Lithofacies and palaeoenvironmental interpretation of the Early Jurassic Höör Sandstone, Southern Sweden

Abstract

Sedimentological analysis of the Early Jurassic Höör Sandstone in Central Scania, Sweden shows that two units representing different lithofacies may be distinguished. The lower Stanstorp Member is characterised by texturally and mineralogically heterogeneous sediments. Mature arenites and immature quartz and subarkosic wackes form two clearly separated groups, interpreted as fluvial channel and alluvial plain deposits respectively. The fluvial character of this member is supported by a dominance of unidirectionally oriented trough sets, abundant plant detritus, the presence of plant roots and palaeosols and a lack of marine body fossils and trace fossils. An intercalated composite polymict conglomerate layer is interpreted as the result of an extraordinary flood. The overlying Vittseröd Member is characterised by mature quartz arenites and large-scale tabular sets with multidirectional orientations. The Vittseröd Member arenites are of storm- and possibly tide-dominated shoreface origin. Bidirectional wave and tide-induced longshore currents and unidirectional onshore migration of sand ridges were the chief depositional processes. Longshore currents towards the NNW prevailed. Upper flow regime features, and erosion and reworking of sediments are attributed to the storm-induced rip currents. Lithofacies characteristics are used to define the following lithostratigraphical units: the Stanstorp and the Vittseröd members, as well as the Höör Sandstone (Fm) above. Lithofacies and palaeoenvironmental characteristics of the Vittseröd Member and their comparison with the facies of the Helsingborg and Döshult members in Western Scania suggest a Sinemurian age for the Vittseröd Member.