e-SOTER General assembly field exercise

Research areas:  Germany, Laos, Thailand, Vietnam
Excursions: AustraliaChina, Germany, Hungary, Morocco, Thailand (NE-part)

Date: September 30 - October 01, 2010

Brief introduction

Starting point of the excursion was the University farm of Gödöllö, which is located in the Gödöllo-Monori hilly region (Stop 1 in Figure1, 2). There, a Kastanozem profile (Profile 1) was visited, and auger samples showing the local soil types (Chernozems, Kastanozems, Phaezems) were discussed. Afterwards, the excursion went eastwards through the pediment area south of the Mátra mountains. At Dormand the excursion route turned northwards, passing the city Eger, and finally climbed up on the karst area of the Bükk mountains, where one Leptosol (Profile 2) and two Luvisol profiles (Profile 3 and 4) were visited (Stop 2). The next stop was at Szarvaskö on the eastern edge of the Bükk Mountains (Stop 3). There, outcrops of pillow basalt and shale with limestone olistoliths were visited. Last but not least, profiles of a Palaeosol (Profile 5, Stop 4), Vertisol (Profile 6, Stop 4) and a Chernozem (Profile 7, Stop 5) in the Mátra pediment area were viewed.  
Figure 1: Excursion route and stops.

The "Gödöllö-Monori hilly region"
The Gödöllö-Monori hilly region, which is part of the "Northern Hungarian Mountain Range". The region is NW-SE oriented with gradually decreasing elevation to the south. The highest point is 344 m asl (Margita, close to Versegyház). The Miocene sandstone and gravel in the northern part and the sandy, clayey deposits in the southern part are covered by loess and by sand near the edges of the area. The creeks and rivers (Rákos, Zagyva, Galga) left behind a wide range of alluvial sediments during the Pleistocene and Holocene, that occur also in the vicinity of the University farm (Figure 2).
The surface is highly dissected by erosion and abrasion that occurred mostly in the Pleistocene and partly in the Holocene. The natural vegetation was (is) oak forest (Quercus cerris and Quercus robur), although the territory of forest is decreasing to the south as the area of pastures, farmland and urban settlements increases. The soils from north to south are mainly Luvisols, Camibsols, Arenosols and Chernozems. The dominant land use in the north is mainly forest 45%, farmland 40% (rye, wheat, barley, corn, sunflower), pasture 8% (mainly in the valley bottoms) and the rest is orchard (apple, apricot and peach).
Climate: the mean annual temperature is 9.5 - 10.0 °C. The annual precipitation is about 600 mm. The number of days with snow cover is about 36-40, and the average depth of snow is about 22 cm. The water table is about 5-6 m in the valleys and 100 m on the top of the hills.

Figure 2: The University farm of Gödöllö in the Gödöllo-Monori hilly region.
Profile 1
Soil type: Calcic, Luvic Kastanozem
Parent rock: fluvial sand, gravel, loess
Position: N47° 34' 47.80'' E19
° 22' 29.94''

Figure 3: Kastanozem from fluvial gravel, sand, loess

The Bükk Mountains
The Bükk Mountains (Hungarian pronunciation: [byk]; literally Beech Mountains) are a section of the Carpathian Mountains in north-eastern Hungary. Much of the area is included in the Bükk National Park - the largest forested national park in Hungary. Although Kékes (1014 m asl), the highest point in Hungary is not here, but in the nearby Mátra Mountains, the average height of the Bükk Mountains with more than 20 peaks higher than 900 m asl exceeds that of Mátra. The highest point of Bükk is Istállóskö (959 m asl), the third highest in Hungary after Kékes and Galyatetö.
The Bükk consists mainly of limestone and dolomite; however slate, sandstone, and volcanic rocks can also be found in the area. The history of the limestone range can be traced as long as the Palaeozoic era, when the edge of today's Carpathian basin sank in and then it was covered by a sea for about 70 million years (from the Carboniferous period till the Permian). All sorts of calcareous and dolomitic sediments and clay deposited on the seabed. Rock formation was followed by heavy volcanic activities in the Triassic and several times again in later periods. As a result slate was formed from the clay and basalt, rhyolite-tuff and other rocks of volcanic origin appeared. The Bükk rose above surroundings about 15 million years ago, and then as a result of continuous weathering, erosion, it has received its present, characteristic form preserving traits of the history of the area.
There are about 800 known caves in the mountain range, including István-lápa, the deepest cave in Hungary (254 m), the archaeologically important Szeleta cave (evidences of prehistoric settlement), the Cave Bath (a main tourist attraction of Miskolc-Tapolca), the  Anna cave, and the Istvan cave. 52 of the caves are protected because of their fauna and micro climate.
The climate of the mountains is very varied, even extreme at some places. The climate at the southern foot of the mountains is warm and dry, while it is typically humid and cool at the plateau and in the canyons - yet freezing is neither uncommon at the bottom of some sinkholes even in the summer.  
Figure 4: Karst plateau in the Bükk mountains.

