Darriwilian (Ordovician) graptolite faunas and provincialism in the Tøyen shale of the Krapperup drill core (Scania, Southern Sweden)

In Scania, southern Sweden, Lower Palaeozoic strata are preserved mainly in the Colonus Shale Trough, an elongated, fault-bounded and NW-SE-trending structure within the Sorgenfrei-Tornquist Zone. The relatively condensed Ordovician succession consists predominantly of graptolitic shales deposited in a foreland basin on a marginal portion of the Baltic plate. Outcrops are generally small and restricted to uplifted fault-blocks. Hence, our knowledge of the stratigraphy and spatial and temporal distribution of the succession is to a large extent based on drillings. A core drilling at Krapperup, northwestern Scania, in 1946 reached a depth of 155.06 m and penetrated a significant portion of the Lower–Middle Ordovician succession. The drilling was carried out by Wargön AB at a site 1.0 km west of the Krapperup castle. The core has diameter of 63 mm, shows no evidence of significant core loss, and is housed at the Division of Geology, Lund University. Graptolites from the lower part of the core, spanning the upper Tremadocian Hunnegraptus copiosus Biozone through the lower Dapingian Pseudophyllograptus angustifolius elongatus Biozone, have been studied by Lindholm (1981, 1991a, 1991b). The succession in the Krapperup core is the only one representing an unbroken shaly sequence across the boundary between the Tøyen Shale and the Almelund Shale, two units that in Scania are usually separated by the early Middle Ordovician (Darriwilian) Komstad Limestone