RHX Dating Update

My collaborators and I mailed out some reports today about Fired Clay Ceramic Rehydroxylation Dating! I am pleased to say that we've completed our work that was supported by a small grant from the National Science Foundation's Division of Behavioral and Cognitive Sciences (Award #1112327) and an Fellowship Award to Patrick Bowen from the DeVlieg Foundation.

I know many people are very excited about RHX dating (and also very skeptical).  I was very excited about the proposed technique when it was published in 2009. This technique proposes to use the clock-like, nano-scale process by which water molecules bond with clay mineral crystals.  By taking an old ceramic sherd, heating it to remove any mass caused by humidity (atmospheric water), measuring it's mass, then firing the sample at a higher temperature to drive off all the rehydrated (adhered) water and rehydroxylated (chemically bonded) water, one can measure the sample's mass without any water present.  After that, carefully tracking the mass of the sample as it quickly starts to reabsorb water from the air allows you to generate an equation that models the time past, the water mass gained, and the rate at which this occurs.  So long as you can match the temperature in the room to the average lifetime temperature of the object, a bit of math lets the lab technician calculate how long it took for the sample to reach the weight at which it was discovered by archaeologists. All my posts about RHX dating are all here.

In 2010, we applied for an NSF grant to study this process and see if we could replicate the findings of the UK researchers that had proposed it.  We did win that grant, but we did some background work and tried to replicate their study. We published our results in 2011.  With that publication under our belt, we reapplied to NSF for more funding to upgrade our lab equipment to match the quality of that being used by the UK team.  At first, we were rejected, but then the NSF found a bit of money that allowed us to improve our instruments.  Using that grant, we purchased a new Citizen CM11 Microbalance along with a Coy Humidity Control Glove Box. This microbalance allows us to measure 0.001 mg of variation in mass, fully two orders of resolution and sensitivity higher than the balance that was available at Michigan Tech before the NSF award! It's was a lesser piece of equipment than we'd hoped to purchase, but it has permitted us to take our experiments to the next level of research quality.

In November-December 2011, We tested the station to determine the stability of humidity and temperature within the box as well as the stability of microbalance while it is reading in the box chamber environment. Between December 2011 and August 2012, Jarek and Patrick collected and analyzed the mass-gain data corresponding to rehydration/rehydroxylation of Davenport sherds and some brick samples from Houghton, Michigan.  After running tests on intact sherds, we also ran some pulverized samples. Jarek and Patrick worked over the data to examine the influence of relative humidity on mass gain and time curves.  From that analysis, we just submitted an article for review and publication. This one deals with the question of which model (expressed in an equation) best describes the samples behavior as they rehydrate and rehydroxylate over time. We also raised some questions about the micropore structure of the sherds and how that influences the model.

Figure 2 is from our report to NSF. It shows the fractional mass versus time obtained for the Davenport pottery sample under constant temperature and humidity (plot on the left hand side). 

Figure 2. Compiled fitting results for intact Davenport sherd in both linear time (left column) and time^1/n with n= 3.77 (right column). Results were obtained at 22^oC and 20%RH.

                  

                   

                  The right-hand plot in Figure 2 also shows the resulting theoretical fit using the following empirical equation describing the mass gain (m) (or fractional mass gain):

where t is the time, β is the term representing physically bonded water, α is the rehydration kinetics term, γ is the rehydroxylation rate, and n is the rehydroxylation exponent.  

Agreement between experimental data and theoretical model is remarkable!  

We found problems that present the researchers with challenges to making RHX a standard archaeometric tool for dating fired clay ceramic artifacts.  I will write more about those in another post, but I can't say too much until our article is published. I'm also excited to report that our initial success led to a new award from NSF (BCS-1219540)!

Our new collaboration will allow our team at Michigan Technological University to coordinate an experiment involving five different international teams of faculty and students (Michigan Technological University, Arizona State University, California State University-Long Beach, Tel Aviv University, and The University of New England) working on new RHX experiments, advised by a team of UK scientists, many of whom initially proposed this technique, and continue to work on it's refinement (Universities of Manchester, Edinburgh, and Bradford).  We will send a set of blind samples for testing to five labs including materials scientists and archaeologists from seven different universities in four countries. 

