Quadra Sand and its relation to the late Wisconsin glaciation of southwest British Columbia

1976 ◽  
Vol 13 (6) ◽  
pp. 803-815 ◽  
Author(s):  
J. J. Clague
Keyword(s):  
British Columbia ◽  
Climatic Change ◽  
Late Pleistocene ◽  
Marine Sediments ◽  
Strait Of Georgia ◽  
Coast Mountains ◽  
Widespread Distribution ◽  
Source Areas ◽  
The North ◽  
Minimum Age

Quadra Sand is a late Pleistocene lithostratigraphic unit with widespread distribution in the Georgia Depression, British Columbia and Puget Lowland, Washington. The unit consists mainly of horizontally and cross-stratified, well sorted sand. It is overlain by till deposited during the Fraser Glaciation and is underlain by fluvial and marine sediments deposited during the preceding nonglacial interval.Quadra Sand was deposited progressively down the axis of the Georgia–Puget Lowland from source areas in the Coast Mountains to the north and northeast. The unit is markedly diachronous; it is older than 29 000 radiocarbon years at the north end of the Strait of Georgia, but is younger than 15 000 years at the south end of Puget Sound.Aggradation of the unit occurred during the climatic deterioration at the beginning of the Fraser Glaciation. Thick, well sorted sand was deposited in part as distal outwash aprons at successive positions in front of, and perhaps along the margins of, glaciers advancing from the Coast Mountains into the Georgia–Puget Lowland during late Wisconsin time.The sand thus provides a minimum age for the initial climatic change accompanying the Fraser Glaciation. This change apparently occurred before 28 800 y BP, substantially earlier than glacial occupation of the southern Interior Plateau of British Columbia. Thus, several thousand years may have intervened between the alpine and ice-sheet phases of the Fraser Glaciation.

Late Pleistocene history and geomorphology, southwestern Vancouver Island, British Columbia

1979 ◽  
Vol 16 (9) ◽  
pp. 1645-1657 ◽  
Author(s):  
Neville F. Alley ◽  
Steven C. Chatwin
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Late Pleistocene ◽  
Vancouver Island ◽  
Glacial Lakes ◽  
Small Lakes ◽  
Strait Of Georgia ◽  
Coast Mountains ◽  
Juan De Fuca ◽  
Juan De Fuca Strait

The major Pleistocene deposits and landforms on southwestern Vancouver Island are the result of the Late Wisconsin (Fraser) Glaciation. Cordilleran glaciers formed in the Vancouver Island Mountains and in the Coast Mountains had advanced down Strait of Georgia to southeastern Vancouver Island after 19 000 years BP. The ice split into the Puget and Juan de Fuca lobes, the latter damming small lakes along the southwestern coastal slope of the island. During the maximum of the glaciation (Vashon Stade), southern Vancouver Island lay completely under the cover of an ice-sheet which flowed in a south-southwesterly direction across Juan de Fuca Strait, eventually terminating on the edge of the continental shelf. Deglaciation was by downwasting during which ice thinned into major valleys and the strait. Most upland areas were free of ice down to an elevation of 400 m by before 13 000 years BP. A possible glacier standstill and (or) resurgence occurred along Juan de Fuca Strait and in some interior upland valleys before deglaciation was complete. Glacial lakes occupied major valleys during later stages of deglaciation.

Late Pleistocene stratigraphy and chronology of lower Chehalis River valley, southwestern British Columbia: evidence for a restricted Coquitlam Stade

2004 ◽  
Vol 41 (7) ◽  
pp. 881-895 ◽  
Author(s):  
Brent C Ward ◽  
Bruce Thomson
Keyword(s):  
British Columbia ◽  
Late Pleistocene ◽  
River Valley ◽  
Glacial Lakes ◽  
Coast Mountains ◽  
Source Areas ◽  
Definitive Evidence

