![Sample our Earth Sciences journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5930/TOC-Subject-Sample-2021-Earth-Sciences.jpg"})
ABSTRACT
The depression of the ancient Lumparn meteorite impact structure is partly infilled by Cambrian and Ordovician sediments, lying nowadays below the seawater. The Ordovician carbonate succession at this site, recognised through erratic boulders and by the drilling project in the late 1950s, is of particular interest due to its isolated and distant location from other areas with Ordovician sediments in the Baltoscandian Palaeobasin. In this study, we present new data on ostracod biostratigraphy and stable carbon isotope chemostratigraphy obtained from three old drillcores. Comparison of ostracod distribution with sections in Estonia generally supports the previous interpretations of a Darriwilian and Sandbian age for the lowermost Tranvik Limestone (which we propose renaming the “orthoceratite limestone” in the Åland Islands area). The uppermost Östersjö Limestone spans almost the entire Katian age. We also observe the global MDICE and GICE carbon isotopic excursions, as well as Katian Rakvere and Saunja excursions, within the Lumparn succession. The Ordovician succession in Lumparn Bay is facially resembling the Estonian Shelf facies of the Baltoscandian Palaeobasin.
Acknowledgements
The authors are grateful to Håkan Pihl (Nordkalk Corp.) for the access to the drillcores and unpublished materials. Two anonymous reviewers are thanked for valuable remarks and comments. This publication was supported by the project PRG1701 from the Estonian Research Agency as well as by the Institute of Ecology and Earth Sciences, University of Tartu. This is a contribution to the IGCP project 735 “Rocks and the Rise of Ordovician Life (Rocks n’ ROL)”.
Disclosure statement
No potential conflict of interest was reported by the author(s).