ABSTRACT Within the Canadian High Arctic, Ellesmere Island represents a key region for improving our understanding of the plate tectonic configuration during the Paleogene times when Arctic Canada and Greenland represented two independently moving plates. Here, we present 4050 line kilometers of new high-resolution aeromagnetic data gathered across an area of 7000 km 2 in the Vendom Fiord region on southern Ellesmere Island. The survey was flown with a two-kilometer line spacing and covered sedimentary rocks of the Franklinian Basin and the partly ice-covered basement rocks of the Inglefield Uplift. Magnetic domains, major lineaments, and depths of magnetic sources as well as magnetic trend lines are detected from total field data. These data and additional ground-based magnetic susceptibility measurements are integrated with exposure information and structural data in order to distinguish whether or not the ca. NNE–SSW trending Vendom Fiord Fault Zone can be related to the Wegener Fault. In addition, high-resolution aeromagnetic data and digital enhancement provide support for early Eocene deformation in the Vendom Fiord region during “Eurekan stage 1,” which seems to be decoupled from Paleocene to early Eocene deformation along the Wegener Fault. A distinct NNE–SSW trending magnetic anomaly characterized by long wavelength is bordered by the Eurekan Fold-and-Thrust Belt in the western survey area. On a regional scale, this anomaly can be traced toward the NE where it represents the boundary between the deep water and shelf sequences of the Franklinian Basin along the Archer Fiord Fault Zone. Based on aeromagnetic anomaly data, the ice-covered boundary between sediments of the Franklinian Basin and the Precambrian basement is identified. High frequency anomalies east of this boundary characterize the basement rocks and show strong similarities to the Kane Basin region in the NE. The similarity of magnetic anomaly patterns in both regions indicates that the NNE–SSW trend of the fault zones in the study area west of the Inglefield Uplift turns continuously into an E–W trend north of the uplift in the Kane Basin region.

Abstract The 400 km long transect through Ellesmere Island is located perpendicular to the North American continental margin between the Arctic Ocean in the NNW and the Greenland–Canadian Shield in the SSE. It provides an insight into the structural architecture and tectonic history of the upper parts of the continental crust. The northernmost segment of the transect is dominated by the composite Pearya Terrane, which amalgamated with the Laurentian margin during the Late Devonian–Early Carboniferous Ellesmerian Orogeny. The Neoproterozoic to Devonian Franklinian Basin is exposed south of the terrane boundary and most probably overlies the crystalline basement of the Greenland–Canadian Shield. The structures along the transect in this area are dominated by kilometre-scale Ellesmerian folding of the Franklinian Basin deposits above a deep-seated detachment, which is suggested to be located at the boundary between the basement of the Canadian Shield and the overlying >8 km thick Franklinian Basin. Following the development of the Late Mississippian–Palaeogene Sverdrup Basin, the complex Eurekan deformation reactivated Ellesmerian thrust faults and probably parts of the associated deep-seated detachment. In addition, large Eurekan strike-slip faults affected and displaced pre-Eocene deposits and tectonic structures, particularly in the northern part of the transect. Supplementary material: The complete transect (Segment 1 to 5) through Ellesmere Island between the Arctic Ocean in the NNW and Kane Basin in the SSE is available at https://doi.org/10.6084/m9.figshare.c.3783608

Abstract The Franklinian Basin extended from northern Ellesmere Island across North Greenland, where its sedimentary infill is exposed from Inglefield Land and Washington Land in the west to Kronprins Christian Land in the east (Fig. 7.1–7.3). The segment of the basin exposed in North Greenland is approximately 800 km long and has a maximum preserved north-south width of 200 km. The thickness of the sedimentary column reaches about 8 km; the main part of the succession is of Cambrian-Silurian age, but it may extend down into the latest Precambrian and up into the earliest Devonian. A distinction into a shelf sequence and deep water trough sequence can be recognized in northern Ellesmere Island and in North Greenland, and the variations in facies with time in the two regions show close parallels. Correlation on group or formation level is often possible across Nares Strait (Peel and Christie, 1982; Peel et al., 1982). Detailed knowledge of the North Greenland sequences, however, permits an integrated account of shelf and trough development in the North Greenland segment of the Franklinian Basin. A craton composed of Archean and Upper Proterozoic crystalline basement rocks, overlain by Middle and Upper Proterozoic sedimentary and volcanic rocks, lies to the south of the Franklinian Basin (Chapter 6). This is now exposed intermittently along the margin of the Inland Ice, and more extensively in eastern North Greenland (Fig. 7.1). In the early Paleozoic, this craton was fringed to the north by an east-west trending shallow marine shelf, Two main facies belts

ABSTRACT The Neoproterozoic–Early Devonian(?) northeast Brooks Range basinal succession of northern Alaska and Yukon represents a peri-Laurentian deep-marine carbonate and siliciclastic succession within the composite Arctic Alaska–Chukotka microplate. The basal Firth River Group consists of a mixed siliciclastic and carbonate succession that is divided into the informal Redwacke Creek, Malcolm River, and Fish Creek formations. New U-Pb detrital zircon geochronology and δ 13 C carb and 87 Sr/ 86 Sr isotopic data from these strata, in combination with previously reported and new trace fossil discoveries, suggest the Firth River Group is Cryogenian(?)–middle(?) Cambrian in age. These strata interfinger with or are depositionally overlain by the siliciclastic-dominated lower Cambrian–Middle Ordovician(?) Neruokpuk and Leffingwell (new name) formations, which potentially record a distal expression of Cambrian extension and condensed passive margin sedimentation along the northern margin of Laurentia. All of these units are unconformably overlain by the synorogenic Clarence River Group, which is divided into the informal Aichilik and Buckland Hills formations. New U-Pb detrital zircon geochronology and previous macrofossil collections suggest the Clarence River Group is Late Ordovician-Early Devonian(?) in age. Here, we present new sedimentological observations, stratigraphic subdivisions, detrital zircon U-Pb geochronology and Lu-Hf isotope geochemistry, detrital muscovite 40 Ar/ 39 Ar geochronology, and carbonate δ 13 C carb and 87 Sr/ 86 Sr isotope geochemistry from the basinal succession that revise previous tectono-stratigraphic models for this part of Arctic Alaska and support correlations with age-equivalent strata in the Franklinian basin of the Canadian Arctic Islands and Greenland.