Sediments in lower Chehalis valley span middle Wisconsin (Olympia nonglacial interval) to Holocene time. Sediments are divided into six units with chronological control provided by 14 new radiocarbon ages. Fluvial gravel spans the transition from the late Olympia nonglacial interval to the early Fraser Glaciation. Glaciolacustrine sedimentation represents the first definitive glacial activity in the valley and indicates that Vashon ice in the Fraser Lowland blocked the mouth of the Chehalis valley at ca. 18–17 ka BP. Ice then flowed down the Chehalis valley. The Chehalis valley deglaciated while ice persisted in the Fraser Lowland, forming another lake. After this lake drained, terraces and fans formed. This style of glaciation–deglaciation is typical of many watersheds peripheral to the Fraser Lowland in that local valley ice was slightly out of phase with ice in the lowland. This resulted in glacial lakes forming during both advance and retreat phases. However, in contrast to watersheds in the northwestern Fraser Lowland, no definitive evidence of a Coquitlam ice advance was found within the Chehalis valley. Although glaciers in the area were likely active and advancing, data from the Chehalis valley indicates that they were not as extensive as previously thought. Since ice source areas in the northeastern Fraser Lowland are in the leeward area of the Coast Mountains, it is suggested that lower precipitation resulted in limited glacier activity there during the Coquitlam Stade.

Late Pleistocene proboscideans and early Fraser glacial sedimentation in eastern Fraser Lowland, British Columbia

1982 ◽  
Vol 19 (5) ◽  
pp. 899-906 ◽  
Author(s):  
Stephen R. Hicock ◽  
Keith Hobson ◽  
John E. Armstrong
Keyword(s):  
British Columbia ◽  
Late Pleistocene ◽  
Silty Sand ◽  
Glacial Lake ◽  
Glacial Ice ◽  
Strait Of Georgia ◽  
The North ◽  
North Side ◽  
History Of ◽  
Glacial Sedimentation

Three recently radiocarbon-dated tusk segments from eastern Fraser Lowland indicate Pleistocene proboscideans (probably mammoths) lived there between 22 700 and 21 400 years ago during early Fraser (for the Fraser Lowland) ice advance into the area. Palynomorphs from silty sand adhering to a tusk indicate the animals grazed on open grassy floodplain. Sedimentologic and altimeter studies of tusk-bearing gravel indicate an early Fraser sandur, at least 10 km long and deposited at the same time as Coquitlam Drift, formed in Chilliwack Valley at the same time that a sandur or kame terrace was deposited against the north side of Promontory ridge. Probably about 21 000 years ago (the time of Coquitlam glacial maximum in western Fraser Lowland) ice blocked Chilliwack Valley, creating a glacial lake whose freshwater, Pediastrum-bearing, laminated silt has been observed up to 200 m asl. Stratigraphy and history of the area following deposition of the above gravels and silt are still uncertain without more chronologic control. However, proboscideans could have migrated southward and westward, away from ice advancing into Fraser Lowland, across ancestral Strait of Georgia via the Quadra sandur, and onto southeastern Vancouver Island to which earliest Fraser glacial ice probably advanced after 17 000 years BP.

Eocene paleo-physiography and drainage directions, southern Interior Plateau, British Columbia

2005 ◽  
Vol 42 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Selina Tribe
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Regional Scale ◽  
River Valley ◽  
Coast Mountains ◽  
Base Level ◽  
The North ◽  
Bedrock Geology ◽  
River Valleys ◽  
Early Cenozoic

A map of reconstructed Eocene physiography and drainage directions is presented for the southern Interior Plateau region, British Columbia south of 53°N. Eocene landforms are inferred from the distribution and depositional paleoenvironment of Eocene rocks and from crosscutting relationships between regional-scale geomorphology and bedrock geology of known age. Eocene drainage directions are inferred from physiography, relief, and base level elevations of the sub-Eocene unconformity and the documented distribution, provenance, and paleocurrents of early Cenozoic fluvial sediments. The Eocene landscape of the southern Interior Plateau resembled its modern counterpart, with highlands, plains, and deeply incised drainages, except regional drainage was to the north. An anabranching valley system trending west and northwest from Quesnel and Shuswap Highlands, across the Cariboo Plateau to the Fraser River valley, contained north-flowing streams from Eocene to early Quaternary time. Other valleys dating back at least to Middle Eocene time include the North Thompson valley south of Clearwater, Thompson valley from Kamloops to Spences Bridge, the valley containing Nicola Lake, Bridge River valley, and Okanagan Lake valley. During the early Cenozoic, highlands existed where the Coast Mountains are today. Southward drainage along the modern Fraser, Chilcotin, and Thompson River valleys was established after the Late Miocene.

