STATISTICAL-ANALYSES OF PALYNOMORPH ASSEMBLAGES IN MIDDLE JURASSIC DEPOSITS (LOWER TO MIDDLE BATHONIAN, BRENT-GROUP, NORWAY)

The Early to Middle Bathonian oi the Brent Group (North Sea) were core d through several Elf Aquitaine exploration wells. The analyzed core s amples provided two sets oi quantitative palynological data from coal and non-coal samples. Palynomorph counts (spores, pollen grains, dinof lagellates, acritarchs, algae and foraminiferal test linings) were use d in multidimensional data analyses. In the first data set (coals), th ree main palynological assemblages highlighting the abundance of Delto idospora, Perinopollenites, Cerebropollenites and Lycopodiumsporites w ere distinguished. The study of the data set from non-coal samples rev ealed the presence of a transport gradient contrasting ''more marine'' and ''more continental'' samples. The ''more marine'' samples are cha racterized by diverse dinoflagellate assemblages and buoyant pollen gr ains such as bisaccates. The ''more continental'' samples exhibit two main environments: Deltoidospora swamps and Perinopollenites lagoons. The palececological trends of the palynomorphs were deduced from the s tudy cf these main gradients. Some inferences are made about the paleo ecological significance of the dinoflagellate assemblages and the diff erent Cheirolepidiaceae pollen grains.