Lochkovian
| Lochkovian | |||||||||||||||||
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| Chronology | |||||||||||||||||
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| Etymology | |||||||||||||||||
| Name formality | Formal | ||||||||||||||||
| Name ratified | 1985[5] | ||||||||||||||||
| Usage information | |||||||||||||||||
| Celestial body | Earth | ||||||||||||||||
| Regional usage | Global (ICS) | ||||||||||||||||
| Time scale(s) used | ICS Time Scale | ||||||||||||||||
| Definition | |||||||||||||||||
| Chronological unit | Age | ||||||||||||||||
| Stratigraphic unit | Stage | ||||||||||||||||
| Time span formality | Formal | ||||||||||||||||
| Lower boundary definition | FAD of the graptolite Monograptus uniformis | ||||||||||||||||
| Lower boundary GSSP | Klonk, Prague, Czech Republic 49°51′18″N 13°47′31″E / 49.8550°N 13.7920°E | ||||||||||||||||
| Lower GSSP ratified | 1972[6] | ||||||||||||||||
| Upper boundary definition | FAD of the conodonts Eognathodus sulcatus and Latericriodus steinachensis Morph beta | ||||||||||||||||
| Upper boundary GSSP | Velká Chuchle quarry, Velká Chuchle, Prague, Czech Republic 50°00′53″N 14°22′21″E / 50.0147°N 14.3726°E | ||||||||||||||||
| Upper GSSP ratified | 1989[5] | ||||||||||||||||
The Lochkovian is one of three faunal stages in the Early Devonian Epoch. It lasted from 419.62 ± 1.36 million years ago to 413.02 ± 1.91 million years ago. It marked the beginning of the Devonian Period, and was followed by the Pragian Stage. It is named after the village of Lochkov in the Czech Republic, now part of the city of Prague.[7] The GSSP is located within the Lochkow Formation at the Klonk Section in Prague.
In North America the Lochkovian Stage is represented by Gedinnian or Helderbergian time.
References
- ^ Kaufmann, Bernd; Trapp, Endres; Mezger, Klaus (July 2004). "The numerical age of the Upper Frasnian (Upper Devonian) Kellwasser horizons: A new U-Pb zircon date from Steinbruch Schmidt (Kellerwald, Germany)" (PDF). The Journal of Geology. 112 (4): 495–501. Bibcode:2004JG....112..495K. doi:10.1086/42107. eISSN 1537-5269. ISSN 0022-1376. JSTOR 421077. LCCN 25013118. OCLC 1608377. S2CID 129963970. Archived from the original (PDF) on February 10, 2024. Retrieved December 16, 2025.
- ^ Algeo, Thomas; Scheckler, Stephen E. (January 29, 1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences. 353 (1365): 113–130. doi:10.1098/rstb.1998.0195. eISSN 1471-2970. PMC 1692181. S2CID 84656565.
- ^ Parry, Stephen F.; Noble, Stephen R.; Crowley, Quentin C.; Wellman, Charles H. (June 15, 2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications" (PDF). Journal of the Geological Society. 168 (4). Geological Society of London: 863–872. Bibcode:2011JGSoc.168..863P. doi:10.1144/0016-76492010-043. eISSN 2041-479X. ISSN 0016-7649. LCCN 79641612. OCLC 1934542. S2CID 128679831. Archived (PDF) from the original on July 11, 2025. Retrieved December 16, 2025.
- ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. December 2024. Retrieved October 23, 2025.
- ^ a b Chlupac, Ivo; Oliver, William (June 1989). "Decision on the Lochkovian-Pragian Boundary Stratotype (Lower Devonian)" (PDF). Episodes. 12 (2): 109–114. Retrieved 18 December 2020.
- ^ Chlupáč, Ivo; Hladil, Jindrich (January 2000). "The global stratotype section and point of the Silurian-Devonian boundary". CFS Courier Forschungsinstitut Senckenberg. Retrieved 7 December 2020.
- ^ "Lochkovian Stage". Encyclopedia Britannica. Retrieved 2 October 2019.