1 West University of Timișoara, 4 V. Pârvan Str., 300223, Timișoara, e-mails: petru.urdea@e-uvt.ro, tambrisalin@yahoo.com

ABSTRACT.- Spontaneous Potential Investigations in Semenic Mountains. The use of geophysical methods such as that of Spontaneous Potential (SP) to investigate areas where the geomorphological processes occur, has the role to identify less visible processes as for example subcutaneous erosion or piping, subsoil water drainage and finding specific spatial differences of these processes. Comparative study of these sites allows correlation between geomorphological factors, soil and climate, but also to observe the evolution of subsurface erosion or underground water infiltration over time. During this investigation a series of mesh grids have been made in areas with different characteristics (lithology, pedology, slope, exposition, etc.) at different time periods in order to spot and analyse the change in data in the chosen sites, various conditions given. Values expressed in millivolts (mV) obtained by the Spontaneous Potential method have been put into an algorithm for interpolation looking to yield a pattern of values of what is happening in the soil during that period of time. Thus, in the autumn, the investigation site at the nivation niche Baia Vulturilor, returned values of between -22.6 mV and 65.6 mV, while in spring in the same site, values were within the range of -14.4 mV / 30.1 mV. On the other hand, on the site of the cryopediment under the Semenic peak, in the spring, return values ranged from -40.4 mV and -1.1 mV. A particular case is that of the glacis near Piatra Goznei peak; in this area anthropogenic electricity influences on soil can be found. Based on some models a trend of water movement in the soil could be established, this depending heavily on the amount of precipitation infiltration, local lithology, depth of soil and their structure, and evapotranspiration process. Water movement in the soil may be a correlation with sediment movement in soil horizons and instability manifested on the slopes.
Keywords: spontaneous potential, piping, subsoil water drainage, nivation niche, cryopediment, Semenic Mountains.