Ordovician sedimentary rocks are exposed in patches across the southern half of Sweden. The northernmost exposure is surrounding the
Siljan Ring, a
Devonian impact crater in
Dalarna. Other outcrops are found west and south of
Örebro, northeast of
Livköping, west and southwest of
Skövde and surrounding
Falköping. Underlying the
Granby crater, west of
Linköping, the Ordovician has a larger exposure. The southernmost Ordovician outcrops are situated in
Skåne, due east of
Lund and at the southeastern tip of Sweden. Most of the island of
Öland consists of Ordovician sediments, where
Folkeslunda is located, the namesake for the formation. Previous names for the formation were Upper Grey Orthoceratite Limestone, Chiron Limestone, Centaurus Limestone and Schroeteri Limestone (lower part). The type section is located in the southeastern part of the parish of
Långlöt and the northeastern part of the parish of
Runsten on Öland. The best section of the unit on Öland is in a quarry close to the road from
Vedby to
Bäcklunda, east of
Hornsjön. The formation is the uppermost unit in the traditional Orthoceras Limestone of Sweden, overlying the
Seby Limestone and the Folkesunda Limestone is overlain by the
Furudal Limestone. The Folkeslunda Limestone dates to the
Lasnamägi stage, part of the Purtse, belonging to the Virunian in the regional stratigraphy of Sweden, corresponding to a late
Darriwilian age of the Middle
Ordovician. The unit is thick in the Vikarby section and thick in the Kårgärde section of the western Siljan Ring. In the Lunne section of
Jämtland the unit is between thick. == Lithologies ==