Print Email Facebook Twitter Pliocene paleoenvironment evolution as interpreted from 3D-seismic data in the southern North Sea, Dutch offshore sector Title Pliocene paleoenvironment evolution as interpreted from 3D-seismic data in the southern North Sea, Dutch offshore sector Author Kuhlmann, G. Wong, T.E. TNO Bouw en Ondergrond Publication year 2008 Abstract A high-resolution 3D-seismic survey from the Dutch offshore sector has been interpreted and subsequently correlated with existing regional seismo-stratigraphic concepts derived from conventional 2D-seismic data sets. The interpreted 13 seismic units have been related to a newly established chrono-stratigraphic framework [Kuhlmann et al., 2006a, b. Chronostratigraphy of Late Neogene sediments in the southern North Sea Basin and paleoenvironmental interpretations. Palaeogeography, Palaeoclimatology, Palaeoecology, 239, 426-455; Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region. Netherlands Journal of Geosciences-Geologie en Mijnbouw, 85(1), 19-35] resulting in up-dated age control for the seismic units. The generation of amplitude maps, time slices and isopach maps from the 3D-seismic data enabled detailed spatial and temporal reconstruction regarding the paleoenvironmental and climatological development as depicted by Kuhlmann et al. [2006a. Chronostratigraphy of Late Neogene sediments in the southern North Sea Basin and paleoenvironmental interpretations. Palaeogeography, Palaeoclimatology, Palaeoecology, 239, 426-455]. The lowermost seismic units S1-S4 comprise condensed Middle Miocene to Piacencian sediments, deposited under warm open marine conditions. These sediments show a uniform seismic facies of low-amplitude reflectors. The boundary of seismic unit S4-S5 (around 2.6 Ma) delineates a shift towards generally colder climate conditions that are connected to the onset of Northern Hemisphere Glaciation. Seismic unit S5 includes alternations of warmer and colder periods. During warmer periods, bottom currents generated elongated structures (2.5-4 km long, 300-500 m wide) on the horizon display. These layers show as well shallow gas accumulations with a more regional extent and are related to coarser-grained sediments sealed by clayey sediments of the cold phases. A homogenous seismic facies is characteristic for the colder periods. Within seismic units S6 and S7, internal fore set structures display the regressional trend related to the cooling of this interval. Seismic units S8-S11 display a pattern of unoriented lineaments which was probably caused by icebergs drifting into the North Sea and souring the sea floor. This finding is in accordance with the shallow marine, arctic conditions of this interval. Within these units a bright spot of 3 by 7 km in size, is interpreted to result from shallow gas accumulation related to a grounded iceberg. This feature represents another, more local area of gas accumulation that is closely related to iceberg activity within the study area. The uppermost seismic units S12 and S13 belong to a fluvial, paralic paleo-environment, that is characterised by aggradational seismic reflectors. Pleistocene glacial valleys were recognised in the upper 200 m below sea floor. © 2007 Elsevier Ltd. All rights reserved. Subject Geosciences3D seismicNorth SeaPaleoenvironmentPlioceneClimatologyEcologySedimentsSeismologyStratigraphyStructural geologyPaleoclimatologyPaleoecologyPaleoenvironmentPaleogeographyGeochronologychronostratigraphyclimate conditionsglaciationNorthern Hemisphereocean basinpaleoenvironmentPlioceneseafloorseismic dataseismic reflectionseismic stratigraphyseismic surveyseismologyAtlantic OceanNorth Sea To reference this document use: http://resolver.tudelft.nl/uuid:f75614bd-0ba5-4f6f-a144-295cb58ac78e TNO identifier 240650 ISSN 0264-8172 Source Marine and Petroleum Geology, 25 (2), 173-189 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.