Ur Project: January 2015

Pseudomorphs on Metal Objects from Ur
A closer look at U.14097 and U.9134 (Penn Museum Nr. 31-17-241 and B17476)
Chisels from PG 1653 and PG 537

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This month’s Blog entry is written by researcher Kyra Kaercher with technical assistance from conservator Tessa De Alarcon. Special thanks to the Conservation Department for the macro photo details of the objects.

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As the Kevorkian Fund Research Assistant working on the Ur Digitization Project, I work with the objects from the excavations and try to match them to Woolley’s records. The past few months I have been focused on the metal tools and weapons, specifically the copper alloys (copper and bronze). When I first started on this project, I noticed the copper alloys fell into two distinct categories. One was reddish-brown, metallic, and had pitting on the surface. The other was blue-green with different textures on the surface. After talking to our conservator, Tessa De Alarcon, I learned the reddish-brown pitted metals are probably caused by an electrolytic reduction treatment of the copper alloys, and the blue-green metals have not been treated with this treatment. I have looked at about 45% of the metals from Ur that are located at the Pennsylvania Museum, and 48% of them were probably electrolytically reduced.

Electrolytically reduced on left and not electrolytically reduced on right.

Electrolytically reduced on left (B16432) and not electrolytically reduced on right (B17476).

Electrolytic reduction treatment was used in order to protect the copper alloys from corrosion. The treatment uses an electric current run through a ionic solution. This method removes the cuprite, or corrosion caused between the copper alloy and the soil minerals. Sometimes a thin layer of new metal is laid on the surface of the object if the solution is not changed regularly. This makes it hard for more chemical analysis to occur, especially surface analysis such as XRF.

Of the remaining 52% of copper alloy objects examined, 33% have pseudomorphs. Pseudomorphs are a mineral compound that appears in an atypical form. Common pseudomorphs are petrified wood and fossils. In metals, pseudomorphs appear where metal has replaced the organic material that is either part of the object, or that the object was lying on when buried. The pseudomorph retains the appearance and dimensions of the original material. The most common pseudomorphs on the metals from Ur are wood, leather, rope, textiles and basketry. The mineralization of the material sometimes contains enough detail to specify the genus and species of the organic.

The two objects I looked at more in-depth were U.14097 (31-17-241) and U.9134 (B17476). These objects are both chisels found in personal graves. U.14097 was found in PG 1653. It is the only object from this grave, and Woolley publishes neither the object nor the grave. U.9134 is one of several objects from PG 537. This grave included spearheads, daggers, a mace, and a saw. Woolley dated this grave to the Early Dynastic III Period (roughly 2600 – 2400 BCE).

Fiber pseudomorphs on U.14097 (31-17-241).

Fiber pseudomorphs on U.14097 (31-17-241).

The fiber pseudomorphs that appear on the chisel from PG 1653 can tell us much about the way rope was manufactured and used at Ur. These pseudomorphs are an example of positive replacement where corrosion products replace the fiber as it decays, forming a positive fiber cast. The close-up view shows us a small string that is braided. Most natural fibers are spun as either an S-spin which is to the right, or a Z-weft which is to the left. This fiber is an S-spin in the single threads that combine to form a three string braid. This object was probably laid on or in a coil of the fiber because it is in a random pattern around one end of the chisel. If the fiber was attaching something to the chisel, or wrapped around one end, a pattern would appear. The preservation of the pseudomorphs is to such a degree that the fiber can be further analyzed, and researchers might be able to identify the species of the fiber.

Textile Pseudomorphs U.14097 (31-17-241) on left, U.9134 (B17476) on right.

Textile Pseudomorphs U.14097 (31-17-241) on left, U.9134 (B17476) on right.

Above are two examples of textile pseudomorphs from the copper chisels. On the left is an example of positive replacement, and on the right is an example of negative replacement. The positive replacement creates a cast of the textile, whereas the negative replacement creates an impression of the textile. In U.14097, the textile is woven, as one can see the individual strands are interwoven with each other. In a better sample, the pseudomorphs may point to a difference between wool and plant fiber (like linen) material. In U.9134, the textile left a very strong vertical impression, and there is some horizontal impressions as well, pointing to a woven textile. These textiles point to the chisels being laid on or near the body probably in association with clothing or they were possibly wrapped in some sort of cloth. The portions with pseudomorphs are not large enough to get a pattern to see if the wrapping was intentional or not.

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Basketry/Matting Pseudomorphs on U.14097 (31-17-241).

 

Above is an example from U.14097 which includes pseudomorphs of basketry or matting. In comparing this specimen with the textiles, we can see that both are woven. However, this is made from a thicker material like reeds rather than fiber. The thicker material points to a plant fiber, which is found in basketry or matting. With the help of a specialist, this plant fiber might be identified down to the species.

