magistrsko delo
Barbara Karničnik (Author), Luka Gale (Mentor), Tea Kolar-Jurkovšek (Co-mentor)

Abstract

V okviru magistrskega dela sem raziskala sestavo in mikrofosile apnencev Zatrniške formacije v Blejskem vintgarju, kjer sem posnela več delnih sedimentoloških profilov, nabrala kompozitne konodontne vzorce in pobrala vzorce za zbruske. Na podlagi slednjih sem opisala mikrofaciese in določila foraminifere in mikroproblematiko. Apnence v posnetem zaporedju predstavljajo trije litološki različki. Prvi litološki različek so plasti masivnega apnenca (wackestone, packstone, grainstone, rudstone) debeline 1 m ali več. V nekaterih od teh plasti lahko opazimo povite laporaste lezike. Drugi facies so plasti mikritnega apnenca (packstone, wackestone in rudstone) z debelino plasti od 10 cm do 1 m. Tretja skupina so kalkareniti (packstone, grainstone) z debelino plasti od 7 cm do 1 m. Določenih je bilo pet mikrofaciesov s podskupinami: bioklastični-intraklastični wackestone (MF1), intraklastični packstone (MF2), dobro sortiran bioklastični-peloidni-intraklastični grainstone/packstone (MF3), intraklastični rudstone (MF4) in dolomit (MF5). Med zrni prevladujejo peloidi in intraklasti. Manj je različnih bioklastov, med katerimi je največ mikroproblematike. Redkejše so bentoške foraminifere, iglokožci, mahovnjaki, spužve, brahiopodi, rdeče in zelene alge, kalcimikrobi, školjke in polži. V netopnem ostanku vzorcev za konodonte so bili pogosti zobje rib ter redki holoturijski skleriti. »Cordevolska«-julska starost apnencev je bila določena z naslednjimi konodonti: Paragondolella foliata Budurov, Quadralella polygnatiformis (Budurov & Stefanov), Quadralella sp., Paragondolella sp., Gladigondolella malayensis Nogami ter Gladigondolella tethydis (Huckriede). Starost apnencev so potrdile še prisotne vrste foraminifer: Austrocolomia marschalli Oberhauser, Cucurbita infundibuliformis Jablonský, Endotriada tyrrhenica Vachard, Martini, Rettori & Zaninetti, Hydrania dulloi Senowbari-Daryan, Koskinobullina socialis Cherchi & Schroeder, Palaeolituonella meridionalis (Luperto), Pseudonodosaria cf. obconica (Reuss), Reophax rudis Kristan-Tollmann, »Trochammina« jaunensis Brönnimann & Page, ?Miliolipora cuvillieri Brönnimann & Zaninetti ter Piallina bronnimanni Martini, Rettori, Urošević & Zannetti. Zatrniški apnenci Blejskega vintgarja so nastajali na nekoliko nagnjenem morskem dnu (vznožje pobočja), ki so ga dosegli distalni turbiditni tokovi in sinsedimentni plazovi, kar potrjujejo teksture, mikrofaciesi ter biota.

Keywords

Južne Alpe;Slovenski bazen;Blejski bazen;pokljuški apnenci;Zatrniška formacija;konodonti;karnij;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL NTF - Faculty of Natural Sciences and Engineering
Publisher: [B. Karničnik]
UDC: 55
COBISS: 1444702 Link will open in a new window
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Other data

Secondary language: English
Secondary title: biostratigraphy and sediemntology of Upper Triassic Zatrnik formation, Slovenia
Secondary abstract: Middle Triassic extensional tectonics led to the formation of various sedimentary basins in the area of today`s Southern Alps. The subject of investigation was the Zatrnik limestone in Bled area. In the Blejski vintgar gorge, several partial sedimentological sections were loged. Samples for conodont analysis and microfacies analysis were taken. Thin sections of standard sizes were prepared in order to supplement field observations with microfacies analysis. Thin sections were also used for determination of microproblematica and foraminifers. Thin-bedded limestone consists of three different kinds of lithologies. First lithology consists of masive limestone (wackestone, packstone, grainstone and rudstone) with beds up to 1 meter thick. Second lithology is represented by medium to thick bedded (from 10 cm to 1m thick) micritic limestones (pakstone, wackestone, rudstone) and the third group are calcarenites (packestone, wackestone) with beds thick from 7 cm to 1 m. Five microfacies types with subgroups were determined: bioclastic-intraclastic wackestone (MF1), intraclastic packstone (MF2), well sorted bioclastic-peloidal-intraclastic grainstone/packstone (MF3), intraclastic rudstone (MF4), dolomite (MF5). Peloids and intraclasts are the most common grains. Microproblematica is the dominating group of bioclasts. Foraminifers, echinoderms, red and green algae, calcimicrobes, brachiopods, bryozoa, sponges, bivalves and gastropods. Fish teeth and holoturias can rarely be found in samples for conodont analysis. Cordevolian to Julian age was determined on the basis of the following conodont species: Paragondolella foliata Budurov, Quadralella polygnatiformis (Budurov & Stefanov), Quadralella sp., Paragondolella sp., Gladigondolella malayensis Nogami and Gladigondolella tethydis (Huckriede). This age is in agreement with findings of foraminifera: Austrocolomia marschalli Oberhauser, Cucurbita infundibuliformis Jablonský, Endotriada tyrrhenica Vachard, Martini, Rettori & Zaninetti, Hydrania dulloi Senowbari-Daryan, Koskinobullina socialis Cherchi & Schroeder, Palaeolituonella meridionalis (Luperto), Pseudonodosaria cf. obconica (Reuss), Reophax rudis Kristan-Tollmann, »Trochammina« jaunensis Brönnimann & Page, ?Miliolipora cuvillieri Brönnimann & Zaninetti and Piallina bronnimanni Martini, Rettori, Urošević & Zannetti. The Zatrnik limestone deposited on the slope of the basin, adjacent to a carbonate platform (toe of the slope), which can be confirmed by the presence of debris flow, sinsediment flow, biota, sedimentary textures and explicit microfacies groups.
Secondary keywords: Southern Alps;Bled basin;Slovenian basin;Pokljuka limestone;Zatrnik formation;conodonts;Carnian;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Naravoslovnotehniška fak., Oddelek za geologijo
Pages: XI, 47 f.
ID: 10978403