Munţii Piule-Iorgovanu. Studiu Geomorfologic
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“Babeş-Bolyai” University Cluj-Napoca Faculty of Geography PhD Thesis PIULE – IORGOVANU MOUNTAINS Geomorphologic study Summary Advisor: Professor Virgil Surdeanu, PhD PhD student: Mircea Ardelean 2010 TABLE OF CONTENTS CHAPTER I – INTRODUCTION I. 1. Geographic position and limits ........................................................ 3 I. 2. Background research ....................................................................... 5 CHAPTER II – GEOLOGIC SETTING AND PALEOGEOGRAPHIC EVOLUTION II. 1. Lithology and structure .................................................................. 8 II. 2. Paleogeographic evolution ............................................................. 17 CHAPTER III – PRESENT DAY MORFOLOGIC CONDITIONS ............... 21 CHAPTER IV – MORFOGRAPHY AND MORPHOMETRIC ANALYSIS IV. 1. Morfography ................................................................................. 29 IV. 2. Morfometry ................................................................................... 34 CHAPTER V – GENETIC TYPES OF LANDFORMS V. 1. Structural and petrographic landforms V. 1. 1. Structural landforms ................................................................... 52 V. 1. 2. Petrographic landforms Landforms developed on cristaline schists ..................... 61 Landforms developed on limestone ................................ 62 V. 2. Denudational landforms ................................................................. 120 V. 3. Fluvio-torrential landforms …........................................................ 138 V. 4. Glacial landforms ........................................................................... 143 V. 5. Periglacial landforms ..................................................................... 187 CHAPTER VI – ACTIVE GEOMORPHOLOGIC PROCESSES …….......... 198 CHAPTER VII – LANDFORMS GENESIS STAGES ..................................... 213 CHAPTER VIII – GEOMORPHOLOGIC ZONING …………....................... 221 References .............................................................................................................. 223 Key words: Piule-Iorgovanu Mountains, Southern Carpathians, glacial landforms, exokarst, endokarst, leveled surfaces, geomorphologic evolution, underground flow 2 CHAPTER I – INTRODUCTION I. 1. Geographic position and limits Piule-Iorgovanu Mountains strech between 22°48’ - 22°59’ long E and 45°16’ - 45°20’ lat N. It makes part of the larger mountain group of Retezat-Godeanu situated in Western part of Southern Carpathians, situated almost in its center. The summit of Piule, of 2081 m represents the highest point of these mountains. Fig. 1 – Position and limits of Piule-Iorgovanu Mountains The entire surface of the massive covers no more than 45 km2, being comparable with other similar massives from Romananian Carpathians – Cozia, Latoriţa, Piatra Craiului. Its area represents 0.27% of that of Southern Carpathians. I. 2. Background research The region analyzed here has never been before the object of a detailed study or of an integrated one, the reasons being its position in the center of the mountains with a rather difficult acces. Only once with starting the coal minning in Petroşani Depression the region has been studied geologicaly in more detail. On a whole, the data have not been gathered togheter in a unique study. The geologic data have been used to explain the general structural and petrographic setting of Southern Carpathians. CHAPTER II – GEOLOGIC SETTING AND PALEOGEOGRAPHICAL EVOLUTION II. 1. Lithology and structure The main geologic components of these mountains are the limestones that give the massive a strong particularity over the neighborough units. The main structures that form the tectonic setting in the area are the: Danubian Autochtone and Getic Nappe. Each of these comprises the cristaline base and its sedimentary blanket. In Piule- Iorgovanu Mountains appear predominantly the formations of Danubian Autochtone. 3 Paleogeographic evolution The main stages of evolution of these area is strong related with the evolution of the Western part of Southern Carpathians. The evolution of Piule-Iorgovanu Mountains was an alternance of predominance of tectcnic factors and erosional factors, which in time had antagonic actions. The tectonic factors tended to raise the area, while the erosional ones lowered it. Each stage of evolution (tectonic or erosional) has left its own trases, which are more or less visible in function of their strenght. CHAPTER III – PRESENT DAY MORFOLOGIC CONDITIONS The main climatic elements taking into analysis are temperature, rainfall and wind regime. Temperature is of great importance, for it determines the existence and alternance of frost cycles, the