Lake Verona’s 33,000-Year Radiocarbon Date
A persistent assertion in Avon Park local history and geographical guides states that Lake Verona is over 33,000 years old, frequently cited without a specific academic reference.[maxwell-1976] Research into the palynological and radiocarbon literature confirms that this date is an authentic, laboratory-verified scientific measurement derived from a deep sediment core collected directly from Lake Verona.[steventon-1986]
The Core Sample and Laboratory Analysis
In April 1985, Dr. Herbert E. Wright Jr. of the University of Minnesota Limnological Research Center collected a sediment core from Lake Verona in Highlands County (27° 36’ N, 81° 30’ W) during regional investigations of Lake Wales Ridge paleoclimate and vegetation history.[steventon-1986]
The core was submitted for dating to the University of Wisconsin Radiocarbon Laboratory, directed by Raymond L. Steventon and John E. Kutzbach.[steventon-1986] An organic gyttja sediment sample extracted from a core depth of 29.64 to 29.74 meters (2964–2974 cm) beneath the water surface yielded a radiocarbon age of:
>33,000 yr BP (Laboratory ID: WIS-1744)
The result was formally published in the journal Radiocarbon in 1986 (University of Wisconsin Radiocarbon Dates XXIII, Vol. 28, No. 3, pp. 1206–1223).[steventon-1986] The notation >33,000 yr BP represents the minimum age threshold detectable under the beta-decay radiocarbon counting parameters used for that sample run, establishing that continuous organic sediment accumulation at the 29.7-meter core horizon began during or prior to Marine Isotope Stage 3 (MIS 3) of the late Pleistocene.[steventon-1986]
Relationship to Lake Tulane and Ridge Paleolimnology
Because nearby Lake Tulane (located less than two miles south in Avon Park) is famous among paleoclimatologists for its continuous 60,000-year pollen record of North Atlantic Heinrich events, some secondary accounts assumed the 33,000-year figure was merely a garbled reference to Tulane.[grimm-heinrich]
The radiocarbon record proves that Lake Verona was sampled independently:
- Two Independent Sites: Both Lake Verona (WIS-1744, >33,000 yr BP at 29.7 m) and Lake Tulane (>50,000–60,000 yr BP) were cored as part of systematic research into Florida ridge solution basins.[steventon-1986][grimm-heinrich]
- Deep Basin Morphology: Lake Verona is not a shallow pond; it is a steep-sided karst sinkhole reaching depths of 60 to 80 feet (18 to 24 meters) in its central depression, allowing continuous lacustrine sedimentation without subaerial desiccation during glacial low-water periods.[swfwmd-verona-mfl]
- Basal Longevity: The age measurement confirms that Lake Verona existed as an active lacustrine sinkhole basin well before the Last Glacial Maximum (ca. 20,000 years BP), preserving an intact environmental record of the pre-settlement Lake Wales Ridge.[steventon-1986]
References
- steventon-1986 — Raymond L. Steventon and John E. Kutzbach. University of Wisconsin Radiocarbon Dates XXIII. 1986. https://doi.org/10.1017/S003382220002047X
- grimm-heinrich — Quaternary Science Reviews. Evidence for warm wet Heinrich events in Florida. 2006. https://www.sciencedirect.com/science/article/abs/pii/S027737910600165X
- swfwmd-verona-mfl — Southwest Florida Water Management District. Lake Verona Minimum Flows and Levels Information and Bathymetry. 2020. https://www.swfwmd.state.fl.us/projects/mfl/lake-verona
- maxwell-1976 — Leoma Bradshaw Maxwell. The First Hundred Years of Avon Park, Florida: 1870–1976. 1976. the-first-hundred-years-of-avon-park_leoma-bradshaw-maxwell_1976.md
Related
- Entity: Lake Verona
- Entity: Lake Tulane
- Report: Lake Wales Ridge Geology and Frost Drainage
- Report: Indigenous Presence on the Lake Wales Ridge
Where this comes from
- Evidence
- corroborated — More than one independent source agrees.
- Review
- unverified — Drafted from sources but not yet checked by a volunteer.
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Sources
- Raymond L. Steventon and John E. Kutzbach, University of Wisconsin Radiocarbon Dates XXIII (1986)
- Quaternary Science Reviews, Evidence for warm wet Heinrich events in Florida (2006)
- Southwest Florida Water Management District, Lake Verona Minimum Flows and Levels Information and Bathymetry (2020)
- Leoma Bradshaw Maxwell, The First Hundred Years of Avon Park, Florida: 1870–1976 (bundle/references/the-first-hundred-years-of-avon-park_leoma-bradshaw-maxwell_1976.md) (1976)
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