Glavni događaji i stadiji u sedimentarnom razvitku paleogenskog bazena Promine (Dinaridi, Hrvatska)

• Main Authors: Babić, Ljubomir; Institute of Geology and Paleontology, Dept. of Geology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia; [e-mail], Zupanič, Jožica; Institute of Mineralogy and Petrography, Dept. of Geology, Faculty of Science, University of Zagreb, Horvatovac bb, 10 000 Zagreb, Croatia
• Format: Text
• Language: English
• Published: Croatian Natural History Museum 2007
• Subjects: aluvij; šelf; Gilbertova delta; sekvencijska stratigrafija; Bazen Promine; Paleogen; Hrvatska; alluvium; shelf; Gilbert delta; sequence stratigraphy; Promina Beds; Paleogene; Croatia; Rasta; Planktonic foraminifera
• Online Access: http://hrcak.srce.hr/28924; http://hrcak.srce.hr/file/45420

Istraživanje taložnih sukcesija u raznim dijelovima eocensko-oligocenskog bazena Promine pokazalo je glavne promjene u razvitku mlađih naslaga Promine. Prva se odnosi na postanak erozijske plohe, koja siječe razne jedinice, od krednih vapnenaca do raznih dijelova starijih naslaga Promine. Ona je nastala u vrijeme pada relativne morske razine i odgovara sekvencijskoj granici. Na toj plohi naklopno se slažu aluvijalni sedimenti u vrijeme najniže relativne morske razine i njena ranog rasta. Naredni glavni događaj označuje transgresivna ploha na aluviju. On je doveo do taloženja vapnenaca sa diverzificiranom biotom u fotičkoj zoni, kao i njihovih lagunarnih ekvivalenata. Uzrok te promjene je u porastu akomodacijskog prostora, koji je nadišao brzinu prinosa sedimenta. Sljedeća promjena odnosi se na taloženje mulja s planktonskim foraminiferama na vanjskomu šelfu, što je posljedica rasta relativne morske razine, koji je prekinuo taloženje plitkovodnih vapnenaca. Tomu je slijedila progradacija šelfa i delte, što je bilo vezano za usporenje stvaranja akomodacijskog prostora u odnosu na brzinu prinosa sedimenta. A study of sedimentary successions in different parts of the Eocene-Oligocene Promina basin has revealed major changes in the evolution of upper Promina Beds (PB). The first one refers to the origin of the erosional surface cutting different units ranging from Cretaceous limestones to different parts of older PB. It was formed during the fall of relative sea-level, and corresponds to a sequence boundary. This surface is overlain by onlapping alluvial sediments during the lowest relative sea level, and its early rise. The next main event is marked by a transgressive surface above the alluvium, that led to the deposition of shallow-marine limestones with diverse biota in the photic zone, as well as their lagoonal equivalents. This change resulted from an increase in accommodation space outpacing the rate of sediment supply. A further change refers to the deposition of mud with planktonic foraminifera on an outer shelf resulting from a further rise in the relative sea-level, which halted deposition of shallow-water limestones. The subsequent progradation of shelf and delta was related to the slowing down of the creation of accommodation space compared to the increase of sediment supply.