Today was the backfill day at the DOTMON site (AZ:CC:4:62 (ASM)). After all the excavating, screening, and paper work, the perfectly square hole (a 1x1m unit) we made in the ground must be backfilled and the site returned to its original state…almost. It is next to impossible to bring it back to how we found it, but we try. This practice is predominantly to clean up our mess and prevent injury, we did put in a 40cm pit after all.
Unlike the meticulous efforts archaeologists put in for excavating, back filling looks barbaric, with an almost haphazard technique of throwing rocks and tossing dirt into the unit. But it isn’t without symbolism. A common tradition is to place a historical item in the unit before sealing the unit. In our case Dr. Hard had tossed a few coins with recent dates in the unit. He said that these were for the next archaeologists who dug the site. It was our way of saying we were here, and now we are part of the history of this site.
Today Dr. Hard’s excavation crew (Megan Brown, Overton Lesley, and Robert Gardner) began to excavate unit Rock Ring A on the DOT MON site (AZ:CC:4:62 (ASM)). My fellow excavators dug into 3, 10cm levels successfully, while I filled out site forms, tags, and screened for artifacts. I wanted to dig so badly that I could feel the trowel burning in my back pocket, waiting to get dirty. But, there were other important tasks that needed to be taken care of before it was my turn to dig a level. Dr. Hard taught me the importance of testing the unit soil and the different types of soil that sand, silt, and clay can make when combined at different percentages. I also learned how to compare the color of the soil with the Munsell soil chart. I then mapped out level 1 and 2 after it had been completed. I felt cool being able to “eyeball” measurements onto the map. I had a blast, or created a blast of dirt while I screened for artifacts. To my surprise I found a lot of obsidian flakes, even in lower levels that were close to bedrock.
Today Andrea Thomas and I continued our excavations in our beloved rock ring designated ‘Feature E.’ It continues to yield interesting results, however, it is very much more than frustrating trying to dig through bedrock – yet we push on! So far we’ve recovered the base of a projectile point, a mano (used for food-grinding purposes), and a suspicious formation of five rocks in the middle of our feature. We will also took flotation samples from the fill underneath those rocks to see if we can get a hold of datable charcoal. A day in the life of an archaeological field school student is sweaty and overwhelming at times, but always exciting and rewarding as well. Today I learned how to create a profile map to understand the stratigraphy of the Northeast and Southeast Quadrant units; this type of map aids in the understanding of the various soils found in the feature, as well as the fill used to create a floor for the structure.
Today I worked with Ian Bates and Lori Barkwill-Love at Round Mountain (AZ:CC:4:61 (ASM)) on Test Unit 4, which is a 1x1m unit just inside a terrace wall. When digging in Test Unit 4, we found this white chert core in level two of the unit at roughly 50-60 cm below the datum. What I found particularly interesting was that the exterior of the core was made of chert, whereas the interior was calcium carbonate. When rubbed with finger, the carbonate leaves a white residue much like chalk. In fact, chalk is a form of calcium carbonate however, I cannot confidently identify this object’s material as chalk. Calcium carbonate is a combination of carbon, oxygen, and calcium and is believed to have been formed indirectly due to an organism intrusion. An example may be a bacteria or a secreting organism such as a bug or ant. We all found this particularly interesting since a core is the beginning rock that is struck for the creation of stone tools, and although chert is a widely used rock for tool creation, calcium carbonate is rarely used for flaking stones for tool production.