engleski

Nearshore deposits in the Middle Eocene clastic succession in northern Dalmatia (Dinarides, Croatia)

The Middle Eocene clastic succession in the Radovin Syncline is approximately 900 m thick and consists of hemipelagic and flysch-type deposits in its lower part, and shallow-marine sediments in its upper portion. The upper portion embraces a unit of sandstones and conglomerates, which is represented by several facies. Flat- and low-angle laminated, and hummocky cross-stratified sandstones (S1) originated by storm-related processes in the shoreface. Cross-bedded sandstones (S2) reflect longshore, offshore, and onshore flows also in shoreface settings. Flat laminated sandstones with planar truncations (S3) reflect swash processes. Some sandstones possibly originated in the offshore transition zone. Conglomerate-sandstone couplets (CS) originated by storm-induced flows in the shoreface. Main conglomerates (CM) mostly reflect various processes and modifications performed in upper shoreface and beachface settings of a reflective coast. Most cross-bedded conglomerates (CX) reflect longshore flows and dissipative conditions. There are also conglomerates which have possibly been deposited by gravity flows related to river floods. The shoreline was oriented NW-SE. The architecture of the sandstone-conglomerate unit is thought to result from the interfingering of deltas and nearshore sandy systems. Deltas were of the shelf-type, and were predominantly "wave-dominated". The sediments studied reflect molasse-type deposition, which was induced by early post-flysch changes in basin evolution and the palaeogeography of the Palaeogene clastic basin in the coastal Dinarides.

nearshore clastics; shoreface; beachface; delta; flysch; molasse; Eocene; northern Dalmatia

nije evidentirano