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

High-resolution δ 13 C org chemostratigraphy links the Decorah impact structure and Winneshiek Konservat-Lagerstätte to the Darriwilian (Middle Ordovician) global peak influx of meteorites

“…A comparison with the established d 13 C chemostratigraphy reveals that the isotope curve through the Winneshiek Shale shows a remarkable similarity to published Darriwilian curves from, for instance, Baltoscandia (e.g. Ainsaar et al 2004Ainsaar et al , 2007Meidla et al 2004;Martma 2005;Kaljo et al 2007;Schmitz et al 2010;Wu et al 2015), the Yangtze Platform of China (e.g. Schmitz et al 2010), the Precordillera of Argentina (Albanesi et al 2013) and eastern North America (e.g.…”

Lower–Middle Ordovician carbon and oxygen isotope chemostratigraphy at Hällekis, Sweden: implications for regional to global correlation and palaeoenvironmental development

“…Wu et al . ). The data from the Mehikoorma 421 drill core in Estonia differ drastically from the other Baltoscandian data sets in that the post‐Kunda interval is characterized by relatively low δ 18 O values.…”

Darriwilian (Middle Ordovician) chemostratigraphy linked to graptolite, conodont and trilobite biostratigraphy in the Fågelsång-3 drill core, Scania, Sweden

“…As is the case in some other sections in southern Sweden (cf. Wu et al 2015Wu et al , fig. 6, 2017 fig.…”

“…However, very little work has been carried out in the Ordovician to integrate graptolite biostratigraphy with chemostratigraphy. A very significant amount of work has been centered on integration of conodont biostratigraphy with δ 13 C chemostratigraphy (e.g., Wu et al 2015Wu et al , 2017Wu et al , 2018Schmitz et al 2010) but the present study is the first to integrate Darriwilian graptolite biostratigraphy with conodont biostratigraphy using δ 13 C chemostratigraphy in an extended succession. The recent availability of a new drill core, the Fågelsång-3 drill core, through the classical graptolite shale succession in the Fågelsång area made this study possible.…”

“…Between approximately 57-m and 44-m core depth there are elevated, rather "noisy" isotope values. An apparent longterm (Floian-Darriwilian) trend, which is currently unnamed but has been informally referred to as the "Floian-Darriwilian Rise" by Wu et al (2015, fig. 5), is previously known from the Holen and Lanna limestones, and the Tøyen Shale, in the platform facies of Sweden and equivalent strata elsewhere in Baltoscandia.…”