Coeval versus reciprocal mixed carbonate–siliciclastic deposition, Middle Devonian Baltic Basin, Eastern Europe: implications from the regional tectonic development

Abstract

The Middle Devonian Narva succession in the Baltic Basin represents a significant turnaround in the history of the basin. The detailed study of core and outcrop sections and the three‐dimensional correlations across the Baltic Basin reveal a carbonate‐dominated, mixed retrogressive succession, overlain by a siliciclastic‐dominated, progradational succession. The palaeogeographic reconstructions show how the shallow, tide‐influenced basin expanded from south‐west to north‐east and, later during the transgression, also to the north, south and east. The transgressive portion of the basin fill is dominated by carbonate‐rich sabkha and supratidal to intertidal deposits on the basin margins, and subtidal carbonates in the basin centre. Siliciclastic material was derived by tidal currents and storm waves from the south‐west through a tidal inlet and flood‐tidal delta complex. This initial transgressive phase is characterized by the lack of subsidence or even episodic uplifts in the northern/north‐western part of the basin margin, shown by convergence of timelines and the thin (30 m) transgressive succession. In contrast, on the southern margin, the facies associations stack vertically into a 70 to 80 m thick succession, indicating significantly higher subsidence rates. The upper part of the transgressive phase indicates subsidence across the whole basin. The upper, progradational portion of the basin fill is dominated by coarse, siliciclastic, tide‐influenced deltaic deposits that rapidly prograded from north‐west to south‐east. This detailed study on the Narva succession shows that siliciclastic and carbonate deposition was coeval and that mixing occurred at different temporal and spatial scales. The mixing was controlled by grain‐size, volume and location of siliciclastic input rather than relative sea‐level changes as suggested in widely used reciprocal mixing models. It is suggested that the forebulge of the Scandinavian Caledonian fold‐and‐thrust belt migrated to the north‐western margin of the Baltic Basin during the earliest Eifelian, as indicated by the lack of subsidence and probable uplift in the northern/north‐western margin during the early transgressive phase. The forebulge migration ceased although the forebulge had already started to subside during the later stages of the transgressive phase. The deltaic progradation is interpreted to be associated with the orogenic collapse and uplift in the Scandinavian Caledonides that caused the erosion of the foreland basin fill and the coarse sediment transport into the Baltic Basin.

A comprehensive approach to the 3D geological modelling of sedimentary basins: example of Latvia, the central part of the Baltic Basin

“…Some hints of the basin inversion tectonics can be traced during the Narva Stage (Ukass et al 2012), which is supported by the sedimentary record of the Narva Stage (Tänavsuu-Milkeviciene et al 2009). Later deformation stages can be traced in the very southwest corner of Latvia, where some normal displacement along the Liepaja-Saldus fault of probably Carboniferous age is recorded (Brangulis & Kaņevs 2002).…”

Sedimentary environments and stratigraphy of the Stipinai Formation (Upper Frasnian, northern Lithuania): a sedimentary record of sea-level changes in the Main Devonian Field of the East European Platform

“…Dur ing the ear li est De vo nian, con ti nen tal-la goonal sed i men ta tion pre vailed in the Bal tic Ba sin ex cept for its northern part, which was up lifted and eroded (Paškevièius, 1997). Sand stone-dom i nated siliciclastic sed i ments were de pos ited from the Pragian un til the end of the Givetian (Tänavsuu-Milkeviciene et al, 2009). Dur ing the Pragian and Emsian, these sed i ments ac cu mu lated on river del tas and in lakes (Paškevièius, 1997).…”

“…Dur ing the Pragian and Emsian, these sed i ments ac cu mu lated on river del tas and in lakes (Paškevièius, 1997). From the lat est Emsian to Givetian, de posi tion oc curred in a tid ally in flu enced delta or in a tide-dom inated es tu ary (see Pontén and Plink-Björklund, 2009;Tänavsuu-Milkeviciene et al, 2009;Lukševiès et al, 2012). How ever, dur ing the Eifelian, siliciclastic de po si tion was in terrupted by an ep i sode of mixed car bon ate-siliciclastic ma rine accu mu la tion (Tänavsuu-Milkeviciene et al, 2008.…”

“…2). The lower Frasnian Amata RS is rep re sented by the Amata For ma tion in Lat via and the up per most part of the Šventoji For ma tion in Lith u a nia (Tänavsuu-Milkeviciene et al, 2009;Lukševiès et al, 2012;Stinkulis et al, 2020). The suc cession is com posed of fine-grained sand stones, siltstones and claystones de pos ited in tide-dom i nated es tu ar ies (Pontén and Plink-Björklund, 2009;Lukševiès et al, 2012).…”

Sedimentary features and their controls in a mixed siliciclastic–carbonate system in a shallow lake area: An example from the BZ‐X block in the Huanghekou Sag, Bohai Bay Basin, Eastern China

“…Two essential types of mixed sediments have been widely proposed, which can be classified as compositional mixing and strata mixing (Chiarella et al, 2017;Mount, 1984;Yang & Sha, 1990). Correct identifications of these different types of mixing and the scale of their occurrence plays an important role in revealing the sedimentary processes and controlling factors of mixed sediment systems (Chiarella et al, 2017;Tänavsuu-Milkeviciene, Plink-Björklund, Kirsimäe, & Ainsaar, 2009). In this way, during the last few decades, an increasing number of studies have improved our understanding to the characterization of mixed sediments.…”