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February 23, 1997:
Mysteries of the Mud Mass

In our excavation, the first and most important work to be done is to define the architecture, which contains the artifacts we find. If we do this correctly, our work for the rest of the season is made easier, since walls and doorways can provide boundaries for several layers and give us clear starting points for excavating. However, if these walls are not well-preserved, consisting of only one or two courses of brick, a simple mistake made in identifying them early on might unintentionally destroy valuable clues to the story of our site.

Draw Fortunately, the area we are currently excavating is covered by a layer of clean, yellow sand immediately below the modern debris. Almost everywhere, once this sand is removed, we are confronted with an apparently uniform level of grey mud mixed with pottery and large chunks of limestone. This "wash" of mud, stone and ceramic is what is left of the mudbrick buildings we are digging, after they had been abandoned and exposed to years of rain, wind and sun. Under these conditions, unbaked mudbricks dissolve and re-harden many times, their individual shapes and colors becoming mixed and obscured, resulting in a confusing mass of mud which archaeologists call "tumble" (a term for fallen walls). While we label this seemingly homogenous layer as a separate "feature" (a term our project uses for any event which left or took away material from the site), saving all the pottery, charcoal, stone tools and bones we can, the real story of what happened inside these buildings, as well as the walls of the buildings themselves, lies hidden underneath. Sometimes, exposing these earlier features can be pretty tricky.

First, before we can remove this brown muddy material, we have to trowel and clean the surface to more clearly delineate what loose bricks, pottery and limestone rubble remain. Afterwards, photographs are taken and the individual stones and sherds are drawn. Back in Boston we use these drawings, which have elevations above sea level,to help us reconstruct the site.

Once we have properly recorded the surface of the mud mass, we approach each square in the same way we think about our site as a whole. In much the same way we formed hypotheses (scientific theories or guesses based on previous evidence) about what our large building might be, which led, in turn, to our choice of where to dig, we also have to form and test hypotheses as to where mudbrick walls might be buried in their squares from the often confusing jumble of pottery and mudbricks in the muddy mass.

mud bricks being excavated To this end there are often several clues. After the surface has been troweled and then dried by the sun, the individual shapes and colors of the bricks reappear. If these bricks are irregular and disjointed, it is a good indication that the feature is mostly bricks which have fallen from a wall and can be safely removed to expose intact architecture. Another clue is the presence (or absence) of ceramic sherds. Although small fragments of pottery as well as charcoal and stone chips were often scooped up with the mud when the bricks were made, larger pieces of pottery usually indicate tumble, and can even be banked up against an ancient wall, revealing its face. Using these clues we normally see the underlying architecture as soon as the obscuring tumble is removed.

When we begin to uncover bricks which appear to be intact (still lying in the wall in which they were laid), individual bricks can be defined by brushing them with a stiff brush after they have dried out a little. Although the ancient Egyptians did not use mortar or baked bricks at our site, the spaces between their mudbricks are softer, and come loose when brushed. Using this technique and noting the location of large sherds, we can decipher many of the mysteries of the mud mass.

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Photos: Carl Andrews

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