scholarly journals Observations on the May 2019 Joffre Peak landslides, British Columbia

Landslides ◽  
2020 ◽  
Vol 17 (4) ◽  
pp. 913-930 ◽  
Author(s):  
Pierre Friele ◽  
Tom H. Millard ◽  
Andrew Mitchell ◽  
Kate E. Allstadt ◽  
Brian Menounos ◽  
...  
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Seismic Analysis ◽  
Rock Avalanche ◽  
Permafrost Degradation ◽  
Depth Estimate ◽  
Coast Mountains ◽  
Conditioning Factors ◽  
The North ◽  
Debris Flood

AbstractTwo catastrophic landslides occurred in quick succession on 13 and 16 May 2019, from the north face of Joffre Peak, Cerise Creek, southern Coast Mountains, British Columbia. With headscarps at 2560 m and 2690 m elevation, both began as rock avalanches, rapidly transforming into debris flows along middle Cerise Creek, and finally into debris floods affecting the fan. Beyond the fan margin, a flood surge on Cayoosh Creek reached bankfull and attenuated rapidly downstream; only fine sediment reached Duffey Lake. The toe of the main debris flow deposit reached 4 km from the headscarp, with a travel angle of 0.28, while the debris flood phase reached the fan margin 5.9 km downstream, with a travel angle of 0.22. Photogrammetry indicates the source volume of each event is 2–3 Mm3, with combined volume of 5 Mm3. Lidar differencing, used to assess deposit volume, yielded a similar total result, although error in the depth estimate introduced large volume error masking the expected increase due to dilation and entrainment. The average velocity of the rock avalanche-debris flow phases, from seismic analysis, was ~ 25–30 m/s, and the velocity of the 16 May debris flood on the upper fan, from super-elevation and boulder sizes, was 5–10 m/s. The volume of debris deposited on the fan was ~ 104 m3, 2 orders of magnitude less than the avalanche/debris flow phases. Progressive glacier retreat and permafrost degradation were likely the conditioning factors; precursor rockfall activity was noted at least ~6 months previous; thus, the mountain was primed to fail. The 13 May landslide was apparently triggered by rapid snowmelt, with debuttressing triggering the 16 May event.

Coquitlam Drift: a pre-Vashon Fraser glacial formation in the Fraser Lowland, British Columbia

1981 ◽  
Vol 18 (9) ◽  
pp. 1443-1451 ◽  
Author(s):  
Stephen R. Hicock ◽  
John E. Armstrong
Keyword(s):  
British Columbia ◽  
Glacial Maximum ◽  
Cascade Mountains ◽  
Short Pulses ◽  
Coast Mountains ◽  
The North ◽  
Glaciomarine Sediments

Coquitlam Drift is formally defined and stratotypes established for it in the Coquitlam – Port Moody area, B.C. It is a Pleistocene formation consisting of till, glaciofluvial, ice-contact, and glaciomarine sediments deposited between 21 700 and 18 700 years BP, during the Fraser Glaciation (late Wisconsin) and prior to the main Vashon glacial maximum at about 14 500 years BP. The drift was deposited in short pulses by valley and piedmont glaciers fluctuating into the Fraser Lowland from the Coast Mountains to the north and Cascade Mountains to the east.

