Ultra-High-Resolution Palynostratigraphy of the Early Bajocian Sauzei and Humphriesianum Zones (Middle Jurassic) from Outcrop Sections in the Upper Rhine Area, Southwest Germany

Abstract

Abstract Marine and terrestrial palynomorphs of the Middle Jurassic, Early Bajocian are documented from three outcrop sections in the Upper Rhine area, southwest Germany. The studied part of the sections corresponds to the Early Bajocian Sauzei and Humphriesianum zones and is independently age dated down to ammonite subzone level. Palynomorph assemblages are quantitatively studied and detailed data are provided. The palynomorph assemblages are discussed and a succession of dinoflagellate cyst stratigraphical events is proposed. The dinoflagellate cyst assemblages are characterized by many first occurrences of known taxa and many new taxa left in open nomenclature. Most of them belong to the family of the Gonyaulacaceae that typically shows very fast evolution at this time. The findings are compared to coeval assemblages from Europe and Australasia. The study provides detailed data on the dinoflagellate cyst succession in a poorly studied time interval at a much finer scale than previously known. It will add valuable information to improve Middle Jurassic palynostratigraphical schemes.