Lake George Prehistoric Underwater Survey

ARCOOP was recently awarded a small matching grant for $19,420 from the Florida Division of Historical Resources, Florida Department of State. With this grant and over $20,000 in matching money and in-kind services and equipment, ARCOOP will conduct a 10-day remote sensing survey of Lake George to find the paleo-St. Johns River channel and identify likely Paleoindian-age landforms that would have been conducive for occupation and examine the mouths of Salt Creek and Silver Glen Spring. A map of our proposed survey tracks is here: Lake George Survey Map

We plan to conduct the survey in December 2017-January 2018

A more detailed description of the project follows:

At the end of the last Ice Age and well into the modern Holocene epoch, Lake George on the St. Johns River was a wide bowl-shaped plain with the paleo-St. Johns and its tributaries running through it. We know the paleolandscape was used by Paleoindians and Archaic people but we want to know what the now flooded looked like and how people exploited it (Thulman 2012). By 6000 years ago the river started rising but the rate and magnitude are unknown. We expect that any archaeological deposits would have been covered and preserved with slowly accumulating sediments as waters rose. These are ideal conditions for preserving submerged prehistoric sites. Other than minor dredging and a WWII-era bombing range in the SE quadrant, the submerged sediments appear relatively undisturbed and available for remote sensing.

We will survey portions of Lake George to (1) better define the paleo-channel of the River and identify tributary channels, (2) map selected areas of the bottom to better define the submerged paleolandscapes surrounding the Paleoindian-age Georgetown Point Site (8PU1470), a large shell mound at the mouth of Silver Glen Run (8LA1-East), and the mouth of Salt Spring Run, and (3) identify potential targets for additional testing by coring, or underwater excavation. Florida’s submerged archaeological record is renowned and provides insights into prehistoric behaviors and material culture that are not available elsewhere (e.g., Webb 2006; Doran 2002).  On the other hand, it is under constant threat from artifact collectors. Lake George is one of the largest, last repositories of undisturbed submerged freshwater prehistoric archaeological sites in Florida; its potential is enormous.

Lake George is the largest lake in the St. Johns River. Bathymetric maps (low quality soundings for fishermen) indicate the lake is 3-4 m (10-12 ft) deep with low slope bottom topography. The paleo-river channel is not apparent in the available bathymetry and is likely buried in Holocene sediments. Peat deposits in the northern part of the lake may preserve organic artifacts, and shell middens, small mounds, rock outcrops, and other sites are likely preserved beneath the bottom. The tannic lake is tidally influenced and the flow sluggish, reducing visibility and making a traditional visual underwater survey with divers impractical.

These factors have largely kept artifact collectors away from deeper parts of the lake, but with the recent FWC crackdown, collectors will be looking for new areas in remote places to exploit. Lake George is under threat. Several years ago, 8PU1470, on the eastern shore of the Lake, was completely collected, destroying perhaps the largest Paleoindian site in Florida (Thulman 2012).

Important sites from later time periods are found on the Lake margins, and this Project could place those sites in better context. On the west side at the mouth of Silver Glen Run, 8LA1-East was investigated for several years as part of a field school sponsored by the University of Florida (Sassaman et al. 2011). The sites on the Run enhance our understanding of the transition from pre-ceramic Mt. Taylor to ceramic period occupations. To the north, excavations in Salt Spring Run (8MR2322) produced similar insights. The effects of water table rise on spring flows and the location of the St. Johns channel in relation to these sites are not understood at this time and could be clarified by the Project.

Major Project Components

The Project is a 10-day remote sensing survey using a side scan sonar and sub-bottom profiler towed by a pontoon boat. Day 1 will define the paleo-river channel and its tributaries with east-west and north-south transects (Fig. 1). Days 2-10 will map the bottom in higher-potential areas, starting near 8PU1470 and the mouth of the spring runs. Mapping loci are subject to change depending on data generated during the work. We will find and follow the paleo-runs to the paleo-river channel, because we believe they would have been preferred site locations in all periods. At Silver Glen and Salt Spring runs we will run transects offshore and search for paleolandscape features to put the associated sites in better context.

Use of the equipment will be donated. SEARCH, Inc. will provide remote sensing equipment and geoarchaeological consultant; Michael Faught. Faught will provide computer processing equipment.

The grant funds will be used to pay for boat fuel, transportation to and from the site, meals, and wages for the field crew of 2-3. Grant and match funds will be used for post-processing data and report preparation.

The Project will produce:

  1. A partial bathymetric and side-scan map of the northern portion of the lake and mouths of the runs, and the probable north-south track of the paleo-channel and tributaries.
  2. Detailed maps of the bottom offshore of the mouth of runs and 8PU1470.
  3. Sub-bottom data and interpretation of the areas covered in #1-2.
  4. Detailed report describing the Project, presenting the results, describing the maps and procedures, and identifying potential archaeological targets may warrant further archaeological investigation.

References
Doran, Glenn H.
2002  Windover : Multidisciplinary Investigations of an Early Archaic Florida Cemetery. University Press of Florida, Gainesville.

Sassaman, Kenneth E., Zackary I. Gilmore, and Asa R. Randall
2011  ST. Johns Archaeological Field School 2007-2010:Silver Glen Run (8LA1). Technical Report 12, Laboratory of Southeastern Archaeology, Department of Anthropology, University of Florida, Gainesville.

Thulman, David K.
2012  Discriminating Paleoindian point types from Florida using landmark geometric morphometrics. Journal of Archaeological Science 39(5): 1599 – 1607.

Webb, S. David
2006  First Floridians and Last Mastodons: The Page-Ladson Site in the Aucilla River. Springer, Dordrecht, The Netherlands.