Loess documentary sites and their potential for geotourism in Lower Silesia (Poland)

1.1 Overview of nature protection forms and history of documentary sites in Lower Silesia voivodship

According to the Act of 16 April 2004 on The Protection of Nature several forms of nature protection can be distinguished in Poland (Table 1).

The last form of nature protection in Poland is the species protection. There were 715 species of plants, 322 species of fungi and 799 species of animals under protection in 2015 (http://www.gdos.govpl).

Each form plays a different role in the Polish system of nature conservation and they have different purposes, different regime of protection and thus, different restrictions on use. In Lower Silesia voivodship there are all types of nature protection (Table 1). The documentary sites are specific elements of protection network, which can partly be combined with the international concept of “hard-and soft-rock” geosites. Before the year 2004 there were no documentary sites in Poland. They were created after the recommendation of The Committee of Ministers of the Council of Europe (CE) on the basis of document: “Recommendation on conservation of the geological heritage and areas of special geological interest” [5].

The Documentary sites are usually not distinguishable on the surface. They often include natural or artificial rock exposure with interesting geological and mineral formations, fossil accumulations and caves, scientifically and teachingly important. There are 177 documentary sites in the entire country, but only 3 in Lower Silesian Voivodship (Table 1).

First documentary site in the Lower Silesia was established in 2010 as “Adit No. 18 in the Underground Tourist and Educational Route in the Old Uranium Mine in Kletno”. The uranium mine is located on the northern slope of Żmijowiec in the Śnieżnik Massif. After World War II it was active in the years 1948-1953, using several medieval tunnels in which iron, silver and copper mining were carried out in the past. The mine consisted of 20 drifts, three shafts, and the accumulated length of all mining excavations was over 37 km. In total, 20 tons of uranium were extracted here [18].

The second documentary site was created in Trzebnica in 2016 and it is known as “Loess of Vine Mountain”. This is an example of soft rock geosite because it contains dust deposits (loess and loess-derived sediments) with a thickness of approx. 6 m. The loess sequence is located in the southern, vertical wall of the excavation with a length of approx. 50 m. It covers a stony pavement of variable thickness (0.0 – 0.7 m), where the Lower Palaeolithic artefacts were found [19, 20].

The third one “Limestone Adit in Ciechanowice” was established in 2017. It is a former, small mine of crystalline limestone. It includes adits with a total length of about 90 m and an exploitation chamber. The width of the tunnel is about 1.8 m and the height oscillates between 1.5 - 2.3 m. The chamber’s width reaches 8 m and its height exceeds 5 m. In addition to geological and biological values, the object is an important element of the history of the mining industry, due to the preserved traces of the use of old mining techniques [21].

2.1 The documentary site "Loess of Vine Mountain" in Trzebnica

Already existing documentary site "Loess of Vine Mountain" (51^∘18’44.45 N, 17^∘4’14.68 E, 192.5 m a.s.l.) was established 23rd of December 2016. It is located in an old clay pit in NE part of the Trzebnica city, ca. 25 km north of Wrocław (Figure 2). Geosite is located in the area of Trzebnica Hills, which is a mesoregion of Silesian Rampart [36].

Figure 2

Location of documentary site "Loess of Vine Mountain" in Trzebnica on the background of digital elevation model.

The protected vertical loess wall is situated in the southern portion of the quarry. The Late Pleistocene loess sequence is 6 m high and 50 m long (Figure 3). The loess and loess derived sediments cover stony pavement, where Lower Palaeolithic artefacts have been found in 1980s [19, 37, 38]. In some parts of the exposure loess was deposited directly on Pliocene clay.

Figure 3

Southern loess wall within the excavation of the Trzebnica brickyard in the 90s of the last century –the place of the present documentary site "Loess of Vine Mountain" (photo: Z. Jary).

The main goal of establishing this documentary site is to preserve the sequence of sedimentary rocks of several

geological formations and environments occurring in the superposition [20, 39]:

• – Neogene (Pliocene) clay deposited in alluviallacustrine environment, deformed in the upper part

  

  Figure 4

  The contact zone between loess and Neogene clay in the southern wall of Trzebnica quarry [20]. 1- Neogene clay; 2- sandy layers; 3- gravelly layers; 4- big gravel bodies; 5- single big stones; 6- till; 7- massif loess; 8- laminated loess; 9- clay laminas; 10- flow structures in loess; 11- sandy laminas in loess; 12- iron structures.

