan and origin of the host magma.

裕二, 折橋; 英樹, 岩野; 岳史, 平田; 徹, 檀原; 裕尚, 新正

doi:10.5575/geosoc.113.366

Cited by 14 publications

(12 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This dyke surrounds volcanic rock and suggests the development of a caldera in the past [ Kawakami et al , ; Miura , ; Miura and Wada , ]. The ages of these felsic rocks have been estimated as ~14.5 Ma to approximately 13 Ma based mainly on K‐Ar dating [e.g., Kimura et al , ; Sumii and Shinjoe , ], 15.5 ± 0.7 Ma to 16.7 Ma ± 1.4 Ma based on zircon U‐Pb dating [ Orihashi et al , ], and 13.3 ± 0.6 Ma to 15.3 ± 0.5 Ma based on zircon fission track dating [ Iwano et al , ]. The felsic magmatism was episodic.…”

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 99%

“…The felsic magmatism was episodic. It has been suggested that these rocks were formed from melted sediments, from either the Shimanto Belt or the underthrust plate, as a result of the subduction of the PSP's hot Shikoku Basin [ Shimoda and Tatsumi , ; Shimoda et al , ] or slab melt of the PSP itself [ Orihashi et al , ].…”

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 99%

See 1 more Smart Citation

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

et al. 2014

View full text Add to dashboard Cite

We review recent progress in geological and geophysical investigation in SW Japan, Nankai Trough, and Philippine Sea Plate (PSP), and propose a hypothesis for the Miocene tectonics in SW Japan driven by middle Miocene swift migration of the TTT (trench-trench-trench) triple junction. The new hypothesis is based on the new interpretations as follows. Near-trench magmatism in the outer zone of SW Japan is ascribed to a collision of proto-Izu arc in addition to the previous model of an oceanic ridge of the Shikoku Basin and hot PSP subduction. The indentation structures at Capes Ashizuri, Muroto in Shikoku, and Shiono on the Kii Peninsula were previously explained by "kink folding" due to recent E-W compression. We alternatively suppose the collision of the active arc or topographic peaks such as seamounts inferred from geological and experimental observations. The main crustal component in SW Japan is suggested to be of igneous plutonic rocks rather than the previous interpretation of Cretaceous to Tertiary accretionary complexes. This is typically illustrated in the outer zone to the north of Capes Ashizuri, Muroto, and Shiono from geophysical observation of gravity anomalies, velocity and resistivity, together with geological estimations of caldera age and the size of its root pluton. Episodic crustal growth due to intrusion of igneous rock and subduction of the PSP may have stopped after approximately 12 Ma and restarted at approximately 6 Ma. Our emphasis for this gap is a cessation and resurgence of subduction rather than the previous interpretation, i.e., decreasing of subduction rate.

show abstract

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 99%

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 99%

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The zircon U-Pb dating method has been used ubiquitously for igneous rock bodies (e.g., Sano et al, 2002;Schmitt et al, 2002 and2003;Orihashi et al, 2007). Recent geochronological studies show that the zircon U-Pb ages of granite bodies can span several hundred thousand to several million years within a pluton (Coleman et al, 2004;Matzel et al, 2006;Schaltegger et al, 2009;Leuthold et al, 2012), interpreted to indicate that the ages represent the interval duration of a series of small intrusions forming a single pluton.…”

Section: Introductionmentioning

confidence: 99%

Zircon growth in a granitic pluton with specific mechanisms, crystallization temperatures and U–Pb ages: Implication to the ‘spatiotemporal’ formation process of the Toki granite, central Japan

Yuguchi

Iwano²,

Kato

et al. 2016

Journal of Mineralogical and Petrological Sciences

Self Cite

View full text Add to dashboard Cite

Zircons collected from a granitic pluton provide evidence of serial growth events with specific mechanisms, crystallization temperatures and U-Pb ages, revealing details of the sequential formation process from intrusion through emplacement to crystallization/solidification. The events have been identified by: 1) the study of the internal structure of zircon using cathodoluminescence, 2) deriving crystallization temperatures using Ti-inzircon thermometry of the internal structure and 3) U-Pb age dating of the internal structure. The magmatic zircons from the Toki granite, central Japan, show two kinds in their internal structure: a low luminescence core (LLC) and oscillatory zonation (OZ). The LLC was produced by interfacial reaction-controlled growth in the granitic magma with cooling from about 910 to 760°C. The formation of OZ occurred by diffusion-controlled growth in a cooling magma chamber from about 850 to 690°C. The U-Pb ages derived from the LLC ranges from 74.7 ± 4.2 to 70.5 ± 1.3 Ma, indicating the incipient intrusion timing of the magma into the shallow crust. The OZ ages distribute from 72.7 ± 0.6 to 70.4 ± 1.7 Ma, which mean the timing from emplacement to crystallization/solidification of the granite pluton. Thus, the serial processes from intrusion through emplacement to crystallization/solidification occurred within a few million years. The old LLC and OZ ages are recognized in the western margins of the Toki granite, implying that the magma forming the western margins was the first to intrude, emplace and crystallize/solidify. The western margins with initial intrusion may accompany the crustal assimilation in order to create sufficient magma reservoir space, which is consistent with larger SrI and ASI values found in the western margins of the granite.

