The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Per Ahlberg

Per Ahlberg

Professor emeritus

Per Ahlberg

Sedimentology of the Lower Ordovician (upper Tremadocian) Bjørkåsholmen Formation at Flagabro, southern Sweden

Author

  • Sven Egenhoff
  • Jörg Maletz
  • Per Ahlberg
  • Allison Mast
  • Åsa M. Frisk
  • Jan Ove R. Ebbestad
  • Warren Newby

Summary, in English

The Lower Ordovician Bjørkåsholmen Formation at Flagabro, Scania, southern Sweden, consists of a 0.8 m thick succession of carbonates with three siliciclastic mudstones, 5, 1 and 100 mm thick, intercalated in the central part of the unit. Carbonate and siliciclastic mudstone beds show both normal and inverse grading. The carbonates are mud-rich and subdivided into a mudstone, a wackestone and a packstone facies. Grain types in the carbonates are mostly shells and shell fragments of brachiopods and trilobites. The carbonate rocks are strongly bioturbated seen as in roundish burrows filled with mud and a clear cement; additionally, bioturbation is reflected in the random orientation of shells. The siliciclastic mudstones are subdivided into two facies; one contains large amounts of shells and is in part grain-supported, the other is matrix-dominated and laminated to massive. The succession reflects sedimentation on a low-inclined shelf equivalent to a mid-ramp to basinal setting. Most mud- and wackestones (facies 3 and 4) represent fair-weather sedimentation, and the intercalated wacke- and packstones (facies 4 and 5) represent concentration of shell debris during high-energy storm. The siliciclastic mudstones in the central part of the succession reflect deposition in a basinal setting. The entire Bjørkåsholmen Formation at Flagabro is equivalent to a lowstand of third (?) order without a well-developed internal cyclicity and is in that respect similar to the Bjørkåsholmen Formation of Öland, but different from the age-equivalent Norwegian sections.

Department/s

  • Department of Geology

Publishing year

2018-01-02

Language

English

Pages

55-65

Publication/Series

GFF

Volume

140

Issue

1

Document type

Journal article

Publisher

Taylor & Francis

Topic

  • Geology

Keywords

  • Bjørkåsholmen Formation
  • carbonates
  • Flagabro
  • siliciclastic mudstones

Status

Published

ISBN/ISSN/Other

  • ISSN: 1103-5897