Mesozoic depositional environments and stratigraphy. Field trip guidebook, Bornholm, Denmark. Arranged for: Norsk Hydro ASA

Nine outcrops will be studied on Bornholm. To minimise the time in the bus, the outcrops will not be in stratigraphic order starting with the oldest deposits and finishing with the youngest. Each outcrop location is described in the Guide book. To ease overview of the stratigraphic relationships between the formations in the different outcrops, a litho-stratigraphic scheme with depositional environments is presented in each locality description. In order to compare the lithostratigraphy and depositional environments with the rest of Denmark, the litho-stratigraphic scheme from Bornholm is found together with lithostratigraphic schemes from the Danish Basin and the Danish Central Graben. The lithostratigraphic scheme from Scania is also presented. Each locality description in the Guide book is also supplied with a geological map of Bornholm where all the locations to be studied are marked.

At each outcrop locality sedimentary facies will be described and depositional environments will be interpreted and discussed. Lateral facies variations will be on focus where the outcrops allow such studies. Sequence stratigraphic studies and discussions will be presented at two or three outcrops.

Three shallow wells have been drilled near coastal outcrop sections. The wells are cored and Gamma Ray measurements have been logged. This allows us to compare GR- log patterns with core descriptions and nearby outcrop descriptions.

Each outcrop locality can be compared with similar deposits in the Danish Central Graben. The floodplain and lake sediments of the Bagå Formation on Bornholm resembles very much to the Middle Jurassic Bryne Formation in the Danish Central Graben. The Up-per Jurassic storm dominated, bioturbated shoreface sandstones of the Heno Formation in the Danish Central Graben have some similarities to the Lower Cretaceous storm dominated sand of the Robbedale Formation, the Amager Greensand and the Bavnodde Greensand formations on Bornholm. The Upper Jurassic storm dominated sandstone of the Hasle Formation on Bornholm is dominated by hummocky cross-stratification (HCS) and represents an end-member of the storm sand formations on Bornholm.