Archaeology of the La Salle Shipwreck Project
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Screening Area
One of the most important and busiest aspects of the excavation was the screening area. All sediment, except that removed from the edges of the cofferdam, was screened for small finds. Small finds, such as beads, rings and straight pins were easily overlooked while excavating. If not for the careful and diligent work accomplished at the screens, these small finds would have been permanently lost. The primary source of manpower at the screens relied on volunteers. Daily, 2-4 volunteers came out with the crew to help work on the screens.
Everyday, the volunteers and 1 or 2 crew members worked at the screens. Sediment-filled buckets from the excavation pit were carried to the screening area and organized in-groups according to provenience. To screen, buckets were lifted and dumped into a series of three screens. The top screen was 1/4-inch stainless steel mesh, the second was 1/8-inch mesh, and the third was 1/16-inch mesh. Using hoses attached to spray nozzles, workers sprayed the sediment through the top screen. The nozzles had several settings for stream strength. This proved extremely useful as different types of water streams worked better in washing different types of soils.
The majority of artifacts found in the screens consisted of brass Jesuit rings, brass straight pins, glass beads, gun flints, lead shot, and other small finds. All artifacts were separated according to type and material and placed in small sealed plastic bags. Each bag had the requisite locational data, including date, quad, unit, and level. Each bag had its own plastic artifact tag. The small round disc was placed in the bag, in addition to having the number on the bag’s exterior. All bags were transported back to the lab each night for stabilization and for temporary storage. The bags stayed at the lab until cataloged, then were shipped to the Conservation Research Lab at Texas A&M for conservation.
Feature Excavation
Several artifacts or artifact groupings were treated as separate features. The features were excavated and recorded both as part of a regular unit and as individual features. Features were classified into four groups; casks, boxes, rope, and miscellaneous. Each type of feature presented a set of unique problems, with its own excavation methodology, recordation and recovery procedures. The following sections outline the methodology for each type of feature.
Cask Feature
The largest group of features comprised 86 casks. Casks were recovered from the forward hold and the after hold of the ship. They represented approximately 12 variations of 3 main sizes, each size containing various types of contents. Contents included bird shot, regular shot, gunpowder, trade goods, tools, ship’s stores and several that are still unknown. Once a cask was fully exposed, the top staves and exposed withies were surveyed with the total data station. Once recorded, the top staves and withies were removed. The staves were placed on a padded wood pallet to create an exploded version of the cask. The staves were displayed in the exact order and orientation as recovered from the cask. Once the top staves were removed, a second set of drawings and photographs were completed. This recorded the cask’s contents, and partially exposed the heads and bottom staves. At this stage, surveying concentrated primarily on the heads, shooting all accessible pieces.
After removing the contents, the remaining bottom staves were cleaned for a final set of drawings and photographs. This set of recordation procedures detailed the cask’s bottom staves and completed all remaining cask measurements. As with the top staves, the bottom staves were placed on a padded wood pallet, labeled, and wrapped with plastic wrap.
There were two exceptions to the pallet method, jacketing and lifting whole. The smallest cask size contained regular lead shot. These casks were either fully excavated or, if preservation allowed, were jacketed whole and removed. None of the gunpowder casks or larger casks were jacketed but some of the larger sized casks were lifted whole. A few small shot casks were concreted sufficiently to be jacketed without fear of breaking apart. The heavy contents crushed the delicate wood staves, weakening their structure; therefore it was necessary to put several layers of plaster around the cask to hold the feature together.
When a cask was jacketed, the top staves and withy, and any exposed elements were drawn, photographed and surveyed. This was the only set of recordation forms for jacketed casks. The first step in jacketing required placing wet paper towels or rags over any exposed cask elements. The paper towels created a barrier between the plaster and the cask, and provided moisture to the wood underneath. Long strips of burlap, cut approximately 2 inches wide by 18 inches long, were soaked in a large bucket containing a wet plaster mixture. The strips were laid on top of the cask and molded to the casks’ exposed staves. Only one layer was applied at a time, allowing each layer to dry and harden. After 2 or 3 layers the cask was undercut, lifted, and placed on a nearby wood pallet for transportation.
