Back اللودفوردي Arabic Ludfordium German Ludfordiense Spanish Ludfordi lade Estonian لودفوردین Persian Ludfordien French Ludfordi Hungarian Ludfordium ID Ludfordiano Italian ルドフォーディアン Japanese
| Ludfordian | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Paleogeography of the Ludfordian, 425 Ma | |||||||||||||
| Chronology | |||||||||||||
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| Etymology | |||||||||||||
| Name formality | Formal | ||||||||||||
| Name ratified | 1980[4] | ||||||||||||
| 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 | Imprecise. Near FAD of the graptolite Saetograptus leintwardinensis | ||||||||||||
| Lower boundary definition candidates | None | ||||||||||||
| Lower boundary GSSP candidate section(s) | None | ||||||||||||
| Lower boundary GSSP | Sunnyhill, Ludlow, England 52°21′33″N 2°46′38″W / 52.3592°N 2.7772°W | ||||||||||||
| Lower GSSP ratified | 1980[4] | ||||||||||||
| Upper boundary definition | FAD of the graptolite Monograptus parultimus | ||||||||||||
| Upper boundary GSSP | Požáry Section, Prague-Řeporyje, Czech Republic 50°01′40″N 14°19′30″E / 50.0277°N 14.3249°E | ||||||||||||
| Upper GSSP ratified | 1984[5][6] | ||||||||||||
In the geologic timescale, the Ludfordian is the upper of two chronostratigraphic stages within the Ludlow Series. Its age is the late Silurian Period, and within both the Palaeozoic Era and Phanerozoic Eon. The rocks assigned to the Ludfordian date to between 425.6 ± 0.9 Ma and 423.0 ± 2.3 Ma (million years ago). The Ludfordian Stage succeeds the Gorstian Stage and precedes the Pridoli Epoch. It is named for the village of Ludford in Shropshire, England. The GSSP for the Ludfordian is represented as a thin shale seam, coincident with the base of the Leintwardine Formation, overlying the Bringewood Formation in England.
- ^ Jeppsson, L.; Calner, M. (2007). "The Silurian Mulde Event and a scenario for secundo—secundo events". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 93 (02): 135–154. doi:10.1017/S0263593300000377.
- ^ Munnecke, A.; Samtleben, C.; Bickert, T. (2003). "The Ireviken Event in the lower Silurian of Gotland, Sweden-relation to similar Palaeozoic and Proterozoic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 195 (1): 99–124. doi:10.1016/S0031-0182(03)00304-3.
- ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. September 2023. Retrieved December 16, 2024.
- ^ a b Holland, C. (1982). "The State of Silurian Stratigraphy" (PDF). Episodes. 1982 (3): 21–23. doi:10.18814/epiiugs/1982/v5i3/004. Retrieved 11 December 2020.
- ^ Lucas, Sepncer (6 November 2018). "The GSSP Method of Chronostratigraphy: A Critical Review". Frontiers in Earth Science. 6: 191. Bibcode:2018FrEaS...6..191L. doi:10.3389/feart.2018.00191.
- ^ Holland, C. (June 1985). "Series and Stages of the Silurian System" (PDF). Episodes. 8 (2): 101–103. doi:10.18814/epiiugs/1985/v8i2/005. Retrieved 11 December 2020.