A middle Pleistocene paleosol sequence from Dawson Range, Central Yukon Territory

Abstract

<jats:title>Abstract</jats:title><jats:p>Four paleosols were intersected in a core drilled into the colluvial fill of a largely buried meltwater channel that was last active during the youngest of the pre-Reid glaciation (0.99-0.78 Ma) in the Dawson Range, Yukon Territory. The paleosols are classified as Podzols. The sedimentary sequence and paleosols indicate that at least two middle Pleistocene glacial and interglacial periods are represented in the core. The mean annual temperature exceeded 0° C for thousands of years in the upland environment of the Dawson Range at 61° N during these interglacial periods.</jats:p>

Investigation of high-level glaciofluvial terraces and re-evaluation of the established soil stratigraphy for Early and Middle Pleistocene surfaces, central Yukon, Canada

“…Pre-Reid glacial deposits are generally poorly preserved across most of the Yukon. The extent, number and timing of pre-Reid glaciations are only partially constrained, comprising at least five glaciations and span from Late Pliocene (2.9 Á/2.6 Myr) to Middle Pleistocene (Jackson et al 1999;Froese et al 2000;Duk-Rodkin et al 2001;Westgate et al 2001;Jackson et al 2002). They have been correlated to the geomagnetic time scale based on the polarity of their deposits or intervening sediments, with limited radiometric dating control.…”

“…It is substantially younger than GtPR1 based on the clay mineralogy and the associated climatic inferences. Evidence exists for both multiple and extensive Middle and Early Pleistocene glaciations in Yukon and western Northwest Territories Bond 1997;Jackson et al 1999;Duk-Rodkin et al 2001), but direct correlation to one of these glaciations is not possible on the basis of soil development alone. Contrasting soil characteristics suggest that the formation of GtPR2 terraces postdates deterioration in interglacial climate from relatively temperate and humid conditions to cool and humid conditions in central Yukon.…”

“…Throughout central Yukon Territory, they have been used to differentiate deposits of various Early to Late Pleistocene glaciations for the purpose of surficial geologic mapping and palaeoenvironmental reconstruction (Hughes et al 1972;Foscolos et al 1977;Rutter et al 1978;Tarnocai et al 1985;Smith et al 1986;Tarnocai 1987;Tarnocai & Smith 1989;Bond 1996;Jackson et al 1999;Ward & Jackson 2000;Duk-Rodkin et al 2001;Froese et al 2001;Nelson & Jackson 2003). Due to the lack of dateable material found within high-level terrace gravels, the presence of palaeosols provides a valuable tool for their correlation and determination of age.…”

Genesis of upland soils, Lewes Plateau, central Yukon. Part 2: Soils formed in weathered granitic bedrock

“…Period (Foscolos et al 1977;Rutter et al 1978;Smith et al 1986;Tarnocai and Smith 1989;Tarnocai and Valentine 1989;Tarnocai and Schweger 1991;Duk-Rodkin et al 1996;Jackson et al 1999). Relict soil features indicative of climates warmer than today include reddening (rubification) of horizons, development of Podzolic Bf and Luvisolic Bt horizons north of their current distribution, and deep sola.…”

Investigation of high-level glaciofluvial terraces and re-evaluation of the established soil stratigraphy for Early and Middle Pleistocene surfaces, central Yukon, Canada

“…Palaeosols found in the central Yukon have been used as a stratigraphic marker in many Quaternary studies. Throughout central Yukon Territory, they have been used to differentiate deposits of various Early to Late Pleistocene glaciations for the purpose of surficial geologic mapping and palaeoenvironmental reconstruction (Hughes et al 1972;Foscolos et al 1977;Rutter et al 1978;Tarnocai et al 1985;Smith et al 1986;Tarnocai 1987;Tarnocai & Smith 1989;Bond 1996;Jackson et al 1999;Ward & Jackson 2000;Duk-Rodkin et al 2001;Froese et al 2001;Nelson & Jackson 2003). Due to the lack of dateable material found within high-level terrace gravels, the presence of palaeosols provides a valuable tool for their correlation and determination of age.…”