The Early Man Site at Warm Mineral Springs,Florida

Abstract

An excavation in stratified sediment more than 13 m. below the present surface of Warm Mineral Springs in Florida has yielded human remains 10,000 years old. Samples of wood from the same level of sediment in the spring in which a human vertebra was discovered provided a radiocarbon date of 10,260 ± 190 years: 8310 B.C. (Gak-3998). Wood samples from the next two superior 0.10 m levels of the test also yielded dates in excess of 10,000 radiocarbon years. A second human bone, a fragmentary ilium, was recovered a few centimeters outside the excavation in the sedimentary zone. These specimens may represent the earliest closely dated human skeletal remains so far discovered in North America.

Results of a geological study are in agreement with the archeological information. Radiocarbon dates on selected charcoal samples are only slightly younger than those reported above. The stratified deposit containing the human remains accumulated on a ledge between 10 m. and 12 m. below present sea level as a series of leaf deposits interbedded with calcitic muds containing fresh-water and land snail fauna. This lower leafy bed represents a stage of fluctuating water level in an open cenote. An overlying calcitic mud with only minor amounts of terrestrial plant debris represents a higher stand of the water table in the cenote. An upper algal sludge layer represents subsequent conditions of a flowing connate spring.

It is evident that the rising potentiometric water level in this large feature correlates with the post-Wisconsin eustatic rise in sea level. The fluctuations suggested by the lowest bed containing the human remains probably indicate variation in amount of precipitation. However, even the calcitic mud and tufa encrustations and formations that formed at the highest stand of water within this event are indicative of a climate considerably more arid than now existing.

Summary geological and archeological data acquired at two other similar solution features in Florida, Little Salt Spring (8 So 18) and Devil's Den (8 Lv 44), where unarticulated human skeletal material and artifacts dating from the late Paleo and A rchaic periods have been found, are included to extend and strengthen the interpretation of the geological sequence and the theory advanced that these sites were primarily utilized as water sources during periods when surface water on the peninsula was less available. There is no evidence that the sinkholes were utilized for habitation or sites of primary burials as has been suggested.

The recovery effort marks the first successful adaptation of standard archeological techniques to the excavation of a submerged prehistoric site.