Varve Deposition and the Sediment Yield Record at Three Small Lakes of the Southern Canadian Cordillera

Desloges, Joseph R.

doi:10.2307/1551776

Cited by 71 publications

(50 citation statements)

References 29 publications

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“…We suggest that glacial activity (abrasion and melt-water transport) is the most important agent to govern sediment flux. The geochemical and physical properties of the sediments agree with findings from other lakes (Ariztegui et al 1997;Desloges 1994;Leemann & Niessen 1994;Leonard 1986b;Leonard 1997;Moore et al 2001;Nesje et al 2001;Vanderaveroet et al 1999). However, there are documented glacier advances in the 12 th and 14 th century (Holzhauser & Zumbühl 1999) that have not affected the sediments of Lake Sils.…”

Section: Limnogeological Development Of Lake Silssupporting

confidence: 81%

The last 1300 years of environmental history recorded in the sediments of Lake Sils (Engadine, Switzerland)

Blass

Anselmetti

Grosjean

et al. 2005

Eclogae geol. Helv.

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Proglacial Lake Sils is located in the Upper Engadine (south-eastern Swiss Alps) at 1800 m a.s.l. and is the uppermost of four lakes in the valley. A highresolution seismic survey combined with geophysical and chemical data of 22 short sediment cores, and 137 Cs, 210 Pb, and 14 C AMS dating provide insight into the sedimentological development of the lake during the last 1300 years. The deposits consist of diffusely laminated clayey silts. In contrast to nearby Lake Silvaplana, no varves could be detected. Sedimentation rates are on average 1.1 mm per year (40 mg cm -2 a -1 ) which is much lower than in the adjacent Engadine lakes. The most prominent sediment feature is a turbidite that was deposited around cal AD 700, has a thickness of up to more than 6 metres and a total estimated volume of 6.5*10 6 m 3 , which is more than the total cumulated sediment mass deposited since that time (4.5 * 10 6 m 3 ).The sediments deposited after around AD 1880 show higher contents of organic carbon (Corg) and biogenic silica (bSi), which suggests enhanced primary production due to increasing tourism in the area and subsequent higher nutrient supply to the lake. Sediments with distinctly lower Corg and bSi concentrations, but with larger grain-size medians and higher mica concentrations were accumulated between AD 1500 and 1880. These features are related to a late period of the 'Little Ice Age' when major regional glacier advances occurred. ZUSAMMENFASSUNGDer von Gletscherwasser gespiesene Silsersee liegt im Oberengadin in den Schweizer Südost-Alpen auf 1800 m ü. M. und ist der Oberste in der Engadiner Seen-Kette. Aufgrund von hoch auflösenden, seismischen Daten und ungefähr zwei Dutzend Sedimentkernen, datiert anhand von 137 Cs, 210 Pb und AMS 14 C, mit anschliessenden geophysikalischen und geochemischen Analysen, kann hier eine breite Datenbasis präsentiert und die sedimentologische Entwicklung des Sees in den letzten 1300 Jahren aufgezeigt werden. Die Ablagerungen sind diffus laminiert und bestehen hauptsächlich aus tonigem Silt. Varven, wie im benachbarten Silvaplanersee, wurden keine erkannt. Die Sedimentationsrate liegt mit 1.1 mm pro Jahr (40 mg cm -2 a -1 ) ungefähr eine Grös-senordnung tiefer als in den anderen Engadiner Seen. Ein bis zu 6 Meter mächtiger Turbidit wurde um AD 700 abgelagert. Das geschätzte Volumen von 6.5*10 6 m 3 liegt wesentlich über dem seither abgelagerten Volumen von 4.5 * 10 6 m 3 .Seit ungefähr AD 1880 wurde in den Sedimenten markant höhere Werte an organischem Kohlenstoff (Corg) und biogenem Silizium (bSi) gemessen. Dies wird auf die seit anfangs des letzten Jahrhunderts stark angestiegenen Touristenzahlen zurückgeführt, was ein erhöhtes Angebot an Nährstoffen im See verursacht hat. In der Periode von ca. AD 1500 -1880 wurden einerseits deutlich tiefere Konzentrationen an bSi und Corg, andererseits besser sortierte und gröbere Sedimente festgestellt und zudem erhöhte Glimmer Werte gemessen. Diese Veränderungen werden mit einer späten Phase der 'kleinen Eiszeit' in Verbindung gebrach...

