Detrital zircon geochronology dating
Normally, core ages would be used as crystallization age as they are first generated and least disturbed part in zircon grains. Mafic volcanic rocks within Early Permian carbonates of the Nansen Formation have been interpreted to mark the end of the Asselian stage Mayr et al.
Sandy Point Formation Omma et al. Descriptive data more common in qualitative analysis Spot Number and nature Fig. Major tectonic events of northern Laurentia are highlighted by black boxes on the right.
Circum-Arctic orogens, terranes, and locations modified from Colpron and Nelson and Pease et al. During the Mesozoic, the main sediment source for the Sverdrup Basin was the exposed Devonian clastic wedge to the south and east of the basin Patchett et al. These data provide important insight into the nature of the source terrane and magmatism cf. In general, zircons from each sandstone sample exhibit a unique spectrum of formative ages, which then can be used to interpret the tectonic setting of the depositional basin e.
The timing of the inheritance curves is derived from the U-Pb detrital-zircon studies Fig. The dark color can be results from the radioactive damage of uranium to the crystal structure. In most cases, data are compared with U-Pb Concordia graphically.
Hyperlink them would help readers to get your ideas easier. These members are stratigraphically equivalent to the Heiberg Group that comprises five formations in the western part of the basin Fig. The first assemblage comprises an age spectrum identical to that of the Devonian clastic wedge in the Canadian Arctic and is termed the recycled source.
Paleo-climatic condition The past climatic conditions humidity and temperature correlating the degree of rock weathering and erosion may be useful for data interpretation. Seismic interpretation of an extinct spreading ridge has a trend that is parallel to the shelves offshore of the western Canadian Arctic Islands and Chukotka Pease et al.
Triassic to Middle Jurassic published detrital-zircon age spectra. Outline of Arctic Alaska represents the restored position prior to the opening of proto-Amerasia Basin, based on Nokleberg et al. Sverdrup Basin map with detrital-zircon sample and volcanic ash bed locations. May add some in the introduction.
Note that coeval magmatism is not observed in the Sverdrup Basin. Sample data Location Longitude and latitude coordinates are often included in sample description so that spatial analysis can be conducted. Although excluding data with huge age uncertainty would enhance the overall zircon grain age accuracy, over elimination may lower overall research reliability decrease in size of the database.
Much of the tectonic history of the basin is understood, with one notable exception, the pre-rift phase of the Arctic Ocean. Map of the Arctic depicting names and locations of basins and regions mentioned in text.