| Title | Late Holocene glacier expansion in the Cariboo and northern Rocky Mountains, British Columbia, Canada |
| |
| Author | Maurer, M K; Menounos, B; Luckman, B H; Osborn, G; Clague, J J; Beedle, M J; Smith, R; Atkinson, N |
| Source | Quaternary Science Reviews vol. 51, 2012 p. 71-80, https://doi.org/10.1016/j.quascirev.2012.07.023 |
| Image |  |
| Year | 2012 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120159 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | British Columbia |
| NTS | 93A/14; 93A/15; 93A/16; 93H/01; 93H/02; 93H/03 |
| Area | Cariboo Mountains; Rocky Mountains; On-off Lake |
| Lat/Long WENS | -120.5833 -120.2500 53.2500 52.8333 |
| Subjects | surficial geology/geomorphology; geochronology; glacial deposits; glaciers; glacier surveys; radiocarbon dates; radiocarbon dating; glacial history; icefields; lithostratigraphy; Castle Creek Glacier;
Chiqui Glacier; Chap Glacier; Cenozoic; Quaternary |
| Illustrations | location maps; ternary diagrams; diagrams; tables |
| Program | People Support |
| Abstract | Castle Creek Glacier in the Cariboo Mountains of British Columbia remained close to its Little Ice Age limit for most of the past 1500 years, without significant recession until the 20th century. This
conclusion is based on radiocarbon-dated detrital and in-situ plant material overrun by the glacier, and the sedimentary record from informally named Oneoff Lake, which received clastic sediments only when Castle Creek Glacier crossed a hydrologic
divide 330 m upvalley of the Little Ice Age limit. Plant macrofossils recovered from the transition between basal inorganic silt and overlying organic silty clay in a sediment core from the lake indicate that the glacier first retreated behind the
divide ca. 10.92e9.70 ka. Ages of 8.97e8.61 and 5.58e5.53 ka on detrital wood from the glacier’s forefield may record earlier advances, but the first unequivocal evidence of glacier expansion is from an overridden stump with an age of 4.96 e4.45 ka.
Continuous accumulation of gyttja within Oneoff Lake, however, indicates that Castle Creek Glacier did not cross the hydrologic divide at any time during the first half of the Holocene. Glacigenic sediments began to accumulate in the lake between
2.73 and 2.49 ka, indicating that Castle Creek Glacier expanded beyond the hydrologic divide at that time. A coincident advance is also recorded in the northern Rocky Mountains of British Columbia at Kwadacha Glacier, which overran a vegetated
surface at 2.69e2.36 ka. Clastic sedimentation in Oneoff Lake ceased soon after the Bridge River volcanic eruption (2.70e2.35 ka), indicating that Castle Creek glacier retreat to a position upvalley of the divide at that time. Sedimentation resumed
before 1.87e1.72 ka when the glacier advanced again past the hydrologic divide. Following a second retreat, Castle Creek Glacier advanced across the divide a final time at ca. 1.54 e1.42 ka. The snout of the glacier remained less than 330 m upvalley
of the Little Ice Age moraine until the early twentieth century when annual moraines indicate rapid frontal recession to a position upvalley of the hydrologic divide. These data collectively indicate that glaciers in the Cariboo Mountains of British
Columbia nearly achieved their all-time Holocene limits as early as 2.73e2.49 ka and climatic conditions in the early 20th century abruptly ended a 1500-year period favoring glacier expansion. |
| GEOSCAN ID | 291577 |
|
|