THE MALACOFAUNA OF LATE HOLOCENE SEDIMENTS OF SROMOWCE ( THE PIENINY MOUNTAINS , SOUTHERN POLAND )

Two subfossil mollusc assemblages have been found near Sromowce, occurring in sediments of the Late Holocene. The older assemblage occurs in sediments dated to the V–XII centuries AD, and the younger one is connected with the sediments created in the two most recent centuries. The former comprises numerous species of forest and mesophilous snails and mass agglomerations of Bythinella austriaca shells. The presence of such a fauna indicates that in the Early Middle Ages, the southward slopes of the main range of the Pieniny Mountains were almost completely afforested. The dominants in the latter assemblage are typical snails of open habitats. The alteration of the malacofauna, being due to the deforestation of a considerable area, reflects a transformation of the natural environment under human impact. Key WordS: snail assemblages, anthropopression, deforestation, thanatocoenoses, malacofauna Folia Malacologica 4/1990 was originally published as No. 1276 of Scientific Bulletins of University of Mining and Metallurgy, Cracow. This digitalised version was prepared by the Association of Polish Malacologists and first published on-line on December 30th, 2016. http://dx.doi.org/10.12657/folmal.004.001 Folia Malacol. 4: 7–24


Introduction
The malacofauna of the Pieniny Mountains was described by URBANSKI (1939), DZI!; CZKOWSKI (1971), andRIEDEL (1976).1tcovers more than 100 species of land snails.This means that about 60% of all the snail and slug species known to belong to the Polish fauna occur now in the small area of the Pieniny Mountains National Park and its close vicinity (RIEDEL 1982(RIEDEL , 1988)).With 15 taxons of freshwater snails and bivalves, it adds up to the real richness of the molluscan fauna, which is due to the very high diversity of habitats and plant communities.the Wide distribution of limestone rocks, the favourable climate, and to the fact that the natural environment protected by means of the National Park and nature reserves has only been slightly changed.In the Plenlny, it was not only in the entire Holocene but also in the cold glaciaf periods, When there were favourable conditions to molluscs to develop.According to URBANSKI (1939URBANSKI ( , 1948) ) in the said region there were refuges that enabled some species to survive through the Periglacial climate phases which repeated several times during the Pleistocene.
The history of the postglacial development of the malacofauna of the Pieniny Mountains and changes in the molluscan assemblages, being due to the natural evolution of the Palaeogeographic environment as well as human impact, have not been the subject of a detailed study so far.Nevertheless, it was as early as in the thirties, when URBANSKI (1939) undertook the task and suggested that it had to be continued.The author has been tilling the gap, by carrying out studies supported by grants for the research project CPBP 04.06.01 being coordinated by the Institute of Zoology, Polish Academy of Sciences.The studies has covered the fauna of carbonate sediments of the Middle and Late Holocene that was found on several localities in the vicinity of Niedzica, Sromowce, andKroscienko (ALEXANDROWICZ 1985, 1989), the fauna of slope sediments occurring in a small cave in the Sobczanski Gorge (ALEXANDROWICZ et at. 1985) and a' fauna connected with radiocarbon-dated slides (ALEXANDROWICZ 1984(ALEXANDROWICZ , 1986(ALEXANDROWICZ , 1988b)).The subJect of the following study are molluscan assemblages found in lluvial sediments of the Late Holocene of the areas of Sromowce Wy2ne and Sromowce NiZne on the Dunajec River.

