"What we thought we knew was an incomplete body of information," said Fredrick Rich, a professor of geology in the department of geology and geography at Georgia Southern University. "Those terrestrial trees, shrubs and herbs didn't live out there all by themselves. I envision a small key, or maybe several small keys just like the islands in Florida Bay.
The study appears in the December 2010 edition of the bi-annual journal, which was distributed in January.
The sample of dark gray lignitic clay and limestone contained pollen from 17 different flowering plants, representing the earliest report of land vegetation to date. It was collected in 2004 by study co-author Curtis Klug, a hydrogeologist with Cardno Entrix, a Fort Myers-based natural resource management and environmental consulting company.
"As we're drilling through the rock and the cuttings come to the surface, we collect them, examine them, and determine the type of rock and its estimated age," Klug said. "As we were drilling, we did go through several lignites, but this was one of the thickest ones we found in this particular well."
The company was digging a 767-meter well for the Greater Pine Island Water Association, a company that uses reverse osmosis to produce drinking water. In this case, the well was used to dispose of excess saline brine, Klug said.
Lignite, also known as brown coal, is geologically younger than higher-grade coals and contains decomposed organic matter, largely plant material from wetlands. Along with the 17 land-based pollens, which included species of trees, palms and possibly ferns representing a climate similar to the panhandle today, the sample also contained at least four examples of marine phytoplankton. The presence of limestone and foraminiferas, single-celled organisms found in all marine environments, indicates the rise and fall of the area's sea level.'/>"/>
|Contact: David Jarzen|
University of Florida