Arctic ocean mega project: Paper 2 – Arctic stratigraphy and regional tectonic structure

Abstract

A seismic stratigraphic framework and basin fill geohistory for Arctic Ocean basins is presented based on data collected by several Russian Government organized expeditions to the Arctic Ocean. This analysis tied together seismic stratigraphic interpretations for the shelf and the deep-water part of the ocean. The stratigraphic framework is based on age data derived from linear magnetic anomalies in the Eurasia Basin, borehole data for the Lomonosov Ridge and Alaska Shelf, and correlations with various regional geological events. Six seismic boundaries were identified and traced regionally over large areas. We present as a hypothesis that the Arctic Ocean probably was formed during four phases with different kinematics: 133-125 Ma – Canada Basin opening, 125-80 Ma – superplume-related tectonics and magmatism in the Alpha-Mendeleev Rise area and adjacent basins, 80-56 Ma - strike-slip fault tectonics, and 56-0 Ma – Eurasia Basin opening. The time interval of 45-20 Ma appears to be a period of large-scale vertical intraplate movements and normal faulting. Climatic events are recorded in the sedimentary cover of the Arctic Ocean. The analyses were based on a comprehensive dataset that included more than 23,000 km of 2D seismic lines, which were acquired in the deep-water part of the ocean, supplemented by a large number of federal and commercial seismic lines, which were acquired for the Russian shelves during the past 10-15 years. In addition, special multiple Russian expeditions collected samples on scarps of the Mendeleev Rise that served as ground truth for the seismic interpretation.