The Seven Rila Lakes
Types
The Seven Rila Lakes are a group of glacial lakes in the Bulgarian Rila mountains
In 1957, Hutchinson[18] published a monograph that is regarded as a landmark discussion and classification of all major lake types, their origin, morphometric characteristics, and distribution.[19][20][21] Hutchinson presented in it a comprehensive analysis of the origin of lakes and proposed what is a widely accepted classification of lakes according to their origin. This classification recognizes 11 major lake types that are divided into 76 subtypes. The 11 major lake types are tectonic lakes, volcanic lakes, landslide lakes, glacial lakes, solution lakes, fluvial lakes, aeolian lakes, shoreline lakes, organic lakes, anthropogenic lakes, and meteorite (extraterrestrial impact) lakes.[20][19][21]
Tectonic lakes
Tectonic lakes are lakes formed by the deformation and resulting lateral and vertical movements of the Earth’s crust. These movements include faulting, tilting, folding, and warping. Some of the well-known and largest lakes on Earth are rift lakes occupying rift valleys, e.g. Central African Rift lakes and Lake Baikal. Other well-known tectonic lakes, Caspian Sea, the Sea of Aral, and other lakes from the Pontocaspian occupy basins that have been separated from the sea by the tectonic uplift of the sea floor above sea level.[18][20][19][21]
Often, the tectonic action of crustal extension has created an alternating series of parallel grabens and horsts that form elongate basins alternating with mountain ranges. Not only does this promote the creation of lakes by the disruption of preexisting drainage networks, it also creates within arid regions endorheic basins that containing salt lakes (also called saline lakes). They form where there is no natural outlet, a high evaporation rate and the drainage surface of the water table has a higher-than-normal salt content. Examples of these salt lakes include Great Salt Lake and the Dead Sea. Another type of tectonic lake caused by faulting is sag ponds.[18][2
