Original paper

Evidence of isochronic transgressive surfaces within the Jade Bay tidal flat area, southern German North Sea coast ? Holocene event horizons of regional interest

Wartenberg, Wolfram; Vött, Andreas; Freund, Holger; Hadler, Hanna; Frechen, Manfred; Willershäuser, Timo; Schnaidt, Stefanie; Fischer, Peter; Obrocki, Lea

Abstract

The sedimentary succession of the Jade Bay in Lower Saxony, southern German North Sea, was examined using percussion core data. 59 cores were drilled within a tidal flat environment to detect the Holocene depositional record and to outline the underlying Pleistocene relief. Geochronology is based on 51 radiocarbon ages and on pollen and macro-remains of encountered Holocene peat layers. A west-east trending stratigraphic cross section spanning ten nautical miles (approx. 18.5 km) reveals different accommodation space conditions underlying one and the same tidal regime. XRF-data obtained by both stationary and handheld scanning techniques was used to trace interferences of different sedimentary environments. Four high-energy chronozones of mid Holocene to late Holocene age were recognised and correlated with the stratigraphic record over long distances. Layers of allochthonous siliciclastic deposits were found cutting sedentary layers and tidal regime sequences associated with sedimentary structures such as rhythmic fining upward sequences, co-existing well rounded clastic components and shell fragments, rip-up clasts, lamination features and basal erosional unconformities. These high-energy related structures document dominant isochronic transgressive surfaces in the stratigraphical record of the Jade Bay area which, so far, have not been depicted in contemporaneous models of tidal depositional environments but play a significant role in the overall coastal evolution.

Keywords

event stratigraphygerman north seahigh-energy depositsholocenejade baysubboreal period northern germanytransgressive surfaces