In this week’s lab, we toured sites of archaeological interest in the Cowling Arboretum with Alex and Nancy Braker, the Arb’s director. We met at the Arb Office and crossed the highway into the Lower Arb, pausing so that Nancy could tell us about the history of the Arb and various points of interest along the way, including the remains of the Waterford mill along the Cannon River. I found the mill site especially interesting because it was a part of the Arb to which I had previously been but never really investigated. I learned that the path leading to the site is on top of the old dyke that held water back to power the mill. Alex pointed out that we can tell it’s an unnatural formation because it runs perpendicular to the Cannon, which is the opposite of what we would expect, and because it is unnaturally straight and uniform.
Nancy then led us on a detour that branched to the northeast off of the path to the mill site. She led us to a mossy outcropping of rock of which she had only recently become aware, and we discussed what it could potentially be. Alex said that holes bored into the rock could indicate the past use of dynamite to quarry stone. Beneath the outcropping were littered bottles and cans from different time periods; many cans were old and rusty with antiquated openings while others were more recent purchases from popular Midwestern beer companies. There were also some old pails or buckets at the site and Alex and the group expressed interest in returning for further investigation in subsequent labs.
We visited the Waterford bridge at the extreme northeastern corner of the Arb and Alex pointed out the sign above it, which indicated when it was built (1909) and who designed and built it along with other details, which represents an important source of information in historical archaeology. We visited the site of the Women’s League Cabin along the western edge of the Lower Arb and ran into some local teens up to something fishy (or skunky). In class, we contemplated the place as a potentially ideal spot for illicit activities due to its proximity to parking and its relatively secluded nature despite being close to the trail, which related to broader ideas about relationships between a place’s unique characteristics and how humans interact with it. At the end of our tour, we visited the Pine Hill Village near the Rec Center and behind Goodhue Hall. We walked several miles, but it was rewarding to see the sites we had read about and explore the possibilities of archaeological work in the field.
In this week’s lab, we put our new knowledge about archaeological survey to good use in a field in the Upper Arb. Before we left for the site, we did some remote sensing work using satellite imagery from Google Maps and a LiDAR map of the area. We also discussed the importance of processing and analyzing artifacts by categorizing them well and then determining their form, function, and chronology based on their attributes. Then we went out into the field to conduct our survey. We split up into two teams and spaced ourselves ten meters apart on an east-west line; the first team of five students walked parallel to the road on the east side of the field and the second team of five was further west into the field’s interior. Each team had four walkers and one recorder, who catalogued artifact finds in each survey unit and noted several other important details like weather conditions and the features of the landscape. I was in the second team and walked the far western edge of the survey unit. In the first survey unit, it was difficult to distinguish between rocks and potential artifacts of brick, tile, or ceramic. Most of what I collected were rocks and I didn’t find anything very exciting. Golf balls from the nearby driving range dominated the end of the first survey unit and the beginning of the second. I also found a piece of glass which was the broken bottom of a bottle and could be precisely dated based on the width of the glass. In the third survey unit, I found a long, bent piece of old metal that could have been part of some farm equipment. I also found some very small, fragile shells, which were interesting. After walking each survey unit, we categorized the finds and put them in bags based on their material. The survey was exciting for me and I enjoyed seeing all the diverse artifacts we gathered from just a small part of a nondescript agricultural field. I gained a new appreciation for those with the ability to separate artifact from rock and had fun during our hands-on experience with the material we had covered through readings and in class.
In this week’s lab, we conducted another site survey, this time at the quarry that Nancy Braker showed us during our tour of the Arb two weeks ago. Before we left for the site, we discussed what we need to consider about a site to approach its survey with the most appropriate techniques and research questions, including the site’s basic physical aspects like size and characteristics, its function, how it’s changed over time, and its local context and interactions with the surrounding area. We also discussed what we need to think about regarding the collection of artifacts, including resource limitations (e.g. money, time, effort, storage, etc.), diagnosticity (some artifacts are more informative than others), and the importance of recording location and collecting ethically.
