New fossil discovery from the Hida metamorphic rocks in the Unazuki area, central Japan.

Hiroi, Yoshikuni; Fuji, Norio; Okimura, Yuji

doi:10.2183/pjab.54.268

Cited by 26 publications

(7 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the formation age of the supracrustal rocks in the two areas appears to be different. The Unazuki schists are believed to be Paleozoic in sedimentation age based upon late Carboniferous fossil discovered in the bedded limestone (Hiroi et al 1978), while recent radiometric dating results (Lee et al 1998; Park & Cheong 1998) suggest that the Okcheon belt formed from late Precambrian to Paleozoic. Also different are Nd model ages of the basement rocks from the two belts.…”

Section: Discussionmentioning

confidence: 99%

Geochemical and Sr–Nd–Pb isotopic investigation of Triassic granitoids and basement rocks in the northern Gyeongsang Basin, Korea: Implications for the young basement in the East Asian continental margin

2002

View full text Add to dashboard Cite

We present chemical and Sr–Nd–Pb isotopic compositions of three Triassic (226–241 Ma) calc‐alkaline granitoids (the Yeongdeok granite, Yeonghae diorite and Cheongsong granodiorite) and basement rocks in the northern Gyeongsang basin, south‐eastern Korea. These plutons exhibit typical geochemical characteristics of I‐type granitoids generated in a continental magmatic arc. The Yeongdeok and Yeonghae plutons have similar initial Sr, Nd and Pb isotope ratios (87Sr/86Srinitial = 0.7041 ~ 0.7050, ɛNd(t) = 2.3 ~ 4.0, 206Pb/204Pbfeldspar = 18.22 ~ 18.34), but distinct rare earth element patterns, suggesting that the two plutons formed from partial melting of a similar source material at different depths. The Cheongsong pluton has slightly more enriched Sr–Nd–Pb isotopic compositions (87Sr/86Srinitial = 0.7047 ~ 0.7065, ɛNd(t) = 3.9 ~ 2.8, 206Pb/204Pbfeldspar = 18.24 ~ 18.37) than the other two plutons. The Nd model ages of the basement rocks (1.1 ~ 1.4 Ga) are slightly older than those of the plutons (0.6 ~ 1.0 Ga). The initial Sr and Nd isotopic ratios of the plutons can be modeled by the mixing between the mid‐oceanic ridge basalt‐like depleted mantle component and the crustal component represented by basement rocks, which is also supported by Pb isotope data. The Sr and Nd isotope data from granitoids and basement rocks suggest that the Gyeongsang basin, the Hida belt and the inner zone of south‐western Japan share relatively young basement histories (middle Proterozoic), compared with those (early Proterozoic to Archean) of the Gyeonggi and Yeongnam massifs and the Okcheon belt. The Nd isotope data of basement rocks suggest that the Hida belt might be better correlated with the basement of the Gyeongsang basin than the Gyeonggi massif, the Okcheon belt or the Yeongnam massif, although it may represent an older continental margin of East Asia than the Gyeongsang basin considering its slightly older Nd model ages.

show abstract

Section: Discussionmentioning

confidence: 99%

Geochemical and Sr–Nd–Pb isotopic investigation of Triassic granitoids and basement rocks in the northern Gyeongsang Basin, Korea: Implications for the young basement in the East Asian continental margin

2002

View full text Add to dashboard Cite

show abstract

“…The Hida gneiss complex has been subdivided into 'inner' lower temperature and 'outer' higher temperature regions, based on the mineralogy of pelitic gneiss (M. Suzuki, Nakazawa, & Osakabe, 1989). (Hiroi, Fuji, & Okumura, 1978). However, crystallization ages of around 1.9 Ga (Cho, Takahashi, Yi, & Lee, 2012) suggest a much older origin for some of the Oki gneiss.…”

Section: Hida-oki Terrane (Ho)mentioning

confidence: 99%

“…Zircon U–Pb geochronology in metamorphic and igneous rocks indicates the main phase of Hida–Oki metamorphism and magmatism took place at around 250 Ma close to the Permo‐Triassic boundary. Fossils of bryozoa and foraminifera give a sedimentary age of late Carboniferous for limestone of the Unazuki schist (Hiroi, Fuji, & Okumura, ). However, crystallization ages of around 1.9 Ga (Cho, Takahashi, Yi, & Lee, ) suggest a much older origin for some of the Oki gneiss.…”

