Sedimentological study of the Jurassic and Cretaceous sequence in the Revinge-1 core, Scania

Abstract: This thesis presents a study of the core from the Revinge-1 borehole from the Vomb Trough. The core displays strata from the Upper Jurassic to the Upper Cretaceous including strata covering the the J/K−boundary . Sedimentological, biostratigraphical and lithological studies (such as SEM-EDX) were performed as to get a multi-disciplinary characterization of the strata. The core have been divided in eight different units, A−H. The basal part of the core includes strata belonging to the Upper Jurassic Fyledal Clay overlain by the Upper Jurassic−Lower Cretaceous Vitabäck Clays of the Annero Formation followed by the Arnager Greensand and the Upper Cretaceous Vomb Formation. The Jurassic and Lower Cretaceous succession is overall dominated by fine-grained siliciclastic deposits such as clays/claystone, siltstone and fine-grained sandstone. The Upper Cretaceous is still siliciclastic but significantly calcareous and in parts characterized as an arenaceous limestone. The Arnager Greensand is a sandy unit rich in glauconite and numerous burrows and has likely been deposited in a shallow marine environment. Biostratigraphical data also suggests a Cenomanian age of the Arnager Greensand. Black and dark grey clays of the Vitabäck Clay does furthermore commonly include a rich and well-preserved fossil fauna of thin-shelled bivalves and bone fish fossils indicating a low energy-environment in a brackish-marine setting. The core furthermore displays an iron ooid-rich interval which is interpreted to be related to a volcanic influence during the Early Cretaceous, i.e. c. 145 Ma in Scania. Palynological data of the unit indicates a Volgian to mid Berriasian age. The basal Fyledal Clay is a yellowish grey clay rich in rootlets, pieces of coal and includes fossil imprints. It was likely deposited in a quiet water environment with lagoons and wet marshes.