Sequence stratigraphy of the Baltic Silurian succession: tectonic control on the foreland infill

Abstract

The Baltic basin overlaps the SW margin of the East European Craton (EEC). During the Silurian its subsidence was governed by the flexural bending of the EEC margin due to the collision of Eastern Avalonia and Baltica. Two mechanisms -orogenesis and dynamic loading -were responsible for the flexural subsidence of the basin. Lithofacies, sequence-and cyclo-stratigraphic analysis were applied to reveal the tectonosedimentary evolution of the Silurian Baltic Basin, focusing on the imprint of geodynamic processes in adjacent orogens on the sedimentary architecture. Adopting a sequence stratigraphic approach, 10 depositional sequences superimposed by the lower rank cycles were identified in the Silurian Baltic Basin. The Llandovely sequences correspond with the initial stage of flexuring. The low terrigenous influx to the basin is explained by the lack of relief in the fold belt and its location at a distance from the orogenic front. The Wenlock-Lower Ludlow sequences reflect the accelerating flexuring. An increase in orogenic-sourced terrigenous material indicates the advancement of the Caledonian orogen. The Late Ludlow Pridoli sequences comprise the final stages of flexuring and basin infilling. Two major provenancescratonic and orogenic -competed to supply terrigenous sediment to the basin during Silurian times.

Upper Homerian (Silurian) high-resolution correlation using cyclostratigraphy: an example from western Lithuania

“…Moreover, the Silurian Baltic Basin experienced a long-term (second order) trend of progressive shallowing during the Silurian. In Lithuania the lateral boundaries of facies, therefore, migrated to the west (Lazauskienė et al 2003). In all investigated boreholes the upper part of the Riga Formation with the Ančia Member was recognized.…”

The Silurian of south-western margin of the East European Platform (Ukraine, Moldova and Romania): lithofacies and palaeoenvironments

“…Nikiforova et al (1972) de scribed reef --build ing or gan isms as well as bioherms within the en tire succes sion in nu mer ous out crops of Si lu rian shal low-wa ter shelf de pos its of Podillya. An other ev i dence of fa vour able cli ma tic en vi ron ments is a per ma nent ex is tence of reefs in sec tions of West ern Lith u a nia (Lazauskiene et al, 2003;Zdana viciute and Lazauskiene, 2007) in the time range from Late Wen lock to Early Pridoli.…”

“…Lithological sec tions al lowed com pos ing a map of Si lu rian oc cur rence with isopachs and fa cies dis tri bution. Cor re la tion of the data on west ern Ukraine with ad ja cent areas of Si lu rian oc cur rence, in volv ing those from Moldova and Ro ma nia (Lodan, 1999;Olaru et al, 2006;Olaru and Þabãrã, 2011;Tari et al, 2014) as well as Po land, Lith u a nia, Lat via and Es to nia (Nestor and Einasto, 1977;Einasto et al, 1986;Lazauskiene, 2003;Porêbska et al, 2004;Zdanaviciute and Lazauskiene, 2007;Ver ni ers et al, 2008;Poprawa and Kiersnowski, 2008;Skompski et al, 2008;£uczy ñski et al, 2009;Poprawa, 2010;Kaljo et al, 2012;Tari et al, 2012;Podhalañska, 2013;Porêbski et al, 2013;Jarochowska and Koz³owski, 2014) allowed elu ci dat ing the oc cur rence of these strata, their thick ness and petrographic com po si tion over the vast ter ri tory within the south west ern mar gin of the East Eu ro pean Plat form, and ob taining the in te gral char ac ter is tics of depositional en vi ron ments in the Si lu rian of the study area. This was a base for palaeoceanographic re con struc tion and elu ci da tion of dif fer ent types of sed i ments and fa cies dis tri bu tion within the south ern palaeoshelf of Baltica.…”

Unconventional Gas Resources in the Paleozoic of Central Europe

“…In the Danish-Polish Trough organic-rich sediments can be more than 200 m thick and are proven source rocks for oils in the Baltic region. In general, depth and maturity of the sedimentary organic matter increase from the northeastern part of the Baltic Syneclise towards the Teisseyre-Tornquist Zone (Lazauskiene et al, 2003;Lazauskiene, 2004, 2007). These features reflect the development of the Baltic Basin as a passive-margin basin during the latest Precambrian to Middle Ordovician (Poprawa et al, 1999).…”

“…The change from a passive to convergent margin setting is recorded by the gradually increasing subsidence which took place during the Late Ordovician-Early Silurian towards the southwest of the basin Correlation of porosity (%) and permeability (mDarcy) of the facies types Dry Aeolian and Damp Aeolian based on 583 datasets from wells a) and for sandstones with important diagenetic types b); IM is flakey illite, CR/CS is radial chlorite/subparallel chlorite, H/CT is tangential chlorite/ hematite (modified after Gaupp et al, 2005). (Lazauskiene et al, 2003). While it is not clear yet whether its black shales of Llandovery age represent economically viable shale gas systems, Poland is certainly the focus of the most intense exploration activities for shale gas in Europe at the time of writing (Durham, 2010) and first wells have been drilled by now.…”