The crustal structure of Melville Bay, northern Baffin Bay

• Main Authors: Altenbernd, Tabea, Jokat, Wilfried, Damm, Volkmar, Heyde, Ingo, Schreckenberger, Bernd
• Format: Conference Object
• Language: unknown
• Published: 2013
• Subjects: Baffin Bay; Canada; Greenland; Arctic; Baffin; Davis Strait; greenlandic; Labrador Sea
• Online Access: https://epic.awi.de/id/eprint/32222/; https://hdl.handle.net/10013/epic.41049

The Baffin Bay, located between Canada and Greenland, developed during Paleocene and Eocene times. Its evolution is closely related to the opening of Labrador Sea and Davis Strait. The crustal structure of the Labrador Sea and Davis Strait has been studied in detail. In contrast, data on central and northern Baffin Bay is scarce. While southern Baffin Bay is underlain by oceanic crust with volcanic margins, the margins of northern Baffin Bay are characterized by serpentinized mantle material. In 2010, a multidisciplinary scientific cruise was conducted to study the crustal structure of central and northern Baffin Bay and to analyse the change from amagmatic to volcanic margins. Refraction seismic profiles were acquired along with other geophysical data in the Greenlandic part of Baffin Bay. We will present a P-wave velocity model and a density model along a profile, which runs from the deep sea area of northern Baffin Bay to the shelf area of Melville Bay. The velocity model was obtained by forward modelling of the data of 28 ocean bottom seismometers (OBS). In combination with potential field data, we divide the 321-km-long velocity model into three different crustal sections. In the central northern Baffin Bay, 6-km-thick sediments overlay a 3 to 5-km-thick oceanic crust. The crust consists of oceanic layer 2 and 3 and thickens towards the continental slope. At the shelf edge, a buried seamount and high velocities of up to 7.2 km/s in the lower crust are indicators for volcanic activity and intrusions of mafic material in this region. These features mark the onset of the ~90-km-wide transitional crust. Basement highs and up to 10 km deep sediment basins characterize the stretched continental crust of Melville Bay. Well-constrained reflections of the Moho can be found at a depth of 22-24 km in many seismic sections. Near the Greenland margin, a basement outcrop, characterized by high velocities, is present.