Pirkle (1984), "... those hypotheses explaining Trail Ridge as a beach ridge
deposited in a wind-wave environment are more consistent with the features of
Trail Ridge sediments than are those hypotheses that explain Trail Ridge as a
spit developed in an environment dominated by current action."
 While the origin of the sand which comprises the ridge may be debatable, it
seems most likely that the sand was reworked from high terraces of the Northern
Highlands, which lies west of Trail Ridge. Reworking occurred as transgressing
seas eroded into the ancient terrace deposits (Pirkle, et al., 1977).

 NATURE AND ORIGIN OF THE TRAIL RIDGE PEAT DEPOSIT

 The organic sediment beneath Trail Ridge has been described as a peat
 (Pirkle and Yoho, 1970), though its petrographic appearance and chemical
 composition are more suggestive of brown coal or lignite. Rich, et al., (1978)
 note that the state of alteration of the sediment is "... similar to some lignites
 from the Gulf Coast Region ... ", and that because of the unusual nature of the
 peat, ... it is viewed as representing an important intermediate stage in the
 alteration of organic materials from peat to brown coal or lignite."
 The sediments examined in this study ranged from brownish-black, dense,
 indurated material to unconsolidated peaty sand. Some core intervals consisted
 of solid plugs of wood (J. Yeakel, personal communication).
 If one examines the elevation of the upper surface of the woody layer, as
 located by coring in the vicinity of Starke, Florida, it may be seen that the
 sediment forms a fairly continuous bed beneath that part of the ridge. Un-
 published data acquired by E. 1. du Pont de Nemours and Company show that
 though the peat surface is irregular, it is remarkably level. Where the peat does
 not exist elsewhere on the ridge, the stratigraphic interval within which it would
 be expected to occur (15 to 18 m depth) is occupied by drab to olive-green clays
 which appear to represent a weathered horizon (Pirkle, et al., 1977). Both peat
 and weathered clay seem to have developed at the same time and occupied the
 land surface atop older, sandy sediments associated with the Northern
 Highlands.
 Preliminary palynological investigation by Rich, et al. (1978) and Rich
 ( 982) show that the peat deposit near Starke was produced by freshwater trees,
 shrubs, and a variety of herbaceous species. Upright trunks found at the top of
 the peat layer indicate that the swamp was buried in place as marine trans-
 gression occurred, and the sands of Trail Ridge began to accumulate (Pirkle,
 et al., 1977).

 SAMPLE PREPARATION AND ANALYSIS

 Samples were taken from two core holes, designated TR 1 and TR 2. The
 cores were taken about 1.5 km apart (figure 2) and, because the organic sediment