Factors influencing solution in karren and on covered karst 289 Hungarian Geographical Bulletin 59 (3) (2010) pp. 289–306. Factors infl uencing solution in karren and on covered karst Márton Veress1 Abstract The eff ect of the following factors on karstifi cation were investigated: the presence of Pinus mugo, slope length, and slope angle (Totes Gebirge, Austria), the wind action (Diego de Almagro Island, Chile), the thickness and quality of covering sedimentary rock (Bakony Mountains, Mecsek Mountains, Hungary) and the role of karst water (tsingies, Madagascar). The methods were as follows. The specifi c cross-sectional area of rinnenkarren and their specifi c shape-parameter in Totes Gebirge were calculated. Morphological maps of sev- eral karren forms at Diego de Almagro Island were prepared and specifi c width of these karren features was also computed. Topographic cross-sections were created and height measurements of Madagascar tsingy areas carried out as well. Vertical electrical sounding (VES) method was applied in the Bakony Mountains and in the Mecsek Mountains. The following conclusions could be established: dissolution is more intense on slopes with Pinus mugo than on bare slopes. Rinnenkarren (channels) may develop under rivulets, but they can be created by seepage, too. The wind moves the water on Diego de Almagro Island, therefore it controls the dissolution process. On the windward side of landforms both the number and the size of karren forms are increased and as a result, the amount of total dissolution is also higher due to the wind eff ect. Tsingies represent the initial phase of karstifi cation. They develop when the karst water table sinks temporarily to a lower level aft er reaching the surface. The covered karst forms of the Bakony Mountains devel- oped at places where the covering sedimentary rocks are thinner, whereas the covered karst features in the Mecsek Mountains developed where the clay beds of the covering sedimentary strata end. Keywords: karren, covered karst, factors eff ecting karstifi cation, plants, dip angle, length of slope, wind, karst water table, thickness of covering sedimentary rock Introduction Karstifi cation is infl uenced by many factors. These are e.g. the characteristics of the limestone (its contamination, fabric, structure, bedding and thickness, the characteristics of the karst movement, the climate and of the soil). The role of these factors were investigated by many authors and the results may be found in standard works on karstifi cation (Sweeting, M.M. 1972; Jennings, 1 University of West Hungary, Institute of Geography and Environmental Science, 9700 Szombathely, Károlyi Gáspár tér 4. E-mail: vmarton@tt mk.nyme.hu 290 J.N. 1985; Trudgill, S.T. 1985; Jakucs, L. 1977; Ford, D.C. and Willams, P.W. 1989, 2007). In this study a few fi ndings from various sample areas will be pre- sented. These phenomena are the following: the presence of Pinus mugo, the slope angle and slope length, the wind action, the position of karst water table (as to the development of surface karst forms), the quality and thickness of the covering sedimentary rock. Sample areas The scope of research included the following areas: Totes Gebirge (Eastern Alps, Austria), Island of Diego de Almagro (Chile), Ankarana tsingy and Bemaraha tsingy (Madagascar), Bakony Mountains and Mecsek Mountains (Hungary). The Totes Gebirge is the remnant of the overthrust fold of Upper Eastern Alps. The mountains are built of Dachsteinkalk. Karren formation in Totes Gebirge mainly takes place on the cuesta surfaces of glacier valleys. Wallkarren are found on the steep slopes of the heads of the cuestas, while rinnenkarren dominate the gentler slopes of the cuestas with bedding planes (Photo 1). The investigations were carried out in the Pinus mugo belt. They ad- dressed the development of channels (runnels), furthermore the relationship Photo 1. A bare slope with small dip angle from Totes Gebirge. – 1 = type A channel; 2 = type B channel 291 between the development of chan- nels in the presence and absence of Pinus mugo, and the dependence on the length of the slope and the slope angle. Diego de Almagro Island is situated in the Patagonian group of islands. The rocks of the island became metamorphosed during the Upper Carbonic tectogenesis (Maire, R. et al. 1999). Three mar- ble stripes edged into the non- karstic metamorphic rocks, which were of lamprophyres and basalt origin (Maire, R. et al. 1999). Upon the marble surface extensive kar- ren forms developed. The most frequent of them are