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Wood Pseudomorphs on U.9134 (B17476).

 

Wood pseudomorphs like those found on U.9134 can be determined by the pattern they leave on the metals. The wood pseudomorphs replicate the cell walls of the wood, leaving an exact copy of the structure. The wood species can be identified based on this replica, and changes to the wood and the soil around the wood can also be detected. Like the fiber, textiles, and basketry, it looks as if the chisels were laid on the wood, rather than being embedded in the wood. On objects such as the axes, wood pseudomorphs appear in the sockets, showing the objects were buried hafted to a wooden handle.

One object may have multiple types of pseudomorphs, showing how the object is made or used. The two chisels shown above were laid on different organics that were then preserved on the chisel itself. Pseudomorphs are useful in that they show organics, that have deteriorated, to such a degree they can be identified down to the species level. This gives us the opportunity to learn much more about the use of these objects, as well as the material used to create these objects. Our website, www.ur-online.org, is up and running, but is still a work in progress. It contains many more images of these objects as well as the other objects in PG 537.

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Sitio Conte in Real Time: February 2, 1940

Came down on a cache of a half dozen apparently complete vessels this afternoon which will be photo’d and taken out tomorrow. A few gold beads found by the workmen in the soil. Also today began to uncover a great mass of broken pottery.

-J. Alden Mason to Horace Jayne, February 2, 1940

In his first letter to the Museum since arriving in Panama eight days earlier, Mason wrote to Director Horace Jayne about their progress thus far. He briefly described their campsite (“everything is perfectly lovely to date”), initial excavation finds (“have found plenty of sherds so far”), and his dwindling budget (“naturally everything has cost about twice as much as the budget allowed”). Even though they suffered insect bites, the team was fairing well, as the “old camp cook who is a find…makes cake, pie, cinnamon buns, etc.,”!

Anticipating the arrival of Robert H. Merrill, surveyor, engineer, and photographer for the expedition and John B. Corning, a research associate in the Museum, as well as Corning’s wife, Julia, to the site, Mason included a post script stating that all had arrived “tired & hungry” that evening.  Now that the whole team was in place, the full scale excavations could begin!

It only took a matter of days for the local workmen, numbering between 20 and 30 each day, to clear out and construct the base camp for the excavation team. Over the course of the 8 days, they’d built a pier and steps to the river, dug three latrines, began construction on two camp houses, three tents, a kitchen, a shelter for the laundress, and a storehouse.

In his description of the sherds and skeletons found so far, Mason wrote that: “today [they] began to uncover a great mass of broken pottery. If you don’t remember the set-up they apparently threw vessels into graves and the fragments scattered over a wide area, and then they walked on them. So hundreds of sherds must be brought home, sorted and the vessels repaired.”

But with thousands of sherds being uncovered, how would Merrill, the surveyor and photographer, be able to accurately record and document all of them for later research?

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Blue lines: multispectral imaging for pigment identification

Visible-induced infrared (IR) luminescence is the invisible light that some materials produce when they are excited with visible light. We can capture that invisible light with a modified camera and use it to identify those materials and find out where they are. For those of you who follow the Artifact Lab Blog, this technique will sound familiar. Molly Gleeson used it to identify Egyptian blue on a shabti box that she was working on. Guess what? The technique can be used to see other materials too! In examining a 12th-century Islamic manuscript, NEP27, I needed to find a way to distinguish between indigo and ultramarine. Both are blue in visible light. Both are made with elements that are below the detection limits on our pXRF, our usual go-to method for elemental analysis.

Detail of marginal elements on page 360 of NEP-27. Notice the blue outlines around the gilded designs.

Detail of marginal elements on page 360 of NEP-27. Notice the blue outlines around the gilded designs.

It was starting to look as if I’d need to take a sample to examine with our polarized light microscope and possibly send out for x-ray diffraction, when my colleague, Tessa de Alarcon, remembered a single sentence in an article on Egyptian blue and Han blue, the same reference that Molly used for her work. What did it say? “The emission of indigo is reported to be at c. 750 nm while that of lazurite at c. 830 nm.” (Verri, 1012) There it was in black and white. The secret to a non-destructive method for answering the question of indigo or ultramarine. Those numbers are the wavelengths of light that they produce when excited. Both are in the infrared range and invisible to our naked eye, but we can see them with our camera. Lazurite is the color component of ultramarine, so if it has emissions that are different from indigo, maybe we could use filters to separate them.

To find out if this would work, I found a couple of dry pigment samples, mixed them up with gum Arabic, and painted them out on a swatch of paper. With this set of knowns, I set up the Mini-CrimeScope, our tunable light source, and the modified camera to try different light and filter combinations. It turned out that only the ultramarine luminesced with exposure to light centered around 455 nm. Using this set up, I tried it out on the manuscript, and sure enough, the blue decorative elements fluoresced just like the natural ultramarine sample.

