Late Miocene sediment delivery from the axial drainage system of the East Carpathian foreland basin to the Black Sea

Abstract

We describe a late Miocene to early Pliocene axial drainage system in the East Carpathian foreland, which was an important sediment supplier to the Black Sea and the Dacian Basin. Its existence explains the striking progradation of the northwest Black Sea shelf prior to the onset of sediment supply from the continental-scale Danube River in the late Pliocene to Pleistocene. This axial drainage system evolved due to the diachronous along-strike evolution of the Carpathians and their foreland; continental collision, overfilling, slab breakoff, and subsequent exhumation of the foreland occurred earlier in the West Carpathians than in the East Carpathians. After overfilling of the western foreland, excess sediment was transferred along the basin axis, giving rise to a 300-km-wide by 800-km-long, southeast-prograding river-shelf-slope system with a sediment flux of ~12 × 103 km3/m.y. Such late-stage axial sediment systems often develop in foreland basins, in particular, where orogenesis is diachronous along strike. Substantial lateral sediment transport thus needs to be taken into account, even though evidence of these axial systems is often eroded following slab breakoff and inversion of their foreland basins.

Late Miocene megalake regressions in Eurasia

“…S1 ). In the western Black Sea region, carbonate platform deposits crop out and are truncated by repeated erosion and karstification episodes 13 , while in the northwestern region riverine-lacustrine successions of an extensive deltaic system developed 14 . Well-preserved aquatic records have been reported in peripheral basins of the southwest Caspian 7 and south Carpathians 15 , but limited biostratigraphic information prevents development of integrated stratigraphies in these regions.…”

Foraminiferal and calcareous nannoplankton biostratigraphy of the upper Badenian–lower Sarmatian strata in the SE Polish Carpathian Foredeep

“…The de po si tion of evaporites re lated to the Badenian Sa linity Cri sis in the Cen tral Paratethys that started at 13.81 ±0.08 Ma (de Leeuw et al, 2010), was ter mi nated when the Cen tral Paratethys re turned to open-ma rine con di tions at 13.36 Ma (Si mon et al, 2019) due to reconnection of the ba sin with the Med i ter ra nean and East ern Paratethys, pri mar ily by tec tonic mod i fi ca tion of the in ter con nect ing gate ways (de Leeuw et al, 2018). In the Carpathian Foredeep and Fore land Ba sin -the larg est Cen tral Paratethyan ba sin -the ma rine shelf-slope fa cies have been re placed, dur ing the late Serravalian and Tortonian, by shell-rich littoral and delta-front de pos its and then by delta-top chan nel and floodplain fa cies that con tin ued un til the end of Messinian in the East Carpathian fore land (de Leeuw et al, 2020).…”

Hydrological Changes in Restricted Basins: Insights From Strontium Isotopes on Late Miocene‐Pliocene Connectivity of the Eastern Paratethys (Dacian Basin, Romania)

“…The quasi-horizontal blue trend-line represents the 87 Sr/ 86 Sr of the open ocean through time (McArthur et al, 2012). Vertical purple lines indicate "flooding" events in the Dacian and Mediterranean Basin based on faunal studies (e.g., Stoica et al, 2013;Roveri, Flecker, et al, 2014 Leeuw et al, 2020;Matoshko et al, 2016). We thus attribute the increase in 87 Sr/ 86 Sr ratios to an increased influence of water coming from the Balta delta.…”

“…During the Khersonian, the water level in the Dacian Basin was relatively low and reflected by delta progradation (De Leeuw et al, 2020;Matoshko et al, 2016) and coastal plains with reddish palaeosols (Lazarev Hilgen et al (2012). The ages of the Dacian Basin stages, in million years, are according to van Baak, Mandic, et al (2015), Palcu et al (2019) and Lazarev et al (2020).…”

“…During the Khersonian, the water level in the Dacian Basin was relatively low and reflected by delta progradation (De Leeuw et al., 2020; Matoshko et al., 2016) and coastal plains with reddish palaeosols (Lazarev et al., 2020; Palcu et al., 2019). The Maeotian transgression terminated the Khersonian, an event dated in Slanicul de Buzau at 7.63 Ma (Lazarev et al., 2020).…”