Ob. Lian et Ej. Hickin, EARLY POSTGLACIAL SEDIMENTATION OF LOWER SEYMOUR-VALLEY, SOUTHWESTERNBRITISH-COLUMBIA, Geographie physique et quaternaire, 50(1), 1996, pp. 95-102
In lower Seymour Valley, much of the sediment derived from the erosion
of valley-side drift (paraglacial sediments) remains in storage in th
e form of alluvial fans and aprons. Fluvial incision into these featur
es has exposed sections for lithostratigraphic and chronological study
. Radiocarbon dating of organic-rich beds within these deposits indica
te that paraglacial sedimentation of lower Seymour Valley commenced be
fore 11.4 ka, was periodic, and was essentially complete by about 9 ka
; Seymour River had incised to its present vertical position by about
5 ka. Furthermore, our radiocarbon ages indicate that, although paragl
acial sedimentation commenced shortly following deglaciation when the
climate was cool and moist, a significant amount of sedimentation occu
rred during a transition from wet and moist climate to warm and dry (x
erothermic) conditions (ca. 10 ka). Charcoal-rich beds indicate that s
ome erosional events may have been a result of slope instability cause
d by fire.