K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance.

Y. Nishimura, Eizou Nakamura, I. Hara

Research output: Chapter in Book/Report/Conference proceedingChapter

10 Citations (Scopus)

Abstract

K/Ar ages have been determined on white micas from four Sangun pelitic schists in the Nishiki-cho and Toyoga-dake areas, Yamaguchi Prefecture. The ages from the Nishiki-cho area are 172 and 175 m.y., while those from the Toyoga-dake area are 264 and 274 m.y. The 12 available measurements on the Sangun metamorphic rocks can be divided into two age clusters, an older cluster around 260 m.y. (Middle Permian) and a younger cluster around 170 m.y. (Middle Jurassic). It is suggested that the two age clusters coincide with the two stages of uplift for the Sangun metamorphic rocks. Thus the older age cluster may indicate the event in which the Sangun metamorphic rocks were emplaced as nappes from the deep tectonic position of glaucophanitic metamorphism into a shallow tectonic position when metamorphism had ceased. On the other hand, the younger age cluster may represent an event related to the beginning of the formation of a pile nappe structure in which the Sangun metamorphic rocks tectonically overlie the Jurassic non-metamorphic equivalents of the Tamba group.-M.Ak.

Original languageEnglish
Title of host publicationJournal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists
Pages11-20
Number of pages10
Volume78
Publication statusPublished - 1983
Externally publishedYes

Fingerprint

metamorphic rock
nappe
metamorphism
Jurassic
tectonics
schist
Permian
pile
uplift
young

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

Nishimura, Y., Nakamura, E., & Hara, I. (1983). K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance. In Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists (Vol. 78, pp. 11-20)

K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance. / Nishimura, Y.; Nakamura, Eizou; Hara, I.

Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists. Vol. 78 1983. p. 11-20.

Research output: Chapter in Book/Report/Conference proceedingChapter

Nishimura, Y, Nakamura, E & Hara, I 1983, K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance. in Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists. vol. 78, pp. 11-20.
Nishimura Y, Nakamura E, Hara I. K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance. In Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists. Vol. 78. 1983. p. 11-20
Nishimura, Y. ; Nakamura, Eizou ; Hara, I. / K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance. Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists. Vol. 78 1983. pp. 11-20
@inbook{8bb67258539a49bfa34a007c01f5f249,
title = "K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance.",
abstract = "K/Ar ages have been determined on white micas from four Sangun pelitic schists in the Nishiki-cho and Toyoga-dake areas, Yamaguchi Prefecture. The ages from the Nishiki-cho area are 172 and 175 m.y., while those from the Toyoga-dake area are 264 and 274 m.y. The 12 available measurements on the Sangun metamorphic rocks can be divided into two age clusters, an older cluster around 260 m.y. (Middle Permian) and a younger cluster around 170 m.y. (Middle Jurassic). It is suggested that the two age clusters coincide with the two stages of uplift for the Sangun metamorphic rocks. Thus the older age cluster may indicate the event in which the Sangun metamorphic rocks were emplaced as nappes from the deep tectonic position of glaucophanitic metamorphism into a shallow tectonic position when metamorphism had ceased. On the other hand, the younger age cluster may represent an event related to the beginning of the formation of a pile nappe structure in which the Sangun metamorphic rocks tectonically overlie the Jurassic non-metamorphic equivalents of the Tamba group.-M.Ak.",
author = "Y. Nishimura and Eizou Nakamura and I. Hara",
year = "1983",
language = "English",
volume = "78",
pages = "11--20",
booktitle = "Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists",

}

TY - CHAP

T1 - K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance.

AU - Nishimura, Y.

AU - Nakamura, Eizou

AU - Hara, I.

PY - 1983

Y1 - 1983

N2 - K/Ar ages have been determined on white micas from four Sangun pelitic schists in the Nishiki-cho and Toyoga-dake areas, Yamaguchi Prefecture. The ages from the Nishiki-cho area are 172 and 175 m.y., while those from the Toyoga-dake area are 264 and 274 m.y. The 12 available measurements on the Sangun metamorphic rocks can be divided into two age clusters, an older cluster around 260 m.y. (Middle Permian) and a younger cluster around 170 m.y. (Middle Jurassic). It is suggested that the two age clusters coincide with the two stages of uplift for the Sangun metamorphic rocks. Thus the older age cluster may indicate the event in which the Sangun metamorphic rocks were emplaced as nappes from the deep tectonic position of glaucophanitic metamorphism into a shallow tectonic position when metamorphism had ceased. On the other hand, the younger age cluster may represent an event related to the beginning of the formation of a pile nappe structure in which the Sangun metamorphic rocks tectonically overlie the Jurassic non-metamorphic equivalents of the Tamba group.-M.Ak.

AB - K/Ar ages have been determined on white micas from four Sangun pelitic schists in the Nishiki-cho and Toyoga-dake areas, Yamaguchi Prefecture. The ages from the Nishiki-cho area are 172 and 175 m.y., while those from the Toyoga-dake area are 264 and 274 m.y. The 12 available measurements on the Sangun metamorphic rocks can be divided into two age clusters, an older cluster around 260 m.y. (Middle Permian) and a younger cluster around 170 m.y. (Middle Jurassic). It is suggested that the two age clusters coincide with the two stages of uplift for the Sangun metamorphic rocks. Thus the older age cluster may indicate the event in which the Sangun metamorphic rocks were emplaced as nappes from the deep tectonic position of glaucophanitic metamorphism into a shallow tectonic position when metamorphism had ceased. On the other hand, the younger age cluster may represent an event related to the beginning of the formation of a pile nappe structure in which the Sangun metamorphic rocks tectonically overlie the Jurassic non-metamorphic equivalents of the Tamba group.-M.Ak.

UR - http://www.scopus.com/inward/record.url?scp=0020866968&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0020866968&partnerID=8YFLogxK

M3 - Chapter

AN - SCOPUS:0020866968

VL - 78

SP - 11

EP - 20

BT - Journal of the Japanese Association of Mineralogists, Petrologists & Economic Geologists

ER -