Precambrian Research 145 (2006) 243–271 Depositional environments at a Palaeoproterozoic continental margin, V¨ astervik Basin, SE Sweden Lena Sultan a,b,∗ , Piret Plink-Bj ¨ orklund a a Department of Geology, Earth Sciences Centre, G¨ oteborg University, Box 460, SE-40530 Gothenburg, Sweden b Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-10405 Stockholm, Sweden Received 7 March 2005; received in revised form 13 December 2005; accepted 20 December 2005 Abstract This study documents: (1) the sedimentary environments and depositional processes and (2) the temporal and spatial relation- ships of sedimentary environments within well-preserved areas in the Palaeoproterozoic V¨ astervik metamorphic siliciclastics in southeastern Sweden. Based on lateral and vertical facies transitions, seven facies associations were documented: fluvial deposits (Facies Association 1), tidal flat deposits (FA 2), tidal channel deposits (FA 3), upper-flow-regime tidal flat deposits (FA 4), tidal bar deposits (FA 5), shoreface deposits (FA 6) and turbidite deposits (FA 7). The documented facies associations reflect deposition on a Palaeoproterozoic continental margin, where rivers drained the continent to the present north/northwest and carried sediment southeastwards. The rivers became tidally influenced further seawards. Sediments accumulated in tide-dominated estuaries, river-dominated deltas and in wave-dominated shallow-water environments. The documented tide-dominated estuary suggests that the coastline at least during some periods was macrotidal (>4 m). The metasediments of the V¨ astervik succession are locally strongly altered by tectonic deformation and metamorphism, and detailed vertical and lateral correlation was possible only in restricted separate areas. Vertical facies transitions show transgressive to regressive deposition in two of the in detail studied areas as indicated by the vertical change from riverine to a shallow marine and back to river deposition in Area 1. In Area 3 the transition occurs from river-dominated deltas into tide-dominated estuaries, succeeded above by river deposition. In the two remaining areas the deposition was overall transgressive as river deposits are succeeded above by deltaic turbidites. Despite the somewhat “fragmentized” character of the V¨ astervik succession this work enabled to recognize general character of the V¨ astervik Palaeoproterozoic continental margin. © 2006 Elsevier B.V. All rights reserved. Keywords: Palaeoproterozoic; Tidal deposits; Tide-dominated estuary; Transgressive; Regressive 1. Introduction This paper reports the first detailed and systematic sedimentologic outcrop study of the Svecofennian ∗ Corresponding author. Tel.: +46 31 773 28 00; fax: +46 31 773 28 49. E-mail address: lena@gvc.gu.se (L. Sultan). V¨ astervik metamorphic siliciclastics in the Baltic Shield (Fig. 1) demonstrating that it is possible to do sedimentological analyses in tectonic and metamorphic areas. The Palaeoproterozoic V¨ astervik Basin has long been known for locally well-preserved primary sedimentary structures and geometries (H¨ ogbom et al., 1910; Gavelin and Russell, 1967; Russell, 1967; Gavelin, 1984). Vertical and lateral facies transitions can be documented within the restricted well-preserved 0301-9268/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2005.12.005