I am very excited!

GlobalPottery Conference

The Utah Pottery Project has been quiet for a while!  I've had other funded research and obligations mentoring graduate and undergraduate students.  Things have started to percolate again, however, so more may be forthcoming this summer!

Meanwhile, I am excited to attend next week's GlobalPottery conference. The meeting is subtitled the First International Congress on Historical Archaeology & Archaeometry for Societies in Contact.

http://globalpottery.ub.edu/

For more than a decade, my colleagues and I have been talking about the growing interest in applying the tools of materials science and archaeometry to examine the global flows of pottery in the early modern and modern worlds.  We spoke about a number of challenges--the scale of the research area, the size of a database necessary to make meaningful statistical arguments, the movement of raw materials and skilled workers within and between geographic regions, the hesitancy to emphasize the value of scientific analysis vs. interpretive practice in American historical archaeology, and the reluctance of anyone to systematically dedicate real-dollar funds to support an overwhelmingly global scientific effort.

After so many years, we are finally going to gather and talk about the issues and perhaps develop a plan.  There has been a clear florescence of research in this area.  If you look at the scholars scheduled to present their work, and the content of their presentations, I think you'll agree that this will be an exciting meeting!

I am honored to participate and gratefully thank the Department of Social Sciences at Michigan Technological University. My department provided some of the financial support I needed to attend the meeting and speak about the Utah Pottery Project.

You can review the Congress program and speakers here:

http://grupcongress.eventszone.net/myCongress5/uploads/documents/pottery12/programmeGP1definitiu.pdf

Lecture at the University of Illinois, Urbana-Champaign, February 24th, 2011

The Utah Pottery Project: Historical and Industrial Archaeology of a Pioneer Industry

Sponsored by the Department of Anthropology and Program in Archaeology at the University of Illinois, Urbana-Champaign.

Location: 209A Davenport Hall, Thurs., February 24, 3:00 pm

Presented by Dr. Timothy Scarlett

Associate Professor, Director of Graduate Studies

Industrial Heritage and Archaeology

Department of Social Sciences

Michigan Technological University

The Utah Pottery Project began as a study of the social business of potting in nineteenth-century Utah, one of the “folk hearths” of the United States. In establishing the project, I sought to design a study that capitalized upon archaeology’s interdisciplinary potential in the broadest sense of that term, intertwining the sciences, arts, and humanities in a single intellectual effort. Now that we have demonstrated the power of this approach, the study is evolving in two directions. First, my collaborators and I continue expanding archaeometric and historical analyses of trade and exchange, tracing routes of social interaction and weighing their significances. At the same time, we have begun detailed, ecobiographic studies of individual potters, shops, and potting groups. Immigrant potters had backgrounds that varied from industrial workers and managers to artisanal apprentices in many different social and technological contexts. The colonization of Utah provides an opportunity to study individuals engaged in social processes which otherwise appear as anonymous in the archaeological record, of particular interest are technological creativity, technology transfer, adaptation, and landscape learning.

Lecture in Salt Lake City, Friday, May 7th.

I am giving a lecture next Friday at the Church History Museum in Salt Lake City.  I will speak at 7 P.M. in the museum auditorium, and their new exhibit of pottery will be open.  The exhibit grew out of the Potters of the Gathering show from last year, but is a new show curated by Kirk Henrichsen.  They will have several archaeological objects on view from both the Utah Pottery Project and Utah State Parks collections, as well as antiques from the Gary and Jill Thompson Collection and the Church History Museum's own collection.

I will talk about last summer's excavation of the Davenport Family Pottery Shop in Parowan.  The museum asked for my abstract and title, and this is what I sent:

Ten Years of The Utah Pottery Project: Archaeological Questions and Answers.

After more than ten years of preparation, Timothy Scarlett led industrial archaeology students last summer to undertake the first major archaeological excavation of a pioneer-era Latter-day Saint pottery shop. In an illustrated lecture, Dr. Scarlett will overview the scholarship of Utah Pottery Project and explain the last summer's discoveries at the site of the Davenport Family Pottery Shop in Parowan, Utah (1855-1888). The results of that excavation and ongoing laboratory research open a fascinating window into challenges and struggles faced by Utah's nineteenth century potters and their families.

