Early Holocene glacier advance, southern Coast Mountains, British Columbia, Canada

Abstract Palynological records of Holocene climate change in the southern Coast Mountains identify the Neoglacial period, subsequent to 6 600 BP, as cooler and wetter than the preceding Hypsithermal. However, geomorphic evidence of alpine glacier advance suggests that there were three distinct cooler/wetter periods during the Neoglacial. By careful selection of a sensitive alpine site this study has enabled the recognition of two of these stages in a palynological record of Neoglacial climate. Pollen spectra, conifer needle macrofossils, organic matter content, and magnetic susceptibility were assessed for a continuous sequence of sediment from Blowdown Lake, which has a basal date older than 4 000 BP. Comparison of the Picea/Pinus pollen ratios from the core with modern surface samples suggests that treeline was at least 100 m above its present elevation until 3 400 BP, indicating that summer temperatures were at least 0.7 ° C above the present. Treeline declined to near present levels by around 2 400 BP. Two subsequent periods of lower treeline were identified which appear to correlate approximately with the Tiedemann and Late Neoglacial periods of glacier advance in southwestern British Columbia. Differences between Picea/Pinus and Abies/Pinus ratios from the core are consistent with the autecology of the species. This suggests that the sensitivity of the pollen ratio approach to reconstructing treeline is dependent on the ratios selected.

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Neoglaciation in the southern Coast Mountains of British Columbia: chronology prior to the late Neoglacial maximum

Canadian Journal of Earth Sciences ◽

10.1139/e86-031 ◽

1986 ◽

Vol 23 (3) ◽

pp. 273-287 ◽

Cited By ~ 113

Author(s):

J. M. Ryder ◽

B. Thomson

Keyword(s):

British Columbia ◽

Early Holocene ◽

Southern Coast ◽

Radiocarbon Dates ◽

Coast Mountains ◽

Glacier Fluctuations ◽

Related Information ◽

Eighteenth And Nineteenth Centuries

Moraine stratigraphy and morphology, radiocarbon dates from Klinaklini, Franklin, Tiedemann, Gilbert, and Bridge glaciers, and related information from elsewhere in the Coast Mountains are used to construct a chronology for glacier fluctuations. The Garibaldi phase of glacier expansion, 6000–5000 14C years BP, at the end of the early Holocene xerothermic interval, is indicated by overridden tree stumps. The mid-Neoglacial Tiedemann advance, 3300–1900 14C years BP, is represented by moraines, till, and meltwater sediments at three glaciers, but only Tiedemann Glacier attained its greatest Holocene extent at this time. Late Neoglacial expansion commenced before 900 14C years BP and continued without notable interruption until glaciers achieved their maximum post-Pleistocene expansion during the eighteenth and nineteenth centuries. Evidence for the Garibaldi and Tiedemann events is scarce within the Coast Mountains because of the more extensive late Neoglacial advance. However, correlative advances have been recognized in adjacent mountains within British Columbia, Washington, and Alaska.

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PRELIMINARY P-T-TIME MODELS FOR REGIONAL METAMORPHISM IN THE MOUNT WADDINGTON AREA OF THE SOUTHERN COAST MOUNTAINS BATHOLITH, BRITISH COLUMBIA CANADA

10.1130/abs/2016am-288005 ◽

2016 ◽

Author(s):

Elizabeth M. Bollen ◽

◽

Harold H. Stowell

Keyword(s):

British Columbia ◽

Regional Metamorphism ◽

Southern Coast ◽

Coast Mountains

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U-PB GEOCHRONOLOGY AND ZIRCON HF AND O ISOTOPE ANALYSIS OF PLUTONS OF THE SOUTHERN COAST MOUNTAINS BATHOLITH, BRITISH COLUMBIA: INSIGHT INTO EPISODIC MAGMATISM IN CONTINENTAL ARCS

10.1130/abs/2017am-307175 ◽

2017 ◽

Cited By ~ 2

Author(s):

Emily C. Homan ◽

◽

M. Robinson Cecil ◽

George E. Gehrels ◽

Margaret E. Rusmore ◽

...

Keyword(s):

British Columbia ◽

Isotope Analysis ◽

Southern Coast ◽

Coast Mountains ◽

Continental Arcs ◽

O Isotope ◽

Insight Into

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Glacier fluctuations during the past millennium in Garibaldi Provincial Park, southern Coast Mountains, British Columbia

Canadian Journal of Earth Sciences ◽

10.1139/e07-019 ◽

2007 ◽

Vol 44 (9) ◽

pp. 1215-1233 ◽

Cited By ~ 34

Author(s):

Johannes Koch ◽

John J Clague ◽

Gerald D Osborn

Keyword(s):

British Columbia ◽

Little Ice Age ◽

Ice Age ◽

Southern Coast ◽

Coast Mountains ◽

The Past ◽

Glacier Fluctuations ◽

Garibaldi Provincial Park ◽

Provincial Park ◽

Past Millennium

The Little Ice Age glacier history in Garibaldi Provincial Park (southern Coast Mountains, British Columbia) was reconstructed using geomorphic mapping, radiocarbon ages on fossil wood in glacier forefields, dendrochronology, and lichenometry. The Little Ice Age began in the 11th century. Glaciers reached their first maximum of the past millennium in the 12th century. They were only slightly more extensive than today in the 13th century, but advanced at least twice in the 14th and 15th centuries to near their maximum Little Ice Age positions. Glaciers probably fluctuated around these advanced positions from the 15th century to the beginning of the 18th century. They achieved their greatest extent between A.D. 1690 and 1720. Moraines were deposited at positions beyond present-day ice limits throughout the 19th and early 20th centuries. Glacier fluctuations appear to be synchronous throughout Garibaldi Park. This chronology agrees well with similar records from other mountain ranges and with reconstructed Northern Hemisphere temperature series, indicating global forcing of glacier fluctuations in the past millennium. It also corresponds with sunspot minima, indicating that solar irradiance plays an important role in late Holocene climate change.

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A debris flow triggered by the breaching of a moraine-dammed lake, Klattasine Creek, British Columbia

Canadian Journal of Earth Sciences ◽

10.1139/e85-155 ◽

1985 ◽

Vol 22 (10) ◽

pp. 1492-1502 ◽

Cited By ~ 48

Author(s):

John J. Clague ◽

S. G. Evans ◽

Iain G. Blown

Keyword(s):

British Columbia ◽

Debris Flow ◽

Debris Flows ◽

Southern Coast ◽

Coast Mountains ◽

Debris Avalanches ◽

Unconsolidated Sediment ◽

Sudden Release ◽

Dammed Lake ◽

Unusual Origin

A very large debris flow of unusual origin occurred in the basin of Klattasine Creek (southern Coast Mountains, British Columbia) between June 1971 and September 1973. The flow was triggered by the sudden release of up to 1.7 × 106 m3 of water from a moraine-dammed lake at the head of a tributary of Klattasine Creek. Water escaping from the lake mobilized large quantities of unconsolidated sediment in the valley below and thus produced a debris flow that travelled in one or, more likely, several surges 8 km downvalley on an average gradient of 10° to the mouth of the stream. Here, the flow deposited a sheet of coarse bouldery debris up to about 20 m thick, which temporarily blocked Homathko River. Slumps, slides, and debris avalanches occurred on the walls of the valley both during and in years following the debris flow. Several secondary debris flows of relatively small size have swept down Klattasine Creek in the 12–14 years since Klattasine Lake drained.

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