Material and methods
The analysed fa\ll'la was found on six localities of the valleys of the streams Potok G~boki, Potok Limbargowy, Potok Macelowy, and Potok Sobczanski (Rg. 1 ).A total of 28 samples of slits, sandy silts, and sands, weighting 2 ... 3 kg each, were taken from outcrops of lluvial sediments.The samples were washed so as to pick up all the mollusc shells and sheH pieces that could be determined.The material obtained in this way comprised more than 7,700 specimens belonging to 64 taxons (Tab.1).The methods used to determine the number of shells representing each taxon, to distinguish ecologic groups and .to include the corresponding taxons, and to set up malacological spectra and association structure diagrams were ones described by LOtEK (1964), PUISSEGUR (1976), andALEXANDROWICZ (1988a).The diversity of assemblages analysed on a basis of sample sets has been expressed as a degree of biotic dispersion, as defined by L.F.KOCH (REYMENT 1971).This value can be conveniently recognized with the use of the association diversity index ADI described by the author (ALEXANDROWICZ 1988a).
In the molluscan assemblages of the sediments of the Late Holocene of the Sromowce area, the share of aquatic fauna shows much variation.This character makes a palaeoecological interpretation, as one which is chiefly based on the analysis of number of taxons and specimens of terrestrial snails connected with various habitat types, difficult.Hence, the malacologlcal spectra to characterize the assemblages of fauna are so construqed that they cover only the land fauna, proportions between the freshwater .snailsand the land ones being drawn In the form of simplicised diagrams, the two elements considered only.The structure of the assemblages of the Potok Macelowy (Mt) and Potok Gleboki (GI) streams has been reconstructed in two steps: for the whole fauna and for the terrestrial one, separately.In this way, it has been possible to determine the ecologic type of both the whole thanatocenosis accumulated by a stream and the thanatocenosis element that comes from the slopes and bottom of the valley, from the surroundings of the sedimentary basin.

Pr.ofiles and outcrops
The stUdy area Is situated on the southward slopes of the main range of the Plenlny Mountains, on the left-hand side of the DunaJec River Valley.The range, consisted of limestone, rnarl, sandstone and slate of the Jurassic age, is cut by short valleys of several streams.The lJpper sedlons of the vaHeys are narrow and V-shaped, while In the lower sections Holocene terraces and aHuvial fans occur.The sedlments of the streams are gravel, sand, silt and mud, with Intercalations of sand and tufa.

The stream Polok Gl~bokl
In the lowest sedlon of the vaHey, near the mouth opening to the vaHey of the Dunajec River, a very conspicuous anuviai fan occurs (Ag.1: Gl).1t Is cut by the recent bed of the stream bordered With scarps, 0.8 ... 1.6 m high.The fan Is composed of gravel intercalated with sand and sandy-silt.
In the gravel, fragments of wood may be found, and the silt contains a rich malacofauna and fine plant debris.In two profiles 50 m far from each other, 8 samples were taken to give more than 600 shell of land and aquatic snails and single shells of bivalves (Fig. 2: Gl).

The Stream Potok Limbargowy
In the valley of the stream, the sediments that contain molluscs occur on two localities: within the terrace situated at the junction of the valleys of the streams Limbargowy and Gr6bka (Fig. 1: Lt) and in the alluvial fan at the mouth of the valley of the Limbargowy Stream to the Dunajec River Valley.(Fig. 1: Ls).The former locality represents a profile of the sediments of the terrace which is 1.3 ... 2.0 m high and is situated on the left-hand bank of the stream.In the lower part of the outcrop there are visible sands and slates of the Sromowce formation (Upper Cretaceous) tat form the rock-base of the said terrace.The flysch-base is covered by gravels that are chiefly composed of pebbles of Hmestone, marl, and sandstone with a sandy-silly matrix.A layer of grey silt and sandy muds with remnants of fauna and flora forms an intercalation between the gravels (Fig. 2: Lt).Three samples of the said profile contained more than 300 shells of snails and bivalves.
The alluvial fan situated in the lowest part of the valley is cut by the bed of the stream that flows on flysch formations of the substrate.In several outcrops there are visible gravels and coarse grained sands with gravel, containing one or two thin intercalations of grey sandy-silt (Fig. 2: Ls).In the sands and silts, fragments of wood occur, while in some of the silt-intercalations there is a poor malacofauna.The molluscan assemblage found in two samples comprised 54 specimens.

The Stream Potok Macelowy
The valley of the stream cuts the mountain range of the Macelowa Mountaln-Podskalnia Mountain, to create a narrow and deep rocky ravine bordered with steep slopes and limestone walls up to 100 m high (the Waw6z Gorczyr'iski Ravine).Down the opening of the ravine, the stream flows through a zone that is mainly composed of flysch, a low terrace being developed on the bottom of the valley.In this part of the valley, on two localities, sediments containing assemblages of sublossil molluscs were found.One of the localities was situated about 700 m below the mouth of the ravine, whereas the other was located in the lowest part of the valley (Fig.

