Abstract

Material from a 229 m deep boring on the island of Anholt in the central part of the Kattegat has been stratigraphically analysed on the basis of its foraminiferal content. Due to the lack of casing in the main part of the bore hole, only very few core samples and some samples from the drilling bit were not contaminated. The results of the foraminiferal analyses have, therefore, to be treated with some reservation. The boring did not penetrate the Quaternary. The bottom 143 m of the boring represents deposits of pre-Eemian, possibly Saalian age. This interval seems to contain three marine interstadials, Anholt 1, 2 and 3, of which the upper interstadial is the warmest. Tills and glaciofluvial sediments are found between the marine sequences. The Eemian is represented by 13 m of marine deposits, which can be correlated with Eemian deposits known from other localities in the Vendsyssel-Kattegat region. They correspond to the Lower Turritella terebra Zone of the Skærumhede Series. The Early Weichselian and the lower part of the Middle Weichselian are missing, while the upper part of the Middle Weichselian, 32 m in all, is represented by marine deposits corresponding to foraminiferal zones known from the Vennebjerg Stadial and the Sandnes lnterstadial in the Vendsyssel-Kattegat region. These Middle Weichselian zones correspond to the upper part of the Portlandia arctica Zone of the Skærumhede Series. The non-marine sequence on top of these deposits is considered to be glacial, belonging to the main Weichselian glacial event. Holocene littoral sands and gravels terminate the Quaternary sequence at Anholt.

Highlights

  • In 1943 a 229 m deep boring was sunk on the island of Anholt in the Kattegat on the initiative of The Ministery of Public Works in Copenhagen

  • In the geological part of the internal report Gry concluded that the Quaternary deposits of the Anholt boring could be subdivided as follows: 0-- 3,0 m marine Holocene sand and gravel

  • The present study shows that the deposits between 3 and 72.7 m depth belong to the Late and Middle Weichselian

Read more

Summary

Introduction

In 1943 a 229 m deep boring was sunk on the island of Anholt in the Kattegat (figs. 1, 2, 3, 4, 5, 6 and 7) on the initiative of The Ministery of Public Works in Copenhagen. N0rvang found faunas which consisted of both boreal and arctic species in these samples He discussed the origin of this series and concluded that it might be either a local till composed of different marine clays or a marine arctic stony clay with arctic foraminiferal faunas, but contaminated by the overlying boreal faunas. In the geological part of the internal report Gry concluded that the Quaternary deposits of the Anholt boring could be subdivided as follows The purpose of the present investigation is to establish as detailed a foraminiferal zonation of the Quaternary deposits in the Anholt boring as possible and to place this within the regional chronology for the Kattegat region (Lykke-Andersen 1987). The knowledge obtained could further our knowledge about basin development in this part of Kattegat

Material and methods
Findings
Conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.