Lower-Middle Ordovician delta C-13 chemostratigraphy of western Baltica (Jamtland, Sweden)

Summary, in English

The province of Jamtland, central Sweden, records a well-preserved but very thin suite of the Lower-Middle Ordovician cool-water carbonates. In this study we present the first carbon isotope profile for these strata on the basis of whole-rock samples from the Brunflo 2 core. The studied succession is 41.55 m thick and includes, in ascending order, the Bjorkasholmen Formation, Latorp Limestone, Toyen Shale, and the Lanna, Holen, and Segerstad limestones. We identify two distinct positive delta C-13 excursions that can be used for intra-as well as inter-continental correlations. A positive excursion in the Toyen Shale probably correlates to the mid-late Floian and the Oepikodus evae Zone in Baltica and Precordillera, and the Reutterodus andinus Zone in North America. A continuous increase in delta C-13 values through the upper Holen Limestone and the preserved part of the overlying Segerstad Limestone is interpreted as the rising limb of the Middle Darriwilian Isotope Carbon Excursion (MDICE), an important tie-point for the global correlation of the Jamtland strata. Negative delta C-13 values associated with the Latorp Limestone may correlate with similar low values in the late Tremadocian and early Floian of the Argentine Precordillera and the Shingle Pass and Ibex sections in North America. (C) 2015 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved.

• Author: Rongchang Wu; Mikael Calner; Oliver Lehnert; Olof Peterffy; Michael M. Joachimski
• Department/s: Lithosphere and Biosphere Science
• Publishing year: 2015
• Language: English
• Pages: 110-122
• Publication/Series: Palaeoworld
• Volume: 24
• Issue: 1-2
• Links: http://dx.doi.org/10.1016/j.palwor.2015.01.003
• Document type: Journal article
• Publisher: Elsevier
• Topic: Geology
• Keywords: Ordovician; Sweden; Carbon isotope chemostratigraphy; MDICE
• Status: Published
• ISBN/ISSN/Other: ISSN: 1875-5887