show abstract

“…It should be noted that there are reports of > 15 Ma zircon ages in the Miocene SWJ Arc, especially in the Kii Peninsula (Figure a; Orihashi et al, ), which suggest the presence of precursory magmatism before the onset of voluminous silicic magmatism throughout the SWJ Arc from ca 14.8 Ma. In order to construct a more detailed model of the Miocene SWJ Arc, it is essential to add the accurate and precise ages of the magmatism in the SVB and the Outer Zone in the future.…”

Section: Discussionmentioning

confidence: 95%

“…U–Pb zircon ages from previous studies are shown. A, Igneous rocks of Shodoshima Island in Northeast Shikoku (Tatsumi et al, ); and B, the Nijo Group in the Osaka area (Shinjoe et al, ) of the Setouchi volcanic rocks; C, Yakushima granite (Anma, ); D, Ashizuri igneous complex (Shinjoe et al, ); E, Ohmine acidic rocks (Shinjoe et al, ); F, Shionomisaki igneous complex (Shinjoe et al, ); G, Kumano acidic rocks (Orihashi et al, ; Shinjoe et al, ); and H, a granitic enclave in a composite dike of Outer Zone acidic rocks in the Yoshino area, Nara Prefecture (Shinjoe et al, ). *1 In the case of A, both the compiled mean K–Ar, fission track and U–Pb zircon ages by Tatsumi et al () and the re‐calculated ages based on the U–Pb zircon data of the previous study are shown.…”

Section: Introductionmentioning

confidence: 99%

Timescale of magma chamber processes revealed by U–Pb ages, trace element contents and morphology of zircons from the Ishizuchi caldera, Southwest Japan Arc

et al. 2017

View full text Add to dashboard Cite

U–Pb geochronology and trace element chemistry of zircons in a microscale analysis were applied to the Ishizuchi caldera in the Outer Zone of Southwest Japan in order to estimate the timescale of the magma process, in particular, the magma differentiation. This caldera is composed mainly of ring fault complexes, major pyroclastic flow deposits, and felsic intrusion including central plutons. Using SHRIMP‐IIe, our new U–Pb zircon ages obtained from the major pyroclastic flow deposits (Tengudake pyroclastic flow deposits), granitic rocks from central plutons (Soushikei granodiorite and Teppoishigawa quartz monzonite), and rhyolite from the outer ring dike (Tenchuseki rhyolite) and the inner ring dike (Bansyodani rhyolite) are 14.80 ±0.11 Ma, 14.56 ±0.10 Ma, 14.53 ±0.12 Ma, 14.55 ±0.11 Ma and 14.21 ±0.19 Ma, respectively. Based on the U–Pb ages, the Hf contents and the REE patterns of the zircons, three stages are recognized in the evolutionary history of the magma chamber beneath the Ishizuchi caldera: (i) climactic Tengudake pyroclastic flow eruption; (ii) Tenchuseki rhyolite intrusion into the outer ring dike and central pluton intrusion; and (iii) Bansyodani rhyolite intrusion in the inner ring dike. These results indicate a magma evolution history of the Ishizuchi caldera system which took at least ca 600 kyr from the climatic caldera‐forming eruption to the post‐caldera intrusions. Our new geochronological data suggest that the Ishizuchi caldera formed as part of the voluminous and episodic magmatism that occurred in the wide zone along the Miocene forearc basin of Southwest Japan during the inception of the young Philippine Sea Plate subduction.

show abstract

U-Pb ages and trace element compositions of reddish, colorless, and detrital zircons in the Kumano Acidic Rocks in the Outer Zone of southwest Japan and origin of the host magma.

Cited by 14 publications

References 50 publications

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

Zircon growth in a granitic pluton with specific mechanisms, crystallization temperatures and U–Pb ages: Implication to the ‘spatiotemporal’ formation process of the Toki granite, central Japan

Timescale of magma chamber processes revealed by U–Pb ages, trace element contents and morphology of zircons from the Ishizuchi caldera, Southwest Japan Arc

Contact Info

Product

Resources

About