Palynology and paleoecology of the Middle Miocene Alum Bluff flora, Liberty County, Florida, USA

Abstract

A diverse assemblage of pollen, spores and fungal elements recovered from deltaic or pro-deltaic sediments of the Alum Bluff Group (Middle Miocene) in the panhandle of Florida, USA, represents the first Miocene systematic palynological study from the state. Forty-three taxa of fungal elements, pteridophyte spores, and pollen of gymnosperms and angiosperms are described. Earlier suggestions of a subtropical to tropical environment based on plant macrofossils is not supported due to the suggested botanical affinities of the pollen and spores. Rather, the botanical affinities of many of the identified palynomorphs suggest a warm temperate to temperate environment similar to that found in the area today. The Alum Bluff Group represents deltaic or pro-deltaic sediments deposited in a high energy depositional environment which supported a warm-temperate flora along a floodplain with elements reflecting the vegetation of the adjacent upland forests.

Keywords:

• pollen
• spores
• Miocene
• Florida
• paleoecology

Acknowledgements

The Nature Conservancy provided a permit for Corbett and others to collect fossil plants on their property. We thank Greg Seamon of The Nature Conservancy who arranged for access to the property; we acknowledge this support to Ms. Corbett. Appreciation is expressed to the Global Geolabs of Medicine Hat, Alberta, Canada, and Russ Harms who processed some of the samples for pollen analysis. We also thank S.A. Jarzen for her careful reading and editing of the manuscript. Carlos Jaramillo read the manuscript and provided critical improvements. We also extend our appreciation to James B. Riding, Editor of Palynology for his assistance and guidance.