Abstract

The Tuktoyaktuk Peninsula is underlain by a complex subcrop pattern beneath the pre-Mesozoic unconformity. The structure can be described as a horst, the Eskimo Lakes Arch, flanked to the southeast by a normal Paleozoic succession including the Imperial Formation, and to the northwest by a repetitive sequence of Paleozoic carbonate units. These carbonates are Landry-equivalent limestones and Middle Ordovician dolomites. Quartzites within the horst are probably Cambrian in age, and belong to a basin that was separated from the Cambrian basin under Anderson Plain. Other rock types on the horst are tentatively assigned a Precambrian age. Some of the observed lithological units can be correlated to Paleozoic formations in the nearby Anderson Plain area, although Middle Ordovician rocks are absent there. Permian rocks are present in the southwest part of the study area. The observed subcrop pattern can only be ascribed to a post-Devonian, pre-Permian deformation, presumably the Ellesmerian Orogeny.