intensity of alteration processes, the status of rainfall, biotic activity etc. 2500 2000 ) m 1500 ( ne udi t i t l 1000 a 500 0 -2-101234567891011 temperatura (° C) Fig. 2 – Mathematical regression between altitude and teperature Fig. 3 – Map of mean annual temperature (in pink: isotherme of 2° C) The rainfall, through its quantity and quality, besides of temperature, has a great influence over the torrential and fluvial processes, taking into account that water and snow are the main factors or modeling. This is more important to take into account because the area is made up of limestone, that react to water not only through erosion, but also through corrosion. It is clearly stated that the intensity of karstic processes in an area is strong related with the quantity of rainfall (Bleahu, 1974). 4 Fig. 4 –Peltier diagram for alteration processes Fig. 5 – Peltier diagram for type of climate Considering the type of climat associated to bioclimatic areas, the alpine zone falls into the boreal climat, while the forest zone is at the limit between the moderate one and the maritime one. CHAPTER IV – MORPHOGRAPHY AND MORPHOMETRIC ANALYSIS IV. 1. Morphography Piule-Iorgovanu Mountains presents theirselves as a main interfluve which forms the devide between Jiu catchement are in South and Lăpuşnicul Mare in North. This interfluve continues the main ridge of Retezat Mountains which links the main ridge of Godeanu Mountains. Fig. 6 – Morphographic map The main ridge has a NE-SW direction and makes the link between the summit of Custura (2457 m) in Retezat Mountains and summit of Paltina (2149 m) in Godeanu Mountains. Between these two summits Piule-Iorgovanu Mountains form a lower sector, mainlz having the aspect of a 5 leveled surface dotted with insular summits. From this 13-14 km long ridge divert on both sides secondary ridges. One can make the remark over the assimetry between the two parts of the ridge: the northern part is very steep over the Valley of Lăpuşnicul Mare, the southern part consisting in smoother slopes. The northern and eastern part overlaps a cuestã. IV. 2. Morphometry Hipsometry Piule-Iorgovanu Mountains have an altitudinal range of 1241 m, between the Piule Peak (20181 m) and he confluence between Jiul de Vest and Buta (840 m), placing these mountains in the middle altitudinal class of Carpathians. Only the closeness of Petroşani Depression makes the altitudes to lower in the SE part. Fig. 7 – Hipsometric map peste 2000 m 1.5 1800-2000 m 21.6 1600-1800 m 24.0 ne 1400-1600 m 24.5 udi t i t l a ltit di di 1200-1400 m 18.6 1000-1200 m 7.0 sub 1000 m 2.8 0 5 10 15 20 25 30 % Fig. 8 – Hipsometric diagram The solpes The slopes analysis was made both in terrain and laboratory. The solpes map resulted in laboratory using as source of modeling the topographic map at scale 1:25.000. The digitized contour lines were interpolated, the result being the Digital Elevation Model. The model was later processed with ArcGIS – ArcMap 9.1 and Idrisi Andes softawares in order to obtain the slopes map. It consists 6 on a raster file, with a 4.2 m resolution, sufficient to permit a fine change of slope on small surfaces and highlight the morphometric characteristics of middle-sized landforms. Fig. 9 – Slopes map The average slope calculated for the whole area is 24.34°. peste 35 grade 14.9 20-35 grade media 53.1 ă 15-20 grade nt 14.3 pa de 10-15 grade 9.2 a i gor e t 5-10 grade 4.6 a C 2-5 grade 1.7 sub 2 grade 2.3 0 102030405060 % Fig. 10 – The procentual distribution of slope categories The larger part of the mountain area is occupied of surfaces with slopes with value over 20° that make more than 50% of area. On limestones these slopes are due both to lithology and structure. Fragmentation of relative altitude The calculation of this parameter can be done using two methods: using hydrographic basins and rectangular arbitrary chosen. The first method has the advantage to being applied to natural existing features where the erosion take places. The disadvantage of it consists in the difficulty of choosing the right size of the basin. When the basin order is smaller the result is a high number of inter-basin areas. The second method has the advantage that the mountain area is covered with 1 km side tiles, which assures a more homogenic sampling. Another advantage consists in the possibility of an easy comparision of this parameter in different zones of the same unit consisting in different lanforms type, different 7 geology, and structure. By using this method we can eliminate the scale effect induced by the first method where the the results is made of basins with different area. The disadvantage of this method states in the fact that the tiles are arbitrary chosen, they having no natural correspondent. We calculated this parameter in ArcGIS-ArcMap 9.1 software, using