Science Links Japan | Jurassic Radiolarians from the Low-grade Metamorphic Zone of the Northern Part of the Chichibu Belt in the Kanto Mountains, Central Japan.

Jurassic Radiolarians from the Low-grade Metamorphic Zone of the Northern Part of the Chichibu Belt in the Kanto Mountains, Central Japan.

Accession number;02A0325296

Title;Jurassic Radiolarians from the Low-grade Metamorphic Zone of the Northern Part of the Chichibu Belt in the Kanto Mountains, Central Japan.

Author; SEKINE K (Chichibu High School, Saitama Prefecture) ()

Journal Title;Bull Natl Sci Mus Ser C

Journal Code:S0397B

ISSN:0385-244X

VOL.27;NO.3/4;PAGE.101-108(2001)

Figure&Table&Reference;FIG.4, TBL.1, REF.21

Pub. Country;Japan

Language;English

Abstract;The northern part of the Chichibu belt in the Kanto Mountains, central Japan, comprises three lithologic units: Kashiwagi unit consisting mainly of lowgrade metamorphosed siliceous tuff and mudstone, Kamiyoshida unit of sandstone and mudstone with subordinate amounts of exotic blocks such as chert, greenstone and limestone, and Kazahaya-toge unit of alternation of sandstone and mudstone. Middle to Late Jurassic radiolarians were newly found from the Kashiwagi unit of the northern marginal part of the Chichibu belt. They are Archaeodictyomitra sp., Eucyrtidiellum sp., Hsuum sp., Pantanellium sp., Parvicingula sp., Podobursa sp., Pseudodictyomitra sp., Stichocapsa sp., Syringocapsa sp. and some unidentified nassellarians. This radiolarian assemblage including the genus Eucyrtidiellum and Pseudodictyomitra indicates the involvement of middle to late Jurassic sediments in the unit. Hence it is concluded that the formation and metamorphic process of the Chichibu belt occured during and after the accretion continued at the late Jurassic, respectively. (author abst.)

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