Page 4 - SEG - First issue

Academic Articles

II- Depositional Environment

- Lake -

As one of many ecosystems lakes have sedimentological
characteristics that distinguish it from other terrestrial sedimentary
environments but first what is a lake exactly ??
a lake is a large body of water that occupies an inland basin

A related term would be pond but the difference between the two that
lakes are great in size and have depth while ponds are shallow water
bodies with small sizes

How do lakes form ?

lake can form from a variety of ways The water in the lakes comes
like from rainfall or melted snow,
1- ancient glaciers sliding and stream and ground water
carving the land and then melting so seepage hence most of the
the water fills the land carved by the lakes are fresh water lakes .
glaciers , this is comment in the there are two types of lakes
northern hemisphere open lakes and closed lakes
2- basins created by tectonic open lakes have an outlet that
movement buckling and breaking lets it's water flow from it
the earth , these basins are then closed lakes have no outlet so
filled with water from rainfall or they tend to be more saline
streams because the still water
3- volcanoes are also another mean evaporates and leaves behind
of creating a basin for water to fill , salts .
after the volcano has become lakes sedimentation and
inactive it leaves a crater that would sediments
be filled with water coming from lakes sediments comprise of
rain or melted snow some times the silts clays and sand sizes
volcano would erupt or the top which are clastic elements , it
would collapse and it would leave a is also has organic matter
depression called caldera that then chemically precipitated
would also be filled with water . material and the ratio between
4- rivers can make lakes when rivers these elements depends on
are meandering and have a sudden the drainage basin ,climate
change of flow (flood) it may make and the age of the lake
a short cut and leave a body of
water Isolated from the river that
kind of lake is then named oxbow
lake because it takes the shape of
the U frame that is put around ox's
necks
5- land slides could cause the
creation of lakes due to barricading
the flow of a stream or a river
creating a dam tat would prevent
the water from flowing
6- artificially made lakes made by
humans digging and letting the man
made basin fill with water from
streams or rivers and then using the
lake to produce electricity and other
uses for mankind

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