1: Mt. Ms).
The former locality is represented by an outcrop in the right-hand side of the stream.lt is a scarp 2 ... 3 m high.In the lower part of the outcrop there is a rock-base composed of steep beds of shales and mudstones of the Sromowce formation.Its roof surface shows signs of limonitisation.The sequence of the sediments covering the rock-base is as follows (Fig. 2: Mtl: 1. 15 cm, fine-grained gravel intercalated by laminae of coarse-grained sand, containing several fragments of coalified wood; 3. 15 cm, medium-grained gravel composed of pebbles of limestone, marl, and sandstone with a clayey-sandy matrix; 4. 1 0 cm, dark grey calcareous silt, conspicuously bedded, with laminae of fine-grained limestone sand; 5. 35 cm, gravel, conspicuously layered, with scarce big boulders of limestone and marl; In the calcareous and sandy silts, mollusc shells occur very numerously.In the lower part of the profile (layers 1 -4), in 5 samples, 4,800 specimens were found (Mt1 ), while in the upper part (layers 6 -9) 1,900 specimens were found in next 5 samples (Mt2).The fragments of coalified Wood, found In the lower and upper parts of the profile, were dated by means of the radiocarbon method, with the following results: -layer 1 (lower part of the profile) -1,430 :!: 60 B.P .(Gd-5112); -layer 9 (upper part of the profile)-900:!: 50 B.P. (Gd-5259).
In the lower section of the valley in question, near Its outlet to the Dunajec River Valley, there Is a low alluvial fan cut by the recent bed of the stream.In several small outcrops, gravels are visible, their thickness being no more than 1 m.They contain thin intercalations of sandy silts and sands, in which scarce mollusc shells and shell fragments were found (Fig. 2: Ms).The assemblage of fauna, coming from three samples, comprised only 40 specimens.

The Potok Sobczanski Stream
The short valley of the stream cuts the mountain range between the Podskalnia and Nowa G6ra Mountains, and the Trzy Korony Mountain.tt creates a narrow and very deep rocky ravine, the Walls of which consist of formations of the Pieniny Limestone Formation.Down the mouth of the ravine (the Waw6z Sobczanskl ravine) the valley becomes wider and on its bottom appear narrow terraces and a conspicuous alluvial fan that passes onto a vast terrace of the Dunaiec River (Fig. 1: Sb).In this section of the valley, in several places, the sediments of the stream are Cut by Its recent bed.In small, outcrops one can observe limestone gravels with scarce.thin intercalations of limestone sands or silts.One of such intercalations was found to contain snail Shells and shell fragments.The assemblage of fauna, collected from two samples, comprises 80 specimens (Fig. 2: Sb).

