Sheinwoodian

Sheinwoodian
Sheinwoodian
433.4 ± 0.8 – 430.5 ± 0.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Paleogeography of the late Sheinwoodian
Chronology
	Subdivision of the Silurian according to the ICS, as of 2021.; Vertical axis scale: millions of years ago.;

In the geologic timescale, the Sheinwoodian is the age of the Wenlock Epoch of the Silurian Period of the Paleozoic Era of the Phanerozoic Eon that is comprehended between 433.4 ± 0.8 Ma and 430.5 ± 0.7 Ma (million years ago), approximately. The Sheinwoodian Age succeeds the Telychian Age and precedes the Homerian Age.^[5]

EtymologyName formalityFormalName ratified1980^[4]Usage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionImprecise. Currently placed between acritarch biozone 5 and LAD of Pterospathodus amorphognathoides. See Llandovery for more info.Lower boundary definition candidatesA conodont boundary (Ireviken datum 2) which is close to the murchisoni graptolite biozone.Lower boundary GSSP candidate section(s)NoneLower boundary GSSPHughley Brook, Apedale, UK
52°34′52″N 2°38′20″W / 52.5811°N 2.6389°WLower GSSP ratified1980^[4]Upper boundary definitionFAD of the graptolite Cyrtograptus lundgreniUpper boundary GSSPSheinton Brook, Homer, England
52°36′56″N 2°33′53″W / 52.6156°N 2.5647°WUpper GSSP ratified1980^[4]

Definition

The Wenlock-Llandovery boundary is defined by the first occurrence of Cyrtograptus centrifugus. The stage is named after Sheinwood village, north of Much Wenlock. The Buildwas Formation of Shropshire, United Kingdom contains the type section.^[6]

References

[5]

[3]

[4]

[6]

Sheinwoodian
433.4 ± 0.8 – 430.5 ± 0.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Paleogeography of the late Sheinwoodian
Chronology

Subdivision of the Silurian according to the ICS, as of 2021.^[3] Vertical axis scale: millions of years ago.