Wednesday, June 24, 2015

Sawmill floors and mission posts: midpoint update at Molino.

We are now in week six of the Pensacola Colonial Frontiers 2015 field school, and still making good progress on both the mission and sawmill portions of the dig.  We have two excavation units still in progress on the lower terrace and bluff slope, and have finished up one very deep and complex "shovel test" (which is actually a mini-excavation unit, dug in levels at Molino instead of the standard top-to-bottom shovel test of the same size, 50x50 cm).  The first is located along the slope below the summit of the bluff but above the sawmill floor on the lower terrace, and was originally laid in to discover the southern boundary of a brick floor discovered last year.  During excavation, students found that the clay comprising the bluff seems to have been truncated and leveled in this area so that the brick floor could be laid adjacent to the cut, and after digging through quite a bit of overlying sediment and debris, yesterday the top of the bricks were finally reached.  Further excavation should allow us to determine more about how this structural feature was constructed, and what the function of this brick floor may have been for the sawmill, especially given the location of what we believe to have been the brick chimney and steam boiler just a few meters to the north.  The brick floor has soot and ash deposits, and charred wood and nails along the edge, all probably associated with the 1884 fire that destroyed Molino Mills.

Melissa and Kelsey working on the bluff-slope unit.

Molded glass from the same unit, with "Montgomery, Alabama" among the markings.

Taylor cleans dirt off the newly-exposed brick floor in this unit.

One of several nails discovered along the margins of the brick floor.

Farther east out on the lower terrace (an area of the site most prone to mosquitoes since it is technically within the floodplain adjacent to the modern swamp bottom), another unit has been excavated through alluvial sand to what appears to be a clay floor, with more evidence of the 1884 fire, as well as a considerable jumble of large mortared bricks that may have been part of one or more collapsed brick piers in this area.  Whether these piers supported mill structures or machinery within such structures has yet to be determined, but this unit is providing great new information about the sawmill.

Olivia, Taylor, Melissa, and Emma hold sheets for shade in Jen's swamp-bottom unit.

Large pier fragments made of mortared brick amidst alluvial sands.

A nearby shovel test just completed and backfilled last week along the base of the upper terrace bluff has provided other clues.  Deep below more recent colluvial and alluvial sediments was found a deposit of broken brick rubble and other debris adjacent to what appears to have been a thick clay pad that may have served as a floor, and which bears a blackened layer on its uppermost surface.  This clay was apparently laid on top of a white sand base, and below both the bricks and the clay-sand feature was the original sand and clay comprising the lower terrace.  Since we got such a small window into these features, interpreting their function will be difficult, but we currently suspect the brick-filled deposit may have been a trench dug between the base of the bluff (where runoff would have flowed during rainstorms) and the prepared clay floor of the sawmill, perhaps in an effort to control drainage around the mill.  A similar brick-filled trench was discovered during the 2010 and 2011 field seasons on the upper bluff, as can be seen in the blog updates here and here.

The surface of the brick-filled deposit and adjacent clay feature (view to north).

Profile view (to east) showing excavated clay feature and remaining bricks in unit walls.

On the bluff summit, two ongoing excavation units continue to provide clues as to the possible Apalachee structure surrounding one of two clay hearth features discovered during our 2012 and 2014 field seasons.  The southernmost unit has been slowed considerably by the careful excavation of the intersecting trench features and clay cap we now believe to have been associated with a log skid road potentially constructed for the Cooper mill during the early 19th century, but in undisturbed deposits below these features several postholes have appeared, at least one of which is substantial and deep enough to have been some sort of wall or roof support post for an Apalachee roundhouse.

Sabrina, Emma, and Darby work on excavating sediments in their unit in the possible Apalachee structure.

Sabrina and Emma show off a completed map of the fully-excavated trench features at the base of their unit.