Congratulations to Jessica Montcalm

On Thursday, April 22nd, Jessica Montcalm successfully defended her Master's Thesis in Industrial History and Archaeology, which she titled: A Burning Question: Archaeology at the Davenport Pottery and Technological Adaptation in the Mormon Domain.

While she has some revisions and editing to finish, her committee was impressed with how much she had learned and accomplished over the last year.  Many of this blog's readers will recall that Ms. Montcalm was the assistant archaeologist during the excavation and field school last summer.  She volunteered her time over the past year both processing and cataloging artifacts in the lab, while also supervising other volunteers in the lab.

I will discuss some of her findings when I speak at the Church History Museum's exhibit opening early in May.

Congratulations to Jessica for all her hard work.

This is the penultimate abstract:

The archaeological excavations and the associated artifact analysis at the Davenport Pottery in Parowan, Utah, serve to inform questions of landscape learning and technological adaptation in unfamiliar geographic settings. Thomas Davenport and his family immigrated to the Utah Territory from Brampton, England, in order to answer the call to gather issued by the leaders of the Church of Jesus Christ of Latter-day Saints. He, along with thousands of other settlers moved into and occupied a geographic region unknown to their prior experience. Studies of prehistoric peoples' colonization of unfamiliar landscapes indicate that unfamiliar and challenging geographical surroundings hinder successful or long-lasting colonization. By contrast, the experience of the Mormon settlers, including Thomas Davenport, provides a unique situation for inquiry in which a large population made use of exhaustive planning and active restructuring of unfamiliar geographic settings, resulting in successful and lasting settlements. Analysis of the archaeological remains associated with the kiln at the Davenport pottery shop provide physical evidence of one man's learning in an unfamiliar landscape. The remains also highlight cultural preferences as a basis for technological choice, and lend to an adaptive technological discussion regarding the form of kiln used by Davenport.

News update: the good, the bad, and the ugly.

The good news:

Now that the academic semester is almost at an end, I will spend a bit of time on the project preparing some artifacts for a new exhibition!  The Church of Jesus Christ of Latter-day Saints' Church History Museum is going to install a version of Potters of the Gathering in their lobby.  The exhibit will open May 7th.  Kirk Henrichsen is using pottery to remind people about nineteenth century foodways and domestic life, to explore the ideal of self-sufficiency in Latter-day Saint communities, and to show people how important archaeology is as a tool to increase our understandings of the past.

Mr. Henrichsen has gathered together some new material for this show.  He will be using most of the important objects from the original exhibit- including the Thompson Collection, the Utah State Parks Collection (including the Deseret Pottery artifacts), and the Utah Pottery Project collection.  He has also found some other cool items to include, such as a Deseret Agricultural and Manufacturing Association Medal from the Territorial Fair, which will be displayed with some award winning pots!  It should be a great show and will be the first time most of this material has been exhibited to the public in Salt Lake City.

The museum has invited me to give a talk at the opening and I am excited to see the new installation.

The bad news:

Both organizations declined the proposals I'd written seeking funds for more work.  One of the grants would have supported additional fieldwork. The other sought funds to allow more experiments to develop and refine ceramic rehydroxylation dating (RHX dating).  No matter how many times it happens, reviewers rejections always sting a little, even when accompanied by encouragement to "revise and resubmit."

Either way, the lack of support funds means that we will box up the artifacts and put more of the analysis on hold for the summer.  I'll be co-teaching the 2010 Industrial Heritage and Archaeology Field School this summer at the site of the Cliff Mine in Keweenaw County in Michigan's Upper Peninsula.

I'll continue to collaborate with my friends in Materials Science.  Since Patrick Bowen was awarded two grants for undergraduate research, we will move as far ahead as we can investigating reydroxylation.  I think he will work with Jarek Drelich to characterize the clay and ceramic used by the Davenports and try to figure out the significance of the different water-absorbtion processes at work in ceramics.

