Megascopic processes reflected in the microscopic realm: sedimentary and biotic dynamics of the Middle Ordovician “orthoceratite limestone” at Kinnekulle, Sweden

Abstract

Megascopic processes reflected in the microscopic realm: sedimentary and biotic dynamics of the Middle Ordovician 'orthoceratite limestone' at Kinnekulle, Sweden

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

“…The many cratonic outcrops in Sweden appear largely homogenous at the macroscopic scale and in Västergötland most outcrops are typically devoid of conspicuous evidence of tectonic activity (cf. Lindskog & Eriksson ; and references therein).…”

“…Typically, the ‘orthoceratite limestone’ is reddish, brownish or grey in colour and consists of calcareous mud mixed with sand‐sized skeletal grains and very limited amounts of terrigenous matter (e.g. Lindskog & Eriksson ; and references therein). Although nautiloid cephalopods, including orthoceratids, are common locally and lend their name to the informal rock unit, many parts of the ‘orthoceratite limestone’ do not contain abundant macrofossils.…”

“…Hence, these limestones are not lithostratigraphically defined and in lack of a revised lithostratigraphical framework they are herein retained as informal and provisional units (cf. Kumpulainen ; Lindskog & Eriksson ). The boundary between the Tøyen Shale and the ‘Lanna Limestone’ closely coincides with that between the Floian and Dapingian global stages (e.g.…”

“…Bergström & Löfgren ). A conspicuous ~1.5‐m‐thick interval of grey limestone, informally known as the ‘Täljsten’, occurs across Kinnekulle in the lower part of the ‘Holen Limestone’ (see Lindskog & Eriksson ; and references therein). Disconformably overlying the ‘Holen limestone’ is the decimetre‐thick ‘Skövde Limestone’, which belongs to the Lasnamägi Baltoscandian Stage and the Dw3 Stage slice of Bergström et al .…”

“…For this study, we collected a composite section at the Hällekis quarry on the northwestern slope of Kinnekulle (WGS 84 coordinates N58°36′33″, E13°23′42″; Figs ). The same section and sample series were recently described in close detail for carbonate microfacies analyses and relative sea‐level reconstructions by Lindskog & Eriksson (), allowing for direct comparison between data sets.…”