20.500.12556/DiRROS-16486 Late-Quaternary evolution of the semi-confined alluvial megafan of Isonzo River (Northern Adriatic): where the fluvial system of the Southern Alps meets the karst The evolution of alluvial megafans has mainly been investigated in unconfined settings; however, at the boundary of these large depositional systems, the development of fluvial channels can be affected by structural constraints with regional extent. Here we present the study of the eastern sector of the megafan of Isonzo River, in the Gulf of Trieste, where this system fed through the southern Alps is constrained by the Karst and Istria cliffs. Although this area is now submerged under the northern Adriatic Sea, stratigraphy from seismo-acoustic profiles, drill cores and multi-beam bathymetry allows us to reconstruct the paleochannel system of the Isonzo River in detail, which was likely active within the period of 21–17.5 ka cal BP, at the end of LGM. This was reconstructed for over 50 km and currently represents the longest abandoned fluvial channel in the Mediterranean seabed. The occurrence of the mountain fringe and competition with nearby alluvial systems forced the paleochannel to follow the present coastline and conditioned the slope of its thalweg to decrease almost to null, resulting the transformation from the megafan to the undifferentiated alluvial plain. marine geology CHIRP stratigraphy bathymetry last glacial maximum adriatic sea true false true MDPI Angleški jezik Ni določen Neznano 2023-05-09 03:34:39 2023-05-31 11:23:50 2023-06-15 09:52:05 0000-00-00 00:00:00 2023 0 0 13 str. no. 5 vol. 13 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2023-05-07 551.7 2076-3263 10.3390/geosciences13050135 151155715 geosciences-13-00135-v2-1.pdf geosciences-13-00135-v2-1.pdf 1 0CE02A4E53B10D487D2E7DA8BF238907 eeea7e29acfb3db7d71591b9f139a50a327558c3b0632283eaf85692d0d9079a f0d308eb-ff85-11ed-a314-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=22481 Geološki zavod Slovenije 0 0 0