The Record of Microbially Induced Sedimentary Structures (MISS) in the Swedish Paleozoic

Microbially induced sedimentary structures (MISS) in siliciclastic shallow-marine strata occur in the lower and middle Cambrian and the Silurian of southern Sweden. These are typically transparent wrinkle structures with a wide range of morphologies. They are exclusively associated with shoreface to lower shoreface environments, characterized by fine-grained sandstone interbedded with mudstone and a Cruziana ichnofacies. Thicker, non-transparent forms with high-relief crinkled surfaces occur in the same paleoenvironments. The landward sand-dominated facies belt with Skolithos ichnofacies (upper shoreface foreshore) lack preserved wrinkle structures. Evidently, wrinkle structures are more common than previously thought in the Swedish Paleozoic and provide an important tool for understanding paleoenvironments and benthic paleoecology in strata largely devoid of body and trace fossils.