Lake Deposits

Lake Deposits


(also lacustrine deposits), sedimentary formations on the floor of modern lakes and of lakes that existed in previous geologic eras. Classified as continental deposits, they also possess features inherent to marine deposits, for example, good sorting of material and horizontal bedding. The distinguishing features of lake deposits are lenticularity, few remains of specific fauna, few remains of terrestrial plants and animals, and a close connection with alluvial and other types of continental sediments. Glaciolacustrine deposits are classified in a separate category.

Mechanical sediments accumulate in freshwater lakes, with fine-grained sediments having pronounced horizontal bedding often predominating; sapropel and diatomite are also common. As lakes become overgrown, they frequently turn into peat bogs. The character of lake deposits changes depending on the climate. In areas with a cold climate fragmental sandy-argillaceous material is deposited, sometimes with banded lamination. In lakes of the temperate zone, iron (bean ores), silica (diatomites), calcium carbonate, and organic matter (peat, sapropel) accumulate along with the fragmental material. In arid zones, where subsaline and saline lakes are found, carbonates, halite, and gypsum are deposited; in lakes without an outlet dolomite sediments and sometimes sodium carbonate are deposited.

In ancient sedimentary strata lake deposits consist of Devonian and Permian clays and marls, dolomites, and salt-bearing deposits.

References in periodicals archive ?
Alvarado (1986, 1994) described the lake deposits at San Miguel de Turrucares in some detail.
To find out, an international team of scientists led out of the University of Copenhagen pulled nine cores of lake deposits from the Peace River drainage area in western Canada.
Mudstones discussed here include recent lake deposits in South America and Africa, modern and ancient lacustrine sediments, Jurassic terrestrial and Cambrian marine deposits, and diagenesis in ancient marine successions.
These silty layers in the strata are interpreted as ancient lake deposits.
To achieve these goals, the candidate and the host institution have designed a project that will integrate new multi-proxy paleoenvironmental data from two lake deposits in the Upper VinalopE Valley (Eastern Spain) with direct archaeological information from Mesolithic and Neolithic sites from the same area.
This paper describes the paleoseismic evidences in the Urao lake deposits.
Intriguingly, these new fossils were discovered in ancient river deposits, as opposed to the ancient lake deposits where feathered dinosaurs are often found in China.
This hole is located on the Andrew Lake fault which controls Areva's End and Andrew Lake deposits and recent discoveries by Cameco.
The many topics discussed include an examination of deltas, sublacustrine fans, the influence of pelagic biotas, organic-rich lake deposits, and saline lakes.
The results of complex examination of lake deposits will enable reconstruction of the history of relief, climate, and vegetation, determination of the development of lakes and their water level, and definition of the character of lake sediment genesis.
The Geordie Lake combined measured and indicated resource for the Marathon and the Geordie Lake deposits is more than 115 million tonnes.
Rocky Mountain lake deposits reveal that America's westward expansion kicked huge amounts of dirt into the air--probably from livestock grazing.

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