Sediment Structure of the Makarov Basin along 81°N

Wilfried Jokat
Alfred Wegener Institute for Polar Research, Bremerhaven, Germany.

The Mesozoic geological evolution of the Arctic Ocean created several basins and ridges, namely the Alpha-Mendeleev Ridge and the Canada and Makarov basins. However, the problem in reconstructing the kinematic of the old part of the Arctic is that almost no basement samples and seismic data exist, which could provide information on the age/structure of the different tectonic elements. It is still under debate if large parts of the Makarov Basin are underlain by continental crust and how its evolution is linked to the Mendeleev Ridge.
Here, we present a seismic transect along the 81°N latitude, which crosses all relevant tectonic structure (Mendeleev Ridge, Makarov Basin, Lomonosov Ridge) of the eastern Amerasia Basin for the first time. The seismic data show that the Makarov Basin contain more than 5 km of sediments, which can be clearly divided into a Mesozoic and Cenozoic portion. The seismic unit, which most likely indicates the rift/drift transition of the Lomonosov Ridge, can be traced across the entire basin. From the depositional character of the seismic units onlapping on the western flank of the Mendeleev Ridge it is obvious that this ridge most likely formed close after the occurrence of the first oceanic crust in that area. No indication for an extinct mid-ocean ridge was found. Such structure might have been destroyed during the formation of the Mendeleev Ridge around 90 Ma. These results will be discussed in view of different tectonic models.

 

AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.

��������������������������������������������������������������������������������������������