Nature and Paleogeography of Middle Permian Floras of Oklahoma as Inferred from Their Pollen Record

Abstract

Pollen and spores have been recovered from the topmost 10-35 feet of the Flowerpot formation (lower Guadalupian) over most of its outcrop in Oklahoma. Of seventy-one species of palynomorphs recognized, forty-six are pollenites and twenty-five are sporites (sensu Potonié and Kremp 1954). The distribution of these taxa gives an indication both of the distribution of the contributing floras and their composition. Two distinct assemblages are found. One is the normal upper Permian assemblage dominated by Lueckisporites virkkiae; it is found at several levels and in most samples. The other assemblage is rich in cryptogamic spores, both trilete and monolete, and is found in a single dark horizon which can be followed over a great distance in both the north central and southwest portions of the state. The former is probably derived from the flora inhabiting the uplands; the latter seems to represent a salt-marsh or swamp flora which developed as the result of a widespread but rather minor regression. A cluster analysis (ramifying linkage) was performed on the generic counts to determine the probable composition of the plant communities. The upland flora consisted of conifers producing bisaccate pollen, and existed continuously over the broad upland surface. The lowland flora, on the other hand, was dominated by gymnosperms of several types but also included a significant proportion of cryptogams. It was restricted to sea margin, floodplain, and other local wet environments during periods of transgression but expanded during periods of regression to contribute a significant portion of the total spore assemblage.