An Upper Triassic, Norian-Rhaetian, outlier in Skåne, southern Sweden

Abstract

A new outlier of Upper Triassic sedimentary strata has been found in a small fault bounded trough within geological domains dominated by Precambrian crys-talline rocks. It was discovered in connection with pre-investigations and exca-vation of a new railway tunnel through the Hallandsås Horst in the north-western part of Skåne. It consists of a 15 m thick succession of pre-Quaternary strata on top of the kaolinized crystalline basement. The lower 10 m consists of red clays, mudstones and sandstones, interpreted as belonging to the Norian Kågeröd For-mation. It is followed by fine and medium-grained, light grey and whitish, cross-bedded sandstones, clays, coals and rootlet beds belonging to the Rhaetian-Hettangian Höganäs Formation. Palynological investigations reveal a rich well preserved palynomorph assemblage of Rhaetian age for the upper part of the section which is interpreted to have been deposited in a brackish-freshwater en-vironment. The new locality together with other scattered outliers north-east of the Kullen-Ringsjön-Andrarum Fault Zone, represent the erosional remains of a pre-existing, much larger distribution of Upper Triassic strata in Skåne