CHARCOAL AND SEDIMENTATION RECORD FROM A FAN AT BEAR FLAT, NORTHEASTERN BRITISH COLUMBIA

Fine textured fans are common on the upper terraces of Peace River in northeastern British Columbia. These fans are constructed by both mudflows and sheet floods involving unstable Glacial Lake Peace sediments. A fan at Bear Flat is dissected by a recent gully incised to a depth of 5 m. The gully walls reveal numerous paleosols, continuous charcoal horizons, and detrital charcoal fragments. We have sampled charcoal from the exposed wall and from drill cores to a depth of 15 m. This site appears to preserve a continuous history of fire and fire-related flows since the late Pleistocene. By radiocarbon dating more than 50 charcoal samples we begin to reconstruct the fire and mudflow history for this site. Our results suggest these events are not random and appear to show periodic behaviour. Meyer et al (1995) noted a possible link between fire frequency and climatic events at Yellowstone National Park. We hope to relate fire history in this area to other forest-fire records, possible climatic forcing, and perhaps aboriginal burning. Nine charcoal bands date between approximately 2000 to 3000 14C yr ago. The lowest continuous charcoal horizon dates to 10,500 14C yr ago and lower detrital charcoal dates to at least 20,000 14C yr ago. These dates in themselves have important implications for the glacial history of this area. .