A palynofacies study of past fluvio-deltaic and shelf environments, the Oligocene-Miocene succession, North Sea Basin: A reference data set for similar Cenozoic systems

摘要: Abstract Correct interpretations of depositional environments are fundamental for evaluating the geological history a sedimentary basin. Palynofacies analyses valuable supplement to sedimentological and seismic studies. In order develop palynofacies reference dataset fluvio-deltaic shelfal successions, study assemblages organic particles from seven different well-defined within uppermost Oligocene – lower Miocene succession onshore Denmark (eastern North Sea Basin) has been performed. The deals with following environments; floodplain, lagoon, washover-fan flat, prodelta, shoreface, offshore transition shelf. were grouped into four major categories; 1) Structured wood particles, 2) Amorphous matter (AOM, in present mainly consisting partly degraded vitrinite), 3) Cuticle membranes 4) Palynomorphs. palynomorphs eight subcategories; Microspores, Non-saccate pollen, Bisaccate Botryococcus, 5) Other freshwater algae, 6) Fungal hyphae –spores, 7) Acritarchs 8) Organic-walled dinoflagellate cysts. A combination univariate box plots multivariate Principal Component Analysis (PCA) data clear revealed quantitative characteristics variations each discrete environment as well their principal similarities differences. spite some natural overlaps, example between lagoon environments, distinct characteristics, e.g. strong dominance shoreface environment, bisaccate pollen flat near absence dinocysts floodplain environment. An overall increase relative abundances decrease non-saccate proximal-distal trend also outlined. This outlines that can be used tool interpreting equivalent settings, preferentially combined other information such data, logs, and/or lithology.