We'll reflect on the reviewers' comments for a few days and then meet to plan the strategy for the rest of the summer and the fall term.

Congratulations to Patrick Bowen

I am pleased to congratulate Patrick Bowen, Michigan Technological University undergraduate student in Materials Science and Engineering.  Mr. Bowen won two major fellowship competitions and he was awarded funds for his ongoing collaborations studying rehydroxylation dating of archaeological ceramics.  He was awarded one of Michigan Tech's Summer Research Experience for Undergraduates (SURF) Fellowships as well as a Michigan Space Consortium Undergraduate Research Fellowship.

Patrick has been an important part of the interdisciplinary research team that Jarek Drelich and I put together to assess this newly published dating technique.  Mr. Bowen, Helen Ranck, and Jessica Beck, three MTU undergraduates in the Departments of Materials Science and Social Science, did exceptional work designing tests to assess the usefulness of RHX Dating for the Utah Pottery Project.  Patrick is presenting the preliminary results of their analysis at MTU's 2010 Undergraduate Research Expo.

The SURF and MSC Fellowship programs are both very competitive and I am proud of Mr. Bowen for his successful applications!

We are waiting to hear decisions on the proposal I wrote to support more field research as well as a National Science Foundation proposal to support more research into Rehydroxylation Dating.

I'm keeping my fingers crossed on our outstanding proposals!

Ash Glazes and the Curious Pits

Last week, I arranged for a local glaze technician, Derik Spoon, to stop in and take a peek at some of the broken bits of pottery still out on the table. Long background story short, I took a pottery class at the local arts center, and imagine my surprise and excitement when the instructor informed us that he just moved to the area from a job as a glaze tech with a major producer of glazes available commercially to ceramic artists across the country... He agreed to stop in and take a look at what we recovered.

He immediately identified the type of glaze used on all of the pieces we had out on the table, and what he had to say ran contrary to everything we thought so far. Derik informed us that every piece on the table was glazed with an ash glaze.

Ash glazes, as Derik explained, are the simplest of glazes to make, consisting of processed ash mixed with clay and water. The ash typically is soaked and filtered through water to draw off the majority of the heavy alkali materials (a convenient by-product of this process is lye, a key ingredient for soap making; it would have been a sought-after product in any pioneering settlement with limited contact to larger supply networks), before being mixed with refined clay. Water is then added to the mix, and the mixture is applied to the vessels. Ash glazes leave very identifiable (to a trained glaze technician) markers on ceramics, including pooling or streaking of colors, and often a gritty appearance on the surface of the vessel. The effects of the glaze naturally differ depending on numerous factors such as the type of wood ash used, the type of clay used, the ratio of ash to clay to water, the firing time and temperature, the amount of fly ash in the kiln during firing, and the final cooling time of the wares in the kiln.

This all leads up to a new theory regarding the "random" ash pits located toward the front of the lot and the enclosed area of clay-like hard pack. These areas could very well have been where Thomas and the family were processing ash with various inclusions (bone, bisqued ceramics) for the purpose of color/effect experimentation, before mixing the ash with the refined clay to glaze the pottery. The material in the enclosure could be the refined clay used in the glaze mixture, or a large, ready supply of pre-mixed clay and ash drawn off of the neighboring ash pits. In any case, this is a very exciting revelation, and it offers possible explanations to the question, "What in the world was going on over there?"

Video of Carol Wright

This short video captures Mrs. Wright's visit to the Davenport Pottery Site in June of 2009.  I am telling her about what the archaeology has taught us about the history of the pottery.  You can see that I am showing her how well her sketch map matched the magnetometry data and our discoveries underground.  I also think you can see her smile at the end.

Mark Dice took part in our field school this summer.  It was his first experience with archaeology.  Mark is a teacher and musician, and he is also a talented media specialist. Mark owns Dice Video and I am very grateful for his help as part of our research team last summer as well as his willingness to share his media kung-fu with us!

Carol Adams Wright, 1908-2009

This weekend, I was saddened to learn that "Christmas Carol" Wright died last October.  I had not heard the news until now, so I set aside a moment in my workday this morning to reflect on Mrs. Wright's contributions to the Utah Pottery Project research effort.

