Old Vero Ice Age Sites Committee
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P.O. Box 351, Vero Beach, FL 32961   

 

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Wednesday, October 18th, 2017

Core Sampling Update Jan 2013

A Report from Dr. Andy Hemmings

There are several goals of our core analysis beyond their immediate utility in the field to cursorily examine them to identify the gross stratigraphic sequences across the site.  Specifically, this means finding the Pamlico sands (roughly 100,000 years old) to the west, the Van Valkenberg over Melbourne (of unknown Holocene into the Pleistocene age- TBD!), and the Silver Bluff Dune (circa 35,000 years old) to the east- all overlaying the Anastasia Formation.  We did our initial assessment after taking these cores by combining the data and notes from previous core samples and excavations, discussion with everyone that has seen stratified exposures at the Vero site, and our hands on discussions of the material in the core segments as they were extracted.  

Data from the cores will partly direct us where to dig, and help us understand the many disturbances to the site, and locate where “packets” of intact sediment layers can be found in all of the tested areas. Core data will help us define the boundaries of the site, especially at the farthest margins as excavation will likely only occur closer to the ponded/stream basin in the foreseeable future. They will also aid us in creating the most comprehensive geologic framework to date based on Sellards’ and later Weigel’s soil sequences. These sequences were not used in their strictest sense in the recent past, so we should eventually get a more complete and correct understanding of what Sellards originally described and Weigel elaborated.  This information can be used along with the recently discovered provenience data written on FLMNH VP specimen cards from the original excavation to reconstruct both the site history up to the original excavation and conduct much better distributional analysis of all of the materials collected at the site by Sellards and Weigel.

Barbara Purdy has generously offered to let me take the first twelve cores to Mercyhurst along with ours. I would like to make this trip in the first half of January if feasible.  Ideally I will collect equipment for the excavation and not return with an empty vehicle.  Once all 35 cores can be set out and discussed Jim Adovasio, Frank Vento, and myself, will essentially triage the cores in order of our most pressing interests, namely proximity to where we think excavation will be most productive.  The first priority is the SW corner of the main canal and lateral E near core 3.  The area on either side of the pit near the railroad tracks on the north side will be the second one to examine. 

Additionally, proper geological and chemical description of the cross site geologic sequences will be of paramount importance as work progresses beyond the initial fieldwork.  Modern description of all three sequences, and any potential new ones, will greatly aid in our understanding of the formation of the Pleistocene basin that was scoured prior to 30,000 years ago, then filled with pond sediments through the end of the Pleistocene, and that were eventually cut by numerous creeks that were undisturbed until 1913.  Further, as/if we are able to directly assign radiocarbon dated ages to the various stratigraphic units we will be able to answer many of the questions that have plagued the site for a century now.

Frank Vento of Clarion University will head the analysis of the sediment cores. He has worked recently on St. Catherines Island, Ga., north of Amelia Island. This work with David H Thomas and others through the AMNH involved looking at barrier islands and buried sediments spanning much of the last 22,000 years.  This period covers almost exactly the time frame of interest to us at Vero from a similar geological setting on the east coast from a few hundred miles away.  We really could not ask for a better comparative situation and analyst. Geomorphological and geoarchaeological investigations on St Catherines Island. http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/6105/A094%20Title%20page,%20table%20of%20contents%20etc..pdf?sequence=3

Dr. Vento and his students will do the analysis. They will begin with the 12 most potentially useful core pieces from a group of likely around 70 from the 35 cores (the ‘fill’ cores will be examined but there is no reason to analysis them in the same fashion as the intact sediment cores). There will be some almost immediate information for us once they begin, but to complete them will take probably all semester at least.  Until we can prioritize the cores it is very difficult to determine how long the work will take.  In any case, we will hear from them as they go along and they have any useful information to give us.

                                                

 

 

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