• – residual Mesopleistocene morainic pavement with Scandinavian erratics strongly deformed mainly in periglacial environment;

• – Pleniweichselian loess sequence with initial tundragley soils, roots horizons and ice wedge casts

  

  Figure 5

  Late Pleistocene loess sequence in Trzebnica quarry (central part of wall shown on figure 3) with initial tundra-gley soils, roots horizons and ice wedge cast. Pleistocene morainic pavement in the floor and colluvial soils in the upper part (20 - modified).

• – Holocene colluvial soils.

There are no doubts that this site is of great importance due to its scientific and didactic qualities. However, its special attractiveness for geotourism purposes should be primarily exposed. Taking into account aesthetic and educational values as a principal for potential geotourists the following geo-features of the documentary site "Loess of Vine Mountain" could be offered (Table 2).

In this excavation periglacial structures left after former ice wedges which are the effect of global climate changes deserve special attention – they are proof of the occurrence and disappearance of permafrost in this area. In that time the annual mean temperature were 10-15 °C lower than nowadays [32, 33].

2.2 “Loess-soil sequence in Biały Kościół” – planned loess documentary site in Strzelin Hills

The loess-soil section Biały Kościół is located in an old clay pit, several meters from the road connecting Strzelin and Henryków (λ = 17^∘01’30”E, φ = 50^∘43’30”N;(Figure 6).The loess profile is placed on the west slope of the Oława valley at an altitude of approximately 185 m.a.s.l. Site is located in the area of Strzelin Hills. The profile location itself is a great asset for planned documentary site. The sequence is situated only 50 m from the voivodship road No. 395. So, reaching this geosite should not be a problem for the potential tourists.

Figure 6

Location of loess-soil section in Biały Kościół on the background of a digital elevation model.

The loess cover in the Strzelin Hills was previously described by Raczkowski [14, 40]. The thickness of loess cover is considerable but very differentiated - from 0 to 15 m. There are typical forms of loess relief: gredas, dry valleys, gullies and closed depressions.

Due to its unique succession, comparable to the typical Late Pleistocene sequences of European Loess Belt, the section in Biały Kościół was presented during several consecutive Loess Seminars organized by the University of Wroclaw [42, 43, 44, 45, 46].

Biały Kościół loess-soil sequence (9 m high) consists of five basic lithopedostratigraphic units (Figure 7) developed during the Late Pleistocene and Holocene: two polygenetic fossil pedocomplexes, two calcareous loess units and modern soil in the top.

Figure 7

Late Pleistocene loess–palaeosol profile in Biały Kościół with OSL (Optically Stimulated Luminescence) dating results obtained for coarse quartz grain (90-125 μm; after 35).

The most important scientific value of the Biały Kościół loess sequence (Figure 7 and 8A,B,C) is very well preserved pedosedimentary record of Late Pleistocene climate changes occurring in the superposition within vertical wall of 9 m high [34, 35, 43, 44, 45, 46, 47]:

Figure 8

Loess section in Biały Kościół. A – The Upper Pleniweichselian loess with Holocene brown soil in the upper part; B - Eemian and Early Weichselian pedocomplex; C - Middle Pleniweichselian pedocomplex (photos: Z. Jary).

• – Eemian and Early Weichselian set of fossil forest soils (pedocomplex) gleyed and deformed by gelifluction in the upper part (Figure 8B;

• – Lower Pleniweichselian carbonate loess with initial gley horizons;

• – Middle Pleniweichselian set of tundra-gley soils (pedocomplex) with permafrost features, deformed by gelifluction and frost heave (Figure 8C);

• – Upper Pleniweichselian carbonate loess with initial gley horizons (Figure 8A);

• – Holocene brown soil (Figure 8A)

From the point of view of potential geotourists and taking into account the aesthetic and educational values of Biały Kościół loess site the following geo-features of this site could be highlighted (Table 3):

Biały Kościół loess profile is situated relatively far from Strzelin city (7 km) in the middle of agriculturally used field thus difficult to control and preserved. But this may change in the near future. There is still a lot to be done in order to prepare Biały Kościół site to become a proper documentary site but with help of local authorities and scientists it seems to be possible. Same as in the other cases well exposed loess profiles may become an interesting offer for the new generation of geotourists [e.g. 15, 16, 48]. There is a constantly expanding group of tourists who willingly discovery the mysteries of the Quaternary epoch recorded at the loess sequences. Of course, it requires a special ways of presentation. The most important thing is to “translate” the scientific results into the language of ordinary recipients using the latest techniques.

