Rock-slope deformation at Affliction Creek, southern Coast Mountains, British Columbia

1990 ◽  
Vol 27 (2) ◽  
pp. 243-254 ◽  
Author(s):  
Michael J. Bovis
Keyword(s):  
British Columbia ◽  
Rock Slope ◽  
Structural Data ◽  
Slope Deformation ◽  
Southern Coast ◽  
Near Surface ◽  
Coast Mountains ◽  
Volcanic Material ◽  
Flexural Toppling ◽  
Tension Cracks

A 7 year record of rock-slope deformation is reported from Affliction Creek, in the southern Coast Mountains of British Columbia. An estimated 3 × 107 m3 of monzonite basement and overlying Garibaldi-aged volcanic material is involved in a slow gravitational movement. Ground-motion vectors suggest that movement has occurred along a deep-seated shear zone and was accompanied by a downslope extension of the moving mass. Near-surface flexural toppling, producing antislope scarps, has taken place where tension cracks crop out on steep slopes or wherever rock faces with strong planar jointing are glacially undercut. Structural data indicate the feasibility of both sliding and toppling at this site.The stratigraphic evidence indicates that most of the tension cracks, grabens, and antislope scarps constituting the slope-movement complex are less than 4300 years old and that many of these landforms may have developed quite recently, as a result of rock-slope debuttressing during the retreat of Affliction Glacier from its late- Neoglacial maximum. Significant variations in the rate of instrumented movements over the 7 year period are not readily accounted for by variations in the level of seismic activity and may be driven by groundwater fluctuations.

Rock slope movements along the Mount Currie "fault scarp," southern Coast Mountains, British Columbia

1995 ◽  
Vol 32 (12) ◽  
pp. 2015-2020 ◽  
Author(s):  
Michael J. Bovis ◽  
Stephen G. Evans
Keyword(s):  
British Columbia ◽  
Ground Motion ◽  
Rock Slope ◽  
Fault Scarp ◽  
Southern Coast ◽  
Coast Mountains ◽  
Slope Movements ◽  
Cast Doubt ◽  
Tension Cracks ◽  
Electronic Distance Measurement

Rock slope movements are reported from Mount Currie ridge, near Pemberton in the southern Coast Mountains of British Columbia. The site displays linear trenches, antislope scarps, and tension cracks typical of mountain ridges undergoing slow deformation; however, the most prominent linear scarp on the ridge has been previously interpreted as a fault scarp. Kinematic tests on rock discontinuities demonstrate the feasibility of both toppling and plane sliding at this site. Ground-motion vectors based on a 4 year, laser electronic distance measurement (EDM) record of slope movements are generally compatible with the results of the kinematic tests. These results cast doubt on a strictly seismic interpretation of the Mount Currie scarp.

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

2007 ◽  
Vol 44 (9) ◽  
pp. 1215-1233 ◽  
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.

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

1985 ◽  
Vol 22 (10) ◽  
pp. 1492-1502 ◽  
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.

Multi-proxy record of Holocene glacial history of the Spearhead and Fitzsimmons ranges, southern Coast Mountains, British Columbia

2007 ◽  
Vol 26 (3-4) ◽  
pp. 479-493 ◽  
Author(s):  
Gerald Osborn ◽  
Brian Menounos ◽  
Johannes Koch ◽  
John J. Clague ◽  
Vanessa Vallis
Keyword(s):  
British Columbia ◽  
Southern Coast ◽  
Glacial History ◽  
Proxy Record ◽  
Coast Mountains ◽  
History Of

Interdecadal patterns of total sediment yield from a montane catchment, southern Coast Mountains, British Columbia, Canada

Geomorphology ◽  
2010 ◽  
Vol 118 (1-2) ◽  
pp. 207-212 ◽  
Author(s):  
Erik Schiefer ◽  
Marwan A. Hassan ◽  
Brian Menounos ◽  
Channa P. Pelpola ◽  
Olav Slaymaker
Keyword(s):  
British Columbia ◽  
Sediment Yield ◽  
Southern Coast ◽  
Coast Mountains ◽  
Total Sediment

Early Holocene climate at Castle Peak, southern Coast Mountains, British Columbia, Canada

1992 ◽  
Vol 95 (1-2) ◽  
pp. 153-167 ◽  
Author(s):  
John J. Clague ◽  
R.W. Mathewes ◽  
W.M. Buhay ◽  
T.W.D. Edwards
Keyword(s):  
British Columbia ◽  
Early Holocene ◽  
Southern Coast ◽  
Holocene Climate ◽  
Coast Mountains

scholarly journals Pollen evidence of Late Holocene treeline fluctuation from the southern Coast Mountains, British Columbia

2002 ◽  
Vol 51 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Martin Evans
Keyword(s):  
British Columbia ◽  
Organic Matter Content ◽  
Matter Content ◽  
Southern Coast ◽  
Coast Mountains ◽  
Alpine Glacier ◽  
The Core ◽  
Surface Samples ◽  
Summer Temperatures ◽  
Glacier Advance

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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