Earth:Sandbian
| Sandbian | |
|---|---|
| 458.4 ± 0.9 – 453.0 ± 0.7 Ma | |
| Chronology | |
| Etymology | |
| Name formality | Formal |
| 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 Nemagraptus gracilis |
| Lower boundary GSSP | Fågelsång section, Sularp Brook, Skåne, Sweden [ ⚑ ] 55°42′49″N 13°19′32″E / 55.7137°N 13.3255°E |
| GSSP ratified | 2002[1] |
| Upper boundary definition | FAD of the Graptolite Diplacanthograptus caudatus |
| Upper boundary GSSP | Black Knob Ridge section, Oklahoma, United States [ ⚑ ] 34°25′50″N 96°04′29″W / 34.4305°N 96.0746°W |
| GSSP ratified | 2006[2] |
The Sandbian is the first stage of the Upper Ordovician. It follows the Darriwilian and is succeeded by the Katian. Its lower boundary is defined as the first appearance datum of the graptolite species Nemagraptus gracilis around 458.4 million years ago. The Sandbian lasted for about 5.4 million years until the beginning of the Katian around 453 million years ago.[3]
Naming
The name Sandbian is derived from the village Södra Sandby (Lund Municipality, Skåne County, Sweden). The name was proposed in 2006.[4]
GSSP
The GSSP of the Sandbian is the Fågelsång section ( [ ⚑ ] 55°42′49″N 13°19′32″E / 55.7137°N 13.3255°E) at Sularp Brook, east of Lund (Skåne, Sweden). It is an outcrop of shale and mudstone. The lower boundary of the Sandbian is defined as the first appearance datum of graptolite species Nemagraptus gracilis in that section.[5]
References
- ↑ Bergström, Stig; Finney, S.; Xu, Chen; Pålsson, Christian; Zhi-hao, Wang; Grahn, Yngve (June 2000). "A proposed global boundary stratotype for the base of the Upper Series of the Ordovician System: The Fågelsång section, Scania, southern Sweden". Episodes 23 (2): 102–109. doi:10.18814/epiiugs/2000/v23i2/003. https://www.researchgate.net/publication/242669276. Retrieved 13 December 2020.
- ↑ Goldman, Daniel; Leslie, Stephen; Nõlvak, Jaak; Young, Seth; Bergström, Stig; Huff, Warren (December 2007). "The Global Stratotype Section and Point (GSSP) for the base of the Katian Stage of the Upper Ordovician Series at Black Knob Ridge, Southeastern Oklahoma, USA". Episodes 30 (4): 258–270. doi:10.18814/epiiugs/2007/v30i4/002. https://www.researchgate.net/publication/279565833. Retrieved 13 December 2020.
- ↑ "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. https://engineering.purdue.edu/Stratigraphy/gssp/index.php?parentid=77.
- ↑ Bergström, Stig; Finney, Stanley; Xu, Chen; Goldman, Daniel; Leslie, Stephen (31 August 2006). "Three new Ordovician global stage names". Lethaia 39 (3): 287–288. doi:10.1080/00241160600847439.
- ↑ Bergström, Stig M.; S. C. Finney; Chen Xu; Christian Pålsson; Wang Zhi-hao; Yngve Grahn (2000). "A proposed global boundary stratotype for the base of the Upper Series of the Ordovician System: The Fågelsång section, Scania, southern Sweden". Episodes 23 (2): 102–109. doi:10.18814/epiiugs/2000/v23i2/003. http://www.stratigraphy.org/GSSP/file38.pdf. Retrieved 20 September 2012.
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