Wenlock (Silurian)

The Wenlock ( rarely also called Wenlockium ) is in Earth's history, a chronostratigraphic series of Silurian. She began geochronological before about 433.4 million years ago and ended about 427.4 million years. It replaces the Llandovery series and is followed by the Ludlow Series.

Nomenclature and history

It is named after the Wenlock Wenlock Edge, a geological event in Much Wenlock in Middle English county of Shropshire. The name goes back to Roderick Murchison, who proposed it in 1833.

Definition and GSSP

The inaccurately determined base between the base of acritarchs - Biozone 5 and the extinction of conodont species Pterospathodus amorphognathoides. The limit is probably near the base of Cyrtograptus centrifugus - graptolite zone. The end of the series is also inaccurate; it is near the base of Saetograptus leintwardinensis - Graptolithen zone. The reference profile ( GSSP = " Global Stratotype Section and Point" ) is for the Sheinwoodium in Bach Hughely, 200 m southeast of the few houses of Leasows and 500 m northeast of the church of Hughely, Apedale ( Shropshire, England).

Subdivision

The Wenlock Series is divided into two geological stages:

• System: Silurian ( 443.4 to 419.2 mya ) Series: Pridolium ( 423 to 419.2 mya ) (not divided into more stages )
• Series: Ludlow ( 427.4 to 423 mya )
• Series: Wenlock ( 433.4 to 427.4 mya ) Level: Homerium ( 430.5 to 427.4 mya )
• Level: Sheinwoodium ( 433.4 to 430.5 mya )

Geological situation at the time of the Wenlock

Characterized this series is produced by the collision of continents Laurentia, Baltica and Avalonia, and the resulting Caledonian orogeny.