Sedimentarna analiza jurskih in krednih plasti profila na Drnohli v dolini Učje : diplomsko delo

Vanutr, Nejc (author), Rožič, Boštjan (mentor), Vončina, Maja (co-mentor)

V sklopu diplomske naloge sem opisal in določil starost litoloških enot na Drnohli v dolini Učje ter napravil korelacijo z Dinarsko karbonatno platformo, Julijskim pragom in Slovenskim bazenom. Raziskovano območje se nahaja v severozahodni Sloveniji v dolini Učje. Območje pripada tektonski enoti Južne Alpe, natančneje Tolminskemu pokrovu. V juri se paleogeografsko območje zahodne Slovenije deli na Dinarsko karbonatno platformo, Julijski prag in Slovenski bazenom. Raziskano območje predstavlja prehodno območje med Dinarsko karbonatno platformo in Julijskim pragom. Profil Učja sem razdelil na štiri litološke enote. Litološko enoto 1 predstavljajo hemipelagični plastnati, mikritni apnenci z vmesnimi plastmi apnenčevih breč in kalkarenitov. V spodnjem delu litološke enote 1 se med hemipelagičnimi apnenci v brečah in kalkarenitih pojavljajo ooidi in grebenotvorni organizmi. V drugi polovici enote omenjena zrna izginejo, pojavijo pa se intraklasti, iglokožci in redka zrna mikroproblematike Tubiphytes sp.. Prav tako se znotraj plasti apnenca pogosto pojavlja tudi gomoljast roženec. Litološka enota 1 spada v srednjo do zgornjo juro. Litološko enoto 2 predstavljajo kondenzirani gomoljasti apnenci tipa Ammonitico Rosso, ki vsebujejo pelagične krinoide Saccocoma sp. in amonite. V spodnjem delu enote se pojavljajo tudi apnenčeve breče in kalkareniti, v katerih prevladujejo peleti in iglokožci, pogosti so tudi Tubiphytes sp.. Starost enote je kimmeridgij in tithonij. Prehod v litološko enoto 3 je postopen in je postavljen na množično pojavljanje kalpionel. Enoto predstavljajo kondenzirani, plastnati mikritni apnenci tipa biancone. Starost enote je tithonij do berriasij. Litološko enoto 4 predstavlja flišne kamnine zgornjekredne starosti. Kamnine vseh litoloških enot so nastale v globokovodnem okolju. Spreminjala se je le količina in vrsta resedimentov iz bližnje platforme ter vrsta pelagičnih zrn, na podlagi česar sem litološke enote med seboj ločil.

• Language: Slovenian
• Keywords: Julijski prag, Dinarska karbonatna platforma, srednja jura, zgornja jura, Južne Alpe
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: [N. Vantur]
• Year: 2023
• Number of pages: X, 43 str.
• PID: 20.500.12556/RUL-145654
• UDC: 55
• COBISS.SI-ID: 151862787
• Publication date in RUL: 04.05.2023

Secondary language

• Language: English
• Title: Sedimentary analysis of the Jurassic and Creataceous beds of the Drnohla section in the Učja Valley : diploma work

Abstract

In this diploma thesis I have described and determined the age of lithological units of Učja section on Drnohla in the Učja valley. I have also done corelation with Dinaric Carbonate Platform, Julian High and Slovenian Basin. Investigated area is located in NW Slovenia in the Učja valley. Area in part of a tectonical unit Southern Alps, more exactly Tolmin Nappe. In Jurassic paleogeographically the area of NW Slovenia was divided into three units: Dinaric Carbonate Platform, Julian High and Slovenian Basin. Investigated area represents transition between Dinaric Carbonate Platform and Julian High. I have divided Učja section into four units. Unit 1 represents bedded and micritic limestones with limestone breccias and calcarenites beds. In breccias and calcarenites in the lower part of Unit 1 ooids and reef grain fragments occurs, while they are in the upper part of the Unit 1 replaced with intraclasts, echinoderms and rare grains of Tubiphytes sp.. In the upper part of Unit 1 chert is also present. The age of Unit 1 is Middle and Upper Jurassic. Unit 2 represents nodular limestone of Rosso Ammonitico type with pelagic crinoids Saccocoma sp. and ammonites. In the lower part of Unit 2 limestone breccia and calcarenites with echinoderms, pellets and Tubiphytes sp. are present. The age of Unit 2 is Kimmeridgian to Tithonian. The transition to Unit 3 is gradual and is set to frequent occurrence of Calpionela sp.. Unit 3 represents nodular and micritic limestones from Tithonian to Berriasian. Unit 4 represents Flysch sedimentation from Upper Cretaceous. Rocks from all units were deposited in deep water environment. During sedimentation the input of resediments from nearby platform and the type of pelagic grains had changed, which was the main factor for dividing Učja section.

• Keywords: Julian High, Dinaric Carbonate Platform, Middle Jurassic, Upper Jurassic, Southern Alps