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Slave Canal mound investigations


Often as I work in the FLMNH Southwest Florida Project computer lab, Dr. Jerald Milanich gaits through and surprises me with a few humorous words of gold advice. When he did so back in April 1995, he really caught my interest. It seems there were several aboriginal mounds close to the Aucilla River which, while of interest to the ARPP, were "too young or dry" for its regular research program. The Project and its supporters were interested in having someone check the mounds out. Milanich's own surface collection at some of these sites had turned up oyster shell, about 6 miles from the coast! Could these sites have been closer to the Gulf in the past, possibly during a period of higher-than-present sea-levels? I quickly responded that, since I was planning to conduct an archaeological survey in May and June, I could probably find time and wherewithal to slog out there in July or August.

Little did I realize what a treat lay in store. After speaking with Dr. Webb, I traveled with Mark Moons (the good), Dan Palt (the bad, veteran of May's survey or "The Brazilian Pepper Nightmare"), and Andy Hemmings (the ugly), to the ARPP facilities. I was warmly greeted by Jack Simpson, after which I proceeded to jump off the dock and break an eardrum on the water's surface. A freak accident? No, Andy was not involved. That night I learned the true value of a great project support team - Dr. Hoyt Home, thank you again. Nevertheless, the next day revealed "wonderful things"

Traveling north up the Slave Canal (itself a historic and archaeological treasure) we stopped and conducted surface collections at four sites. The first two were lithic scatters in the canal and on the stream Robert Patton banks, where a slight rise was noted - most likely a natural levee with cultural deposits on it. The third site was a collection of historic structures and features, including what appeared to be at least one small building and three small (3') circular stone enclosures. Some pieces of metal that appear to be barrel-hoops suggested that the enclosures were used for storage. Ceramic whiteware sherds found nearby date to about 100 years ago.

The fourth site we came to was the place we had come to see. A small slough running from the Southeast joined the Slave Canal stream on its east bank. To the north of this small slough and up the eastern bank of the Slave Canal was a crescent-shaped ridge about 6 feet high and 200 feet long. The ridge was wide enough to taper gradually into a distant stream-terrace, about 100-150 feet from the running water. It was widest at the confluence of the slough and stream, with most of its thickness to the east of that point. Our surface collection that day included several chert flakes, potsherds, and a few oyster shells, just as Milanich had described. Even though Jack said that a larger mound was farther upstream, I knew that this site could answer the relevant questions; Could the inhabitants of the Slave Canal mound sites have been obtaining their oysters in the immediate vicinity? What culture inhabited the mounds (and how long ago)? I returned to Gainesville determined to explore these questions.

In late November, Andy, Mark, Dan, and I were able to return to Site 4 for four days. I had decided that the best way to proceed was to do a small (1m x 1m) test excavation in an area that appeared to contain the full stratigraphic sequence; Pottery and shell would provide materials for accurately dating the mound's development and use; Bulk samples taken from each stratum could be used to answer the question "how far were these people going for their seafood?" At the same time, we needed to know how far the mound is above present-day Mean Sea Level; If present Gulf sea level curves are correct and the midden materials do not seem to have been transported long distances, then the mound might be expected to date to a time of higher-than-present sea level. The distance above present MSL should then correspond to the proposed magnitude of that high water stand. So while two of us worked on the test pit, the other two sought to link Site 4 to the elevation marker at the Page/Ladson site.

The surveying ended up taking more time than was expected, simply due to the distances we had to cover and our inability to secure a laser transit for the weekend. Additionally, we found that the Page/Ladson datum is not tied to MSL. However, an absolute elevation benchmark was located (on the main highway bridge) in preparation for finishing the instrument work quickly next time.

The most exciting aspect of the four days was the test Pit Although several (3'- 8' in diameter) looter's pits pocked the surface of the mound, we found an area near its greatest thick ness that appeared unspoiled and was very close to the water. I proposed that this area might contain the fullest stratigraphic sequence for the midden. A 1m x 1m excavation unit was laid out there with sides facing the cardinal directions. Excavation proceeded in 10cm levels. Where soil color, texture, or inclusions changed during excavation, the natural stratigraphy was traced. All soil was screened through hardware cloth.

The first stratum consisted of black (10 YR 2/1), sandy humus with numerous small roots, some king's crown (MPEongena corona, a brackish/saltwater snail), other shell, bone, some potsherds, and a nail. Level 1 was entirely within this stratum. Although formal analysis is not complete, the majority of sherds found in this level were Sand-Tempered, Plain.

In Level 2, we began to notice a slight color change (10 YR 3/1 - very dark grayish brown) in the southeast and northeast corners of the excavation. These areas turned out to have little depth, forming shallow "lenses" within Stratum 1; They may represent small deposits of ash or other refuse dumped on the surface of the midden. More oyster shell appeared in level 2, along with pieces of freshwater snail shell. Perhaps most signifigantly, Level 2 contained a great number of Deptford check-stamped sherds and Swift Creek complicated-stamped sherds. Also, pieces of low-grade quartz crystal and a biface were recovered. The biface appears to be a knife, although it may have been reworked from a spearpoint. From its style, it originated either as a member of the Lost Lake group (here, Bolen Plain: 8000-7000 BC), or its slightly later form, the Kirk Corner Notched group (7500-6900 BC). From A.; its appearance in a ceramic level, and B.; through careful examination of the tool's surface, it seems clear that the inhabitants of the site found this knife which had been lost or discarded millennia earlier, resharpened one working edge, and put it back into use.

On the basis of soil color alone, it is unclear if Level 3 is still part of Stratum I. After a full profile is uncovered and all materials are analyzed, this will be resolved. Level 3 contained many less Swift Creek sherds than level 2, several Deptford sherds, and several pieces of partially-baked clay and sandstone. Under three especially large pieces of gritty material (6-10 cm), a heat-altered biface preform was recovered. Both the associations between these artifacts and their respective conditions indicate an area where (at least one instance of) heat-alteration of chert was conducted.

(Mark Muniz excavates a test unit in the mound)

As exciting as these preliminary results are, they are all we have for now. Running out of time as our classes, jobs, and cold weather bore down, we had to cease excavation. Much time and effort was put into devising a way to shelter the test unit from the elements. This spring we hope to complete the test unit and elevation readings. It's exhilarating to consider the information we will gain onDeptford peoples. We already know they lived in the area from 500 BC to AD 200, with an economy that emphasized aquatic resources (see Milanich: The Archaeology of Pre-Columbian Florida, pp. 111-150). Most large Deptford sites are near the coast, and several smaller inland sites are known. The Slave Canal Mound may tell us more about the interactions between coastal and inland sites. Further, the transition from Deptford to Swift Creek assemblages occurred in the eastern panhandle about AD 250-300, indicating the spreading influence of traditions from Georgia. Understanding the environmental setting of the Slave Canal Mound may help explain how and why this transition occurred.