Then, we went to the quarry site, which the Tuesday group had sketched a map of and divided into 16 squares, each 25 square meters in area (five by five meters). We began surveying units and a small group of students used a differential GPS to collect coordinates. I oversaw the surveying, assigning pairs to survey units and orienting them using the blue flags that the Tuesday group had put up. I also copied the map from Tuesday and tracked which units were being surveyed and by whom. In observing the survey, it was clear that artifact density around unit L10 was high relative to units farther away. Pairs of surveyors in units closer to J10 took longer, although this isn’t necessarily due to a higher artifact density and could also be related to the thoroughness of survey and time taken to clear the unit of dead leaves and other detritus. Additionally, it was clear that units containing part of the slope were difficult to survey. Towards the end of the lab, I took lots of pictures of survey unit L10 in a kind of bubble over the square, which will be used for a photogrammetric representation of the unit.
In this week’s lab, we started excavation at the potential quarry site. Before we left for the Arb we discussed what Tuesday’s lab had done and then outlined the plan for our lab session. We thought about potential excavation sites on the side of the dike to see any stratigraphy and find any clues regarding the structure of the dike, and in survey unit L10, which had been fully surveyed on Tuesday. When we got to the site, we split into three groups. One worked on mapping the area with the differential GPS, another started excavation on L10, and a third worked on clearing the base of the outcrop of rock outside of the survey grid. Cleaning the leaves, moss, wood, rocks, and dirt to expose the rock beneath could give us a more complete picture of the site and potentially reveal some clues as to its use. I used a trowel and brush to clear the ledge adjacent to the survey grid. There was a great number of rocks and a lot of dirt covering the stone at the base of the outcrop. It was difficult to clear it all away in a manner that didn’t cover up some part that had just been cleared. The soil was very dark, dense, and moist, and home to a lot of little critters and intricate root systems that we were careful not to destroy. There were a lot of rocks of about the same size, which was interesting because the rock didn’t seem brittle or easily breakable. This may point to quarrying activity. The part which I cleared was relatively flat with a lot of dirt piled on top probably after sliding down the slope from above. There were a few large cracks or seams in the rocks which were difficult to follow very far and keep clear of dirt. The lack of drill holes indicating dynamite use was slightly discouraging, but it could be that the blocky nature of the rock negates the need for drill holes and allows dynamite to simply be placed in a seam. It took a long time to clear a relatively small area and I wish I could’ve exposed more to give us a clearer picture of the underlying rock, but I remain optimistic that the site was once a quarry and look forward to digging deeper in the future.
In this week’s lab, we continued projects from past weeks, including further DGPS work and excavation at the quarry site and in a trench opened on Tuesday at the dike. The Tuesday group had the pleasure of working with retired Carleton geology professor Mary Savina and she provided some interesting information about the outcrop of rock around which our site is based. She said the type of rock is typically quarried in southern Minnesota and is loose enough that dynamite is unnecessary. Thus, it is not cut in uniform blocks but instead serves as rubble and could have been used in creating earthworks like the dike. The rock which I helped clean off last week was markedly different from the looser rock higher up; it was not as fractured and extended horizontally into a relatively flat platform unlike the cracked, blocky rock face above and thus probably is where quarrying stopped. This week, I helped with excavation on the dike, which was exciting because that’s where we hope to find rock from the quarry site as evidence to support our hypotheses that the site was indeed once a quarry and that rock from it was used in constructing the dike. We cleaned the trench up and got down to context two (Tuesday had excavated most of context one), and then excavated it and stopped at context three.
The dirt throughout was marbled and mottled, and since we were not finding any artifacts, we decided that it was best for future excavation to focus on moving quickly and figure out contexts after excavation instead of taking time on site to carefully discern when a present context had ended and a new one had started. It was very cool to see stratigraphy physically in the field instead of simply in a book or on a screen. It was also nice to adjust our methodology based on considerations of the goals, limitations, and progress of our work. Context one was composed mostly of brown soil that was slightly sandy and contained two rocks that extended into context two, which was mostly sandy, light brown or orange soil. Context three, where we stopped, was very dense, rich, dark brown soil. I’m very excited to see what further excavation exposes at the dike.
In this week’s lab, we continued excavation in the second trench at the quarry site and in the trench at the dike. Before we split into teams and started working, Alex pointed out some of the products of the Tuesday group’s work. The flat slabs of rock at the base of the quarry had been cleaned off well and made visible the connection between the lower rock that divided into steps and the upper rock that was quarried and broke easily into chunks. Further excavation in the first trench at the quarry site on Tuesday revealed the same pattern on the ground further away from the rock face, which was really interesting. It might also explain the location of trees at the site. Seeds and roots can find their way between the cracks of the quarried rock and move it more easily in the process of growing, but the solid slabs of stone characteristic of the second type of rock would inhibit tree growth.
