Composition and provenance of Neogene sedimentary rocks of Dilj gora Mt. (south Pannonian Basin, Croatia)

The petrographic composition and transport direction of medium and coarse-grained clastic material of Dilj gora Mt. which is located in the south Pannonian basin, shows that this area experienced several changes in provenance of the detritus through the Neogene. Detritus for the oldest Lower Miocene (Ravan unit) was generally transported from the south and most probably derived from clastic and carbonate sediments and metamorphic rocks of the Internal Dinarides. Detritus of the Lower-Middle Miocene (Tuk unit) probably originated by weathering of acid magmatic and metamorphic rocks, with significant input of materials from local sources, primarily from the Internal Dinarides and from Pozeska gora and Dilj gora Mts. During the entire Middle Miocene (Zdenci, Dubovik and Glogovica units), and through the older part ofthe Late Miocene (Croatica and Pavlovci unit), the deposition of siliciclastic gravel and sandy detritus was less significant. Only the Middle Miocene deposits (Kasonja unit) contain clastic detritus derived from granitoids, metamorphic and sedimentary rocks of the hinterland. The source area of this detritus was most probably in the Slavonian Mts. (Papuk, Psunj, Pozeska gora Mt.) or the mountains of northern Bosnia (Motajica Mt.). At late Upper Miocene times (Andrasevec and Nova Gradiska units), detritus was derived from different metamorphic and older sedimentary rocks. The structural and mineralogical maturity of these sediments, and their transport directions, indicates an Alpine-Carpathian provenance of the material. Most of the detritus of the Pliocene sediments (Cernik unit) also belong to an Alpine-Carpathian provenance, however a small part of it is of local origin and came from uplifted and mainly sedimentary rocks. Various textural characteristics and diverse modal compositions were determined, and the provenance of Neogene clastic material of Dilj gora Mt. can be attributed to differing source rock compositions and locations of source areas. However, they are also the product of different controls on sedimentation, including different rates of subsidence and extension of the Pannonian Basin (PB) interrupted by compressional events, basin water-level fluctuations connected with global sea-level changes and infilling of PB by delta progradation.