Malacofauna of older sediments
The richest molluscan assemblage occurs in the sediments of the Young Holocene terrace in the valley of the stream Potok Macelowy (Mt).ft comprises 49 species out of which 46 were found in the lower and 42 in the upper part of the profile (Tab. 1 ).70% of the species were snails prefering shady habitats, while mesophilous ones covered 25% and aquatic molluscs -5%.There was only one taxon to represent the open environment snails.As concerns the number of specimens, the dominant element of the assemblage was Byt/J;ilella austr;aca which is a snail that inhabits streams and springs, living in cold water of a constant temperature.The shells of the taxon comprised 60% of the assemblage of the lower part of the profile and 50% of that of the upper part of the profile.
Acan!/Jinu/a act-ea/a.were found in a large number.Snails of ecologic group 2. prefering shady or partly shady habitats, comprised 13%, their main representative being M/rea c;ysta/l!ila.Shells of snails of ecologic groups 3, 5, and 7 were unnumerous.whereas mesophilous snails being typical of humid habitats (ecologic group B) covered nearly 50% of the total number of specimens.
Out of the latter.however.it was only Ca;yc/J;um !rtdenlillum (Rg. 3) the shells of which dominated.
The structure of the molluscan assemblage in question has been determined by the value of the constancy index (C) and dominance index (D) of each taxon.The points that correspond to all the species lie on the margins of the diagram (Fig. 4: Mtl. it is only Bytlltilella austnaca.a dominant taxon, for which the indices riched a maximum value, while Ca;ycll;um !ndentatum and l/llrea c;ysta/l!ila are characteristic taxons of the assemblage.From among the species represented by unnumerous specimens, two groups can be distinguished.one of them comprising species ol a    The described malacofauna can be interpreted as a thanatocenosis consisted of two different but synchronous elements (a mixocenosis -ALEXANDROWICZ 1988a).On of the elements is the assemblage of freshwater molluscs with B}'fhine#a aus/rtaca.This is a typical fauna of the upper course of streams and of areas rich in springs of water of a constant, low temperature (HASSLEIN 1960(HASSLEIN , 1966)).Such a fauna is characteristic of the sedimentary environment of the sediments forming the terrace of the Potok Macelowy and can be regarded as an autochthonous component.that is, a necrocenosis.The other element covers land snail shells coming from the closest vicinity of the locality and, part of them, from the upper section of the valley (allocenosis).
The fauna of the Late Holocene terrace of the stream Potok Macelowy Is all the same throughout the studied profile.The value of the association diversity index ADI, calculated for all the ten samples of the lower and upper parts of the profile altogether, is low: ADI = 0.478.This reflects a considerable stability of the conditions of the sedimentary environment throughout the formation of the terrace.The gravels, sands, and silts were accumulated at overflows of the stream.Part of the bottom of the valley was covered by either a forest or humid habitats shaded to a various degree, whereas the slopes were covered by a deciduous or mixed forest.In the VIcinity of the described locality there were neither sunny glades nor humid meadows and Waterlogged habitats.The presence of lithic and xeric habitats occurring in the gorge Waw6z Gorczynskl, about 700 m far from the described locality, in the upper part of the valley, has not been marked In the molluscan assemblage.
The malacofauna of the sediments creating the terrace of the stream Potok Limbargowy (Ltl comprised 44 species (Tab.1).Half of them were species prefering shaded habitats.belonging to ecological groups 1, 2, and 3. Mesophilous taxons of ecologic group 7 were also numerous, Whereas only several taxons represented each of the other groups.Shells of freshwater molluscs comprised about 25%.Specimens of 1Jftl1i1elfa austl'iaca were particularly numerous, being accompanied by L)'fW1ilea tn.ncalu/a and Pisidtm personatum.As to the land fauna, the MSI malacological spectrum is similar to the MSS spectrum.Shells of the forest snails occurred in a considerable number (ea.40%), the most numerous species being AepopiJe#a pua.The fauna found In the se<liments of the terrace of the stream Potok Limbargowy is similar to the one described above.1t Is a thanatocenosis (mixocenosis) corresponding to the assemblage With ~ austnaca_ containing a diversified assemblage of land snails.This Indicates a very high degree of the afforestation of the slopes bordering the valley of the stream, and also the Presence of sun-exposed habitats and waterlogged ones in the stream basin.

