Print this pageSequence Stratigraphic Implications of Tectonism, Eustasy and Palaeoceanography of a Rifted Seaway: Jurassic of East Greenland
SURLYK, FINN
Break-up of the supercontinent Pangaea was initiated in the Late Permian and proceeded through Triassic time. In the Jurassic an extensive system of shallow rifted seaways extended from the Arctic Ocean in the north to the Tethys Ocean in the south over distances of 4000-5000 km. The Jurassic of North Europe and around the Norwegian-Greenland Sea offers a spectacular example of a palaeoceanographic setting with no recent analogues. A system of narrow relatively shallow straits formed part of a rifted seaway connecting the Arctic and Tethys Oceans. Tectonism included formation of major rift domes in late Early Jurassic time and block faulting and tilting in the Late Jurassic. Eustatic and tectonically induced sea-level changes resulted in alternation of periods with full marine communication through the seaway allowing faunal exchange and periods with isolated landlocked gulfs. During sea level lowstands vigorous tidal current systems existed resulting in deposition of heterolithic deposits in the Early Jurassic and clean tidal sands in the Middle and latest Jurassic. Sea level highstands resulted in development of stratified water masses and deposition of organic-rich muds in the Early and Late Jurassic. The combined effects of sealevel changes and tectonic style led to deposition of a set of predictable sedimentary facies types.