Mrs. Wright was Thomas and Sarah Davenport's great-granddaughter.  Carol was born to Thomas Davenport Adams and Luella Redd Adams on Christmas day in 1909, an event for which she earned her nickname "Christmas Carol."  The potters, Thomas and Sarah Davenport, were Carol's father's mother's parents.  Carol's grandmother's siblings spent their youth working in the pot shop, perhaps also her grandmother at times. Carol's father worked at the shop when he was young and also spent his youth paying amid the shop's ruins before they were torn down.

Carol was practically a living eye-witness with first-hand knowledge of a Utah pottery.  When I first met her in 1999, her memories of her youth and the stories told by her parents and grandparents were still sharp and clear records of the mid-nineteenth century.  She welcomed me into her home and shared all her knowledge with me, at a time when I was a total stranger in the community.  I had simply knocked on her door to ask about the history of empty lot next door.  The sketch map that I drew with Mrs. Wright in 1999 guided our excavations and her stories helped us to find the shop's clay beds.

To the best of my knowledge, she was the last person in that generation in the entire state of Utah.  The last to talk with people that had worked at potting to make a living.  While some may still recall the Ogden or Provo factories of the 1920s and 30s, Carol had living memory from a pioneer-era pot shop.

I will forever be grateful that Mrs. Wright shared her stories with me.  She was trusting, open, and kind when I was a young student-researcher, living out of my old truck, and walking around town with little else except my dusty notebook and enthusiasm.

Rest in peace, Mrs. Wright.  Thank you.

Several Utah newspapers and ABC News 4 printed her Obituary last October, in 2009.

Lab Update- Dec. 3, 2009

Jeffrey Lee and Allison Mehlenbacher have been working hard with Jessica Montcalm, washing, cataloging, and labeling the fragments of Davenport-made ceramic from the cellar pit feature at the site.  Their efforts have begun to yield fruit!  This week they finished labeling the artifacts from level 12, the largest and most densely packed layer of pottery waster fragments in the feature.  

Jeff and Allison are now starting to sort out another level:

Now that the individual pieces are labeled, they are beginning to reconstruct ceramic vessels.  This is like doing a jigsaw puzzle, but where someone removed 2/3 of the pieces, scratched off the puzzle picture or pattern, and warped, charred, and burned those fragments that remain.  Despite those challenges, Jeff and Allison have already been able to substantially reconstruct two basins.  I'm not sure what this vessel form is, but we are all excitedly discussing various possibilities!  They are deep, tall basins with wide mouths, straight, but sloped sides, and flat rims.

Rehydroxylation Dating-- 10-21-09 update

Our collaborating student researchers are making steady progress in their efforts to replicate the ceramic rehydroxylation dating technique published by Moira Wilson and her colleagues over the summer. If you wish to read all my posts about rehydroxylation, click here.

Helen Ranck, Patrick Bowen, and Jessica Beck have been working on different parts of the problem and they've learned a great deal so far.

Here is one of Helen's graphs that describes the mass gain of one of her test samples:

She and Patrick have been trying to find out the best way to keep the sherds at a constant temperature and atmosphere while the fragment absorbs water. Patrick has discovered some key changes in practice that have really helped reduce the variation in calculated dates, bringing the projections closer to our expectations. Jarek Drelich, associate professor in Michigan Tech's Materials Science and Engineering department, has been very helpful working with them both.

Jessica Beck has finished some of her testing. She calculated the porosity of a group of the sherds using a methodology outlined by the National Institute of Standards and Technology (NIST). Jessica discovered that the Davenports' earthenware ranges from 10%-15% porous, and that both the median and the mode will be around 13% or 14%. I'm looking forward to her final conclusions and her estimates on firing temperature as revealed through her other testing!

Lab photo update

The students are working on their projects and Jessica is making progress on cataloging the collection from the Davenport Pottery site dig.

Max and Allison are cataloging their pottery frags and getting ready to start their cross-mending study.


Frank is studying the charcoal we recovered from our flotation of sediment samples. He hopes to describe the Davenport family's choices for fuel use when firing their kiln. He's examining little chunks of charcoal with an optical microscope.


