Impressamergel Formation

The Impressamergel Formation is a geologic formation in Germany. It preserves fossils dating back to the Jurassic period.

Impressamergel Formation
Stratigraphic range: Oxfordian
TypeFormation
UnderliesWohlgeschichtete Kalk Formation
OverliesOrnatenton Formation
Thickness25 to 125 metres
Lithology
PrimaryLimestone
Location
CountryGermany

History edit

The term was proposed by Gert Bloos, Gerd Dietl and Günter Schweigert in 2005 for a lithostratigraphic rock formation. The name goes back to the term Impressakalke introduced by Friedrich August Quenstedt in 1857. The name is derived from the brachiopod Terebratula impressa (today Aulacothyris impressa ).

Definition and distribution area edit

The Impressamergel formation includes dark gray to light gray limestones with some embedded limestone beds. The lower limit is relatively well defined by the change in color (from "brown" to "white" Jura). The upper limit is formed by the onset of the limestone of the Wohlgeschichtete Kalk Formation . It meshes with the Lochen Formation especially in the higher part and is increasingly replaced by this formation. In the Upper Rhine Valley, it is represented by Kandern Formation , Korallenkalk Formation and Nerineenkalk Formation . The distribution of the Impressamergel formation extends over the entire Swabian Alb to the Wutach area.

See also edit

References edit

  • Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.