dissolutional basins (kamenitzas), rinnenkarren, meanderkarren, wandkarren, rip- ple karren and remnant forms (e.g. shadow dune karren inselberg, whaleback dune karren inselberg, Photo 2). These were described by Jaillet, S. and Hoblea, F. 2000. (2000) and Veress, M. et al. (2006). According to Maire, R. et al. (1999) the amount of the rainfall can reach 8000 mm/year. The duration of rainfall can be several hours a day. The wind has played an important role in the development of the karren features of the island. According to Zamora, E. and Santana, A. (1979) the average velocity of the wind can be 60–80 km/h, but sometimes it reaches 150–200 km/h. The infl uence of the wind on the formation of karren was investigated with a spe- cial reference to the dissolution on Diego de Almagro Island. The Island of Madagascar is built mainly by gneiss. Jurassic and Eocene limestone occur in small expansions. The characteristic karst type of the island is the tsingy (the Ankarana tsingy, the Bemaraha tsingy, the Namoroka tsingy and the Bemarivo tsingy). Collapse dolinas occur in many karst areas of the is- land and diff erent kinds of them were distinguished (Rossi, G. 1986). Solution dolinas however occur on the higher karst plateaus exclusively, e.g. on Kelify Plateau (Rossi, G. 1986) and in the higher part of the Bemaraha tsingy (Balázs, D. 1980). The amount of the rainfall decreases from north to south. It is 2200 mm/year on the Ankarana tsingy, and drops down to 1100–1500 mm/year on Photo 2. Shadow dune karren. – 1 = direction of wind 292 the Bemaraha tsingy. Also there is a southward decrease in the duration of rainfall events. The maximum altitude of the surface of the Ankarana tsingy is higher than that of the Bemaraha tsingy (it is 295 m on the Ankarana Litt le tsingy, 318 m on the Ankarana Great tsingy, 75 m on the Bemaraha Litt le tsingy and 190 m on the Bemaraha Great tsingy). The karst water table may occur on the bott om of the grikes of the Bemaraha Litt le tsingy. Its depth compared to the surface is about 25 metres on the Bemaraha Litt le tsingy, while it is about 140 metres on the Bemaraha Great tsingy (Veress, M. et al. 2008a, 2008b). Since the tsingies can be found close to the sea, the sea-level fl uctuations caused a rapid change in the karst water table level, with high intensity and in the im- mediate vicinity of the tsingies. The reason for it was that the rivers which are the local erosional bases of the tsingies did not exist at the time of the rise of the sea level. Thus the River Manambolo which is the erosional base of the tsingies with an altitude of 50 m, occurred under the sea level when the rise of the sea level exceeded 50 metres. The eff ect of the karst water table on karstifi cation of the surface was analysed on Madagascar. The tsingy karst is built by assemblages of large-sized grikes (Photo 3, Veress, M. et al. 2008a, 2008b). The depth of the grikes is between 0.5–7 metres on the Ankarana tsingy, while they can reach a depth between 10–120 metres on the Bemaraha tsingy. Clints of various dimension and pinnacle with diverse shape and size are among grikes (Rossi, G. 1986; Veress, M. et al. 2008a, 2008b). Rillenkarren, kamenitzas, pits, rinnenkarren occur in great density on the clints and pinnacles of the tsingies (Veress, M. et al. 2008a, 2008b). Photo 3. Grike systems from the Bemaraha tsingy (Delaty, J.N. et al. 2006) 293 The Bakony Mountains in Hungary are a type of faulted mountains built of Mesozoic and Eocene calcareous rocks. The surface of the 300–500 m high blocks is covered with loess and partly with various types of loess loam. These are the covered karst surfaces of the mountains. The calcareous fl oor is dissected under the covering sedimentary rocks, because karstifi cation al- ready happened previously on the surface of these rocks (Végh, S.-né 1976). The covered karst forms are limited in size and they have a low density in the Bakony Mountains (Veress, M. 2008, 2009). The Mecsek Mountains are faulted-folded structures. The northern- most margin of the West Mecsek built of Triassic limestone is aff ected by karstifi cation. Limestone is superimposed by loess and sandy-clayey cover sediment. Two generations of dolines were distinguished by Szabó, P.Z. (1968) on this covered karst surface. The older generation of dolines are the larger landforms of those developed on the limestone fl oor, therefore they are solu- tion dolines, being lined or fi lled with sediments completely. The latt er (buried dolines) do not have depressions on their surface. The