Rhaetic to Lower Liassic palynology of the onshore south-eastern North Sea Basin

Abstract

Rhaetic to Lower Liassic microfloras of gymnospermpollen, microspores and aquatic palynomorphs from outcrops and cored wells in southern Scandinavia and NW Germany are investigated. 146 groups of palynomorphs, mainly species are presented from the Danish borehole Rødby 1. Based mostly on restudy of the holotypes 24 new combinations for species/varieties occurring in Rødby 1 are proposed. One new species , Corollina zwolinskai ranging from Lower to Middle Rhaetic is described.

The range of polynomorphs, mainly species are noted in the wells: Rødby 1, Maasbiüll 1 and Eitzendorf 8 and in a composite section from Scania. The following miospore zones are defined: The Corollina Enzonalasporites Zone (? Norian - Lower Rhaetic), the Ricciisporites Conbaculatisporites Zone (transition (Lower-) Middle Rhaetic), the Rhaetipollis Limbosporites Zone (Middle Rhaetic), the Riciisporites Polypodiisporites Zone (Upper Rhaetic), the Pinuspollenites Trachysporites Zone (Lias alfa 1-2) and an unnamed zone with Cerebropollenites macroverrucosus (Lias alfa 3 to beta to ?, upper boundary not defined). Within the Corollina Enzonalasporites Zone the following subzones are defined: The Corollina Porcellispora Subzone, the Granuloperculatipolis Subzone and above the Enzonalasporites Conbaculatisporites Subzone. The two latter subzones are probably restricted to the Lower Rhaetic. The zones and subzones are used to correlate the mainly non marine deposits of Rødby 1, Scania, Poland and E. Germany with the more marine deposits of NW Germanu.

In Scania the stratum typicum of the stratigraphically important species Limbosporites Lundbladi Nilsson is shown to be (Middle) Rhaetic. Unmixed Lepidopteris and Thaumatopteris macrofloras are of (Middle) Rhaetic and Lias alfa age, respectively.

In E Germany the topmost "Middle Keuper" sensu Schulz is transferred to the Lower Rhaetic.

In Poland the Drawno Beds are shown to be Lower Rhaetic and the Weilichowo Beds to be Middle (to Upper) Rhaetic.

Rødby 1 is correlated lithostratigraphically with wells in NW Germany mainly on basis of the clay colours (red and green in the Lower Rhaetic, dark grey in the Middle Rhaetic, brown to light greenish grey in the Upper Rhaetic and dark grey in the basal Liassic). The lithostratigraphy agrees closely with the palynostratigraphy in Rødby 1.