engleski

Coherent provenance analysis of terra rossa from the northern Adriatic based on heavy mineral assemblages reveals the emerged Adriatic shelf as the main recurring source of siliciclastic material for their formation

Coherent provenance studies of soils that take into account data processing and the limitations arising from the physiochemical properties of the source material are scarce. In this study, the provenance of four terra rossa soils on the Istrian peninsula and four terra rossa soils on the island of Susak is investigated based on the heavy mineral assemblages of the soils and their potential sources. The heavy mineral data are treated as compositional data, which means that the information is stored in the ratio between the components and not in absolute values. The provenance of the allochthonous soil components showed that they originated from the now submerged alluvial plain i.e., emerged Adriatic shelf, mainly fed by alpine material during low sea levels. In the case of Savudrija loess and red paleosol and partly Koreniki sections, the allochthonous material originated from the local Eocene flysch, also windblown from the emerged shelf. The degree of mineral weathering, which correlates with the Fed/Fet and the total portion of heavy minerals, shows that this allochthonous component is a parent material of the terra rossa soils, not an impurity. Thus, the main role of the carbonate rocks with which the terra rossa soils are associated is to maintain a specific and favorable conditions for their formation. The origin of the parent material is associated with sea level oscillations, i.e., in times of low sea level the material was windblown from the emerged shelf, onto the land, this recurrent process can probably be traced back to the Oligocene. During periods of high sea level, i.e., warmer periods, terra rossa formed. Thus, the formation of terra rossa soils in the northern Adriatic is a recurrent process that may have begun at least since the Miocene. Consequently, abundance of terra rossa on the eastern Adriatic coast is due to a large emerged shelf area that supplied the carbonate platform with siliciclastic material during low sea levels.

Terra rossa ; Heavy minerals ; Sediment provenance ; Compositional data, northern Adriatic

nije evidentirano