younger and smaller dolines have developed in the sedimentary rock cover. These dolines are cov- ered karst features. There is a high density of the dolines (solution dolines and covered karst dolines alike) in the Mecsek Mountains. Their values can even reach 137 pieces/km2 and 164 pieces/km2, respectively (Hevesi, A. 2001; Lippmann, L. et al. 2008). The thickness and quality of the covering sedimentary rock were in- vestigated to establish the relationship between the overlying sedimentary rock and covered karstifi cation. Methods The width and the depth of karren forms along profi les were measured on bare slopes of the Island of Diego de Almagro. Similar measurements were carried out both on bare slopes and slopes with Pinus mugo in Totes Gebirge where they are located closely to each other. Several profi les were erected here in three-metre distance from each other in areas with minor dip angle and bare slopes. The depth and width of the channels were also measured along these profi les. The specifi c width (c) and the density (ρ) of the karren forms on the Island of Diego de Almagro were computed. The values of (c) and (ρ) of the forms as well as the specifi c cross-section areas of the channels (A) and shape- parameters of the channels (f) were also calculated for the study area in Totes Gebirge (Veress, M. et al. 2008c, 2010). The above parameters can be calculated as follows: – – 294 Where Wk is the width of a channel along the profi le (if the calculation of spe- cifi c width is to be meant for the channel, its width is concerned), A0 the cross-section area of a channel along the profi le, f0 the shape of a channel along the profi le, l the length of the profi le, where w is the width of the channel, d the depth of the channel. The average cross-section area of the channel (A) and the average channel shape (f) were calculated as well. To calculate (A) and (l) the overall cross-section areas and the overall shapes of the channel were divided with the number of the channels. Function relationships were searched between D (the distance between the upper margin of the slope and the site of the profi le), A and f. The karren features of the leeward slopes and windward slopes were compared on Diego de Almagro Island. Karren forms were mapped on Diego de Almagro Island. The thickness and the quality of diff erent beds and that of the cover- ing sedimentary rock were measured with vertical electrical sounding (VES). Geoelectrical-geological cross sections were constructed. The morphology of the limestone fl oor, the thickness and the structure of the covering sedimentary rock and its beds may be determinant along these geoelectrical-geological cross sections (Veress, M. 2008). Results The impact of plants, dip angle and the length of slope on karren formation Based on the measurements it can be stated that the specifi c cross section areas of channels are more extensive on slopes with Pinus mugo than on bare slopes (9.12 dm2/m vs 3.65 dm2/m, respectively). According to the measurements by Mariko, S. et al. (1994) the cause of it is that the snow which covers vegetation – – – – 295 in high mountains has a high CO2 content. Pinus mugo cannot photosynthesize under the snow but it is able to dissimilate. Therefore the dissolution capacity of the meltwater originating from the Pinus mugo patch is higher. Channels develop under rivulets (Trudgill, S.T. 1985; Ford, D.C and Williams, P.W. 1989). According to Veress, M. et al. (2008c) the channels may develop in two ways: due to percolation or due to rivulets. Aft er fi lling of the channel the meltwater seeps between the snow and the limestone during the development generated by percolation. The current of this water is laminar and it dissolves the side and the bott om of the channel. Rivulet generated development can change into percolation generated development at the same channel, and vice versa. The specifi c cross section area of the channel and the specifi c shape of the channel also depend on the dip angle of the slope with Pinus mugo (Veress, M. et al. 2008c; Veress, M. 2010). The velocity of the fl ow is higher on a steeper slope. The greater velocity induces turbulent fl ow which in turn increases the rate of dissolution. Therefore dissolution is also more intense on slopes of greater dip angles covered with Pinus mugo. The fl ow velocity may change only if the water fl ows on the slope but it cannot change in case of seepage. During the percolating generated development the incision of the channel does not depend on the dip angle. Therefore