Malacofauna of younger sediments
In the alluvial fan of the stream Potok Gleb<>ki at Srornowce WyZne (GI) a rich molluscan assemblage was found to occur, comprising 45 taxons (Tab.1).The MSS malacologlcal spectrum indicates that forest species comprised 40% of the assemblage while the shares of the remaining groups were approximately equal.The MSI malacological spectrum Illustrates a very big share of shells of Vallonia pulc/Je//aand J/. cos/a/a which are land snails being typical of open environment (ecologic group 5).This element comprised more than half of the total number of specimens (Fig. 3: Gl).In the structure of the described molluscan assemblage, Va//on;a pulc/Jella.with its greatest values of constancy and dominance (C5-D5).was the dominant.The characteristic taxons of the assemblage were Va//on;a cos/at a. Ca;yciJ;um tndenliltvm, and BytiJ;ilella avstr;aca (C5-D3, C4-D3).There were also some other species of a high constancy.They were forest snails: Vllrea /ranssytvan;i::a.Monac/Jok/es 1ilcamata.lsognomostoma isognomostoma (C5-D2).snails prefering shaded habitats: M/rea c;ystalllila.Ar;aata arbustorum (C4-D2).a species of open environment: Puptlla muscorvm (C4-D2).and a hygrophilous species: Succtilea pvlris (C4-D2l Most of the taxons can be considered accessory elements with C2-D1 and C1-D1 (Fig. 4: Gl).The structure of the assemb"lage covering only land snails did not differ from the one describea above, the dominants and characteristic species (except BytiJ;ilella auslnaca) showing the same C and D indices.
The malacofauna of the alluvial fan of the stream Potok Gteboki was medium-diversified.The ADI index calculated for the eight samples altogether is ADI = 0.606.lt reflects the character of the assemblage being rather uniform and recognizable as a mixed thanatocenosis with a very large share of land snails (a paraautochthonous element).Freshwater molluscs were mainly represented by BytiJ!iJe//a austrtilca whereas the main representative of land snails were Valloa!il pu/c/Je//a which is a species connected with open environment.a.o. with meadows with a dry substrate or of a medium humidity.The occurrence of the hygrophilous species Succi/lea pu/rls indicates very humid habitats locally existing on the bottom of the valley.The numerous species of forest snails, being a component of the assemblage, are typical of the deciduous and mixed forests which now are widely distributed on the slopes of the valley in the basin of the stream Potok Gleboki.
The sediments of the alluvial fan of the stream Potok Limbargowy (Ls) were found to contain a poor molluscan assemblage consisted of 19 taxons (Tab. 1 ).The MSS malacological spectrum has shown approximately equal shares of species of ecologic groups 1, 5, 7. and 10. mesophilous snails of medium-humidity habitats slightly prevailing.The shells of lands snails covered more than 90% of the total number of specimens.The MSI malacological spectrum characterizing the land fauna has indicated a very conspicuous dominance of specimens of Va//on;a pu/c/Jella and Pup;l/a muscorum belonging to ecologic group 5.The shells of slugs were also found to occur rather numerously, which is worth of attention (Fig. 3: Lsl.
In the alluvial fan of the stream Potok Macelowy (Ms) there was found a molluscan assemblage consisted of only nine species of ecologic groups 1, 2, 5, 7, and 10.The shares of particular taxons representing the groups were equal and the MSI spectrum indicated a conspicuous quantitative dominance of the shells of typical snails of open environment (ecologic group 5).These were Va//oa;a pu/c/Jella and Pupilla mvscori.IIJJ (Tab. 1. Fig. 3: Msl. The sediments accumulated at the mouth of the gorge W?!w6z Sobczanski (Sb) were found to contain a malacofauna consisted of 15 taxons belonging to 6 ecologic groups .(Tab. 1 ).The share of the shells of freshwater snails.which were only BytiJI/lella austr;aca.was 8%.More than 60% km and is 1.9 km long.
The molluscan assemblages occurring in the alluvial fans of the four streams In question reflect.to a certain degree, the afforestation of the basins.The malacological spectra characterizing the land fauna of the younger series of the sediments point out that the share of typical snails of an open environment is 50 ... 60% whereas the forest snails and the ones that mostly live in forests cover only 15 ... 25% (Fig. 3: Gl, Ls.Ms, Sb).
No species connected with rocky walls and xeric habitats were found to be a component of the assemblages.lt was only at the outlet oJ the Wawoz Sobczariski gorge where single shells and shell fragments representing ecologic group 4 were found, occurring in recently accumulated calcareous sands and gravels.Such shells, however, had been found in tufa in the Waw6z Sobczanski gorge, where many of them had occurred about 400 m above the outcrop of the sediments of the alluvial fan (ALEXANDROWICZ 1989).
The thanatocenoses of the younger series of the sediments were connected with areas part of which were allorested and the rest were covered with meadows and grazing lands and fields, the proportions between them having been similar to those observed at present.As a result of the transport and deposition of shell material in the montane streams, a considerable part of the snail shells were damaged or eliminated.Hence.the alluvial fans that were growing at the mouths of the valleys were relatively enriched in only those shells which had had a small distance to cover.As a result, the assemblages ol subfossil molluscs occurring in the sediments in question are poor and at the same time they are characterized by the dominance of snails that Inhabited the lower section of the valley (typical species of deforested lands).
In the older series of the sediments there occurs a fauna that consists of the same taxons but the shares of its components are completely dillerent.respectively.The numerous occurrence of the shells of forest snails and of snails prefering shaded habitats belonging to ecologic groups 1, 2 and 3 (40 ... 50%) along with the almost complete lack of typical species of an open environment, indicate that the thanatocenoses were being accumulated when forests were widely distributed.
The subfossll molluscan assemblages of the sediments much resemble the forest fauna of the Pieniny Mountains National Park, described by URBANSKI (1939), DZIE;CZKOWSKI (1971), and RIEDEL (1976, 1982), although they contain a considerable admixture of the shells of mesophilous snails (C3;yc!J;i/m triden/3/um) and freshwater snails (8}'1/Jine/13 3Uslriilc3) Hence, one can suppose that when the older series of the sediments were being formed the total area of the basins of the four streams was covered with a forest.In the period between the formation of the terraces (older sediments) and the formation of the alluvial fans (younger sediments) a considerable part of the area got deforested, which resulted in an increase in erosional processes and In a change in molluscan assemblages.

