Humphriesioolite Formation

from Wikipedia, the free encyclopedia
Lithostratigraphy of the South German Jura .
Abbreviations:
  • Humph.-Fm. = Humphriesioolite Formation
  • L.Bk-Fm = Lying bench lime formation
  • H.Bk-Fm = hanging bank lime formation
  • Zm-Fm = cement marl formation
  • S.-Fm = Solnhofen formation
  • Rö.-Fm = Rögling formation
  • U.-Fm = Usseltal formation
  • Mö.-Fm = Mörnshein formation
  • N.-Fm = Neuburg formation
  • R.-Fm = Rennertshofen formation

    • The Humphriesioolite Formation is a lithostratigraphic formation of the southern German Jura . It is underlain by the Wedelsandstone Formation , and regionally differently overlaid by the Main Roe Stone Formation and Hamitenton Formation . It interlocks regionally with the Ostreenkalk formation and reaches a thickness of up to about 10 m. It is dated to the higher sub-bajocium .

    History and naming

    The Humphriesioolite Formation was proposed by Gert Bloos, Gerd Dietl and Günter Schweigert in 2005. It is named after the ammonite Ammonites humphriesi (today Stephanoceras humphriesianum ). A type locality, as it is actually required to define a lithostratigraphic unit, has not yet been determined.

    Definition and distribution area

    The Humphriesioolite Formation mainly comprises Eisenoolith banks and claystones, in its upper part also non-oolithic fine sand clay marl, the so-called "Blagdeni banks". The thickness varies in the area of ​​the Swabian Alb between 6 and 10 m. The distribution area extends from the Westalb over the Klettgau to the Lörrach area. It interlocks there with the Ostreenkalk formation, also in the area from Gosheim to the east. The lower limit is formed by the upper limit of the so-called blue limestone (uppermost part of the frond sandstone formation), the upper limit is at the upper edge of the Blagdeni layers or at the lower edge of the subfurcate oolite.

    Temporal scope and breakdown

    The sediments of the Humphriesioolite Formation were deposited during the lower sub- Bajocian. The Humphriesioolite Formation includes at most the ammonite zone of Stephanoceras humphriesianum , which is further subdivided into three subzones romani subzone, humphriesianum subzone and blagdeni subzone. In the Upper Rhine Valley and on the Swabian Alb (east of Gosheim) it changes into the Ostreenkalk formation. The Humphriesioolite Formation is formally not further subdivided into sub-formations. However, in the upper part it contains the Blagdeni layers, several meters thick.

    literature

    • Gert Bloos, Gerd Dietl & Günter Schweigert: The Jura of Southern Germany in the Stratigraphic Table of Germany 2002. Newsletter on Stratigraphy, 41 (1-3): 263-277, Stuttgart 2005 ISSN  0078-0421

    Web links