Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia
Conodonts from the type region of the Oandu Regional Stage (Katian, Upper Ordovician) in NE Estonia were studied. Here, the lower boundary of the stage corresponds to a discontinuity surface at the base of the Hirmuse Formation and, in conodont succession, is marked by the disappearance of Semiacont...
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| Format: | Article |
| Language: | English |
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Estonian Academy Publishers
2017-02-01
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| Series: | Estonian Journal of Earth Sciences |
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| Online Access: | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2017/issue_1/earth-2017-1-1-12.pdf |
| _version_ | 1828881301582643200 |
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| author | Peep Männik |
| author_facet | Peep Männik |
| author_sort | Peep Männik |
| collection | DOAJ |
| description | Conodonts from the type region of the Oandu Regional Stage (Katian, Upper Ordovician) in NE Estonia were studied. Here, the lower boundary of the stage corresponds to a discontinuity surface at the base of the Hirmuse Formation and, in conodont succession, is marked by the disappearance of Semiacontiodus sp. and Besselodus? sp. The most characteristic taxa of the Oandu Stage are Phragmodus undatus, Icriodella cf. superba and Plectodina sp., which are rare or missing below and above this stratigraphic interval in Estonia. The comparison of conodont faunas from North and South Estonia suggests that the strata in North Estonia correspond to the upper part of the Oandu Stage only as identified in sections in South Estonia. However, the position of the lower boundary of the stage in South Estonia is highly problematic. The boundary between the Amorphognathus tvaerensis and A. superbus conodont zones in Estonia lies within the (upper) Oandu Stage. |
| first_indexed | 2024-12-13T10:03:54Z |
| format | Article |
| id | doaj.art-ba91cb2c4bc3489da6ae84abb3b8da11 |
| institution | Directory Open Access Journal |
| issn | 1736-4728 1736-7557 |
| language | English |
| last_indexed | 2024-12-13T10:03:54Z |
| publishDate | 2017-02-01 |
| publisher | Estonian Academy Publishers |
| record_format | Article |
| series | Estonian Journal of Earth Sciences |
| spelling | doaj.art-ba91cb2c4bc3489da6ae84abb3b8da112022-12-21T23:51:35ZengEstonian Academy PublishersEstonian Journal of Earth Sciences1736-47281736-75572017-02-0166111210.3176/earth.2017.0210.3176/earth.2017.02Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE EstoniaPeep Männik0Institute of Geology at Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia; peep.mannik@ttu.eeConodonts from the type region of the Oandu Regional Stage (Katian, Upper Ordovician) in NE Estonia were studied. Here, the lower boundary of the stage corresponds to a discontinuity surface at the base of the Hirmuse Formation and, in conodont succession, is marked by the disappearance of Semiacontiodus sp. and Besselodus? sp. The most characteristic taxa of the Oandu Stage are Phragmodus undatus, Icriodella cf. superba and Plectodina sp., which are rare or missing below and above this stratigraphic interval in Estonia. The comparison of conodont faunas from North and South Estonia suggests that the strata in North Estonia correspond to the upper part of the Oandu Stage only as identified in sections in South Estonia. However, the position of the lower boundary of the stage in South Estonia is highly problematic. The boundary between the Amorphognathus tvaerensis and A. superbus conodont zones in Estonia lies within the (upper) Oandu Stage.http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2017/issue_1/earth-2017-1-1-12.pdfconodontsbiostratigraphyOandu StageKatianUpper OrdovicianEstonia. |
| spellingShingle | Peep Männik Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia Estonian Journal of Earth Sciences conodonts biostratigraphy Oandu Stage Katian Upper Ordovician Estonia. |
| title | Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia |
| title_full | Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia |
| title_fullStr | Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia |
| title_full_unstemmed | Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia |
| title_short | Conodont biostratigraphy of the Oandu Stage (Katian, Upper Ordovician) in NE Estonia |
| title_sort | conodont biostratigraphy of the oandu stage katian upper ordovician in ne estonia |
| topic | conodonts biostratigraphy Oandu Stage Katian Upper Ordovician Estonia. |
| url | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2017/issue_1/earth-2017-1-1-12.pdf |
| work_keys_str_mv | AT peepmannik conodontbiostratigraphyoftheoandustagekatianupperordovicianinneestonia |