Alexandru ONACA, Petru URDEA, Adrian ARDELEAN & Raul ȘERBAN
West University of Timișoara, Department of Geography, Blvd. V. Pârvan, no. 4, Timișoara, 300223, Romania,
alexandru.onaca@cbg.uvt.ro

ASSESSEMENT OF INTERNAL STRUCTURE OF PERIGLACIAL LANDFORMS FROM SOUTHERN CARPATHIANS (ROMANIA) USING DC RESISTIVITY TOMOGRAPHY

Full text

This study presents the use of DC resistivity tomography for the detection of periglaciallandforms structure from Southern Carpathians. Direct-current (DC) resistivity tomography has beenapplied to six periglacial landforms from the alpine domain of Southern Carpathians for the first time inRomania. Due to important differences in the electrical resistivity of the subsurface materials it waspossible to determine the internal structure and the thickness of the periglacial landforms. A rock glacier(Roșiile) from Parâng Mountains, two patterned ground sites from Țarcu Mountains, as well as twosolifluction phenomena and a scree slope from the central part of Făgăraș Mountains were investigated bymeans of 2D resistivity imaging. The electrical resistivity measurements indicated the presence ofsediments cemented by ice and ice lenses in Roșiile rock glacier. The large depth of the active layer andthe low content of ice suggest that the permafrost exists in marginal condition and is not in equilibriumwith the present climate. A chaotic structural pattern characteristic for the near-surface layer of thepatterned ground was interpreted as the result of actual frost heaving. The solifluction lobe and terraceswere analyzed comparatively displaying a relatively thin mixture of unconsolidated unfrozen sedimentsaffected by seasonally frozen ground. One scree slope from Văiuga glacial cirque was investigated in asimilar manner revealing a thick mantle of unconsolidated stratified periglacial deposits