development due to rivulet can dominate on slopes with Pinus mugo. Type A and type B channels were distinguished on bare slopes with small dip angles (Photo 1). Type A channels have small sizes, V cross sections, small catchment areas, small specifi c cross section areas and great shapes. Due to the latt er one, the specifi c cross section area of type A channels which can be found along a profi le is small and their specifi c shape-parameter is great (Table 1). Type A channels do not have tributary channels. Type B channels have U cross sections, extensive catchment areas, great cross section areas, and small shapes. Due to the latt er one, the specifi c cross section area of type B channels which can be found along a profi le is great and their specifi c channel shape-parameter is small (Table 1). Type B channels have tributary channels of type A. Type A channels dominate bare slopes with great dip angles. There is a dense network of channels on such steep slopes. There is a functional relationship among d and the specifi c cross sec- tion areas of type B channels and the specifi c shape-parameter of type B chan- nels on bare slopes of small dip angles (Veress, M. 2010). The specifi c cross section areas of these type B channels can be greater while the specifi c shape- Table 1. Parameter values of type A and type B channel of some bare slopes from Totes Gebirge Type A channel Type B channel Mark of the slope n Ρ T t f l n ρ T t f l slope marked I/9/1 slope marked I/9/2 slope marked I/9/3 11.8 24.6 9.8 1.3 1.6 1.1 100.7 153.7 94.0 67.1 107.2 89.6 3.2 3.1 2.4 1.9 1.9 2.3 3.3 5.7 3.6 0.4 0.3 0.4 183.0 305.4 172.6 278.5 699.2 420.4 0.3 0.4 0.4 0.6 0.8 1.1 296 parameter of the channels can decrease in the function of d (Figure 1). It is only possible if an increasing amount of water fl ows across the lower and lower parts of the channels for even longer time. The cross section area of the channel will increase due to the growing amount of water. The channel will incise due to the growing existing rivulet as dissolution at the bott om of the channel will take more time. Hence type B channels increase due to rivulets. Such functional connection cannot be established in case of type A channels. Therefore type A channels develop due to percolation. The infl uence of the wind on solution and karren formation The rate of dissolution of marble is 0.06 mm/year on Diego de Almagro Island (Hoblea, F. et al. 2001). The rate of dissolution of limestone is 0.015 mm/year in the Alps (Bögli, A. 1961). The speed of dissolution is as many times higher on the island as the rainfall is more abundant than in the Alps. At the same time the karren forms of the island sometimes can be tenfold or fi ft y times larger in size than the karren forms of the Alps. The cause of the development of the greater sizes is that the wind moves the surface water into a narrow stripe. Therefore dissolution is concentrated only in limited place. Dissolution does not take place in leeward for example behind boulders. Thus shallow dune karren inselbergs develop at these places (Figure 2, Photo 2). The following facts prove the eff ect of wind action: The residual forms (karren inselberg) have W–E trend. The windward sides are steep, the leeward sides are gentle. The remnant forms have a streamlined shape (Photo 2). The wind controls the process of dissolution in the following manner: The wind moves the water from west to east. The wind separates the sheet water into rivulets as observed on nu- merous occasions. Wind action could increase the rate of dissolution; also dissolution of higher intensity contributes to the development of larger karren forms. It might happen in the following way: More rainwater falls on the windward slope than on the leeward slope (per time unit). The wind makes the raindrops move therefore the dissolution is stronger on the windward slope than on the leeward one. According to calcula- tions of Szunyogh, G. (2004, 2005) the rate of denudation is four times higher if the angle of the slope is 70° and the velocity of the wind is 10 m/s than in calm conditions with the direction of the wind being perpendicular to the slope. High wind velocity increases the speed of the fl ow, which causes tur- bulence. The intense collision of raindrops and snowfl akes produces a similar eff ect. – – – – – – – 297 Fig. 1. Functional relationship between the various parameters of the type B channels on a bare slope of Totes Gebirge. – a = f0-D functions of the channels; b = f0-d functions of the channels, F0 cross section area of