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Text Description: The tephra is present in the upper part of a 2-m-thick gully-fill deposit, the gully being incised about 10 m into the Klondike gravel, close to the level of the highest terrace along the Klondike River. The gully-fill sediments consist of 0.5 m of matrix-supported gravel overlain by 1.5 m of massive to crudely stratified, organic-rich silt. Discontinuous pods of Jackson Hill tephra, up to 3 cm thick, occur 50 cm below the surface in this silt. The lower diamict is interpreted as a hillslope deposit derived from downslope movement of the Klondike gravel into the gully, while the overlying silt is thought to represent retransported loess. Fine grain size. Consists mostly of bubble-wall glass shards with feldspar, orthopyroxene, clinopyroxene and minor amounts of green or red amphibole, titanomagnetite, ilmenite, apatite and zircon. From Preece et al. (2011): 3 cm thick; pumice, bubble-wall shards, spheres with a small amount of brown glass; in brown organic silt overlying Klondike Gravel; field name 799a References:  The variegated (VT) tephra: A new regional marker for middle to late marine isotope stage 5 across Yukon and Alaska A catalogue of late Cenozoic tephra beds in the Klondike Goldfields and adjacent areas, Yukon Territory Glass-fission-track ages of late Cenozoic distal tephra beds in the Klondike district, Yukon Territory |
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