Microscopy lab

.docx

School

Southern Methodist University *

*We aren’t endorsed by this school

Course

2463

Subject

Material Science

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by CoachHorseMaster1048 on coursehero.com

Lab Number 4: Microscopy of Ceramics Lab Section: N-17 Nov. 3, 2023 Lab Number 4: Microscopy of Ceramics Introduction and Background During this lab, each lab group, acting as microarchaeologists, was presented with two trays containing ceramic assemblages from The Jorgeson Site and The K Ranch Site, both of which are in North Dakota. These assemblages are from two single components, “Protohistoric earth lodge village sites located on the Missouri River in North Dakota” (Lab Guide). Drastic changes occurred to the ceramics within the Northern Plains region directly after the interactions with Euroamericans. It is argued that vessels became fragile and poorly made after the Euromericans' presence based on observations that looked at the differences in rim forms, the wall thickness of the ceramic, and a lack of quality temper due to low-quality skillmanship (Hollenback, 2016). In comparison with other regions of the United States of America, contact with the Euroamericans happened relatively late for the Northern Plain tribes. The first direct contact with the Euroamericans was at the start of the eighteenth century, predominantly because of the fur trade (Hollenback, 2016). These trade goods are believed to have come before the epidemics that these tribes faced, such as smallpox, which is believed to have created this problem of poorer quality ceramics being produced (Hollenback, 2016). There needs to be more research into this connection, which is what we have been contracted to do. For this lab, I have two research questions that I hope to answer. The first is whether there is any technological evidence of an epidemic at either the Jorgeson Site or the K Ranch Site? My second is, what are the clear changes in the ceramics from pre-epidemic to post-epidemic? We currently need to find out if the epidemic impacted each site. We also need to find out what the 1

Lab Number 4: Microscopy of Ceramics consequences of the epidemic were on each type of ceramic. I have created two hypotheses through my research questions and the unknown facts. My first hypothesis is if there is a noticeable change in the quality of the temper located at the same site, the higher-quality temper is pre-epidemic, and the low-quality temper is post-epidemic. My second hypothesis is if the scale for pebble sorting is considered “fair” or better, then the ceramic is from before the epidemic. Methods The way that I was able to answer my research questions was through closely examining the ceramics on both trays and figuring out what each ceramic sherd was. For example, we would determine if a ceramic sherd was part of the body, the neck, or the rim. The next step was to measure the wall thickness of each ceramic sherd through the use of calipers, giving a highly accurate measurement of the thickness in millimeters. If the ceramic sherd was a rim, we would use the Rim Diameter Chart to give an estimate of the original vessel diameter. The final step of the methodology my group and I used was the Dino-Lite microscope. We took a photo of a “clean break” for each ceramic sherd using a minimum magnification of x20, which allowed for a clear image of the temper within each ceramic sherd. From this image, we started by measuring the size range of the temper inclusions. We would then describe the temper inclusions through the photograph and would compare our picture with a template for each area that we wanted to describe. The areas we want to describe are sorting, roundedness and sphericity, and density percentage. The last aspect of our method is to finally describe the ceramic sherd from the color to the texture. Our group did a total of ten ceramic sherds split in half between the two site locations. The resources that my team used were the templates that were provided in the lab guide to allow us to compare sorting, roundedness and sphericity, and density percentage. The 2

Lab Number 4: Microscopy of Ceramics next resource was the Rim Diameter Chart, which allowed us to put a rim sherd on the chart and be able to get an understanding of the original vessel. The final resource that was used during this lab was the TA, who helped us work the Dino-Lite microscope and figure out what the best “clean break” was for each ceramic sherd. Results and Analysis Our first ceramic sherd assemblage is from the Jorgeson Site with site number 51AM11. This assemblage had two vessel portions, two rims, and three bodies. When looking at the wall thickness for these vessels, these are all less than 1 centimeter. Sherd number one is a tan, spotted, and scuffed vessel. The photo number is 511AM11-1, and it was found to be a rim with a thickness of .496 centimeters. The rim diameter is five and is 22% complete, according to the Rim Diameter Chart. We used a magnification of 20x for this sherd and found that the temper sorting is number two, which is a poor-quality temper. The temper angularity is classed as number four, which is sub-rounded with low sphericity. The temper density percentage is 5%, and the temper size range is 0.5 – 3 millimeters. Sherd number two is described as a gray, brown spotted vessel with lines. The photo number is 511AM11-2, and it was found to be a rim with a thickness of .692 centimeters. The rim diameter is four and is 25% complete, according to the Rim Diameter Chart. Again, we used a magnification of 20x and found that the temper sorting is ranked as number three, which is fair quality temper. The temper angularity is classed as number four, which is sub-rounded with a high sphericity. The temper density percentage is 5%, with a temper size range of 0.5 – 1.0 millimeters. Sherd number three, the vessel is described as black with small cracks and is large compared to the other sherds. The photo number is 511AM11-3, and it is found to be a body with a thickness of .775 centimeters. We used a magnification of 20x and found that the temper sorting fell into the number two category: poor-quality temper. The 3

Lab Number 4: Microscopy of Ceramics temper angularity is classed as number three, which is sub-angular and has a low temper sphericity. The temper density percentage is 5%, and the temper size range is 0.5 – 3 millimeters. Sherd number four, the vessel is described as small, tan, and shaped triangularly. The photo number is 511AM11-4 and is found to be a body with a thickness of .977 centimeters. We used a magnification of 20x and found that the temper sorting is ranked as four, which is a good quality temper. The temper angularity is classed as a number 4, which is sub-rounded with a high sphericity. The temper density percentage is 20% and has a temper size range from 0.5 – 2.0 millimeters. The final sherd is sherd number five and is described as small, black, and ridged. The photo number is 511AM11-5 and is found to be a body with a wall thickness of .711 centimeters. We used a magnification of 20x and found that the temper sorting is ranked as three, which is fair quality temper. The temper angularity is class five, which is rounded with a high temper sphericity. The temper density percentage is 5%, with a temper size range of 0.5 – 1.0 millimeters. Our second ceramic sherd assemblage is from the K Ranch Site with site number 51DW12. This assemblage has two vessel portions, four bodies, and one pipe. The wall thickness for all but one is greater than 1 centimeter, which is interesting compared to the Jorgeson site. Sherd number one is described as red, small, and thick. The photo number is 51DW12-1 and is found to be a body with a wall thickness of 1.048 centimeters. We used a magnification of 20x and found that the temper sorting is ranked as one, which is a very poor temper. The temper angularity is class two, which is angular with a low temper sphericity. The temper density percentage is 5%, with a temper size range of 0.5 – 3.0 millimeters. Sherd number two is described as black, speckled, and large. The photo number is 51DW12-2 and is found to be a body with a wall thickness of .644 centimeters. We used a magnification of 20x and found that the temper sorting is ranked 4

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help