Geology and Soil Conditions in the Český Krumlov Region
 

This area is dominated by a crystalline of the Vltava-Danube area known as moldanubicum. From a stratigraphical point of view, all major structural units, series, can be found here. The unvaried series of the crystalline is characterized by a rather monotonous structure and acidic rocks. Varied series, with large quantities of small inserts of variant rocks, often of the basic nature, run across the Český Krumlov region. Among other units, there are also series of mica schist and Kaplicke mica schist gneiss and two granolith systems (Kristanov and the Blansky woods). This provides for a greatly varied geological structure of the region which is without parallel in the South Bohemia area.

Geologic map of the Český Krumlov region

Among the rocks, which make up the major part of the sole of the border part of the region and which are sporadically found inland as well, there are various types of granites and granodiorites. Mica schist and mica schist gneiss in Kaplicko and biotite paragneiss are other significant rocks which, in a wide-belt parallel with the Kaplicke mica gneiss series, fill the central part of the region and are the constitutive rock of the varied crystalline series. Besides other types of gneiss and pegmatites, basic rocks are the most important when considering the occurrence of botany and fauna. They create many minor and major inserts in varied crystalline series. These are especially crystalline limes, erlany and amphibolites, the occurrence of which gives the nature of the Český Krumlov region many typical features. Serpentinites have a similar function. They are usually found on the perimeter of granolith systems.

Šumava National Park and Nature Reserve, Bear path - formation named "chapel" (remains of the ice age) 
The Český Krumlov region is also remarkable from a mineralogical point of view. Especially interesting are the rocks of the granolith system, serpentinites and the products of their transformation. The Křemžská hollow is known for its granoliths, eclogites, ultrabasics, opals, garnets and many other rocks. Moldavites can be found near Besednice, Vrabce and in other places.

The occurrence of minerals in the region is also relatively rich, even though the beds are small and do not meet most of the requirements for the modern, high-capacity, exploitation methods. The beds of ledge silver ore around Český Krumlov, Chvalšiny and other places (albeit important only from a historical point of view) are the most popular. The geest beds of nickel ore in the serpentinite area of the Křemžská hollow are more significant and they are a regional peculiarity. The limonite iron ore has its origin in the serpentite geest and was processed in the defunct Adolfov works (now Artypa Holubov).

  Graphite
 
Regarding non-ore materials, the graphite beds scattered in the varied crystalline series are the most remarkable; its exploitation exists only in the Český Krumlov area. The exploitation of crystalline lime in Vyšný at Cesky Krumlov has been stopped, although it still continues near Blizna. For standard building needs, there are two quarries open (exploitation of granitoids) at the foot of the Blansky woods - the Zrcadlová works above Chvalšiny and Plešovice. Both are located on CHKO territory, but the exploitation is to be gradually moderated due to the excessive dust, noise and irreversible changes in the land.

In the region, the most significant beds of peat (highland and transitional type) were flooded by water from the Lipno reservoir; the area between Světlík and Blatná is currently the most important exploited bed. Other large peateries (in the Svatotomašské range, in the Novohradské hills) are today declared as small-area reserves.


Geotectonic map of the Český Krumlov region 
Soil in the region corresponds to the diversity of the geological structure, the climate and the original and transformed vegetation cover. Regarding agriculture, the soil is mostly thin and its attributes are more suited for forestry (especially the geest of amphibolic-biotite syenite of the Rastenberg type in the area of Želňavske range and the Weinsberg-type biotite granodiorite in the Novohradské hills, in its piedmont in the Kaplicko area and the border regions of Vyšebrodsko and the Svatotomašske range - even on a simple stroll, one cannot fail to notice the vitality of the local woods). The Central European brown soil is the most frequent zonal soil type, rendzina on crystalline lime and magnesium rendzina on serpentite are the most interesting (for vegetation). A large part of the soil in the region has been affected by the high level of groundwater (gley and peat soil); the percentage of permanently swamped soils has been increasing in the last few years, because a large part of formerly cultivated land is incult.

(vd)
 

Further information :
Description of Natural Conditions in the Český Krumlov Region
Geological Structure in Český Krumlov and its vicinity
History of Mining in Český Krumlov

 



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