A Revised Core-Seismic Integration in the Molloy Basin (ODP Site 909): Implications for the History of Ocean Circulation in the Arctic-Atlantic Gateway

• Main Authors: Gruetzner, Jens, Geissler, Wolfram, Gebhardt, Catalina, Matthiessen, Jens
• Format: Conference Object
• Language: unknown
• Published: 2019
• Subjects: Arctic; Arctic Ocean; Greenland; Northeast Atlantic; Svalbard
• Online Access: https://epic.awi.de/id/eprint/49607/; https://hdl.handle.net/10013/epic.0af37e6a-a972-4511-affb-08ffabfc9c11

The modern polar cryosphere reflects an extreme climate state, which developed through stepwise global Cenozoic cooling. In this context the polar gateways played pivotal roles in changing the global hydrography. The Arctic Ocean was isolated from any global thermohaline circulation system during large parts of its Cenozoic history. This gradually changed when Greenland and Svalbard started to move apart from each other initiating the opening of the Arctic-Atlantic Gateway (AAG), the only deep-water connection, which allows an exchange of water masses both at the surface and at depth with the World's oceans (e.g., Rudels 2015). Based on DSDP and ODP drilling campaigns (Legs 38, 104, 151, 162), and with the help of geophysical datasets, knowledge on the tectonic evolution of the Northeast Atlantic Basins and continental margins increased. However, crucial issues like the exact timing of tectonic phases and stratigraphic events and how these phases and events translate into seismic reflection stratigraphy are still a matter of debate. Previous seismic processing and interpretation in the area concentrated on the general low-resolution picture of the basement structure and overlying sediments and a first general interpretation of the glacial history along the NE Greenland margin (Berger and Jokat, 2009). In our study we re-process the available reflection seismic data with means of f-k-filtering and deconvolution in order to improve the resolution of the internal sedimentary structure and to achieve a better insight into internal reflection characteristics and the geometry of the sediment packages. Here we present first re-processed seismic lines that were collected in 2002 with RV Polarstern in the Molloy basin. We can demonstrate that we gain much higher resolution in the uppermost section, which significantly improves the interpretation of the shallowest part of the seismic profiles. An important profile is line AWI-20020300 that crosses ODP Site 909 (Myhre et al., 1995), a key site to date the late opening ...