Palynofacies and palynology of the Cenomanian-Turonian deposits in ODP 174AX Bass River core, New Jersey : Depositional environment, vegetation history, petroleum potential and climate changes during the Oceanic Anoxic Event 2

At the Cenomanian-Turonian (~94 Ma) boundary, sudden and major disruptions in the oceanic systems occurred. The disruptions led to the establishment of worldwide oceanic anoxia and deposition of organic-rich sediments. This event, the C-T Oceanic Anoxic Event (OAE2), is one of several OAEs occurring in the Cretaceous. OAEs are not very well understood and much research has been done since the concept was first proposed. However, the research has almost exclusively been concerned with the mechanisms for unleashing these events and the consequences in the marine environments. Little research has been done concerning the surrounding landmasses and what impact an OAE had on the terrestrial ecosystems. Palynofacies and palynological analyses with emphasis on the terrestrial palynomorphs were performed on material from the Bass River core ODP 174AX in New Jersey. This material is also used in the PhD-project "Ocean biogeochemistry in the mid-Cretaceous: reconstructing the nutrient-biosphere-climate link" at Utrecht University. Geochemical data from this project were incorporated with the present thesis. The analyses determined the palaeoenvironment, vegetation history, source rock potential of the C-T deposits as well as identifying a possible connection between the OAE2 and climate changes. The sediments were deposited on a stable, dysoxic, neritic shelf with a strong terrestrial signal from the proximal delta. On adjacent land the vegetation was open-canopied woodland typical for the mid-Cretaceous, southeastern North America, with wetlands surrounding the delta. The heavy influence of the delta or the location is hindering the establishment of anoxia and subsequent organic carbon burial, which is characteristic for OAE2 deposits. However, vegetation changes and geochemical data in the OAE2 interval in Bass River exhibit traits similar to the Plenus Cold Event. This event was probably caused by the rapid carbon burial and CO2-drawdown during the OAE2.