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Section: Limnogeological Development Of Lake Silssupporting

confidence: 81%

The last 1300 years of environmental history recorded in the sediments of Lake Sils (Engadine, Switzerland)

Blass

Anselmetti

Grosjean

et al. 2005

Eclogae geol. Helv.

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“…We suggest that, in some cases at least, the rhythmically laminated portions of the core sequence record the release of fine subglacial material because of significant ice ablation and glacier retreat, probably related to increased summer temperatures (cf. Desloges, 1994;Lemmen et al, 1988). The duration of the longest rhythmite sequence recorded here (beginning FIGURE 8.…”

Section: Interpretation Of Faciesmentioning

confidence: 95%

“…Sturm and Matter, 1978;Desloges, 1994). This paper describes sediments obtained from a glacier-fed lake in a small drainage basin in Banff National Park.…”

Section: Introductionmentioning

confidence: 99%

Glaciolacustrine sediments and Neoglacial history of the Chephren Lake basin, Banff National Park, Alberta

Dirszowsky¹,

Desloges²

2002

gpq

Self Cite

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AbstractModern and historical sedimentation in Chephren Lake are examined in order to assess the relations between glacier activity, sediment production, and the lacustrine depositional record. Bottom sediment data and lake morphology indicate that sediments in the distal part of the lake primarily settled from suspension and that glaciers are the most important source. A 4.3 m core obtained from the distal sediments reveals that accumulation of fine, glacially-derived material has increased since at least 2 420 BP. Simple geochemical indicators reflect this and support regional evidence for progressive (though punctuated) climate deterioration through the Neoglacial period. Distinct rhythmite sequences (especially beginning ca. 3 460, 2 330, 1 470 and 530 BP) are thought to represent minor glacier retreats which help define separate phases of Neoglacial advance identified by previous workers. In contrast, increasing slope stability indicated by a reduction in graded sand and clast facies may be specific to slopes overlooking the coring site.

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“…Perkins and Sims, 1983;Leonard, 1986;Wolfe and Teller, 1993;Desloges, 1994;Leemann and Niessen, 1994;Hardy et al, 1996). In biochemically controlled aquatic systems, however, the relationship between climate and varve formation is more complex.…”

Section: Introductionmentioning

confidence: 99%

The separation of the influence of nutrients and climate on the varve time-series of baldeggersee, Switzerland

Lotter

Birks

1997

Aquatic Science

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The varve data-set from a freeze-core taken in the deepest part of Baldeggersee was subjected to different multivariate statistical analyses in order to estimate the amount of variance in the varve thickness measures explicable by past climate and by the trophic state of the lake. A comparison of two different time-periods (1902 to 1992 versus 1920 to 1980) revealed that the lake restoration programme since 1982 has had a significant impact on the formation of the seasonal layers. Results of the partitioning of the variance in the varve thickness measures showed that about two thirds of the variance are unexplained by a climate and trophic state model and that trophic state explains 6%, whereas climate accounts for about 28 % of the variance before the effect of lake restoration had a strong impact on the varves. Among the climate parameters the amount of annual precipitation is a strong predictor for explaining the thickness of both dark layer and total couplet thickness, whereas summer precipitation is important for the thickness of the light layer.

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Varve Deposition and the Sediment Yield Record at Three Small Lakes of the Southern Canadian Cordillera

Cited by 71 publications

References 29 publications

The last 1300 years of environmental history recorded in the sediments of Lake Sils (Engadine, Switzerland)

The last 1300 years of environmental history recorded in the sediments of Lake Sils (Engadine, Switzerland)

Glaciolacustrine sediments and Neoglacial history of the Chephren Lake basin, Banff National Park, Alberta

The separation of the influence of nutrients and climate on the varve time-series of baldeggersee, Switzerland

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