High resolution trilobite stratigraphy of the Lower–Middle Ordovician Öland Series of Baltoscandia

Abstract

The first ever list of the regional Öland Series (Tremadocian to mid Darriwilian) trilobites and agnostids from the whole of Baltoscandia is compiled. The study includes revision of systematics as well as vertical and horizontal distribution. This is necessary because of the uneven state of knowledge, some faunas having being studied recently, others not for more than a century. Three successive faunal types are recognized: the Olenid Fauna surviving from the Cambrian in black bituminous shale facies, the immigratingCeratopygeFauna, and the stabilized Asaphid Fauna. The latter fauna collapsed in the middle of Darriwilian and gave way to a set of new post-Ölandian faunas.

Cambrian stratigraphy of the Tomten-1 drill core, Västergötland, Sweden

“…Lehnert et al , 2013Calner et al 2013). The presence of the trilobite species Varvia breviceps and Megistaspis estonica in the Latorp Limestone in the Tomten quarry (Thorslund 1937;Tjernvik 1956) is consistent with the above interpretation (see Pärnaste et al 2013), but the local Ordovician trilobite zonation remains to be documented in detail.…”

Lower–Middle Ordovician δ13C chemostratigraphy of western Baltica (Jämtland, Sweden)

“…The correlation chart for the Ordovician in the Brunflo area provided by Wickström (2007) is followed herein ( Fig. 3; based on Bergström, 1971;Lindström, 1971;Löfgren, 1994;Karis, 1998;Wickström, 2007;Pärnaste et al, 2013).…”

“…Chart showing the correlation of lithostratigraphy in Brunflo with the Baltoscandian graptolite, trilobite, and conodont zones. Modified fromBergström (1971),Lindström (1971),Löfgren (1994),Karis (1998),Wickström (2007),Maletz and Ahlberg (2011) andPärnaste et al (2013).…”

On the lower boundary of the Floian Stage in Estonia

“…Megistaspis estonica, which is characteristic of the Päite Member, defines the Pärnaste et al (2012), with refreshed graptolite data by Maletz & Ahlberg (2011), conodont data by Viira (2011), and following the revised global standard (Bergström et al 2009). uppermost trilobite zone of the Billingen Regional Stage. In Estonia the first trilobites appear at a level where sandy terrigenous rocks are replaced by calcareous ones, i.e.…”

“…The calcareous beds of the Mäeküla Member (upper Leetse Formation) contain very rare, poorly preserved trilobites, which were recently restudied (Pärnaste 2003(Pärnaste , 2006a(Pärnaste , 2006bPärnaste et al 2009). The taxonomic association of trilobites in Estonia differs from that in Sweden (Pärnaste 2006a;Pärnaste et al 2012;Bergström et al 2013) and complicates the correlation between these regions. Mainly, the research (of H. P.) was stuck at the unpublished new species mentioned by Tjernvik as being characteristic of the M. aff.…”