The role of clay minerals in the activation of the Kostanjek landslide : master's thesis

Klizište Kostanjek najveće je klizište u Republici Hrvatskoj. Od njegova pokretanja 1963. godine provedena su brojna geološka i geodetska istraživanja kako bi se razumijele okolnosti koje su dovele do njegova nastanka i koje uzrokuju pokretanje još i danas. Tijekom godina učinjeno je svega nekoliko mineraloških istraživanja, usprokos činjenici da obimom podataka koje pružaju mogu značajno doprinjeti uspješnoj inženjerskogeološkoj interpretaciji. Cilj ovog rada bio je detaljno analizirati minerale glina u sedimentu klizišta Kostanjek neposredno ispod, iznad i u zoni klizne plohe. Granulometrijskim, detaljnim mineraloškim analizama, te analizama kapaciteta kationske zamjene, osim prikaza, interpretacije i integracije novostvorenih podataka, procijenjena je i njihova učinkovitost u datim uvjetima. Ovime je razmotrena problematika utjecaja mineralnog sastava na pojedine analitičke metode, gdje je posebna pozornost obraćena izazovu uspješne provedbe analize kapaciteta kationske zamjene u laporima. Spomenutim analizama utvrđena je prisutnost u inženjerskom smislu nepovoljnih minerala smektita i miješanoslojnih minerala glina u sedimentu klizišta, te visoki udio karbonatnih minerala, gdje se osobito ističe aragonit, koji utječu na određivanje kapaciteta kationske zamjene. Osim toga, na temelju razlike u svom mineralnom sastavu, potvrđeni su ranije ustanovljeni intervali unutar jedinstvene litostratigrafske jedinice, što može upućivati na izvor stvaranja klizne plohe i pokretanja klizišta.Abstract: The Kostanjek landslide represents the largest landslide in the Republic of Croatia. Since its first occurrence in 1963, many geological and geodetic investigations have been made in order to gain a better understanding of the circumstances that led to its initiation and still cause movement to this day. During the years, few mineralogical analyses have been made, despite the significance of the volume of information they provide in a successful geoengineering interpretation. The main objective of this thesis was to conduct a detailed analysis of clay minerals in the sediments of the Kostanjek landslide in the slip surface area. Through analyses of grain size, detailed mineralogical and cation exchange capacity (CEC) analyses, along with the chance to display, interpret and integrate newfound data, an assessment was made regarding their efficiency in given settings. In this sense, the issue of the influence of mineralogy on analytical methods was addressed, especially that of marls on CEC. In using the aforementioned analyses minerals unfavorable in engineering, namely smectite and mixed-layer minerals, were established, as well as a high content of carbonate minerals, most notably aragonite, which affect CEC determination. In addition, based on mineralogical difference, the presence of previously identified distinct intervals in a single litostratigraphic unit was confirmed. This can attest to the origin of the slip surface and the landslides movement