This week I also taught the students the basics of archaeological drawing, drafting, and illustration. We learned by drawing two random objects from the stuff that I keep around the lab for activities just like this. This year we drew a mini-terra cotta warrior, lent to us by Pat Martin, and a model of someone's thumb.

Jeremy was doing a measured drawing using drafting tools.

After working with measured drawings, we also used digital photographs as tools to produce our drawings, but still working free-hand. I taught them stippling, a standard technique for technical illustration. Alison is drawing the thumb in these photos.

This photo and drawing are of the same thumb, but don't show the same view. You'll notice that the light falls from the left in the photo and the right in the drawing. This drawing was by Jessica Beck and was her first attempt to anything like this!

The students didn't finish any drawings, since these objects were just for exercises. If anyone ends up drawing objects in their project, we'll post the final drawings here. Over the summer, we also did technical drawings of the pottery in the Utah State Parks collection. Perhaps we will post some of those drawings as well.

Bleeding for my craft

Hi All,

A brief update from the lab. Today I taught the students how to make stone tools, often called "flint knapping." Several of the students were really looking forward to this activity. They were pretty excited to try working the obsidian nodules into biface tools.

I'm afraid there weren't any budding Homo erectus the group, but they could have passed for Homo habilus.

All in all, however, they did better than Jessica and me. The total injury count (requiring band-aids):

Professor: 2

TA: 2

Class: 1 (and there are five of them!)
Next week, we are going to talk about glassmaking and archaeological analysis of glass, but we will also pull out the lithic fragments from the Davenport site and apply some of the practical skills everyone learned, using the new vocabulary to say, "This is the proximal and medial segment of a secondary reduction flake, complete with hackle lines and an eraillure scar indicating the striking platform above the bulb of percussion."

Mobile blog post

154 Years Ago This Week

A little while ago, Noel Carmack emailed me about our research on the Davenport Pottery. Mr. Carmack teaches painting and drawing at the College of Eastern Utah. He wrote to me because he and Charles M. Hatch are just finishing a manuscript for publication with USU Press. They have edited the journals of James Henry Martineau, an early resident of Parowan and a surveyor.

Mr. Carmack wrote to me that he'd discovered something in Martineau's diary and he wanted to exchange information. In particular, he said to me that on October 29, 1855, Martineau had written:

"Oct. 29/To day, Thomas Davenport opened his kiln of Pottery. This is the first ever made south of Provo. I got two jars, some bowls and two meat dishes."

I was very excited by this reference because this diary entry had captured the exact day when the Davenports opened their first kiln of ware produced at their shop in Parowan. Readers that have been following the blog will remember Thomas's words transcribed from his now missing diary:

"I arrived in Parowan on November 4, [1852]. . . . I farmed and worked at my pottery trade until November 1855. I burned my first kiln, but it was nearly all broken. . . . I had another son born, but he only lived until August and died of the flu. . . . I burned another kiln of pottery but it was mostly broken. In the fall of 1856 we [Thomas and Sarah Burrows Davenport] got our endowments at Salt Lake City and stayed there until the spring of 1857. I then burned another kiln and about one third of these pieces were good. In 1851 [sic; 1859?] I built a house with six rooms and we moved into it. I had now learned to burn my ware without breaking it" (Nielsen 1963: 103).

Martineau's diary shows us that this transcription of Thomas Davenport's diary is probably accurate and that the Davenports opened their first kiln on October 29th, 1855------ 154 years ago (next week)! We also know that it took almost exactly three years to the day for the Davenport family to set up their household, farm, and shop until the first kiln firing.

My deep thanks to Noel for emailing me with this information.

Rehydroxylation Dating-- testing a new tool!

While we were digging in the field this summer, a team of seven materials scientists (led by Moira Wilson) from the University of Manchester and the University of Edinburgh and Ian M. Betts, an archaeologist with the Museum of London, published a paper in the Proceedings of the Royal Society A called "Dating fired-clay ceramics using long-term power law rehydroxylation kenetics."

