Open AccessPalynological zonation and stratigraphy of the Jurassic section in the Gassum No. 1-borehole, Denmark
Author(s) -
Karen Dybkjær
Publication year - 1988
Language(s) - English
Resource type - Journals
eISSN - 2597-2979
pISSN - 1395-3842
DOI - 10.34194/seriea.v21.7040
Subject(s) - palynology , geology , gymnosperm , paleontology , stratigraphy , biostratigraphy , microspore , borehole , acritarch , pollen , taxon , section (typography) , tectonics , ecology , stamen , advertising , business , biology
The Jurassic section of the Danish onshore borehole Gassum No. 1 has been investigated palynologically. 126 palynomorph-taxa have been recognized, consisting mainly of microspores and gymnosperm pollen. The palynomorphs are treated morphosystematically. 71 samples were prepared and the relative abundances determined in 32 representative samples. 5 spore- pollen zones, A to E, have been defined based on the stratigraphical ranges and abundances of specific taxa. Correlating with data from Northwest Europe allows the zones to be dated as follows: Zone A: Late Rhaetian, Zone B: Hettangian, Zone C: Early Sinemurian to ?Pliensbachian/foarcian, Zone D: Kimmeridgian/ Early Volgian, Zone E: Middle Volgian. The relative abundances of the main morphological groups of palynomorphs have been calculated and their stratigraphical variations correlated with previously proposed Early Jurassic sea-level changes.