Abstract

Palynology offers no support for placement of a system boundary at the base of the Gearyan Stage in Kansas. The Virgilian and Gearyan Stages of Kansas are, palynologically, so closely related that they must be considered together as a part of a fundamental chronologic unit (a system). Gearyan spores and pollen demonstrate no profound floral change from the underlying Virgilian. The culmination of monolete spore genera, the limited occurrence of bisaccate, striate forms and the continuance of numerous Pennsylvanian trilete spores are together taken as positive evidence of the Pennsylvanian age of the Virgilian and Gearyan collectively. The plant fossil Callipteris conferta is rejected as an infallible indicator of Permian time because it has been demonstrated that Callipteris bearing beds and associated strata of Kansas contain palynomorphs intimately related to Virgilian assemblages. Furthermore, both Callipteris conferta (Sternberg) and Callipteris nicklesi (Zeiller) have recently been reported from the Stephanian C (Assise d’Avaize) stratotype. There is, relative to the assemblages of the underlying strata, a pronounced numerical increase in bisaccate pollen in the Wymore Shale, Chase Group. This situation continues into the lowermost beds of the Cimarronian Stage. The numerical increase in pollen preserved in the sediments during this segment of earth history (Wymore Shale to basal Wellington Shale) is interpreted as representing floral response to environmental changes. The abundant pollen are considered to be harbingers of the explosive evolutionary outburst of the bisaccate, striate pollen types reported from younger strata and recognized as “typically” Permian. The “typically” Permian pollen genera are but feebly represented in the Gearyan of Kansas.