the channel, f0 the cross section shape of the channel, d. distance between the upper margin of the slope and profi le site (similar signs are calculated F0 and f0 values of the same channel at various profi le sites) 298 The wind increases pressure, therefore atmospheric CO2 penetrates into the water. According to Veress, M. et al. (2006), as a result the dimension of the dissolution is increased by 0.18 mg/l in case of laminar water current if the velocity of the wind is 100 km/h. The collision of the raindrops and snow- fl akes also increases pressure. According to our calculations the pressure will increase up to 130% in the water if the velocity of the wind is 50 km/h, therefore solubility will increase 1.3 times at laminar fl ow (Veress, M. et al. 2006). The eff ect of karst water on the development of the tsingies Rainfall percolating along cracks created the Ankarana tsingy by dissolution (Balázs, D. 1980; Rossi, G. 1986; Veress, M. et al. 2008b). The great grikes of the Bemaraha tsingy developed when small grikes and caves coalesced into each other. They might have developed due to the collapse of caves. The former – Fig. 2. The development of the ’shadow dune karren inselberg’ (Veress, M. et al. 2006). – a = the water moving to the east dissolutes the surface except the part of the surface which is behind the boulder; b–c = elevation develops at the wind shadow; d = where the wind shadow surface ends the surface dissolutes behind the boulder too, the elevation budds; 1 = marble; 2 = puddle; 3 = wind direction; 4 = dissolution; 5 = dissolution at sheet water 299 caves were created under the karst water table in the phreatic or epiphreatic zone (Figure 3, Veress, M. et al. 2008a, 2008b). The sea level had been 60–70 metres higher before the Ice Age com- pared to nowadays (Mitchum, R.M. et al. 1977). Therefore the karst water table was about 60–70 metres higher compared to that of nowadays on the tsingies. (Tectonic uplift was not taken into account because since the beginning of the Ice Age the rise has not been substantial.) Other factors also infl uence the level of karst water table such as the distance between any parts of the karst and temporary base level and the cavity index of the rock. The farther is the site of the karst from the contemporary base level the higher is the karst water table. For example it is 200 m higher even at a distance of 25 km from the contemporary base level in the Bakony Mountains, as shown by karst water table maps (Lorberer Á. and Maucha, L. 1982). Its vertical oscillation may even reach 100 metres in dolomite with lower cavity values in the Bakony Mountains, according to the data gained from a karst table observing well in Hárskút, Hungary (Böcker, T. 1972). The surfaces of the Madagascar tsingies were close to karst water table before Ice Age. (The karst water might create lake or lakes on the deeper parts of the Bemaraha Litt le tsingy.) Therefore dissolution might happen during arid seasons and low tides or in the glacial stages of the Ice Age on the surface. Therefore in these cases the karst water table sank deeper in the rock. Where the karst water table was higher than the surface of the tsingy (Bemaraha Litt le tsingy) dissolution took place in the glacial stages of Ice Age, when the karst water table was located lower than recently. Dissolution of short time dura- tion has not stimulated the development of solutional dolina. This landform develops where all of the rock is dissolved over a certain area. This process needs a prolonged dissolution. The cavity level was nearer to the surface on the Bemaraha tsingy than on the Ankarana tsingy. On the one hand it is because the surface of the Ankarana tsingy is higher than that of the Bemaraha tsingy. On the other hand the Manambolo River kept the karst water table 50 m higher above the sea-level during Ice Age on the Bemaraha tsingy. Formation and development of the two tsingies were diff erent from each other as the grikes and the caves could not coalesce to each other on the Ankarana tsingy because of the deeper level of the caves. The coalescing process could happen on the Bemaraha tsingy because the caves were nearer to the surface. The infl uence of the sedimentary rock on covered karstifi cation Data are available on the thickness and the quality of the covering sedimen- tary rock, the morphology of the limestone fl oor of 37 pieces of covered karst forms in the Bakony Mountains, and of 21 pieces of covered karst forms in 300 the Mecsek Mountains. (Veress, M. 2004, 2007, 2008, 2009). According