Petrologic and stratigraphic characteristics of rocks in Skrad area : master’s thesis

Na širem području Skrada, terenskim radom i laboratorijskim istraživanjima, izdvojeno je šest litostratigrafskih jedinica. To su: (1) pješčenjaci, šejlovi i konglomerati permske starosti; (2) dolomiti u izmjeni s crvenim i zelenim klastitima karničke starosti; (3) glavni dolomit noričko-retske starosti; (4) vapnenci i dolomiti sinemurijplinsbahijske starosti; (5) vapnenci s gastropodima, brahiopodima i litiotidima plinsbahijske starosti; (6) mrljasti vapnenci toarcijske starosti. Djelovanjem mehaničkih i kemijskih procesa na sedimentne stijene istraživanog područja formiran je specifičan reljef okolice Skrada. Odlike toga reljefa su zaravnjeni dijelovi terena te područja s kanjonima i strmim liticama. Zaravnjena područja se nalaze na najvišim nadmorskim visinama te su na njima česti izvori i povremeni i/ili stalni vodotoci, a dominantno su ta područja izgrađena od klastičnih stijena litostratigrafske jedinice (1). Kanjoni i strme litice nalaze se na nižim dijelovima terena te su prekriveni s manje vegetacije i teže su dostupni, a izgrađeni su dominantno od karbonatnih stijena litostratigrafskih jedinica (3) i (4). Rezultati istraživanja petroloških i stratigrafskih značajki stijena i rasprostranjenosti litostratigrafskih jedinica potvrđuju njihovu povezanost s procesima formiranja reljefa okolice Skrada i značajnog krajobraza Vrajži prolaz i Zeleni vir. Svi rezultati istraživanja sintetizirani su i integrirani u GIS bazu podataka.Abstract: Six lithostratigraphic units were defined in Skrad area through fieldwork and laboratory analysis. These are: (1) sandstones, shales and conglomerates of Permian age; (2) dolomites in alteration with red and green clastics of Carnian age; (3) Main Dolomite of Norian-Rhaetian age; (4) limestones and dolomites of Sinemurian- Pliensbachian age; (5) limestones with gastropods, brachiopods and litiotides of Pliensbachian age; (6) spotted limestones of Toarcian age. The effects of mechanical and chemical processes of sedimentary rocks of the study area formed the specific relief of Skrad area. The characteristics of this relief are flattened areas of the terrain and areas with canyons and steep cliffs. Flattened areas are located at the highest altitudes, often with casual and/or permanent watercourses, and these areas are predominantly built of clastics of lithostratigraphic unit (1). Canyons and steep cliffs are located on the lower parts of investigated area, less covered with vegetation and hardly available. These areas are built predominantly of carbonates of lithostratigraphic units (3) and (4). Research results for petrological and stratigraphical features of rocks and distribution of lithostratigraphic units confirmed their association with the processes of relief formation in Skrad area and especially in significant landscape Devils passage and Green whirlpool. All research results are synthesized and integrated into a GIS database