PALYNOLOGY AND PALEOECOLOGY OF A
 LIGNITIC PEAT FROM TRAIL RIDGE, FLORIDA

 by
 Frederick J. Rich

 INTRODUCTION

 An extensive bed of lignitic peat lies beneath the sands of Trail Ridge, in
Bradford and Clay counties, Florida (figure 1). The organic sediment is
commonly very woody and is associated with tree trunks, stumps, and limbs.
It is usually encountered during sand dredging at the E. I. du Pont de Nemours
and Company Trail Ridge Mine, where the organic layer underlies heavy-mineral
bearing sands.
 Early in 1979, the Florida Bureau of Geology, in cooperation with du Pont
was able to take two cores of dark brown, lignitic sediment from Sections 30
and 31, T 7 S, R 23 E of the Starke, Florida, quadrangle (figure 2). This paper
is a report on the palynological composition of the sediment, and presents a
discussion of the relationship between the organic sediments and the origin and
age of Trail Ridge.

 LOCATION AND CHARACTERISTICS OF TRAIL RIDGE

 Trail Ridge is a linear sand body which lies on the Atlantic Coastal Plain of
Georgia and northern Florida. It extends from a position near the Altamaha
River in Georgia to a point 209 kilometers south in Bradford and-Clay counties,
Florida (figure 1). According to Pirkle (1984) the ridge ranges from about 43nm
(meters) to a little more than 52 m above sea level in Georgia, and lies between
51 m and about 76 m above sea level in Florida. The ridge is composed
primarily of loose to slightly indurated quartz sand which, in some places, may
have three percent heavy minerals. Important ore minerals include ilmenite,
leucoxene, rutile, and zircon. In addition, tourmaline, kyanite, staurolite"and
other minerals are present (Pirkle, et al., 1977).
 The-origin-of Trail Ridge has been a matter of debate for many years.
Doering (1960) and Alt (1974), for example, envision the ridge as having been a
spit which built southward from Georgia into Florida during some ancient
period of marine transgression. White (1970) and Pirkle (1972), on the other
hand, consider the ridge to have formed as a beach ridge along the shore line of
the coastal plain at the height of a marine transgression. The favored theory
seems to be the beach ridge hypothesis advanced by Pirkle and Yoho (1970) and
refined by Pirkle (1972), Pirkle (1977) and Pirkle, et al. (1977). According to

The author is presently at the Department of Geology and Geological Engineer-
ing, South Dakota School of Mines and Technology, Rapid City, SD 57701.