Aktywność neotektoniczna Pasma Lubania (Gorce) na podstawie analizy parametrów morfometrycznych

Abstract

Neotectonic activity of Lubań Range (Gorce Mts.) based on morphometric indices.A b s t r a c t. The aim of this paper is to use a relative tectonic index (Iat) in order to evaluate tectonic activity in the intermediate mountain area of the Lubañ Range. To estimate the tectonic activity in the study area, we analyzed 6 DEM derived geomorphic indices for 66 basins: the stream-gradient index (SL), asymmetry factor (Af), basin shape ratio (Bs), hypsometric integral (Hi), valley floor width-valley height ratio (Vf) and mountain-front sinuosity (Smf). These parameters were combined to obtain the relative tectonic activity index (Iat). According to Iat values, ca. 25% of the Lubań Range was classified as areas of relatively high tectonic activity and ca. 72% as moderately tectonically active. The Iat values suggest a higher relative tectonic activity in the western part of the range, since some morphometric indices, like HI and SL, indicate a higher rate of tectonic uplift along the Dunajec Fault and normal faults on the northern slopes of the Lubań Range. The rate of the tectonic uplift obtained from the Iat values is similar to that derived from river incision. Morphometric analysis as well as field evidence of active tectonics, such as triangular facets, suggest a high rate of tectonic uplift along the northern margins of the range and probably along the eastern slopes of the Lubań Range. The high relative tectonic activity on the southern slopes in the western part of the Lubań Range is probably related to active subsidence of the Nowy Targ Basin.