| Title | Calibration of Middle to Upper Jurassic palynostratigraphy with Boreal ammonite zonations in the Canadian Arctic |
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| Author | Nguyen, A V; Galloway, J M ; Poulton, T P; Dutchak, A |
| Source | Bulletin of Canadian Petroleum Geology vol. 68, no. 3, 2021 p. 65-90, https://doi.org/10.35767/gscpgbull.68.3.65 |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200747 |
| Publisher | The Canadian Society of Petroleum Geologists |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Nunavut |
| NTS | 38G; 38H; 48G; 48H; 58G; 58H; 68H; 68G; 78G; 78H; 88G; 88H; 89; 79; 69; 59; 49; 39; 560; 340; 120 |
| Lat/Long WENS | -120.0000 -60.0000 84.0000 75.0000 |
| Subjects | environmental geology; fossil fuels; arctic geology; Paleogene; palynology; pollen; pollen analyses; paleoenvironment; temperature; biostratigraphy; Middle Jurassic; Sverdrup Basin; Paleozoic |
| Illustrations | location maps; geological time charts; tables; figures; columnar sections |
| Program | GEM2:
Geo-mapping for Energy and Minerals TransGEM |
| Released | 2021 08 04 |
| Abstract | Quantitative palynostratigraphy of the Middle to Upper Jurassic strata of the Sverdrup Basin is used to calibrate palynomorph signatures to Boreal ammonite occur-rences to improve high-latitude
chronostratigraphy and supplement a paucity of Upper Jurassic paleoclimatic data in Arctic Canada. Terrestrial palynological signatures of Middle and Upper Jurassic strata of the Sverdrup Basin, Arctic Canada, are assessed with associated Boreal
ammonite occurrences to generate a multi-taxon biostratigraphic scheme to improve inter- and intra-basin correlations. Palynological analyses of two stratigraphic sections exposed on Axel Heiberg Island, Arctic Canada, generated a succession of six
informal palynoassemblages related to closely co-occurring ammonite assemblages. The ammonite assemblages are a result of both endemic evolution of Boreal lineages within this relatively isolated Arctic basin (i.e. Middle and Upper Jurassic
Cardioceratidae) and replacement at the superfamily level due to periodic incursions of southerly faunas into the basin. These migrations imply periods of connectivity with more southern basins that may be related to transgressive flooding, tectonic
opening of north-south seaways and associated climate variation. Evidence for regional climate variation is supported by the taxonomic composition of terrestrial palynomorph groupings. Changes in the relative abundance of ecologically important spore
and pollen taxa are consistent with a climatic shift from warm-temperate in the Late Toarcian-Early Bajocian to more arid and cooler conditions during the Middle Jurassic. Communities of Cupressaceae-Taxaceae and parent plants of Laricoidites magnus
with an understory of ferns characterized the Late Toarcian-Early Bajocian, whereas the cooler conditions of the Middle Jurassic promoted expansion of coniferous plant communities in the hinterland. The latest Jurassic was characterized by the return
of temperate conditions and Cupressaceae-Taxaceae conifer communities. |
| Summary | (Plain Language Summary, not published)
Quantitative and statistical palynology was used to link palynomorph signatures to rare Boreal ammonite occurrences in Sverdrup Basin, Arctic Canada.
This approach is designed to improve inter- and intra-basin stratigraphic correlation for Middle and Upper Jurassic rocks. |
| GEOSCAN ID | 328112 |
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