Paleontološke i sedimentološke značajke dva krpasta grebena u mastrihtskim i paleocenskim karbonatnim naslagama uvale Likva, otok Brač (Hrvatska)

master's thesis

• Title (english): Paleontological and sedimentological characteristics of the two patch reefs in the maastrichtian and palaeocene carbonates of the Likva Cove, the island of Brač (Croatia)
• Author: Sonja Jurić
• Mentor: Maja Martinuš (mentor)
• Committee member: Maja Martinuš (predsjednik povjerenstva)
• Committee member: Jasenka Sremac (član povjerenstva)
• Committee member: Dražen Kurtanjek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geology); Zagreb
• Defense date and country: 2021-02-26, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology; Geology and Paleontology

Abstract

U gornjokrednom i paleocenskom dijelu slijeda uvale Likva nalazi se nekoliko
dobro očuvanih razina koraljno-stromatoporoidnih grebena. Unutar grebena uočeni su različiti
trošni ostaci koji se morfološki mogu grupirati u dvije skupine. Prva skupina predstavlja
domaste forme sa strukturama nalik „prstima“ koji najvjerojatnije pripadaju koraljima, a
druga skupina su nepravilne i kuglaste forme koje se nalaze oko domastih formi ili zasebno i
vjerojatno pripadaju spužvama (najvjerojatnije stromatoporoidima). Prilikom terenskog
istraživanja u listopadu 2020. godine, detaljno su istražene dvije grebenske razine unutar
slijeda Likva: jedna unutar mastrihtskog i jedna unutar paleocenskog dijela slijeda. Novo
prikupljeni uzorci, kao i oni prikupljeni na ranijim istraživanjima, korišteni su za
paleontološke i sedimentološke analize. Analiza mikroskopskih izbrusaka omogućila je
određivanje i interpretaciju dijagenetskih i mikrofacijesnih značajki karbonatnih stijena.
Ostaci organizama i sediment pronađeni u obje grebenske razine su slični, što govori u prilog
relativno brzom uspostavljanju povoljnih uvjeta za razvoj istih nakon izumiranja na kraju
krede.

Abstract (english)

In the Upper Cretaceous and Palaeocene part of the Likva Cove section, there are
several well-preserved levels of coral-stromatoporoid reefs. Within the reefs, various
weathered remains have been observed and morphologically grouped in two groups. The first
group represents domal forms with „finger-like“ structures which most likely belong to corals,
and the second group represents irregular and bulbous forms which are found around the
domal forms and likely belong to sponges (probably stromatoporoids). During field research
in October 2020, two reef levels within the Likva section were investigated in detail: one reef
from the Maastrichtian and one from the Palaeocene part of the section. Newly taken samples,
as well as samples collected from previous investigations, were used for palaeontological and
sedimentological analyses. Analysis of microscopic thin sections enabled the determinations
and interpretations of diagenetic and microfacies characteristics of carbonate rocks. The
remains of organisms and sediment found in both patch reef levels are similar, which implies
of the relatively rapid establishment of favourable conditions for their development after the
extinction at the end of the Cretaceous.

• Keywords: koralji; krpasti grebeni; mastriht; paleocen; stromatoporoidne spužve
• Keywords (english): corals; Maastricht; Palaeocene; patch reefs; stromatoporoid sponges
• Language: croatian
• URN:NBN: urn:nbn:hr:217:643111
• Study programme: Title: Graduate university study of 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: 2021-04-28 10:39:48