A revised stratigraphic framework for Cretaceous sedimentary and igneous rocks at Mokka Fiord, Axel Heiberg Island, Nunavut, with implications for the Cretaceous Normal Superchron

• Main Authors: Evenchick, Carol A., Galloway, Jennifer M., Saumur, Benoit M, Davis, William J.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: Arctic; Nunavut; Heiberg; Axel Heiberg Island; Paterson; Isachsen; Mokka Fiord; sverdrup basin
• Online Access: http://hdl.handle.net/1807/93557; http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2018-0129

New data and interpretations on geological relationships of igneous rocks at Mokka Fiord, Axel Heiberg Island, Nunavut, provide insight into the timing and nature of magmatism associated with the Sverdrup Basin and High Arctic Large Igneous Province (HALIP). Field relationships indicate that the igneous rocks, previously interpreted to be volcanic flows, are most likely an intrusive unit discordant to regional bedding. An intrusive origin helps resolve chronostratigraphic inconsistencies in previous work. The host rocks are palynologically constrained to be late Barremian to late Aptian in age and are interpreted to be Paterson Island or Walker Island member of the Isachsen Formation. If the igneous body is intrusive, itâ s previously reported Ar-Ar age (102.5 Âą 2.6 Ma) is no longer in conflict with accepted stratigraphic interpretations and probably reflects the emplacement age of the intrusion. Lingering uncertainties in interpreting the normal and reverse magnetic polarities determined in the previous work remain, and both are considered viable. Although this uncertainty precludes definitive conclusions on the significance of paleomagnetic data at Mokka Fiord, examination of the stratigraphic, paleomagnetic, and geochronologic relationships there highlight potential for the study of excursions, or reversed magnetic polarity subchrons, in the Cretaceous Normal Superchron elsewhere in the HALIP. Keywords: Sverdrup Basin, HALIP, paleomagnetism, stratigraphy, palynology The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.