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TitleClimate change impacts on continental weathering through the Middle Jurassic to Lower Cretaceous of Sverdrup Basin, Canadian Arctic
AuthorGalloway, J; Grasby, S; Swindles, G; Dewing, K
SourceGeophysical Research Abstracts vol. 16, 2014 p. 1
LinksOnline - En ligne
Year2014
Alt SeriesEarth Sciences Sector, Contribution Series 20130409
PublisherEuropean Geophysical Union
MeetingEuropean Geosciences Union General Assembly 2014; Vienna; AT; April 27 - May 2, 2014
Documentserial
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceNunavut
NTS69E/04
AreaEllef Ringnes Island
Lat/Long WENS-99.7667 -99.7500 78.1167 78.0833
Subjectspaleontology; environmental geology; Nature and Environment; climate; climatic fluctuations; paleoclimates; paleoenvironment; Sverdrup Basin; Hoodoo Dome H-37 well; climate change; Mesozoic; Cretaceous; Jurassic
ProgramSverdrup Sedimentary Basin, GEM: Geo-mapping for Energy and Minerals
AbstractJurassic to Cretaceous strata of Sverdrup Basin, Canadian Arctic Archipelago, contain marine and non-marine successions that can be studied to reconstruct ancient paleoclimates and paleoenvironments that are poorly un- derstood in high-latitude regions. We use element geochemistry integrated with palynology to study a continuous Aalenian to Albian-aged succession preserved in the Hoodoo Dome H-37 oil and gas well located on southern Ellef Ringnes Island near the centre of Sverdrup Basin. Cluster analysis (stratigraphically constrained incremental sum of squares; CONISS) is used to delineate four geochemical zones that are broadly coeval with major changes in palyno-assemblages interpreted to reflect changes in regional paleoclimate. Zone 1 (late Aalenian to Bathonian) is characterized by palynomorphs associated with humid and warm climate conditions. The chemical alteration index (CAI) is high in this interval, expected under this a humid and warm climate. A transition to a seasonally arid and warm climate occurred in the Bathonian and persisted until the Kimmeridgian or Valanginian (Zone 2). This interval is characterized by decreased chemical weathering, indicated by a drop in CAI. The onset of Zone 3 (Kimmeridgian or Valanginian to late Barremian or early Aptian) occurs during a transition to humid and cool climate conditions and is associated with a period of regional uplift and rifting. Zone 3 is marked by a substantial and progressive drop in CAI, indicating a transition from a weathering to transport-dominated system, possibly associated with landscape destabilization. Reduced tectonic activity in Zone 4 (early Aptian to early or mid Al- bian) shows a return to active chemical weathering, possibly associated with landscape stabilization, suggested by a continued increase in pollen from upland coniferous taxa. The geochemical and palynological records of Middle Jurassic to Lower Cretaceous strata of the Hoodoo Dome H-37 oil and gas well show close correlation, indicating long-term linkages of terrestrial plant communities and weathering processes.
Summary(Plain Language Summary, not published)
Jurassic to Cretaceous strata of Sverdrup Basin, Canadian Arctic Archipelago, contain marine and non-marine rocks that can be studied to reconstruct high-latitude paleoclimates and paleoenvironments that are poorly understood for these time periods. We use element geochemistry integrated with palynology (pollen and spores) to study a continuous succession of strata preserved in the Hoodoo Dome H-37 oil and gas well drilled on Ellef Ringnes Island near the centre of Sverdrup Basin. Using statistical analyses, we delineate four "Geochemical Zones" that are broadly coeval with major changes in pollen and spore abundances interpreted to reflect changes in regional paleoclimate. The consistency of the geochemical and pollen and spore dataset suggest long-term linkages of terrestrial plant communities and weathering processes.
GEOSCAN ID293516