Changes during the historical period
The southward slopes of the Pieniny Mountains were, for a very long time, not under human Impact leading to the degradation of natural environment.In the vicinity of Sromowce, localities of natural settlement have been known, however, they were connected with the Late Glacial Period The intensive development of colonization in the Sromowce region proceeded in the Xlllth and XIVth centuries.1t was then when the castle situated on the Zamkowa G6ra Mountain, in the Trzy Korony Mountain range, the village of Sromowce (the left-hand bank of the Dunaiec).and a monastery (the so called Czerwony Klasztor) were built (Kot.ODZIEJSKI et al. 1982).As a result of this colonization, a vast area of little diversified relief and small height differences of 1 00 ... 140 m got deforested.1t is a zone of outcrops of Upper Cretaceous marls, sandstones, and shales, Which border the main range of the Pleniny Mountains from south; the range is characterized by large height differences (300 ... 500 m) and deeply-cut valleys.The forests of the Pieniny Mountains were for a long time being exploited and it it were not for the creation of the National Park, they would not exist today.
On the deforested areas which had been converted to araole lands or pasturies, the processes 01 erosion and denudation were intensified.Initially, their intensity was limited, which was due to the fact that the fields were cultivated every three or two years, but In the recent centuries.since the Yearly ploughing and the raising of root crops had started, the erosion of soil and rainwash • became much more intensive.This brought about the deepening of the bottom of the valleys, slits In the older and mediaeval terraces and their bases, and the formation of alluvial fans.The said Processes were followed by the development of a fauna that could survive in such a deforested habitat, under human impact.
The molluscan assemblages found in the older and younger series of the sediments in the valleys of the left-hand tributaries of the Dunaiec River very well reflect the environmental changes caused by man in the historical period.Such environmental changes were observed by various authors, as EVANS (1972).LOZEK (1982).ALEXANDROWICZ (1988).
The dominant element of the freshwater fauna of the Late Holocene sediments of the Sromowce area is the stenothermic species Bytllme/la auslrtaca.The species was recorded from sediments of various ages.among them lrom all the climatic phases of the Holocene (LOZEK 1964(LOZEK . 1982) ) while in the Polish part of the Central Carpathians it is largely connected with the Upper Holocene.The mass occurrence of the shells of Bytllt/le/la auslr/aca is a typical character of the malacofauna of the Late Holocene tufas found in the region situated at the loot of the Carpathians.in the Pieniny Mountains. and Outer Carpathians (ALEXANDROWICZ 1985).This is also characteristic of the two molluscan assemblages described.
of the specimens, and mainly the species Va//on;il pu/cllella.were a fauna of open environment.a rather wide, low terrace covered by meadows and pasturies, passing into an alluvial fan.The stream Potok Limbargowy has a considerably smaller basin (1 .3sq.km), its valley length being 1.8 km and the dillerence of height of 230 km.I In the upper part of the basin there are glades and montane meadows, while in the lower one there are fields.The degree of allorestalion is uo to 38% here.The valley of the stream Potok Macelowy is 3.1 km long.The basin, covering an area of 2.7 sq. km, out of which 40% are allorested, has a height dillerence of 280 m.In its upper part, the .valley has steep slopes, allorested or rocky, while in the lower part the slopes are little slanting and quite deforested.The basin of the stream Potok Sobczanski shows the largest dillerences in height (31 0 m) and a considerable allorestatlon (65%).lt covers an area of 1.5 sq.

(
Kot.ODZIEJSKI et al. 1982).The afforestation of the area during the Holocene.as well as the configuration of the land, did not favour the development of the Neolithic colonization, though traces of the presence of the Neolithic/Bronze Age man were recorded from this part of the Valley of the Dunaiec River.From the beginning of the Christian era to the Early Middle• Ages, the area in question stayed outside a zone of colonization.The natural conditions that occurred then Were expressed in, a.o., a moderate intensity of erosional processes.That period corresponds to the fauna of the terrace of the stream Potok Macelowy.The fauna occurs is sediments, the age of Which is determined by two dates (in the floor and in the roof): 1,430 :!: 60 years B.P. and 900 :!: 50 years B.P., respectively.This means that the sediments in question were being formed from the middle of the Vth century to the beginning of the Xllth century.The sedlments and malacotauna of the terrace of the stream Potok Limbargowy can be acknowledged as being of the same age.