• Title/Summary/Keyword: graptolite

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Graptolites from the Lower Ordovician (Tremadoc) Mungok Formation in Danyang area, Korea

  • Kim, Jeong-Yul;Cho, Hyun-Su;Park, Ye-Ri
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.603-612
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    • 2007
  • Lower Ordovician (Upper Tremadoc) graptolites were found for the first time at the two sections of the Mungok Formation in Danyang area: the Seokgyori and Daejeonri sections. The graptolites from these sections comprise two species of two genera: Adelograptus brevibrachiatus and Psigraptus jacksoni. The graptolite faunas of the sections in the area show simple composition relative to Yeongwol area; they appear to be correlated to: (1) the Adelograptus cf tenellus Zone of Yeongwol area, (2) the Adelograptus cf. tenellus Zone of Yukon, Canada, (3) the Psigraptus Zone of Tasmania, Australia, and (4) the Psigraptus jacksoni Zone of Jilin, China. The age of graptolite beds of the Mungok Formation at Danyang appears to be early Upper Tremadoc of the Lower Ordovician.

Graptolites from the Jigunsan Shale of Taebaeg Area, Korea

  • Kim Jeong Yul;Kwon Ji Yeun;Kim Kyung-Soo;Cho Hyun Su
    • Journal of the Korean earth science society
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    • v.26 no.2
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    • pp.137-148
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    • 2005
  • Five species of graptolites were discovered from the Jigunsan Shale of Taebaeg area, Korea. They are herein described as Archiclimacograptus riddellensis (Harris, 1924), Pseudamplexograptus distichus(Eichwald, 1840), Hustedograptus teretiusculus(Hisinger) sensu Jaanusson, 1960, Hustedograptus vikarbyensis (Jaanusson, 1960), and Hustedograptus sp. The graptolite assemblage from the Jigunsan Shale corresponds to those of the Pseudamplexograptus distichus zone in the Baltic and German areas and the geologic age of graptolites bearing beds of the Jigunsan Shale might be late Middle Llanvirn.

Early Ordovician (Tremadocian) Graptolites from the Mungok Formation, Yeongwol, Korea: Biostratigraphy and Correlation

  • Kim, Jeong-Yul;Cho, Hyun-Su;Jin, Yeong-Pil
    • Journal of the Korean earth science society
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    • v.27 no.7
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    • pp.745-756
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    • 2006
  • Early Ordovician graptolites from the Mungok Formation of Yeongwol area, Korea comprise seven species belonging to six genera: Callograptus curvithecalis, Callograptus sinicus, Aspidograptus lotolatzensis, Dendrograptus suni, Dictyonema uniforme, Adelograptus cf. tenellus, and Psigraptus jacksoni. Two graptolite zones with three subzones are recognized in the eight sections of the Mungok Formation. The Adelograptus Zone is correlated with (1) La 1b of the Lancefield Formation of Victoria, Australia, (2) the Adelograptus-Clonograptus Zone of the Yehli Formation of Jilin, China, and (3) the Adelograptus Zone of the Road River Formation of Yukon, Canada. It suggests that the upper part of the Mungok Formation corresponds to early Late Tremadocian of Early Ordovician.

Late Tremadocian Graptolites from the Mungok Formation of the Namaeri and Baeiljae Sections at Yeongwol, Korea

  • Kim, Jeong-Yul;Choi, Sang-Kook;Jin, Young-Pil;Kim, Kyung-Soo
    • Journal of the Korean earth science society
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    • v.30 no.5
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    • pp.646-659
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    • 2009
  • The early Ordovician graptolites from the upper part (Tumok Member) of the Mungok Formation of the Namaeri and Baeiljae sections at Yeongwol consist of five species belonging to five genera. They are Adelograptus cf. tenellus, Callograptus sp., Dendrograptus suni, Dictyonema sp., and Psigraptus jacksoni. Of these 5 species, Psigraptus is the most excellent index fossil for international correlation with the early Ordovician strata. Adelograptus cf. tenellus from the Mungok Formation of the Namaeri and Baeiljae sections is also recognized with especially short stipe relative to Adelograptus tenellus. Three graptolite zones (such as Adelograptus, Psigraptus, and Dendroid type zones) are correlated with those of Canada, Australia, and China, respectively. The upper part of the Mungok Formation is assigned to the late Tremadocian.

A New Graptolite Species Adelograptus brevibrachiatus from the Mungok Formation of Yeongwol Area, Korea

  • Cho, Hyun-Su;Kim, Jeong-Yul
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.563-571
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    • 2007
  • Adelograptus brevibrachiatus sp. novo is erected for materials previously referred to as Adelograptus cf. tenellus from the circum-Pacific area. The species shares many morphological characteristics with Adelograptus tenellus from Europe but differs from it by possessing typically short stipe lengths throughout rhabdosome due to less thecal density along the stipes. Taxonomic characteristics of A. cf. tenellus reported from circum-Pacific area are compared with each other. The paleogeographic distribution of A. tenellus seems to be restricted within Europe, while that of A. brevibrachiatus within circum-Pacific area.

Graptolite Biostratigraphy of the Mungok Formation (Early Ordovician) in the Hwabyung Area, Yeongwol, Korea (강원도 영월 화병 지역의 전기 오르도비스기 문곡층의 필석 생물층서)

  • Kim, Teak-Ja;Jin, Young-Pil;Kim, Jeong-Yul
    • Journal of the Korean earth science society
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    • v.24 no.8
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    • pp.668-683
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    • 2003
  • Five species of graptolites belonging to four genera were described from the upper part of the Mungok Formation in the Hwabyung area of Yeongwol, Korea. They are Dendrograptus sp., Callograptus curvithecalis Mu 1955, Adeiograptus tenellus Linnarsson, 1871, Adelograptus sp., and Psigraptus jacksoni Rickards and Stait, 1984. Most of them are reported for the second time in Korea, and the occurrence of Psigraptus is the sixth time ever in the world, following the Yukon Territory of Canada, the Vctoria and Tasmania areas of Australia, and the Jilin and Hebei areas of China. Based on the graptolites, three biozones were recognized from the upper part of the Mungok Formation in the Hwabyung area: the Adelograptus Zone, the Callograptus-Dend개graptus Zone, and the Psigraptus Zone, in ascending order. These graptolite zones are correlated with the La 1.5 Zone (Psigraptus and Clonograptus Zone or Assemblage 3) of Vctoria, Australia, the Psigraptus Zone of the Road River Formation in Yukon, Canada, and the Psigraptus Zone of the Yehli Formation of Hunjiang, Jilin, nonh China. Therefore, according to the graptolites and their biozones, the age of the upper part of the Mungok Formation is assigned to be early Late Tremadoc.