Section: Geological Terranesmentioning

confidence: 99%

The basement geology of Japan from A to Z

et al. 2020

View full text Add to dashboard Cite

The Precambrian and lower Paleozoic units of the Japanese basement such as the Hida Oki and South Kitakami terranes have geological affinities with the eastern Asia continent and particularly strong correlation with units of the South China block. There are also indications from units such as the Hitachi metamorphics of the Abukuma terrane and blocks in the Maizuru terrane that some material may have been derived from the North China block. In addition to magmatism, the Japanese region has seen substantial growth due to tectonic accretion. The accreted units dominantly consist of mudstone and sandstone derived from the continental margin with lesser amounts of basaltic rocks associated with siliceous deep ocean sediments and local limestone. Two main phases of accretionary activity and related metamorphism are recorded in the Jurassic Mino-Tanba-Ashio, Chichibu, and North Kitakami terranes and in the Cretaceous to Neogene Shimanto and Sanbagawa terranes. Other accreted material includes ophiolitic sequences, e.g. the Yakuno ophiolite of the Maizuru terrane, the Oeyama ophiolite of the Sangun terrane, and the Hayachine-Miyamori ophiolite of the South Kitakami terrane, and limestone-capped ocean plateaus such as the Akiyoshi terrane. The ophiolitic units are likely derived from arc and back-arc basin settings. There has been no continental collision in Japan, meaning the oceanic subduction record is more complete than in convergent orogens seen in intracontinental settings making this a good place to study the geological record of accretion. Hokkaido lacks most of the Paleozoic history recognized in Honshu, Shikoku, Kyushu, and the Ryukyu Islands to the south and its geology reflects the Cenozoic development of two convergent domains with volcanic arcs, their approach, and eventual collision. The Hidaka terrane reveals a cross section through a volcanic arc and the main accretionary complex of the convergent system is represented by the Sorachi-Yezo terrane.

show abstract

“…1, 2 , which differ from those of the other Plicatiferina species. Stepanov, 1939 : Moscov-ian-Asselian of the Verkhoyansk Mountains, northern Urals and Bashkiria, southern Urals Stepanov, 1939;Mironova, 1967;Solomina, 1978;Alexandrov and Einor in Einor, 1979;Kalashnikov, 1980Kalashnikov, , 1986Klets, 2005 ; Plicatiferina pseudoplicatilis Stepanov, 1948 : Kasimovian-Asselian of Bashkiria, southern Urals Stepanov, 1948;Mironova, 1967;Garanj et al, 1975 Hiroi, 1978;Hiroi et al, 1978, Itoshiro, Gifu Prefecture Konishi, 1954Hiroi, 1981 , andFujikuradani Nakatatsu Mine , Fukui Prefecture Yamada, 1967;Ishiwatari, 2006 see Fig. 1.A , central Japan.…”

Section: Plicatiferina Borealicamentioning

confidence: 99%

Late Carboniferous brachiopod Plicatiferina from Nishiamada, Fukui Prefecture, central Japan, and its tectonic implications

Tazawa

Anso

Umeda

et al. 2010

Jour. Geol. Soc. Japan

View full text Add to dashboard Cite

New fossil discovery from the Hida metamorphic rocks in the Unazuki area, central Japan.

Cited by 26 publications

References 2 publications

Geochemical and Sr–Nd–Pb isotopic investigation of Triassic granitoids and basement rocks in the northern Gyeongsang Basin, Korea: Implications for the young basement in the East Asian continental margin

Geochemical and Sr–Nd–Pb isotopic investigation of Triassic granitoids and basement rocks in the northern Gyeongsang Basin, Korea: Implications for the young basement in the East Asian continental margin

The basement geology of Japan from A to Z

Late Carboniferous brachiopod Plicatiferina from Nishiamada, Fukui Prefecture, central Japan, and its tectonic implications

Contact Info

Product

Resources

About