Cretaceous fossil birds from Hornby Island (British Columbia)

2005 ◽  
Vol 42 (12) ◽  
pp. 2097-2101 ◽  
Author(s):  
Kurt Morrison ◽  
Gareth J Dyke ◽  
Luis M Chiappe
Keyword(s):  
British Columbia ◽  
Marine Sediments ◽  
West Coast ◽  
Marine Ecosystems ◽  
Fossil Birds ◽  
The West ◽  
Strait Of Georgia ◽  
Fossil Bird

We present the first records of Mesozoic fossil birds to be described from British Columbia. New fossil avians from the Campanian Northumberland Formation on Hornby Island (Strait of Georgia) add to the known distributions of two groups of fossil birds during the latter stage of the Mesozoic. New specimens referred to the clades Ornithurae and Enantiornithes demonstrate the presence of a diverse marine avifauna in Canadian Pacific marine sediments prior to the Cretaceous–Tertiary (K–T) boundary. These new fossil bird remains from coastal rocks on the west coast of British Columbia lend further support to suggestions that ocean-going birds were important constituents of marine ecosystems in the terminal stages of the Mesozoic.

Age of the Bowen Island Group, southwestern Coast Mountains, British Columbia

1990 ◽  
Vol 27 (11) ◽  
pp. 1456-1461 ◽  
Author(s):  
R. M. Friedman ◽  
J. W. H. Monger ◽  
H. W. Tipper
Keyword(s):  
British Columbia ◽  
Middle Jurassic ◽  
Volcanic Rocks ◽  
Sedimentary Facies ◽  
Lower Jurassic ◽  
Coast Mountains ◽  
The North ◽  
Metavolcanic Rocks ◽  
Lake Formation ◽  
Island Group

A new U–Pb date of [Formula: see text] for foliated felsic metavolcanic rocks of the Bowen Island Group, from Mount Elphinstone in the southwesternmost Coast Mountains of British Columbia, indicates that there the age of this hitherto undated unit is early Middle Jurassic. These rocks grade along strike to the north-northwest into a more sedimentary facies, which north of Jervis Inlet contains a probable Sinemurian (Lower Jurassic) ammonite. The Bowen Island Group thus appears to include Lower and Middle Jurassic rocks and to be coeval in part with volcanic rocks of the Bonanza Formation on Vancouver Island to the west and the Harrison Lake Formation within the central Coast Mountains 75 km to the east.

Mid-Holocene Glacier Peak and Mount St. Helens We Tephra Layers Detected in Lake Sediments from Southern British Columbia Using High-Resolution Techniques

2001 ◽  
Vol 55 (3) ◽  
pp. 284-292 ◽  
Author(s):  
Douglas J. Hallett ◽  
Rolf W. Mathewes ◽  
Franklin F. Foit
Keyword(s):  
British Columbia ◽  
High Resolution ◽  
Lake Sediments ◽  
Tephra Layer ◽  
Coast Mountains ◽  
The North ◽  
Subalpine Lakes ◽  
Tephra Layers ◽  
Depth Relationship ◽  
Mount St Helens

AbstractA Glacier Peak tephra has been found in the mid-Holocene sediment records of two subalpine lakes, Frozen Lake in the southern Coast Mountains and Mount Barr Cirque Lake in the North Cascade Mountains of British Columbia, Canada. The age–depth relationship for each lake suggests an age of 5000–5080 14C yr B.P. (5500–5900 cal yr B.P.) for the eruption which closely approximates the estimated age (5100–5500 14C yr B.P.) of the Dusty Creek tephra assemblage found near Glacier Peak. The tephra layer, which has not been reported previously from distal sites and was not readily visible in the sediments, was located using contiguous sampling, magnetic susceptibility measurements, wet sieving, and light microscopy. The composition of the glass in pumice fragments was determined by electron microprobe analysis and used to confirm the probable source of this mid-Holocene tephra layer. Using the same methods, the A.D. 1481–1482 Mount St. Helens We tephra layer was identified in sediments from Dog Lake in southeastern British Columbia, suggesting the plume drifted further north than previously thought. This high-resolution method for identifying tephra layers in lake sediments, which has worldwide application in tephrachronologic/paleoenvironmental studies, has furthered our knowledge of the timing and airfall distribution of Holocene tephras from two important Cascade volcanoes.

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