245 Shovel Tests All in a Row

— by Dr. Peres

We are nearing the end of our second week of field school, which means we are nearing the end of our survey work. Survey work is an important, though labor-intensive, part of archaeology. It allows us to explore a site that has never before been excavated to learn more about how big and deep the deposits are. As of today we finished shovel testing in all areas but one — the last area is for tomorrow. Why do we choose to shovel test vs. other survey methods? Shovel tests are not too big which means less disturbance to any potential intact deposits, yet they are big enough to give us a good snapshot into what lies beneath the surface.

Measuring depth of shovel test after finding an artifact in the screen.

Measuring depth of shovel test after finding an artifact in the screen.

Digging shovel tests is part skill, part art form, part determination, and part brute force. Yes, any non-archaeologist can dig a round hole in the ground, but we do it in a very systematic manner. We dig some, screen the dirt, look for artifacts or other evidence of previous human occupation, and measure the depth if we find any. We have a minimum depth we must meet, which varies by site. We analyze the soils as we dig, noting the texture, major ingredients of the soil (sand, silt, clay), and the color. All of that information is recorded and at what depth any changes occurred.

Jesse Tune uses brute force to get through natural sandstone in the shovel test.

Jesse Tune uses brute force to get through natural sandstone in the shovel test.

 

We space our shovel tests at regular intervals, typically 10 m (~33 ft.), 20 m (~66 ft.), or even 50 m (~164 ft.) apart. We place in them in straight lines parallel to one another, called transects.

 

Shovel test crews along the baseline (fence) before setting out on north-oriented transect lines (which is to the left in this picture).

Shovel test crews along the baseline (fence) before setting out on north-oriented transect lines (which is to the left in this picture).

 

To keep track of where the shovel tests have been dug in relation to the landscape and one another, we draw field sketch maps (which always have important pieces of information like a North arrow, scale, key — those are just out of the frame of the picture here). We flag each shovel test with locational and inventory information so that Tim can come back and use a sub-meter GPS (read high degree of accuracy in locating them on the ground) to plot them in digitally.

Field sketch map of Area F. Filled in circles means the shovel test had some sort of artifact or other evidence for previous human occupation.

Field sketch map of Area F. Filled in circles means the shovel test had some sort of artifact or other evidence for previous human occupation.

 

Last, but certainly not least, our remote sensing crew worked super hard and finished up the field pictured below, and then some. Tomorrow we get to pick some places to survey “just for fun” to see what we can see. I am hoping for a potential historic period brick kiln!

GPR work in the last block of this field. Hooray!

GPR work in the last block of this field. Hooray!

 

Check back with us tomorrow as we wind up our second week and take a much needed and well deserved break over the three day holiday weekend!

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3 thoughts on “245 Shovel Tests All in a Row

  1. Watching you guys do this fieldwork in Rutherford County each day and following the blog posts is incredibly interesting and fun. Confession: I went through a geology minor and two anthropology degrees and never once—never once—heard or saw the term “gley.” Thanks for the education and the nice shovel test photograph.

    I was wondering something. In the second photograph above, the caption under Jesse says he is breaking through “sandstone” in his shovel test pit. I am not aware of any sandstone formations in Rutherford County, so I would think this must have been some relatively small sandstone inclusion suspended in the soil matrix. Do you have any idea how it got there and what its natural source may have been?

    I am asking because sandstone sharpening and abrading tools are commonly found on Middle Archaic and Late Archaic Period sites in the Nashville Basin, and these sandstone tools are fairly course-grained and deep red in color. Mentally, the Cumberland Plateau is usually the automatic, default “go to” source for sandstone, but in the Western Highland Rim in the vicinity of Montgomery County, Tennessee, and Todd County, Kentucky, the remnants of sandstone formations quite literally cap fairly accessible hilltops, especially near the Jefferson Davis Monument in Todd County. I have always wondered whether some of this Archaic Period sandstone raw material in the area could have been traded into the Nashville Basin from there or whether some of the highest hilltops in the Nashville area have accessible sandstone caps that could have been the actual sources of this lithic raw material. Once again, do you guys have any idea how Jesse’s hunk of sandstone got there? Thanks!!!

    • Response by Jesse Tune, RCARP Co-Director

      Your comment on the sandstone is a good one. Rutherford County, as well as most of Middle Tennessee, does not have much sandstone. When we first noticed small pieces of sandstone in some shovel tests, I, too, thought it may be evidence of an Archaic occupation. However, after inspecting some of the historical features on the property we found numerous retaining walls and rock-lined paths were created from large blocks of sandstone. Also, large sandstone blocks can be seen eroding from several of the fields around the project area.

      As it turns out, the geology surrounding the project area is rather unique compared to the rest of Rutherford County. Rutherford County, and the entire Central Basin, is generally known for lots of limestone fairly close to the surface. The area we are working is slightly higher in elevation and marked by steep hill slopes and valleys, unlike the typically flat topography of the Central Basin in Middle Tennessee. As a result, several different geologic formations are exposed here. The bottom of the valleys where we are working consists of the typical Rutherford County, Ordovician Period fossiliferous limestone. Above that limestone formation there is a thin bed of Silurian Period sandstone that is overlain by fossiliferous, cherty limestone, overlain by a shale formation, and finally capped by lower Fort Payne cherty limestone.

      Your question highlights the importance of thoroughly understanding the lithic landscape of a study area. Until we poured through the geological reports for the area, the presence of so much sandstone was a mystery. As it turns out, we are working in a rather unique part of Rutherford County where there is an erosional remnant of a sandstone formation. Archaeologists need to be well-versed in a multitude of other disciplines be able to tease out the cultural from the non-cultural.

      Thanks for your interest in our project and following the blog!

      • Thanks Jesse. Sandstone is indeed a fickle thing—often popping its little head up in some small amount where one least expects it. Once upon a time, this happened on one of my environmental projects in another state. For a few of days, people just sat around, scratched their heads, and thought: “How in the…did that get there?” The geology of the area had been studied to death for years, but this thin bed of sandstone turned out to be little more than a footnote to local geology—something that was known to be there but still fairly easy for well-trained geologists to miss during their background research for the project area.

        Have a great Memorial Day weekend!!!

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