Detail of page 360 illuminated with 455nm light captured in infra-red, grey scale. The blue lines seem to disappear and are hard to distinguish from the paper. They didn’t disappear though; they’re fluorescing!

Detail of page 360 illuminated with 455nm light captured in infra-red, grey scale. The blue lines seem to disappear and are hard to distinguish from the paper. They didn’t disappear though; they’re fluorescing!

The false color image helps to visualize which areas are luminescent. In the photo, the information from the IR photo replaces the red channel, so the red lines around the decorations are the luminescent parts . Or in this case, the ultramarine!

Detail photographs of page 360 illuminated with visible light and with 455nm light captured in infra-red combined into a false color image. The blue lines now appear red, helping to show where the luminescence took place.

Detail photographs of page 360 illuminated with visible light and with 455nm light captured in infra-red combined into a false color image. The blue lines now appear red, helping to show where the luminescence took place.

This wasn’t true across the board, but the blue decorations don’t look the same throughout either. I’m not sure if this means that ultramarine was used in some areas, but not others, or if different sources of the pigment have enough variation to produce different results. My samples included different sources for the ultramarine, which were also variable with their luminescence, so I’m thinking that the luminescent component might be variable depending from batch to batch. I’m still working on the details to see if we can use this as a diagnostic technique, but this is a promising development!

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A Summer Day in the Village of Yassıhöyük

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YH fields mostly owned by the villagers

Farmers and shepherds begin work at daybreak. Fields surround the village in a 2-5 km distance. At daybreak, with the call to prayer local farmers are on tractors and modern harvesters; lorries start rolling across the landscape loaded with migrant workers that include women and children.

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Migrant workers posing in front of the camera

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Checking crops

In the fields wheat and barley are checked for ripeness, sugar beet and onion plots weeded and irrigated.

Soon the shepherd starts his long daily journey through the meadow, across the steppe vegetation toward Sakarya river, tingling of sheep bells fill the air:

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Morning milking of sheep

At the home front women are moving in a fast pace: milking, preparing breakfast for the men who will go home from sun-struck fields for late breakfast and a short rest before returning to the fields until lunch time.

Women, besides their daily chores of cooking and baking, washing, caring for young children, have to attend to food preparation for winter storage—jams from garden produce of dried apricot and sour cherries, sun-dried vegetables, tomato paste, pickled cucumbers and others from the vegetable garden; Turkish white cheese made from a combination of sheep and cow milk is put into tin containers to age till winter.

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Sub-basement storage of vegetables and cheese for winter

Some food preparations are more labor intensive such as cutting up macaroni from freshly made dough and “tarhana” soup. The latter is a super organic food, all ingredients are farm grown–it consists of yoghurt, flour, tomato, mint and red pepper, all combined and let to dry in the sun. It is then powdered and kept in jars. It is the staple food in the winter. Women generally work together on such activities which last several weeks.

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Food preparation in groups of relatives and neighbors

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In addition to food preparation, wool processing is also communally done by close kin; sheared wool is washed in the village fountain, dried and fluffed and stuffed into bedding.

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Wool processing, from shearing to carding

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Another time-consuming and manually done women’s task is applying plaster on mud-brick houses annually (both exterior and interiors).

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Annual plastering and white washing of mudbrick houses

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Thursdays are market days in Polatlı. Some villagers in the region bring their garden produce and cheese to the market. Women vendors take some time to frequent clothing stores and check out the gold jewellery in local shops.

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Thursday food market in Polatlı which is the district capitol, where from foodstuffs to animals, housewares are sold

Back in the village the day ends with a spectacular crimson sunset. As evening light settles on the distant landscape, the contours of the tumuli come into view. In the coolness of the evening farmers and shepherds return home, the sheep bells echo in the still of the night as a long line of white wooly sheep and goats traverse the landscape from a long, ardous hike. At home women begin to set the dinner table while the müezzin is calling for the evening prayer.

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A view over 110 tumuli near Gordion and the region

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Sitio Conte in Real Time: January 26, 1940

Tire trouble near Penonome. En route Panama to Cocle

1/26/40 Taken by S.K. Lothrop

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The Masons running a rapid in the Rio Grande de Cocle.

1/26/40 Taken by S.K. Lothrop

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Sitio Conte in Real Time: January 23, 1940

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Sitio Conte in Real Time: January 22, 1940

5 lbs onions $.30
10 tins Maxwell’s coffee 1# $6.00
6 paq. Salada tea $1.50
1 bag Flour Gold Medal 98# $3.25
25 lbs Chinese rice $1.50

Receipt from Compañia Kito Chen, S.A., January 22, 1940

On this day 75 years ago, J. Alden Mason went grocery shopping. So what do you feed a small army of diggers and day laborers in 1940 Panama? Check out the receipt from Kito Chen, S.A., a Chinese wholesale retail food company in Panama City, Panama.

