| Titre | A candidate for the Global Stratotype Section and Point at the base of the Serpukhovian in the South Urals, Russia |
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| Auteur | Richards, B C; Nikolaeva, S V; Kulagina, E I; Alekseev, A S; Gorozhanina, E N; Gorozhanin, V M; Konovalova, V A; Goreva, N V; Joachimski, M M; Gatovsky, Y A |
| Source | Stratigraphy and Geological Correlation vol. 25, 7, 2017 p. 697-758, https://doi.org/10.1134/S0869593817070036 |
| Année | 2017 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20182369 |
| Éditeur | Pleiades Publishing Ltd |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1134/S0869593817070036 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Diffusé | 2018 01 26 |
| Résumé | (disponible en anglais seulement)
The Verkhnyaya Kardailovka section is one of the best candidates for the GSSP (Global Stratotype Section and Point) at the base of the Stage (Mississippian).
For boundary definition, the first appearance of the conodont Lochriea ziegleri Nemirovskaya, Perret et Meischner, 1994 in the lineage Lochriea nodosa (Bischoff, 1957)?L. ziegleri is used. L. ziegleri appears in the Venevian Substage somewhat below
the base of the Serpukhovian in the Moscow Basin. The position of the FAD of L. ziegleri within the Hypergoniatites?Ferganoceras Genozone is confirmed and lies between 19.53 and 19.63 m above the sectionÕs base. Before 2010, deep-water stylonodular
limestone containing the boundary in unnamed formation C at Kardailovka was well exposed but only 3 m of Visan strata cropped out immediately below. Recent trenching exposed another 10 m of underlying Visan carbonates in formation C and older Visan
siliciclastics and volcanics in unnamed formation B. The contact between formation B and underlying crinoidal limestones in unnamed formation A representing the middle Visan Zhukovian (Tulian) regional Substage was excavated. The boundary succession,
situated in the Magnitogorsk tectonic zone above the Devonian Magnitogorsk arc and Mississippian magmatic and sedimentary rift succession, was deposited west of the Kazakhstanian continent during closure of the Ural Ocean. In the lower part of the
section, Visan tuffaceous siliciclastics and volcanics of formation B record rapid deepening after deposition of neritic middle Visan crinoid lime grainstone of formation A and subsequent subaerial exposure. The overlying condensed upper Visan to
Serpukhovian succession in formation C comprises deep-water limestone deposited in a sediment-starved basin recording minor turbidite influx and carbonate-mound development. The ?13Ccarb plot shows a positive shift of 1ä V-PDB (from +2 to +3ä)
between 17.0 and 17.75 m (3.05 and 1.97 m below FAD L. ziegleri). The ?18Oapatite graph displays a prominent upward shift from 19.9 to 21.1ä V-SMOW (at 19.15 to 19.51 m) in the nodosa Zone below FAD of Lochriea ziegleri. © 2017, Pleiades Publishing,
Ltd. |
| GEOSCAN ID | 310949 |
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