Beaufort Formation (Late Tertiary) as Seen form Prince Patrick Island, Arctic Canada

Abstract

The Beaufort Formation, in its type area on Prince Patrick Island, is a single lithostratigraphic unit, a few tens of metres thick, consisting of unlithified sandy deposits of braided rivers. Organic beds in the sand have yielded more than 200 species of plants and insects and probably originated during the Pliocene, when the area supported coniferous forest. This Beaufort unit forms the thin eastern edge of a northwest-thickening wedge of sand and gravel beneath the western part of the island. These largely unexposed beds, up to several hundred metres thick, include the Beaufort unit and perhaps other older or younger deposits. On the islands northeast and southwest of Prince Patrick Island (Meighen Island to Banks Island), the name Beaufort Formation has been applied to similar deposits of late Rrtiary age. Most recorded Beaufort beds on these islands are stratigraphically and paleontologically equivalent to the "type" Beaufort, but a few sites that have been called Beaufort (such as Duck Hawk Bluffs and the lower unit at Ballast Brook, on Banks Island) differ stratigraphically and paleontologically from the "type" Beaufort. This paper recommends that these deposits (probably middle Miocene) and others like them be assigned new stratigraphic names and not be included in the Beaufort Formation as now defined. Informal names Mary Sachs gravel (Duck Hawk Bluffs) and Ballast Brook beds are proposed as an initial step. Formal use of the name Beaufort Formation should be restricted to the western Arctic Islands.

Stratigraphic and Paleoenvironmental Reconstruction of a Mid-Pliocene Fossil Site in the High Arctic (Ellesmere Island, Nunavut): Evidence of an Ancient Peatland with Beaver Activity + Online Appendix Figures S1 and S2 (See Article Tools)

“…The deposits have been interpreted as braided river deposits and contain fossilized plant material, particularly moss and wood (Fyles, 1990). The Beaufort Formation extends along the western margin of the CAA from Banks Island northward to Meighen Island (Fig.…”

“…The Beaufort Formation extends along the western margin of the CAA from Banks Island northward to Meighen Island (Fig. 1), and as originally defined, excludes possible time-equivalent "high-terrace" deposits on Ellesmere Island and elsewhere (Fyles, 1990;Fyles et al, 1994). It is beyond the scope of this manuscript to determine whether the Beaufort Formation should be redefined to include the latter sediments.…”

“…The thickest Pliocene deposits are referred to as the Beaufort Formation and are formed by an extensive braided river system. These deposits are represented today by a northwesterly thickening unit that extends in a belt, 1200 km along the western margin of the CAA (Fyles, 1990). Exposures of the Beaufort Formation are known to be up to 60 m thick and include mummified wood and peat (Fyles, 1990;Davies et al, 2014).…”

“…These deposits are represented today by a northwesterly thickening unit that extends in a belt, 1200 km along the western margin of the CAA (Fyles, 1990). Exposures of the Beaufort Formation are known to be up to 60 m thick and include mummified wood and peat (Fyles, 1990;Davies et al, 2014). Reflection seismic data (Prince Patrick Island) and exploration well data (Meighen Island) indicate the thickness of the Beaufort Formation (onshore) to be from several hundred meters to one kilometer (Fyles, 1990).…”

“…Exposures of the Beaufort Formation are known to be up to 60 m thick and include mummified wood and peat (Fyles, 1990;Davies et al, 2014). Reflection seismic data (Prince Patrick Island) and exploration well data (Meighen Island) indicate the thickness of the Beaufort Formation (onshore) to be from several hundred meters to one kilometer (Fyles, 1990). In the eastern CAA, small exposures of potentially time-equivalent deposits are known as the "high-terrace" deposits.…”