I continued working at the dike trench this week, as it is important for my final project. As decided last week, we changed our method of excavation. We almost exclusively used shovels to excavate soil in sections that were ten to fifteen centimeters deep. The soil was then sifted for artifacts, but none were found. After excavating to the appropriate depth, we cleaned up the edges of the trench and leveled out an area on the slope adjacent to the trench but outside its boundaries to stand on and allow us better access for shoveling. The Tuesday group excavated to context five, so we began with context six and ended the day halfway through context eight. The soil remained consistently dark and dense but we further revealed an interesting stratigraphy on the sides of the trench. We also noticed an increase in roots as we excavated further.
The sides of the trench reveal that the dark, dense soil that extends from context three downwards slopes along the side of the dike and never makes its way to the surface. In addition to the sandy, light brown soil of context two, it is covered by the loose, brown loam of context one on the side of the dike. The more we excavate the more interesting the picture becomes, but as we turn to final projects I am very excited to see what we can find regarding earthwork construction and documentary history of the dike and potentially figure out whether there is a stone core under all that dirt.
In this week’s lab, we worked on artifact cleaning, cataloging, and analysis. I worked with Sachit and we decided to go through the golf balls we had collected from our field survey during week three. There were 19 golf balls from SU-C02, which we washed off and divided into 10 lots based on brand, design, and color. Then we conducted brief research based on these factors to try and determine when the golf balls entered the market and thus establish an earliest possible date for their deposition in the field. Our research was a very interesting exercise. Some brands had distinct designs and names for every new golf ball model and it was thus easier to find a date. One brand, Titleist, even had an article on their website called “How to Tell Which Year Your Titleist Golf Ball is From” based on the stamps on the side of the ball. For other brands, an earliest possible date could be found in equipment reviews or announcements about product introductions. It was very difficult to find information about some brands to date the golf balls or even verify that the brand existed. Our teaching assistant, Sam, said that if people were indeed intentionally golfing the wrong direction they would be more likely to do so with golf balls they were comfortable losing, either those from the driving range that weren’t theirs or ones of lower quality that they owned.
Sachit and I went through artifacts from four more survey units, all of which included golf balls (20 more in total) but also glass, shells, metal, plastic, and ceramic. Most of the artifacts were very small and it was difficult to glean much information from them. The one piece of glass we cataloged looked like part of the bottom of a bottle but wasn’t diagnostic. The ceramic sherd we cataloged was interesting but very small and hard to identify. The golf balls were far more abundant and dominated much of our work. A strange piece of metal we processed was very rusty and filled with dense earth, but once cleaned looked to be part of a door knob.
We entered all of the information about the lots into a spreadsheet and uploaded pictures of the findings from each survey unit we cataloged to the shared class drive. Our lab period taught me that artifact cataloging and analysis takes a significant amount of time and attention. It also highlighted how important it is to be diligent and detailed in recording artifact information so that finding a specific artifact later is simple and doesn’t require combing through thousands of other artifacts because the initial data was insufficient or entered incorrectly.
In this week’s lab, I returned to the Arb with Alex and four other students to continue working on the trench at the dike, which Tuesday’s lab group had deepened. We were looking for a layer of rocks to establish a connection between the quarry and the dike, but we did not find anything except dirt. The depth and narrowness of the trench made it difficult to continue excavating with a shovel, so we also used a trowel and dustpan. It was also only feasible to have one person excavating, so additional activities included sifting excavated dirt, chatting, throwing dirt clods at trees, and digging a small test hole near the dike to investigate soil composition, which wasn’t distinguishable from the earth in the dike. Thus, the dark brown soil that has dominated our trench since context three seems to have come from nearby and was not brought in from another location. While we were unable to confirm our hypotheses about the relationship between the dike and the quarry, our excavation still provided informative stratigraphy and it is important to make our findings public and available. Additionally, I am excited to work on the energetics project to figure out the volume of the dike and how many person-days it took to construct.