Three Michigan Technological University students, Helen Ranck, Patrick Bowen, and Jessica Beck, are trying to replicate the technique.

Materials scientists and engineers have known that ceramic minerals slowly reabsorb water from the environment after they are fired. Dr. Wilson's team discovered that the rate at which environmental water recombines with clay minerals as hydroxyls is governed by a kinetic law at the nano-scale. They found that the rate was influenced by temperature, but was not changed by the quantity of water present in the environment.

Scientists could actually measure the rate of water mass gain for any given ceramic fragment by heating a sample in a kiln and then waiting and measuring the increase in mass as the clay molecules slowly recombined with environmental moisture at a known temperature. Lab researchers can then calculate the date of firing with these known measurements:

1. This determined rate of water mass gain.

2. The mass of the sample after excavation (when it contained all the re-bonded water).

3. The mass of the sample after the test firing (mass of the ceramic fragment minus the molecularly recombined water mass that it had absorbed since it was fired).

4. The average temperature through time the sample experienced since firing in the depositional environment.

Of course, including the +/- error, universal in archeometric dating.

If this technique works as well as the authors assert, it will add another powerful tool to archaeological techniques around the world. It will also revolutionize the Utah Pottery Project. Remember that one of the main goals of our archaeological research is to reconstruct the learning process through which these individual potters or potting groups, such as the Davenport family, adapted their skills and knowledge to Utah's new environment and raw materials.

One of the biggest problems we've had is that we can not use the ceramic fragments themselves to date the features full of broken kiln wasters, such as Andy's excavation of the cellar feature this summer. We rely upon stratigraphic clues (that waster pile is older than X, but younger than Y) or other artifacts found in the deposits, like stylish imported ceramic fragments, which can be dated. The features full of industrial wasters only rarely also contain other clues, however.

There are some other archaeometric techniques archaeologists use to date ceramics directly, such as Archaeomagnetic Dating and Optically Stimulated Luminescence. These techniques are useful also, but are either very specific to only work on kiln foundations (archaeomagnetic) or expensive and require expertise we don't have (OSL or TL). Either way, most of those techniques work better when applied to the distant past, and not the nineteenth century.

Historical Archaeology is like ethnoarchaeology in many ways. Given that we are studying people and sites in the historic period, we know a great deal more about accurate temperatures than archaeologists studying deep antiquity. I have the advantage of knowing the year, and even the month, during which some of these ceramics were fired. I hope we can test and refine the technique to higher levels of precision.

If this technique works as described, we will have an inexpensive tool that will allow us to build direct chronologies from the waster fragments. We will be able to sort the Davenports' waste into categories and know which ones reflect the steep learning curve from the 1850s and which pieces have clues about ongoing improvement and the training of the next generation of potters!

Moira Wilson corresponded with me over the summer while we were digging, and I appreciate her encouragement to consider application of her team's work. I am excited to be working with this puzzle with Jaroslaw W. Drelich, an associate professor in MTU's Department of Materials Science and Engineering. The original article appeared here. Useful discussions and interesting commentary about rehydroxylation dating appeared here, here, and particularly here.

First Fall Term Update!

The Utah Pottery Project is back on-line at this blog and on Facebook!

After a long break from the research blog, I am again posting updates. Starting today, I will write about our laboratory research. As we wash, catalog, and label the artifacts from last summer's dig at the Davenport Pottery Site, I'll post progress reports and connect the fieldwork with our lab analyses. Several interesting analyses are developing, and I will post updates when I can.

If I'm lucky, perhaps some of the students will write about what they are trying to learn in their projects.

There are several people helping out with the lab work and analyses right now. Jessica Montcalm, the project field director, is leading the processing of the artifacts in the lab, managing the flow of cleaning, conserving, and cataloging. Frank McGuire has also continued on since his time in the field. He has been helping Jessica to process the finds. This week, Frank and Jessica finished floating the soil samples taken during the dig this summer. The students enrolled in my Archaeological Sciences class helped with this process as they learned about floatation, archaeobotany, and geoarchaeology during the first few weeks of the term.

In this picture, Frank is measuring sample volume and mass before floatation.

