Sedimentarni razvoj intramontanih bazenov na stičišču Alp, Dinaridov in Panonskega bazena v pliocenu in kvartarju : doktorska disertacija

Mencin Gale, Eva (author), Šmuc, Andrej (mentor), Anselmetti, Flavio (co-mentor)

Pričujoča študija obravnava pliocensko-kvartarno sedimentarno evolucijo rečnih sistemov v Slovenjgraškem, Nazarskem, Velenjskem, Celjskem, Dravsko-Ptujskem in Krškem bazenu, ki se nahajajo na jugovzhodnem delu Alpskega predgorja. Glavni cilj je določiti sestavo, morfostratigrafijo, provenienco, sedimentacijsko okolje in starost sedimentov z geomorfološkimi, sedimentološkimi, geokemičnimi, mineraloškimi in biostratigrafskimi metodami. Pliocensko-kvartarni sedimenti so bili odloženi v rečnih okoljih (prepletajoči sistemi in prehodni sistemi med prepletajočim in meandrirajočim tokom) in s sedimentacijo v aluvialnih/koluvialnih vršajih. Sedimenti so ohranjeni v obliki zaporedja teras, na nastanek katerih je močno vplivala tektonska aktivnost. Na podlagi geomorfoloških analiz smo opredelili spodnjo, srednjo in zgornjo terasno skupino, katerim smo interpretirali poznopleistocensko, srednjepleistocensko in plio-zgodnjepleistocensko starost. Slednja skupina se nanaša na t. i. »pliokvartarne« sedimente, kot so le-ti poimenovani v tradicionalni literaturi. Analiza provenience je bila osredotočena na plio-zgodnjepleistocenske sedimente in je vključevala litološko in mikrofacielno analizo klastov. V Slovenjgraškem bazenu, bazenu Nazarje, Velenjskem, Celjskem in Dravsko-Ptujskem bazenu rezultati kažejo na lokalno provenienco s krajšim transportom, v Krškem bazenu pa na distalno provenienco z daljšim transportom. Na podlagi analize provenience in predhodnih raziskav je bil opredeljen dolgoročen razvoj rečne mreže. Ugotovljeno je bilo, da se je znatna sprememba zgodila na prehodu iz miocena v pliocen, pri čemer se je današnja rečna mreža osnovala najkasneje v plio-zgodnjem pleistocenu. Odsotnost (ali zelo nizka vsebnost) karbonatnih klastov v plio-zgodnjepleistocenskih sedimentih je bila interpretirana kot posledica klimatskih (raztapljanje) in neklimatskih faktorjev (bližina izvornih kamnin, razvoj rečne mreže in površinska geologija). Na splošno pa prostorska razporeditev pliocensko-kvartarnih sedimentov razkriva tektonsko aktivnost v medgorskih bazenih tekom njihovega razvoja ter s tem omogoča vpogled v evolucijo razvoja pokrajine.

• Language: Slovenian
• Keywords: paleookolje, provenienca, morfostratigrafija, medgorski bazen, “pliokvartar”, kvartar, rečno okolje, razvoj pokrajine
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: NTF - Faculty of Natural Sciences and Engineering; FGG - Faculty of Civil and Geodetic Engineering
• Publisher: [E. Mencin Gale]
• Year: 2021
• Number of pages: XVIII, 187 str., 2 str. pril.
• PID: 20.500.12556/RUL-127012
• UDC: 55
• COBISS.SI-ID: 62546947
• Publication date in RUL: 13.05.2021

Secondary language

• Language: English
• Title: Pliocene to Quaternary sedimentary evolution of intramountain basins at the junction of Alps, Dinarides and Pannonian Basin : doctoral dissertation

Abstract

This study focuses on the Pliocene-Quaternary sedimentary evolution of the fluvial systems in the Slovenj Gradec, Nazarje, Velenje, Celje, Drava-Ptuj and Krško Basins in the south-eastern Alpine foreland of Slovenia. The main aim was to determine the composition, morphostratigraphy, provenance, sedimentary environment and age of the deposits using geomorphological, sedimentological, geochemical, mineralogical and biostratigraphical methods. Pliocene-Quaternary sediments were deposited in fluvial (braided and wandering river systems) and alluvial/colluvial fan environments. The sediments are preserved in the terrace staircase sequences, formation of which is strongly controlled by tectonic activity. Based on geomorphological analyses, low-, middle- and high-level terrace groups were constrained and tentatively attributed to Late Pleistocene, Middle Pleistocene, and Plio-Early Pleistocene, respectively. The later term was introduced to replace the traditional term “Plio-Quaternary”. The provenance analyses focused on the Plio-Early Pleistocene sediments and included lithological and microfacies analyses of the clasts. For the Slovenj Gradec, Nazarje, Velenje, Celje and Drava-Ptuj Basins, a local provenance with relatively short transport, and for the Krško Basin a distal provenance with longer transport was deduced. Based on the provenance analyses and published data, the long-term development of the drainage network was interpreted. Major changes occurred during the transition from Miocene-Pliocene and at the latest at Plio-Early Pleistocene the drainage network reached conformity with the present one. The enigmatic absence (or very low content) of carbonate clasts in the Plio-Early Pleistocene sediments was interpreted as the result of an interplay of climate (dissolution) and non-climate related factors (vicinity of source rocks and development of the drainage network and surface geology). Overall, the spatial distribution of the Pliocene-Quaternary landforms revealed tectonic activity in intramontane basins during their development, from which the landscape evolution was deduced.

• Keywords: paleoenvironment, provenance, morphostratigraphy, intramontane basin, “Plio-Quaternary”, Quaternary, fluvial environment, landscape evolution