Upper Cambrian trilobite biostratigraphy and taphonomy at Kakeled on Kinnekulle, Västergötland, Sweden
A section through the Upper Cambrian black shales and limestones at Kakeled on Kinnekulle, Västergötland, Sweden, extends from the lower-middle part of the Agnostus pisiformis Zone into the Peltura scarabaeoides Zone. Fossils are usually preserved only in the stinkstones, but in the A. pisiformis Zone trilobites can be found also in the shales. Lithologically, the stinkstones can be subdivided into primary coquinoid limestone, which include the majority of the fossils, and early diagenetically formed limestone. The orientation of cephala and pygidia of A. pisiformis were measured on four shale surfaces and one stinkstone surface. The majority of the shields were deposited with the convex side up and showed a preferred orientation, suggesting that their positions were affected by currents. Above the A. pisiformis Zone the section comprises the Olenus/Homagnostus obesus Zone (0.30 m), the upper part of the Parabolina spinulosa Zone (0.05 m), the Peltura minor Zone (1.15 m), and the Peltura scarabaeoides Zone (2.50 m). The Leptoplastus and Protopeltura praecursor zones are missing. The Olenus/H. obesus Zone is represented only by the O. gibbosus and O. wahlenbergi subzones, whereas the O. truncatus, O. attenuatus, O. dentatus, and O. scanicus subzones are missing.
Key words: Trilobita, biostratigraphy, alum shale, depositional environment, Upper Cambrian, Kakeled, Kinnekulle, Sweden.
Fredrik Terfelt [Fredrik.Terfelt@geol.lu.se], Department of Geology, GeoBiosphere Science Centre, Sölvegatan 12, SE−223 62 Lund, Sweden.
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