|The Middle Miocene to Recent Davis Strait Drift Complex: implications for Arctic–Atlantic water exchange|Nielsen, T.; Andersen, C.; Knutz, P.C.; Kuijpers, A. (2011). The Middle Miocene to Recent Davis Strait Drift Complex: implications for Arctic–Atlantic water exchange. Geo-Mar. Lett. 31(5-6): 419-426. hdl.handle.net/10.1007/s00367-011-0245-z
In: Geo-Marine Letters. Springer: Heidelberg; Berlin. ISSN 0276-0460, more
|Authors|| || Top |
- Nielsen, T.
- Andersen, C.
- Knutz, P.C.
- Kuijpers, A.
A large-scale contourite drift complex has been recognised on multi-channel 2D reflection seismic data acquired in the south-eastern Davis Strait and adjacent Labrador Sea slope offshore West Greenland between 63°–66°N. Based on well-tie data, the drift complex developed from the Middle Miocene to the Recent. It has been mapped in a wide variety of water depths ranging from about 700 m, at a NNW-ESE-elongated crest located above structural highs in the Davis Strait, to more than 2,000 m beyond the slope to the Labrador Sea. The overall drift geometry has been described by subdivision into two first-order seismic units, enabling the generation of time-isochore maps. The reflection patterns demonstrating current-related deposition are illustrated by seismic examples. The time-isochores of the two first-order seismic units show lateral changes in their depocentres: the lower unit is absent in a zone slightly displaced south-westwards of the present-day crest, indicating changes in the prevailing deepwater current system during the Early Pliocene. The observations can be explained by two alternative palaeoceanographic scenarios: (1) either the present-day oceanographic setting with Arctic–Atlantic water exchange across the Davis Strait was largely established by the mid-Miocene, with only minor adjustments during the Early Pliocene caused by tectonic movements, or (2) it became established during the Early Pliocene as a consequence of enhanced northward flow across the Davis Strait due to lowering of the sill depth.