The underground configuration of the Plitvice Lakes consists of various geologic features.
Generally, the whole area of Plitvice Lakes National Park can be attributed to the South-East European karst area.
The typical feature of this karst area is brittle or porous rock, mostly limestone or dolomite.
This configuration creates different geomorphological phenomena being referred to as dolina (sinkhole), polje, uvala, ponor, etc.

In the future, the analysis of underground water courses could be an interesting field of research for speleologists.
Up to now, little has been known about these unexplored courses.
At first sight, a lack of water in the karst region could be ascertained.
However, this is only the case on the surface.
The major part of natural phenomena takes place underground, where an abundance of water exists.

Due to the features of limestone, many rivers drain away into the rock.
Therefore, extensive underground river systems exist.
Upon reaching hard rock, rivers emerge on the surface.
This phenomenon of underground karst rivers (Croatian rijeka ponornica) can also be observed at the Plitvice Lakes.

Tufa sediments have been formed from the Pleistocene onwards in sinkholes or depressed areas between the surrounding mountains.
Generally seen, the underground of the Plitvice Lakes could be categorized into two zones.
The Upper Lakes in the south predominantly consist of dolomite rock.
The Lower lakes in the north predominantly consist of limestone rock.
Dolomite rock is slightly harder than limestone.
Though fragile upon physical influence, dolomite rock has lower water permeability properties.
In contrast, limestone rock is more compact and massive, but has a higher water permeability.

From an aerial perspective, significant differences between the terrain of the Upper and the Lower Plitvice Lakes can be observed.
At the Upper Lakes several little lakes have formed parallel to each other and a rather shallow water flow can be observed.
The Lower Lakes, however, are much larger and virtually drill their path through the rock.
Furthermore, there are only a few lakes at the Lower Lakes.
They have formed a canyon, which continues as river Korana.
The underground configuration of the Plitvice Lakes consists of various geologic features. Generally, the whole area of Plitvice Lakes National Park can be attributed to the South-East European karst area. The typical feature of this karst area is brittle or porous rock, mostly limestone or dolomite. This configuration creates different geomorphological phenomena being referred to as dolina (sinkhole), polje, uvala, ponor, etc.
In the future, the analysis of underground water courses could be an interesting field of research for speleologists. Up to now, little has been known about these unexplored courses. At first sight, a lack of water in the karst region could be ascertained. However, this is only the case on the surface. The major part of natural phenomena takes place underground, where an abundance of water exists.
Due to the features of limestone, many rivers drain away into the rock. Therefore, extensive underground river systems exist. Upon reaching hard rock, rivers emerge on the surface. This phenomenon of underground karst rivers (Croatian rijeka ponornica) can also be observed at the Plitvice Lakes.
Tufa sediments have been formed from the Pleistocene onwards in sinkholes or depressed areas between the surrounding mountains. Generally seen, the underground of the Plitvice Lakes could be categorized into two zones. The Upper Lakes in the south predominantly consist of dolomite rock. The Lower lakes in the north predominantly consist of limestone rock. Dolomite rock is slightly harder than limestone. Though fragile upon physical influence, dolomite rock has lower water permeability properties. In contrast, limestone rock is more compact and massive, but has a higher water permeability.
From an aerial perspective, significant differences between the terrain of the Upper and the Lower Plitvice Lakes can be observed. At the Upper Lakes several little lakes have formed parallel to each other and a rather shallow water flow can be observed. The Lower Lakes, however, are much larger and virtually drill their path through the rock. Furthermore, there are only a few lakes at the Lower Lakes. They have formed a canyon, which continues as river Korana.
Plitvice Lakes National Park