to VES measurements 78 per cent of the covered karst forms occur above mounds of the limestone fl oor in the Bakony Mountains (Figure 4). The morphology of the limestone fl oor is indicative of the development of the covered karst forms because the covering sedimentary rock is thinner above the mounds of the limestone fl oor, than above its depressions. The thickness of the inner sediment Fig. 3. The development of the Bemaraha tsingy. – 1 = limestone; 2 = crack; 3 = direction of dissolution; 4 = karst water; 5 = oscillation of karst water table; 6 = infi ltration into the karst; 7 = soil; 8 = collapse; 9 = uplift ; 10 = cave fi lled with karst water; 11 = the cave above karst water table; 12 = grike part which developed above the karst water table; 13 = part of grike developed under the karst water table; I = initial phase; II = present phase 301 rock of karst forms above the mounds does not reach 6 metres (the thickness is measured below the bott om of the depression). Only 7 covered karst forms have external sedimentary rock cover with a thickness greater than 6 metres (its size may be measured at the margin of the depression). But the thickness of the covering sedimentary rock above the depressions of the limestone fl oor always exceeds 6 metres and it oft en reaches 10, or 20 metres depth. Water percolating into the thinner sedimentary rock can reach the limestone fl oor easier above the mounds. It could also be established that 26 forms occur at the Fig. 4. Covered karst dolinas developed above the mounds of the limestone fl oor (Bakony Mountains, Kőris Mount, Veress, M. 2008). – 1 = limestone; 2 = limestone detritus; 3 = limestone detritus (with clay); 4 = clay (with loess and limestone detritus); 5 = clay; 6 = number and place of VES measuring; 7 = geoelectrical resistance of the beds (Ohm); 8 = depth of the bott om of the geoelectrical beds (m); 9 = penetration of the VES measur- ing; 10 = border of the geoelectrical beds; 11 = mark of the covered karst form; 12 = pit; 13 = elevation on the limestone fl oor; 14 = paleokarst depression of the limestone fl oor; 15 = syngenetical (the karst form and the pit are of the similar age) covered karst form above the elevation of the limestone fl oor; 16 = postgenetical (the karst form is younger than the pit) covered karst form above the elevation of the limestone fl oor. Note: the karst forms (marked E-6 and E-7) developed with the sinking of the surface, further with the sinking of the uppermost beds (due to the loss of the matt er of the covering sedimentary rock 302 bott om of the valleys of the covering sedimentary rock. Hence the denudation of the surface adds to that of the covered karst forms. It means that denuda- tion causes the further thinnering of the sedimentary rock cover. Naturally the development of the covered karst depressions rather promotes the increase of the water at the bott om of the valleys than somewhere else. VES measurements testify about the covered karst forms of the Mecsek Mountains having developed in the areas of the lined or fi lled solution doli- nas. They formed where clay beds or sequences containing clay wedge out Fig. 5. Covered karst doline which developed at wedges out of permeable, fi lled and buried solution doline (Mecsek Mountains, from the area of Czigány land near Orfü). – 1 = lime- stone; 2 = limestone detritus (sand?); 3 = soil; sand; silt; 4 = clay (with limestone detritus and sand); 5 = sand, loess (with limestone detritus); 6 = number and place of VES measuring; 7 = geoelectrical resistance of the beds (Ohm); 8 = depth of the bott om of the geoelectri- cal beds (m); 9 = penetration of the VES measuring; 10 = border of the geoelectrical beds; 11 = mark of the covered karst form 303 (Figure 5). Out of the 21 covered karst formations there are 16 with such at- tributes. (The cause of this phenomenon is as follows: the water percolates into the karst where clay beds wedge out. The water creates a pit on the limestone fl oor.) The matt er of the covering sedimentary rock can be transported into the pit. A blind burrow develops in the sedimentary rock. A covered karst forms due to the sinking or breakdown of the covering sedimentary rock above the blind burrow (Veress, M. 2008, 2009, Figure 6). Fig. 6. Covered karst form which developed at the margin of the permeable beds wedged out which is above a fi lled solution doline. – 1 = limestone; 2 = sand-loess (with limestone detritus; 3 = clay (with limestone detritus and sand); 4 = soil, sand, silt; 5 = water fl ow on the surface, and water infi ltration