Late Triassic and Early Jurassic palynology of the Höganäs Basin and the Ängelholm Trough, NW Scania, Sweden

Abstract: A palynological study has been conducted on Late Triassic and Early Jurassic outcrop- and borehole sections of the Höganäs and Rya formations, NW Scania. The diverse and generally well preserved palynomorph assemblages can be divided into three miospore zones: (1) the latest Rhaetian-?Hettangian Transitional interval; (2) the Hettangian Pinuspollenites-Trachysporites Zone; and (3) the Sinemurian Cerebropollenites macroverrucosus Zone. Uppermost Rhaetian palynomorph assemblages have previously been considered to be absent in Scania, but are recovered from two borehole sections. All assemblages represent on-shore floras affected by occasional marine influences. The presence of well-preserved palynomorphs in nearly all assemblages indicate minimal transport during dispersal and deposition. The relatively high spore/pollen ratios suggest that deposition took place in close proximity to the parent flora. A transition in the flora at the boundary between the Triassic and Jurassic is demonstrated by the high abundance of fern spores and bryophytes in the uppermost Rhaetian assemblages, in contrast to the more frequently occurring conifer pollen in the Hettangian and Sinemurian. The assemblages are similar in composition to others deposited in paralic environments in Denmark and Scania, but differ from more distally settled ones in the Danish Basin.