GEOSCAN Search Results: Fastlink


TitleStructural evolution and basin architecture of the traill ø region, NE Greenland: a record of polyphase rifting of the east Greenland continental margin
AuthorParsons, A J; Whitham, A G; Kelly, S R A; Vautravers, B P H; Dalton, T J S; Andrews, S D; Pickles, C S; Strogen, D P; Braham, W; Jolley, D W; Gregory, F J
SourceGeosphere .,
Alt SeriesNatural Resources Canada, Contribution Series 20170009
PublisherGeological Society of America
Lat/Long WENS -30.0000 -15.0000 76.0000 70.0000
Subjectssedimentology; structural geology; tectonics; basins; sedimentary basins; sedimentation rates; sea floor spreading; tectonic evolution; mudstones; deformation; geological evolution; basin evolution; plate tectonics; rifting; rifts
Illustrationslocation maps; geological sketch maps; stratigraphic cross-sections; stratigraphic columns; tables; photographs; cross-sections, structural
ProgramWestern Cordillera, Redefinition of crustal blocks, GEM2: Geo-mapping for Energy and Minerals
AbstractFault block basins exposed along NE Greenland provide insights into the tectonic evolution of East Greenland and the Norway-Greenland Sea. We present a new geological map and cross sections of the Traill Ø region, NE Greenland, which formed the western margin of the Vøring basin prior to Cenozoic seafloor-spreading. Observations support a polyphase rift evolution with three rift phases during Devonian¿Triassic, Jurassic¿Cretaceous and Cenozoic times. Greatest amounts of faulting and block rotation occurred during Cenozoic rifting, which we correlate with development of the Continent-Ocean Transition after ~56 Ma and the Jan Mayen Microcontinent after ~36 Ma. A newly devised macrofaunal-based stratigraphic framework for the Cretaceous sandy mudstone succession provides insights into Jurassic¿Cretaceous rifting. We identify a reduction in sedimentation rates during the Late Cretaceous. This corresponds to a transition from structurally-confined to unconfined sedimentation that coincides with increased clastic sedimentation to the Vøring and Møre basins derived from East Greenland. With each rift phase, we record an increase in the number of active faults and a decrease in the spacing between them. We attribute this to fault block rotation which leads to an excess build-up of stress that can only be released by the creation of new, steep faults. Additionally, we observe a stepwise-migration of deformation towards the rift axis that we attribute to pre-existing lithospheric heterogeneity that was modified during subsequent rift and post-rift phases. Such observations are not readily conformable to classic rift evolution models and highlight the importance of post-rift lithospheric process that occur during polyphase rift evolution.
Summary(Plain Language Summary, not published)
Rift basins along NE Greenland provide record the geological evolution of East Greenland and the Norway-Greenland Sea. We present a new geological map of the Traill Ø region, NE Greenland. Observations support a multi-phase rift evolution with three rift phases. Greatest amounts extension occurred during the formation of oceanic crust in the final rift phase. A new fossil-based framework for the Cretaceous strata provides insight into Jurassic¿Cretaceous rifting. Changes in sedimentation rates correspond to changes in basin size and coincides with increased sediment input derived from East Greenland into basins off the west coast of Norway. With each rift phase, the number of active faults increases and the spacing between them decreases. Additionally, we observe a migration of deformation during each new rift phase rifting, governed by pre-rift and post-rift processes. Our findings highlight the importance of post-rift processes that occur during multi-phase rift evolution.