into the covering sedimentary rock; 6 = suff usion; 7 = pit; 8 = blind burrow; 9 = buried solution doline; 10 = covered karst form; I = cross-section; II = view from above; Ia = the fl owing water of the surface and that of the permeable beds of the covering sedimentary rock seeping into the limestone at places where the permeable beds wedge out; Ib = pit develops; Ic = a blind burrow develops; Id = a covered karst form develops above the blind burrow by sinking of the covering sedimentary rock (suff usion doline) 304 Conclusions Karren formation is more intense on slopes with Pinus mugo than on bare slopes. The channels of the slopes with Pinus mugo develop due to rivulets. Channels with small catchment areas on bare slopes are exceptions. The channels may be formed due to rivulets and by percola- tion of the water on bare slopes. Channels can develop due to perco- lating with greater chance if the dip angle is smaller and the slope is shorter. The wind has an eff ect on dissolution. Large-size and elongated forms develop on Diego de Almagro Island if the velocity of the wind is high enough and its direction is constant. The rate of the dissolution in- creases too on the windward side if considerably strong winds blow. The development of the tsingies of Madagascar is only partially due to the specifi c climate. In its development the karst water table has played a more important role. Tsingies might develop because karst wa- ter was close to their surfaces. There is not a direct connection between the quantity of the rainfall and the development of the tsingy. (E.g. pre- cipitation is less on the Bemaraha tsingy of a larger size.) Therefore the tsingy represents the initial phase of karstifi cation and it has remained in the phase where the karst water table was the most infl uential fac- tor in its development. The development of the tsingy began already before Ice Age. The distance which is between the karst water table and the surface of the tsingy controlled the size and morphology and the process of tsingy formation. The covered karst form developed above the mounds of the limestone fl oor, or in the denudation stripes of the covering sedimen- tary rock. Primarily they are on those denudation stripes (valley bot- toms), where mounds can be found on the limestone fl oor. It means that the covering sedimentary rock is the thinnest at these places and this is why water can percolate through the covering sedimentary easily. The clay beds of older dolines make the development of the karst forms possible. Where the clay beds end the water can infi ltrate from the surface. The amount of infi ltrated water also increases at these places, because the water of the clay surface parts may infi ltrate there. This process is helped by older lined dolinas. Namely surface fl ow of the rain which falls on their areas is not possible. 305 REFERENCES Balázs, D. 1980. Madagaszkár karsztvidékei (Karst areas on Madagascar). Karszt és Barlang 1. 25–32. Böcker, T. 1972. A karsztvizek mozgásviszonyai természetes körülmények között . In II. Anyag- és Energiaáramlási Ankét. Eds.: Szádeczky-Kardoss, E. and Pécsiné Donáth, É. Budapest, Akadémia Kiadó, 107–121. Bögli, A. 1961. Karrentische – ein Beitrag zur Karstmorphologie. Zeitschrift für Geomorphologie 5. (3): 185–193. Delaty, J.N., Dobrilla, J.C. and Wolozan, D. 2006. Observation concernant les Tsingy de Madagascar et plus particulièrement ceux de Bemaraha. Spelunca 103. 39–44. Ford, D.C. and Williams, P.W. 1989. Karst Geomorphology and Hydrology. London, Unwin Hyman, 601. Ford, D.C .and Willams, P.W. 2007. Karst Hydrogeology and Geomorphology. Second Edition, London, Wiley, 562. Hevesi, A. 2001. A Nyugati-Mecsek felszíni karsztosodásának kérdései. Karsztfejlődés 6. Szombathely, BDF Természetföldrajzi Tanszék, 103–111. Hoblea, F., Jaillet, S. and Marie, R. 2001. Erosion et ruissellement sur karst nu en con- texte subpolaire océanique: les iles calcaires de l’archipel de Patagonie chilienne. Karstologia 38. 13–18. Jaillet, S. and Hoblea, F. 2000. Une morphologie originale liée au vent: Les ”fusées” ou ”crêtes éoliennes de lapiaz” de l’ile Madre de Dios (Archipel Ultima Esperanza, Patagonie, Chili); 10e Rencontre d’Octobre; Spéléo-club de Paris, 73–76. Jakucs, L. 1977. Morphogenetics of karst regions. Budapest, Akadémia Kiadó, 284. Jennings, J.N. 1985. Karst Geomorphology (Revised and expanded edition of Jennings, 1971). Oxford and New York, Basil Blackwell, 293. Lippmann, L., Kiss, K. and Móga, J. 2008. Az Abaliget-orfűi karszt karsztos felszínformái- nak vizsgálata térinformatikai módszerekkel. Karsztfejlődés 13. Szombathely, BDF Természetföldrajz Tanszék, 151–166. Lorberer , Á. and Maucha, L. 1982. A Dunántúli-középhegység karsztvízszint térképe. Budapest, VITUKI Vízrajzi Intézet, 138. Maire, R., Pernette, J.F. and Fage, L.H. 1999. Les „glaciers de marble” de Patagonie, Chili. Un karst subpolaire océanigue de la zone australe. Karstologia 33. 