Profile 2
Soil type: Rendzic Leptosol
Parent rock: limestone
Position: x: 753938, y: 305155

Figure 5: Leptosol on limestone.

Profile 3
Soil type: Cutanic, Vertic Luvisol (Ruptic, Epidystric, Clayic, Chromic)
Parent rock: gravel, sand
Position: x: 758053, y: 304767

Figure 6: Luvisol from gravel and sand.

Profile 4
Soil type: Cutanic, Leptic Luvisol (Humic)
Parent rock: limestone
Position: x: 757966, y: 304573 

Figure 7: Luvisol on limestone.

Pillow lavas
A complex of pillow lavas, gabbro bodies and dykes as well as syngenetic ultramafics, occurs near the Szarvaskö village on the southwestern slope of the Bükk Mountains. Fractional crystallization of basaltic magma with tholeiitic geochemical characteristics at hypabyssal (4-6 km) levels resulted in the formation of the minor acid intrusions (plagiogranite), as well as plagioclase peridotite and wehrlite. The parental magma of the complex penetrated through a sequence of turbidite sediments a few kilometers thick: so the processes of fractional crystallization acted in various levels of the crust (Hovorka and Spišiak, 1993). Radiolarian faunas indicate that theses pillow lavas resulted from a rifting during Middle Jurassic (Late Aalenium, Bajocian), contemporaneous with the subduction-related turbidites in the Meliata-Hallstatt ocean and with the likewise subduction-related rhyolitic volcanism in the southern transitional zone. It is therefore perhaps a back-arc rifting during the subduction of the Meliata-Hallstatt ocean. However, it cannot be excluded that the closing of the Meliata-Hallstatt ocean and the contemporaneous rifting and sea-floor spreading in the western Bükk ocean are unrelated to each other, because the Middle Jurassic is the rifting time of several oceans in the Western Tethys (e.g. Vardar ocean, Penninic ocean, Magura ocean) (Kozur, 1991).        

Figure 8: Pillow lavas near Szarvaskö.

Shale with limestone olistoliths
At the train station of Szarvaskö Jurassic shale with Triassic limestone olistoliths is exposed. These olistoliths were formed by gravity sliding of limestone from a platform into adjacent basins.                   

Figure 9: Shale with limestone olistolith at Szarvaskö train station.

Mátra Pediment area
Quaternary erosion and resedimentation on the M
átra Pediment
From the beginnings of the Quaternary period the Pannonian lithosphere has been subject to large scale bending. As a result of increasing intraplate stresses the Transdanubian Central Range and peripheral areas of the basin experienced uplift, while subsidence of some of the internal sectors accelerated. The initiation of arctic glaciation and the resulting advance of inland ice in Europe undoubtedly also had effects on the Pannonian basin.
Geological overview of 
Mátra pediment area
The oldest known rocks in the area compose a 500 m thick stratovolcanic complex, consisting of andesitic lava-flows and pyroclastics that fill a Neogene structure in front of the Southern Mátra Hills. They are covered by shallow marine to terrestrial sediments (including lignite), characteristic of the marginal sectors of the Pannonian basin. In Late Panonnian times the depositional environment was that of an alluvial plain, with delta-platforms extending into the basin. Quaternary sediments were deposited on top of the eroded surface of this alluvial plain. The nonconformity and the associated topography (with a palaeorelief of as much as 30 meters), related to the Late Pannonian uplift of the Mátra Hills resulted in an increased rate of sediment transport as well. a complex system of colluvial and alluvial fans of gravel, sand, clay and resedimented red-clay from palaeosols were formed on the pediment of the Mátra Hills (Franyó 1982). Loess and "loess-like" sediments of Würmian age occur in this area as vestiges of a once continuous loess-blanket (Füköh, 1999).
Soils and soil derived sediments
A red soil-sediment complex (up to 6m in thickness), overlying the truncated Pannonian strata is present in several places along the Matra Foothills. Similar red clays are widespread in Hungary underneath the Quaternary loess. These clays have been used as an end-Pliocene datum representing the last spell of warm Mediterranean-type climate before early Pleistocene cooling and drying began (Pécsi, Bronger, Székely and others). Based on its smectite content and the abundant shrinking and swelling structure the red clayey soil would qualify as Vertisol. Its thickness and other evidence suggest that the red clay complex is not an in-situ pedogenic product. Pedorelict grains and soft-sediment deformation in the clay can be taken as evidence of resedimentation. Large biogalleries and small fecal pellets of soil dwelling fauna however, suggest that in situ pedogenesis contributed to the formation of the red clay complex. Fecal pellets of insects and galleries found at depths far below their normal habitat in soils indicate that pedogenesis was repeatedly interrupted by sedimentation. The Mátra Mountains still bear remnants of a former red soil blanket suggesting that they are the most probable source area. Mineralogical comparison of the two red clays reinforces this idea.