As the receipt show’s, Mason purchased quite a variety of nonperishable foods and some general goods like toilet paper and washing soap. Not surprisingly, there are a lot of familiar brands on this list, like Fleishman yeast, Campbell’s Soup, Heinz, and Ivory soap.   Mason spent a grand total of $170.75 with this first food order for the expedition camp. Which, according to historical price calculators found online, equals somewhere between to $2,799.451 to $2,852.942  We arrived at these numbers based on Mason’s notes (and on Lothrop’s recommendations) that most of their camp accounts were kept in American dollars, accepted widely in Panama at the time.

Considering Mason’s work team could fluctuate between 7 and 30 laborers, depending on the scale of work to do for the day, I wonder how long it was before they had to restock the “Heinz Tomatoe Katsup,” the “Premier’s tongue” (whatever that is!), the “Maxwell’s coffee,” or the “Sardinia Honeymoon” to name a few?

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1 The Inflation Calculator
2 Historical Currency Conversions

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Sitio Conte in Real Time: January 20, 1940

We are going up to the camp early this afternoon to get things started, find out the lay of the land, and get a better idea of what to buy.

J. Alden Mason to John Corning, January 20, 1940

Finally in Panama after their “swanky” voyage on the Grace Line, Mason wrote to John Corning about continued preparations for the expedition now that some of the team had arrived.  Samuel Lothrop, of the Peabody Museum, who excavated at Sitio Conte nearly ten years early was working with Mason for the first couple of weeks.  Armed with Lothrop’s experience and connections in Panama, they were doing last minute shopping in the city before they made their way to the site to start digging!

01-20-40_letter1We have a copy of the contents of the box that Mason mentions Lothrop received back from Mr. Curtis.

01-20-1940_equipment-listThis is just a small sample of the tools and equipment that Mason and his team amassed. In addition to the items they brought with them, they made frequent trips to purchase things while in Panama, and still needed to have last-minute equipment shipped to them from Philadelphia during the expedition.

p.s. At the end of Mason’s letter, he adds that they “located in town Lothrop’s old cook who is apparently a Jamaican and talks English.”  So what do you stock an archaeological expedition’s kitchen with in 1940? Next up on Real Time in Sitio Conte!

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Fall 2014 Roundup of Student Events

[By Charlotte Matthai, member of the Clio Society–Penn Museum’s undergraduate student interest group]

Clio LogoDuring the fall 2014 semester, Clio Society went behind-the-scenes of the Penn Museum, meeting some of the people who make all of it possible and exploring the mysteries and hidden gems of storage. We met Jenn Reifsteck from Public Programs, who trained us on Cartifacts, an in-gallery program that provides hands-on experiences about topics related to Museum galleries. We also took a tour of ethnographic and archaeological storage areas with Collections staff to learn about different environmental requirements for the preservation of diverse materials.

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Clio Society members learn about the gallery Cartifacts.

Clio’s most memorable event was the Halloween Party in the Lower Egyptian Gallery. Decked in creative costumes, the Penn student community was invited to the event featuring re-created ancient board games, mummy room tours with Physical Anthropology Curator/Keeper of Collections Dr. Janet Monge, and a screening of National Treasure: Book of Secrets with hilarious commentary from our very own Penn graduate students, who proved to know way more about history and research than Benjamin Gates (aka the infamous Nicholas Cage)!

Later in the semester, Clio Society gave their first self-researched tours of the museum. What kind of tours, you may ask? At the beginning of the semester, Clio members picked an artifact or gallery that interested them and began research using the Online Collections, readings from classes, and from meeting with Museum Curators and Keepers. The tour included the Egypt, China, and Etruscan galleries, highlighting well-known artifacts and giving fresh insights onto less-popularly known objects as well. Creating these tours takes extra research and initiative, but these dedicated students enjoy it for various reasons, ranging from a way to delve deeper into one of their class subjects or as a way to learn about something new.

About the group: Clio Society brings together Penn students who share a common interest in and appreciation for museums, culture, and art. Members will gain a greater understanding of world cultures, arts and culture professions, and the museum field. We promote student awareness of the Museum’s collection, exhibitions, and resources, and host a wide variety of programs and special events specifically for students.

Halloween Party

All smiles while we set up for the Halloween event.

Halloween Party fun

Grabbing some food before the movie begins at the Halloween event.

For more information email cliosociety@pennmuseum.org
Find out about student events by following the student Facebook page.

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Sitio Conte in Real Time: January 17, 1940

Approaching Panama Canal after a lovely calm clear warm swanky trip. Pass thru canal tomorrow. Regards to all.

J. Alden Mason, January 17, 1940

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