Naslov
Lacustrine basin to delta evolution in the Zagorje Basin, a Pannonian sub-basin (Late Miocene: Pontian, NW Croatia)

Autori
Kovačić, Marijan ; Zupanič, Jožica ; Babić, Ljubomir ; Vrsaljko, Davor ; Miknić, Mirjana ; Bakrač, Koraljka ; Hećimović, Ivan ; Avanić, Radovan ; Brkić, Mato

Izvornik
Facies (0172-9179) 50 (2004), 1; 19 - 33

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Lacustrine delta; Friction-dominated effluent; Mouth bars; Pannonian Basin; Zagorje Basin

Sažetak
Pontian deposits of the Zagorje Basin constitute a coarsening-upward succession, which reflects the infilling style of this Pannonian sub-basin, i.e. the progradation of clastic systems into the brackish lake. Six facies differentiated correspond to lake floor, channelled slope, distal and proximal pro-delta, distal and proximal mouth bars, and lagoon/bay to swamp and alluvial environments. The deposition in the mouth-bar area was dominated by frictional forces. The upper-stage plane-bed sands are the main mouth-bar facies, which is uncommon in the geological record. The main factors for the origin of such bars include an abundant sand supply by the high-energy fluvial system(s), low-energy of the receiving basin and shallow depositional depth. Prolonged, catastrophic floods generated sustained hyperpycnal flows, which bypassed the mouth-bar area and fed the slope/pro-delta. The high ratio between sediment supply and subsidence rate resulted in a fast moving 'progradational wave', which involved the entire SW Pannonian Basin, including the Zagorje Basin.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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