Figure 10: The Mátra pediment area (foreground) and the Mátra Mountains (background).     
Profile 5
ár - soil profile
Parent (rock) material: loess, translocated soil material from weathering of andesite
Position: N47° 42.41' E19
° 52.76'
Elevation: 143 m asl
At the site the original horizons are distorted and a traditional soil profile description based on a sequence of genetic horizons cannot be applied. The current surface, which is truncated due to mining activities, has a mollic epipedon formed in calcareous loess. Below about 60 cm average the soil is mixed with zones of white CaCO3, red silty clay, yellow clay loam and some grey clay. The red silty clay material appears within the matrix as tubular fillings, 5-15 cm in diameter, and as elongated drops or as streaks. In some areas, thin layers of contrasting white, red and grey appear compressed and bent from the horizontal up to peaks. The whole horizon is impregnated with calcium carbonate including numerous granules ranging in size from 1 mm up to 10 cm. The calcium carbonate seems to be pure calcite and does not show evidence of biologic precipitation. The underlying material is a grey clay layer with prismatic and blocky structure and average thickness of 40 cm resting on silty calcareous Pannonian sediment (Figure 11).  

Figure11: The Atkár soil profile. 

The soils preserved in these sites suggest a sequence of different environments. The red clayey material is believed to be eroded from the M
átra and now covers earlier sediments. The red material was mixed into the other layers by extensive activity of burrowing animals. The calcium carbonate that is abundant in soils and palaeosols of the Mátra pediment was leached from Pleistocene loess that covered the red palaeosol. The large amount of CaCO3 accumulated in the lower layers suggests that there must have been several meters of loess deposition that eroded in the meantime. The stable isotopic investigations support this idea (the O18/C13 composition of selected samples have similar ratios as calcium carbonate accumulations in Pleistocene loesses in Central Europe). A clay layer between the palaeosol and the deeper Pannonian sediments trapped the leaching of lime and caused saturated conditions during cold, wet periods of the Pleistocene. Repeated freezing and the weight of materials above caused the displacement and distortion of horizons and burrows into complex patterns. Load casting, slope mass movements are also believed to support deformations. It is also possible that semi liquid layers were distorted by seismic activity.

Profile 6
Soil type: Mollic, Calic Vertisol (Humic, Eutric)
Parent rock: loess
N47° 44' 14.42'' E19° 52' 36.64''

Figure 12: Vertisol from loess.

Profile 7
Soil type: Vermic, Calcic Chernozem (Pachic)
Parent rock: loess
N47° 41.486'  E19° 36.569' 

Figure 13: Chernozem from loess.


Füköh, L., 1999. Data on the Quaternary development of the Mátra foreland. Folia Historico Naturalia Musei Matraiensis 23, 97-101.

Hovorka D., Spišiak, 1993. Mesozoic volcanic activity of the Western Carpathian segment of the Tethyan Belt: Diversities in Space and Time. Jb. Geol. B.-A., 136,4: 769-782.

áth, Z., Michéli, E., Mindszenty, A., Berényi-Üveges, J., 2005. Soft-sediment
deformation structures in Late Miocene-Pleistocene sediments on the pediment of the M
átra Hills (Visonta, Atkár, Verseg): Cryoturbation, load structures or seismites? Tectonophysics 410, 81-95.

Kozur, H., 1991. The evolution of the Meliata-Hallstatt ocean and its significance for the early evolution of the Eastern Alps and Western Carpathians. Palaeogeography, Plaeoclimatology, Palaeoecology, 87: 109-135.

Szent Istv
án Uíversity, 2010. e-SOTER General Assembly Field exercise, Hungary, unpublished.

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