Thursday, November 24, 2011

Documenting the Late Prehistoric Period Village

Another research question of ours has to do with the age of the apparent stockade enclosure we first identified in 2010.  We now know that there were at least two, and possibly three, concentric lines of large wooden posts that formed a defensive barrier around the eastern section of the Heckleman site.  In 2010 we learned that one line of this fortification crossed over the filled oval enclosure trench, placing its construction sometime after the Early Woodland period.  We also discovered that this same post line was interrupted by a Late Prehistoric period pit feature (Feature 10-02) that contained sherds of Mixter Dentate pottery.   Thus, this line of posts must have been removed before the digging of the pit feature, which I guessed to be sometime around AD 1350 based on the presence of the Mixter type pottery.   As mentioned in my July 17, 2011 post, we were fortunate to discover one post mold (PM-18) in the outer line of the stockade that contained a rather large piece of wood charcoal, something that has rarely occurred at Heckleman. The figure below shows the location of PM-18.

  I submitted this charcoal sample for radiocarbon dating and the results reveal that the material was burned between AD 1410 and 1450.  This is a very tight date range as calibrated radiocarbon dates go, so I was very pleased.   We are not sure if the large chunk of charcoal in PM-18 is an actual introduction of some burned firewood after the post itself rotted, or if it represents a surviving fragment of the post itself, which were often charred at their tips to prevent rotting.  In either case, the burning of such a large piece of wood most certainly occurred near to the time of the erection of the stockade wall.   Thus, we now have direct evidence to confirm the presence of an enclosed Late Prehistoric period (Sandusky Tradition) village site at the Heckleman site during the early fifteenth century AD. 

Friday, November 11, 2011

Even Older Than We Thought

In October, I submitted five samples of charred plant material from the 2011 excavations at the Heckleman site for radiocarbon dating. Some of the results were what I expected, but others surprised me. Perhaps the most surprising was the rather ancient date on charred food(?) residue found on the interior of a large, thick pottery body section from the oval enclosure ditch (Feature 11-01). These section was found in the bottom fill layer of the ditch and is similar to sherds found within the ditch over the last two seasons. This particular sherd--carefully reconstructed by Meghan M.--appears to retain the base of a broken lug handle as shown in the image below.

The resulting radiocarbon age on the residue produced a calibrated date range of 800 BC to 670 BC. This new date places the construction of the oval enclosure some 300 to 500 years earlier than previously thought, making it one of the oldest such constructions in Ohio.   The only other enclosure of comparable age, to my knowledge, is the Dominion Land Company earthwork in Franklin County, Ohio, near Columbus.   This early age also indicates that the oval enclosure was likely constructed prior to the parallel ditches which enclose the eastern end of the promontory.  FARC excavations over the last three seasons have recovered more recent (Middle to Late Prehistoric period) artifacts in the fill of these twin ditches.   So, it seems that the Heckleman site is getting older all the time.