The other unit to the northeast came down on at least two postholes, one of which is similarly deep and substantial, and which may also be part of the structure we are looking for.  This unit is presently being profiled (scale drawings of stratigraphic layers and other features in all four walls) before backfilling.

Olivia, Brenna (Darby's sister), Jillian, and Darby work on mapping Olivia's unit.

Olivia takes measurements for a profile map of her neatly-excavated unit.

We have also been employing some additional technology in our fieldwork this summer, including the new, the old, and the super-old.  The "new" technology was a ground penetrating radar (GPR) operated by Archaeology Institute archaeologist Jennifer Melcher last week with the assistance of our students.  This instrument provided a readout of subsurface disturbances under the grassy field where previous shovel testing suggests there may have been a sawmill-era residence or other structure on the bluff summit away from the main mission and mill complex, and results will be ground-truthed soon with additional shovel tests in the areas where possible anomalies appeared.

Melissa, Jennifer Melcher, and Darby take readings with the GPR.
The "old" technology is a standard optical transit, which has been serving as a reliable backup for our laser-enabled total station unit that occasionally has "issues" (or which may need to be set up in a different area of the site).  Dr. Worth trained several students in the use of the transit (which he was originally trained to use during 1980s-era archaeology), and it continues to serve well for checking elevations during fieldwork.

Jillian and Darby work on leveling the optical transit.

Olivia and Jillian take elevations using the transit and metric stadia rod.
The "very old" technology tried over the past week was a "smudge pit" created in a metal can in order to generate sufficient smoke to keep the mosquitoes and yellow flies at bay.  While labor-intensive, this technique has proved effective, though building a hot fire in the middle of the summertime conditions on site sometimes seems to counteract the benefits gained by the smoke.  Based on several days of experimentation by Dr. Worth, the operation of a smudge pit seems to depend on generating a hot enough fire using oak or other woods that build up a solid base of coals, and then periodically adding green or moist wood on top of the coals to generate the most smoke.  When the fire is burning hot, the smoke largely disappears, but when the smoke is best, there is a risk that the fire and coals will die out (plus the smoke is actually so copious that it can be hard to breathe).  The key seems to be in balancing the two forces (coal-generating hot fire and smoke-generating smoldering coals), and this may indeed explain why most in-ground smudge pits found archaeologically here at Mission Escambe seem to have been fed with corn cobs, which could easily soak up water and then smolder for a while on a bed of live coals inside a structure.  The fire was probably generated in the main hearth, and the smudge pit was used sparingly to generate just enough smoke to expel the bugs.

Closeup of the "smudge can" in operation.

View of the bug-scattering smoke wafting across the dig site.

During one of our rain days, the students from both the Colonial Frontiers and Arcadia UWF field schools traveled to First City Art Center in downtown Pensacola, where they were able to take part in a special demonstration and workshop on glassblowing arranged for the UWF group.  Students were even able to make their own colored glass globe ornaments for a modest price, learning some of the basics of the ancient art of glassblowing.  This was a great way for students and staff alike to get the experience of seeing and participating in the creation of glass objects not dissimilar from the hand blown glass bottles that we find fragments of routinely at Molino.  We are very grateful to the folks at First City Art Center for hosting the UWF group.

The 2015 Colonial Frontiers crew at First City Art Center.

Olivia heats the glass in the furnace while rotating it.

Melissa blows air into the glass bubble to create a globe.

Jillian carefully shapes the glass using a wooden block soaked in water.
Finally, on a happy side note, one of our current student supervisors, Kayla Rowe, got married this past weekend, and a number of members of our past and present Molino archaeology crews attended the Hawaiian-themed wedding (group picture below).  We wish Kayla and her husband all the best in her future happiness!

Molino attendees to Kayla Rowe's wedding; pictured are Chelsea Randall, John Worth, Michelle Pigott, Jen Knutson, Sabrina Cummings, Kayla Rowe, Kristin Parrish, Jillian Okray, Emily Dietrich, and Melissa Maynard.

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