The Winneshiek Shale is a Middle Ordovician shale deposit exposed within an ancient meteorite impact crater near Decorah, Iowa, roughly four hundred and sixty million years old, preserving an unusual, isolated marine fauna that includes one of the oldest known eurypterids and a jawless fish found nowhere else, protected from open ocean conditions by the crater's semi-enclosed basin. The deposit's crater setting makes its fauna distinct from other Ordovician sites of similar age.
Connections
Associated With
Source Winneshiek Shale (Wikipedia)
Source Winneshiek Shale (Wikipedia)
Caused By
Source Winneshiek Shale (Wikipedia)
In Discipline
Source Winneshiek Shale (Wikipedia)
In the Other Atlases
Found In
Also in Geography Atlas: where this subject is found.
Sources
Winneshiek Shale (Wikipedia)
Caused By: Sedimentation, Lead paragraph
The shale's depositional environment is reconstructed as a calm marine basin or estuary with an anoxic, low-pH seabed.
Associated With: Ordovician, Lead paragraph
The Winneshiek Shale (originally the Winneshiek Lagerstätte) is a Middle Ordovician (Darriwilian-age) geological formation in Iowa.
Associated With: Ordovician, Lead, age Ordovician
The Winneshiek Shale (originally the Winneshiek Lagerstätte) is a Middle Ordovician (Darriwilian-age) geological formation in Iowa.
Associated With: Shale, Lead, rock Shale
The Winneshiek Shale (originally the Winneshiek Lagerstätte) is a Middle Ordovician (Darriwilian-age) geological formation in Iowa.
In Discipline: Stratigraphy, Lead paragraph
The Winneshiek Shale (originally the Winneshiek Lagerstätte) is a Middle Ordovician (Darriwilian-age) geological formation in Iowa
View the SourceReader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.
Sign in to dispute this or suggest a correction.