Foraminiferska zajednica srednjeg šelfa Sredozemnog mora (odobalje Sicilije)

master's thesis

• Title (english): Foraminiferan assemblage from the middle shelf of the Mediterranean Sea (Sicily offshore)
• Author: Tamara Damjanović
• Mentor: Vlasta Ćosović (mentor)
• Mentor: Igor Felja (mentor)
• Committee member: Vlasta Ćosović (predsjednik povjerenstva)
• Committee member: Igor Felja (član povjerenstva)
• Committee member: Nenad Tomašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geology); Zagreb
• Defense date and country: 2020-02-20, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology; Geology and Paleontology

Abstract

U Sicilijanskom kanalu, na dubini od 69 m uzorkovana je plitka sedimentna jezgra. Sedimentna jezgra podijeljena je svakih 5 cm (s izuzetkom najmlađih 5 cm jezgre) u 2 cm debele poduzorke koji su bili mikropaleontološki i granulometrijski analizirani. U sklopu mikropaleontološke analize određeno je ukupno 12 rodova i 20 vrsta foraminifera. Izračunati su indeksi bioraznolikosti, te indeks kisika i akumulacije bentičkih foraminifera, a bentičke foraminifere grupirane su prema ekološkim zahtjevima. Na temelju ekoloških zahtjeva i zastupljenosti vrsta u zajednici, definiran je samo jedan biofacijes, biofacijes Brizalina spathulata, Valvulineria bradyana i Bulimina marginata. Brojčano najzastupljenije vrste toleriraju manje količine otopljenog kisika, a prema indeksu otopljenog kisika uvjeti u okolišu su nisko do srednje oksični. Broj planktonskih foraminifera u zajednici smanjuje kako su intervali stariji, dok zastupljenost vrsta tolerantnih na obogaćenje organskom tvari raste. Granulometrijska analiza pokazala je sastav sedimenta koji odgovara mulju, pretežito sastavljen od praha te je kroz intervale ujednačen, a veličina čestica odgovara području šelfa.

Abstract (english)

At the offshore of Sicily (Mediterranean Sea), a short (35 cm) sediment core from a depth of 69 m was recovered. Chosen 2 cm thick intervals were micropaleontologically and granulometrically analyzed. Altogether, 12 genera and 20 species were determined from eight studied samples. Biodiversity indexes, indexes of oxygen concentration (BFOI) and accumulation rate of benthic foraminifera (BFAR) were calculated, whereas the benthic foraminifera were grouped according to ecological preferences. The biofacies named as Brizalina spathulata, Valvulineria bradyana and Bulimina marginata has been recognized based on abundances of species according to the environmental requirements. The dominant species in the assemblage tolerate dysoxic condition, thus the BFOI index, point to low to medium-oxygenation. The number of planktonic foraminifera in the assemblage decreases with the core depth, while the number of species tolerant to organic matter increases. The granulometric analysis showed mud sediment mainly composed of silt prevails throughout the whole core.

• Keywords: šelf; mulj; bentičke foraminifere; indeksi bioraznolikosti
• Keywords (english): shelf; mud; benthic foraminifera; indexes of biodiversity
• Language: croatian
• URN:NBN: urn:nbn:hr:217:071957
• Study programme: Title: Graduate university study of Environmental Geology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra geologije (magistar/magistra geologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-07-14 07:55:13