Clinoforms as paleogeographic tools: Development of the Danube catchment above the deep Paratethyan basins in Central and Southeast Europe

Abstract

The Miocene marine basins of Central and Southeast Europe, once comprising the Paratethys Sea, were gradually filled with sediments during the Neogene and turned to be the catchment area of the proto‐Danube and finally that of the modern Danube. Seismic data from various parts of the large Danube catchment area show that these several hundred meter deep basins were filled by lateral accretion of river‐transported sediments, appearing as shelf edge scale clinoform sets in seismic profiles. The direction of shelf edge progradation is NW to SE (N to S, W to E) in each basin, except for the Dacian basin where NE to SW direction prevails. The age of the clinoform sets is generally younging downstream: 19–18 Ma in the North Alpine Foreland basin, 14–13 Ma in the Vienna basin, 10–9 Ma in the Danube (Kisalföld) basin, 8.6–4 Ma in the Central Pannonian basin (Alföld), ?9–5 Ma in the Dacian basin, and 6–0 Ma in the Euxinian (Black Sea) basin. In spite of this geographical and temporal pattern, only the Danube (Kisalföld) and the western and central part of the Central Pannonian basin were filled by the proto‐Danube shelf accretion. Formation of the Danube, as a longitudinal river of the Alpine foreland that gradually elongated to the east and followed the retreating shoreline of the Paratethys, most probably took place at the beginning of the Late Miocene, ca. 11 Ma ago, thus the Early and Middle Miocene shelf advance in the North Alpine Foreland and Vienna basins, respectively, cannot be attributed to a „paleo‐Danube”. The clinoform systems of the Dacian basin are coeval with those of the upstream Central Pannonian basin, indicating that by the time the Danube sedimentary system reached the Dacian basin, it was already a shallow basin. The vast clinoforms of the northwestern Euxinian shelf also significantly overlap in age with the Pannonian basin ones; only the <4 Ma part of the shelf accretion can be attributed to the Danube sensu stricto.

Clinoforms and clinothems: Fundamental elements of basin infill

“…Magyar et al, 2019 , have studied a series of deep marine and Caspian‐type deep lacustrine shelf‐edge–scale clinoforms in Neogene (Paratethyan) foreland basins. Through their seismic data analysis, the authors document shelf‐edge–scale (hundreds of m elevation) clinoforms that prograded into deep marine or lacustrine basins.…”

“…These authors have developed an innovative stratigraphic forward model where empirical relationships are utilized to calculate the water and sediment discharge from rivers and coeval lake level during wet-dry cycles at 10s of kyr time (Lyons, Scholz, Buoniconti, & Martin, 2011). The relationships between clinothem fills of marine and lacustrine basins are also outlined and discussed by Magyar et al, (2019), who describe the evolution of many Central-Eastern European Miocene deep-water lacustrine and marine foreland basins (including the already mentioned Pannonian Basin) and their progressive infill by fluvio-deltaic clinothems. These authors also highlight the same differences in sequence stratigraphic style and reservoir dispersal between marine and lacustrine basins.…”

“…Downslope fining and widening of channels, as well as downslope changes in type of sediment density flows are documented, along with degree of amalgamation inside channels. Magyar et al, 2019, have studied a series of deep marine and Caspian-type deep lacustrine shelf-edge-scale clinoforms in Neogene (Paratethyan) foreland basins. Through their seismic data analysis, the authors document shelf-edgescale (hundreds of m elevation) clinoforms that prograded into deep marine or lacustrine basins.…”

“…Clinothems record incremental sedimentary basin filling over a wide range of temporal and spatial scales (Magyar, Krezsek, & Tari, 2019; Olariu et al, 2019; Patruno & Helland‐Hansen, 2018; Zhang, Olariu, Steel, & Kim, 2019). In particular, three major scales of clinoforms can be differentiated on the basis of vertical relief of the foresets: delta scale (tens of metres relief); shelf‐edge scale (hundreds of metres), common in noncontinental margin settings, and continental‐margin scale (thousands of metres; Figure 1).…”

“…Eberli & Ginsburg, 1987; Patruno, Reid, & Jackson, 2018; Tesch, Reece, Markello, Laya, & Pope, 2019), and are being increasingly documented in ancient lacustrine successions (e.g. Liu et al, 2020; Magyar et al, 2019; Sztano et al, 2013), including on Mars (Grotzinger et al, 2015). Clinothems are some of the most important sedimentary ‘sinks’ (Figure 2), and are key for many sedimentary, stratigraphic and palaeo‐environmental analyses (e.g.…”