3.1 Cultural heritage and its influence on tourist movement in the vicinity of loess documentary sites

Loess areas in the Lower Silesia are usually accompanied by the rich cultural heritage. They are associated not only with historical times but also with prehistory. The archeological sites represent different cultures throughout the history of human activity, although their potential for tourism development is almost unused. The Lower Paleolithic settlement, the oldest traces of human occupation in Poland, was found on the western slope of Vine Mountain in Trzebnica [19, 37]. Rich in archaeological sites is also an area in the vicinity of Biały Kościół loess site.Among the numerous sites, the open-air site in Henryków dating back on the Early Gravettian age (28.5 - 31.5 ka BP) deserves attention [49]. However, the greatest value, from the tourism development point of view, of this area there are the historical monuments. The documentary sites in Trzebnica and Biały Kościół could be an excellent complement for tourists visiting well-known medieval monasteries [50]. Around 8 km south of the Biały Kościół loess site the Cistercian Monastery in Henryków is located (Figure 9A) It was mentioned for the first time in documents from 1222, when the Duke Henry I the Bearded gave his permission to found a branch of the Cistercian here. The abbey is also important for Polish history [51]. A Latin chronicle „The Book of Henryków” compiled at Henryków abbey in the 13th century contains the first known sentence written in Polish language [52]. The very precious Cistercian complex, both historically and architecturally, compresses: the Church of the Assumption of the Blessed Virgin Mary and the St. John the Baptist Church, dating back to the 13th century, the monastery, the farm buildings and surrounding park with centuries-old trees [53]. Just 7 kilometers north of the Biały Kościół there is Strzelin. Although the city was largely destroyed during World War II, some high-class monuments have been preserved. One of them is Romanesque St. Godehard’s Rotunda founded in the 11th century and rebuilt in the 13th century [53] (Figure 9B)

Figure 9

Cultural heritage located near the loess documentary sites: A - Cistercian Monastery in Henryków; B - Romanesque St. Godehard’s Rotunda in Strzelin; C,D - Sanctuary of St. Jadwiga in Trzebnica (photos: Z. Jary, P. Owczarek, W. Jary).

Trzebnica is also a town rich in historical monuments. In the proximity to the Trzebnica loess documentary site an important pilgrimage center is located. In 1202 the Silesian Piast duke Henry I the Bearded and his wife Saint Hedwig of Andechs founded here a Cistercian convent - the first in Poland, which is contemporary the Sanctuary of St. Jadwiga in Trzebnica (Figure 9C,D) The vast monastery complex consists of abbey church and residential buildings [54]. The church was built in the late Romanesque and Gothic style, to which baroque additions were made from 1741 [55]. The abbey also became a mausoleum of many rulers of the Lower Silesia. Currently, there are no information about loess documentary sites near these historic buildings, which are numerously visited by tourist and pilgrims. The authors see great potential in the geotourist development in these areas, among others, through comprehensive approaches and couplings of cultural tourism with geotourism.

However, the documentary site is potentially an excellent geotourist resource, but it is necessary to indicate the risks that may be brought by the tourist usage [48]. First of all, it should be emphasized its relatively low resistance to degradation compared to typical geotourist values. Soft rocks are easily damaged by erosion and the impact of mass movements (earthslide, mudslide) if they are not properly secured and used. Surface runoff, connected with rainfall or snowmelt, can affects the destruction of exposure by draining the top layer, which is not protected. Another element that may limit the development of tourism based on the discussed value is its temporary availability. The specificity of soft rocks makes it difficult to keep the loess wall constantly unchanged. Over time, its readability is blurred, and the outlay should be refreshed from time to time, which is associated with additional costs and the need for constant monitoring of the value. Another threat is the uncontrolled development of vegetation and destructive influence of roots. As a result, after some time the value will be illegible to the potential tourist, eventually it may also be destroyed. Another issue is the dangers arising from the incorrect use of land unveiling by the local community. It happens that the place situated on the sidelines of the locality becomes a place of illegal storage of garbage. This results not only in a significant decrease in the attractiveness of the asset, but even its destruction. A specific threat to this type of asset may also be the low level of awareness of the importance of this type of heritage for general knowledge about climate change over time. This may change, but it is associated with changes in the education process, especially for young people, which in the future may change the situation.