After putting samples of dirt from different features and soil layers into water, light organic matter floats to the surface where we catch it for analysis. This method allows us to find seeds, charcoal fragments, bits of wood and shell-- lots of detail about the environment surrounding the site!

Jessica and Frank have help from some of the students enrolled my Archaeological Sciences course at Michigan Tech. Some of the class members have elected to study the Davenport Pottery dig artifacts for their semester research projects.

Allison and Jeff have decided to study the artifacts from the cellar feature that Andy excavated over the summer. They are going to help clean and label all the fragments from this feature so that they can try reconstructing all the broken pots. They will take out all the sherds, like the large ones pictured in the bucket below, and spread them out on the lab tables like a giant archaeological jigsaw puzzle!

Filling the units!

Filling...




Mobile blog post

Backfilling and the Future

Today we will backfill all our units.

The research now transitions into the lab and the library. The blog won't end here. Over the summer, we'll make more entries about the other excavation units. Perhaps some of the students will finally write for the blog and post photographs. Jessica and I will keep updating the blog all next year during the analysis and write up, as we complete artifact analyses, lab tests, and experiments.

These are some of the overall site pictures that we took before sunrise yesterday, when the City of Parowan lent us a cherry-picker bucket truck.

This picture shows the relationship between the kiln, the cellar, and the northern workshop building.

Here is a detail shot of the kiln, showing the fully excavated firebox, flue, and outline:

Another overall shot that shows the relationship between the opening of the trench that leads to the firebox and the opening of the workshop basement door:

A great picture of this great crew on the last day, just before we broke up for our final jobs:

Lines in the sand (and ash, bone, and pottery)

As Frank and myself opened up the new unit 26s 18w it was because of a promising shovel test pit between 26s 18w and 28s 18w.On the magnetometer reading there was an anomaly located there, which we thought might yield another kiln or industrial structure (having found one kiln we were anxious to locate another). At the bottom of the test pit we found pieces of brick and also some clay and ash. To the left is a closing picture of 28s 18w, with the shovel test pit to the north and what turned out to be Dr. Scarlett's shovel test pit from 2001. In the bottom right corner there was another ash pit, and by the end of both 28s and 26s Frank and myself would be buried under a myriad of forms relating to these puzzles. With an old shovel test pit and an ash pit found, we turned our attention to 26s 18w, north of the unit pictured in an attempted to locate a possible foundation.

During the course of our dig in the unit we found numerous ash pits, a pile of pottery and household waste, and some fence posts from the 20th century.To the left, you can see an ash pit in the top of the unit with the ash, bone, and pottery pit in the center and the shovel test pit towards the bottom. While a foundation failed to materialize we did uncover some very interesting stratigraphy, or layers of soil in the side walls. It looked as if pits has been dug, filled with ash and other debris and had nearby topsoil layered over it.

So as Frank and myself dug out the ash, bone, and pottery debris pit in the center of the unit we got about 20-25cm down. However, if we had stayed in the center of the unit we might have missed the bigger picture in 26s 18w. As this picture show, the side walls brought forth much more questions. The dark ash pit it the far wall and then towards the right the ash and clay that was at the bottom of the test pit. Also the debris at the bottom of the shovel test pit turned out to be a ash and clay pit dug into the surrounding reddish brown soil (which can be seen to the left of the picture). So what we had in this unit were four ash pits dug into the soil, maybe at different times; all of the pits were covered with the reddish brown soil. One possible answer is they were dug then covered over by nearby topsoil? Still the question remains, why dig a pit to throw ash, bone and pottery in when the ash and pottery could have been left on the surface.

In the end the soil came to the reddish brown layer with no remaining ash pits-and we had some great examples of stratigraphy.In the picture to the right you can see

e the dark ash pit suspended in the side wall, higher up than the bottom of the ash, bone and pottery pit that was in the center. Usually the older artifacts are buried deeper in the soil; however with the various heights of the deposits that basic idea is also called into question in this unit. We found some great pieces of local pottery in the central pit, two fence posts and some great differentiation in the soil of the side walls. Each day brings us a more complete understanding of the site, and even more questions regarding the uses and functions of simple features like ash pits.