25–44. Mariko, S., Bekku, Y. and Koizumi, H. 1994. Effl ux of carbon dioxide from snow covered forest fl oors – Ecological Research 9. 343–350. Mitchum, R.M., Vail, R.R. and Thompson, S. 1977. Seismic stratigraphy and global changes of sea level. The depositional sequence as a basic unit for stratigraphic analysis. In Seismic stratigraphy – applications to hydrocarbonate explanation. Ed.: Payton, C.E. American Assoc. Petr. Geol. Mem. 26. Rossi, G. 1986. Karst and structure in tropical areas: the Malagasy example. In New direction in karst. Eds: Paterson, K. and Sweeting, M.M. Proceedings of the Anglo–French Karst Symposium. Norwich, Geo Books. 189–212. Sweeting, M.M. 1972. Karst Landforms. London, The Macmillan Press Ltd., 362. Szabó, P.Z. 1968. A magyarországi karsztosodás fejlődéstörténeti vázlata. Értekezések 1967–1968, MTA Dunántúli Tudományos Intézet, Budapest, Akadémia Kiadó, 13–25. Szunyogh, G. 2004. Talajnélküli mészkőfelszínek leoldódási idejének elméleti vizsgálata. Karsztfejlődés 9. Szombathely, BDF Természetföldrajzi Tanszék. 35–51. 306 Szunyogh, G. 2005. Theoretical investigation of the duration of karstic denudation on bare, sloping limestone surface. Acta Carsologica 34. (1): 9–23. Trudgill, S.T. 1985. Limestone geomorphology. New York, Longman, 196. Végh, S.-né 1976. A Dunántúli-középhegység karsztjának anizotrópiája és annak bányavíz védelmi következményei. Geonómia és Bányászat 9. 163–171. Veress, M. 2008. A mészkőfekü morfológiájának hatása a fedett karsztosodásra az Északi- Bakonyban. Karszt és Barlang 28. 33–54. Veress, M. 2009. Investigation of covered karst form development using geophysical meas- urements. Zeitschrift für Geomorphologie (in press) Veress, M., Lóczy, D., Zentai, Z., Tóth, G. and Schläffer, R. 2008a. The origin of the Bemaraha tsingy (Madagascar). International Journal of Speleology 37. (2): 131–142. Veress, M., Péntek, K., Zentai, Z. and Mitre, Z. 2008c. Development of rinnenkarren on bare slopes and on slopes with dwarfpine. Szombathely, Geographical studies of the University of West Hungary, University of West Hungary, Faculty of Sciences, 52–68. Veress, M., Szunyogh, G., Zentai, Z., Tóth, G. and Czöpek, I. 2006. The eff ect of the wind on karren formation on the Island of Diego de Almagro (Chile). Zeitschrift für Geomorphologie 50. 425–445. Veress, M., Zentai Z. and Tóth G. 2008b. The origin of the Madagascar tsingy and the devel- opment of their forms. Szombathely, Geographical studies of the University of West Hungary, University of West Hungary, Faculty of Sciences, 69–94. Zamora, E., Santana, A. 1979. Caracteristicas climaticas de la costa occidental de la Patagonia entre las latitudes 46°40’ y 56°30’ s. Anales Inst. Patagonia 10. 109–154. << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.7 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. Stvoreni PDF dokumenti mogu se otvoriti Acrobat i Adobe Reader 5.0 i kasnijim verzijama.) /ITA /JPN /KOR /LTH /LVI /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor prepress-afdrukken van hoge kwaliteit. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.) /NOR /POL /PTB /RUM /RUS /SKY /SLV /SUO /SVE /TUR /UKR /ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.) /HUN >> /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ << /AsReaderSpreads false /CropImagesToFrames true /ErrorControl /WarnAndContinue /FlattenerIgnoreSpreadOverrides false /IncludeGuidesGrids false /IncludeNonPrinting false /IncludeSlug false /Namespace [ (Adobe) (InDesign) (4.0) ] /OmitPlacedBitmaps false /OmitPlacedEPS false /OmitPlacedPDF false /SimulateOverprint /Legacy >> << /AddBleedMarks false /AddColorBars false /AddCropMarks false /AddPageInfo false /AddRegMarks false /ConvertColors /ConvertToCMYK /DestinationProfileName () /DestinationProfileSelector /DocumentCMYK /Downsample16BitImages true /FlattenerPreset << /PresetSelector /MediumResolution >> /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles false /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /DocumentCMYK /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> ] >> setdistillerparams << /HWResolution [2400 2400] /PageSize [612.000 792.000] >> setpagedevice