Varved Clays

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Varved Clays

the sediments of lakes that are located near the terminus of an inland glacier. Varved clays are characterized by fine regular bedding consisting of summer and winter layers which are composed of coarser (sandy-silty) or finer (clayey) material, respectively. The thickness of a pair of layers is usually less than 1 mm but may sometimes reach several cm. In lake sections adjacent to the glacier, the thickness of the layers is usually greater than in sections that lie at a distance from the glacier. Within the large layers there is microbedding, which is associated with changes in the weather and the intensity of glacier thawing. Varved clays are found in Byelorussia, the Baltic republics, and in the northern European USSR. Abroad they are found in Scandinavia, in northern Poland, and the German Democratic Republic. A calculation of the number of annual layers is used for the geochronology of glacial and postglacial ages.

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References in periodicals archive ?

Studies of varved clays in West Virginia by Janssen and McCoy (1953) placed the minimum duration of Lake Tight at 6,500 years.

A New Map of Pleistocene Proglacial Lake Tight Based on GIS Modeling and Analysis

Van Asch, "Factors controlling the movement of a landslide in varved clays near La Mure (French Alps)," Bulletin de la Societe Geologique de France, vol.

Preferential Water Infiltration Path in a Slow-Moving Clayey Earthslide Evidenced by Cross-Correlation of Hydrometeorological Time Series (Charlaix Landslide, French Western Alps)

Due to scarcity of terrestrial plant macrofossils preserved in Late Glacial sediments, especially in varved clays, AMS [sup.14]C data are still scanty, which prevents working out more precise Late Glacial time control and ice recession chronology in Estonia.

Late Glacial vegetation, sedimentation and ice recession chronology in the surroundings of Lake Prossa, central Estonia/Taimestik, sedimentatsioon ja jaa taandumise kronoloogia Hilis-Glatsiaalis Prossa jarve umbruses Kesk-Eestis

Lake Timiskaming (100 km long, 200 m maximum depth) is the postglacial successor to glacial Lake Barlow; Barlow varved clays are present below the floor of Lake Timiskaming as far south as the McConnell Moraine (Fig.

Ongoing neotectonic activity in the Timiskaming--Kipawa area of Ontario and Quebec

The other type of sand is formed as a result of submarine erosion of Late Pleistocene varved clays up to 30 cm thick (alternating varved horizontal layers of brown clays and grey silty layers) are located in the nearshore, whereas below the sand accretion terrace on the bottom surface there are traces of submarine erosion, indicating sediment transport in NW direction.

Coastal processes in the eastern gulf of Finland--possible driving forces and the connection with nearshore development/Rannikuprotsessid Soome lahe idaosas: mojutegurid ja seos rannikuvoondi arenguga

The till is overlain by glaciolacustrine sands, silts or varved clays, up to 25 m in thickness.

Influence of the bedrock topography on oil shale mining in North-East Estonia

The thickness of soft varved clays amounts to 10 m.

Development and protection of the coasts in the Tallinn area/Tallinna piirkonna rannikute kaitse ja arendamine

Most of it is composed of Late Weichselian till and glaciolacustrine sand, silt and varved clays of the Baltic Ice Lake, and the Holocene marine and aeolian deposits.

Chronology of Late Saalian and Middle Weichselian episodes of ice-free lacustrine sedimentation recorded in the Arumetsa section, southwestern Estonia/ Hilis-Saale ja Kesk-Weichseli jarvelise settimise episoodide kronoloogia Arumetsa labiloikes Edela-Eestis

In some places contemporary marine deposits are missing and Upper Pleistocene varved clays are exposed on the seabed.

Sea floor deposits in Keibu Bay and Nova Bay (northwestern Estonia) and the adjacent offshore area/Setete kujunemisest Nova ja Keibu lahes (Loode-Eesti) ning nendega piirnevas avamere osas

Glaciolacustrine varved clays in the northern part of the lake depression were deposited approximately between 13 500 and 13 100 cal years BP.

Ostracod assemblages indicating a low water level episode of Lake Peipsi at the beginning of the Holocene/Ostrakoodikooslused Peipsi pohjasetetes kinnitavad jarve arengu madalaveelist perioodi Holotseeni algul

Evidence is derived from the occurrence of varved clays in the Tanassilma-Viljandi valley, particularly in the Navesti Depression, where in the vicinity of the railway bridge varved clay lenses can be found between till layers.

Geological history of Lake Vortsjarv/Vortsjarve geoloogilisest arenguloost

Following the ice retreat from the central and southern parts of the study area in the Saadjarve Drumlin Field, the deposition of glacial varved clays took place over a relatively short time period (up to 63 years).

Water-level changes and palaeogeography of proglacial lakes in eastern Estonia: synthesis of data from the Saadjarve Drumlin Field area/Ida-Eesti jaapaisjarvede veetaseme muutused ja paleogeograafia: uusi andmeid Saadjarve voorestiku piirkonnast