Friday, July 25, 2014

Last Dig Day

Often archaeologists discover most of their finds toward the end of the dig. It's a bit of a frustrating conundrum! On Gwen's last dig day, she took lots of pictures of a house the MSU team was excavating.

In a smaller pit feature, we found exposed bone, likely from a meal of a larger bird like the geese and ducks that still inhabit the nearby Emiquon Nature Preserve. Bones and scraps like this are tossed into a garbage pit where we find them today. Obviously, it is helpful to know what the people are eating, but quantity of materials also helps us know how many people may have been living there. For example, if we find large quantities of deer bones we know deer were abundant at that time. We might go further and see if they are using the bones to make tools, like needles, awls, hoes from deer mandibles and scapulae.
We also see a reddish chunk of sandstone in the lower right hand corner of the image. It was exposed to fire at one point, as the sandstone is red. 

The morning weather was unsettled and scattered showers kept hitting the site. But the clouds cleared quickly and by ten in the morning, we were enjoying sunny weather. We can continue to dig during a light rain, with the use or tarps and tents (which also keep the glaring sun off of us on hot days). But we have to 'tarp up' the dig site in heavy rain. This means we must cover every inch of the excavated area with a large tarp, using sandbags to try to seal and secure the edges. Nevertheless, rain water will still percolate into the excavation. It is, after all, a big hole in the ground. Sometimes pumps must be used to siphon the excess ground water out of the excavated areas. 

At the house, we see a cross section or profile of the excavation. Charred logs are easy to see- possibly a sign that the house building burned in a fire. Already removed from this section were 3 or 4 other charred logs. 

This is a closeup of the image above, where we saw evidence of charred logs. You can see that the soil here is yellow and lighter in color than the surrounding soil. The lighter soil is the natural floor of the house when the original residents lived there. In other words, it is ground level. All the darker dirt on top is from the plow zone or A horizon fill- this is soil, organic material, artifacts, and naturally accumulating materials that fill in where the house used to be.
Usually, these homes were built by digging a basin into the earth, then building short walls around the edges. Imagine the classic 'sunken living room' in a modern house- except the entire house is sunken. 


Here you see a large pit feature in the earliest stages of excavation. Across the approximate center is a string, which marks the diameter of the circular shape of the feature. The string provides a straight line, making it easier to know where to dig. You start by digging on one side of the string giving us a clean profile wall along the string. 
This is the same pit feature as above, but digging has commenced. Digging occurs in 10 centimeter deep increments, creating levels that are clean scraped, mapped, and photographed for documentation. The reason for going down 10 centimeters at a time is so you can see the pit feature as it progresses down. This also saves the excavators and screeners from processing clay-like b-horizon soil that is not part of the feature.

Same feature, clean scraped and ready for photography- You can faintly see the edge of the feature where the darker soil meets a lighter, yellow soil, near the upper left hand side of the photograph. So where we see this soil demarcation, the edge of the pit feature is established. 

Here is another example of bisection lines. This feature has not been excavated at the time of the photograph. 

One of the MSU students excavated this feature- a post mold with the remains of the charred post still visible. You can see the bisected profile wall clearly here. Once the feature has been photographed, the charcoal is carefully removed and wrapped in tin foil to protect the friable material. Samples are sent to the lab for analysis of the type of wood used. It could also be dated for age. 

A large fragment of decorated pottery- I found this in the pit pictured above. 

This is an exciting find- burned roofing thatch that had fallen into the pit feature we were digging. Likely to be made from grasses, thatching was used for covering the roof of a structure- probably a home. Preservation in this pit is good, as charcoal often degrades easily. 

Here we see the pit feature containing the charred roofing thatch. We can also see the straight bisection line dividing the pit in half, as well as the excavation boundaries. Each level is 10 centimeters deep, and like stairsteps. Of course, the pit would not have originally been dug in stairsteps- this is a result of careful excavation which shows the borders of the pit at each 10 centimeter level. 

A photo showing the entire excavation block in which we worked. Our pit with the charred thatch is in the center of the image. In the upper left hand side is another large pit feature- you can see that the walls are almost straight down, rather than stepped. This is because the pit is deep and cylindrical in shape, where as the charred thatch pit is more shallow and the walls are bowl shaped. However, later in the dig we discovered that what we thought was a shallow bowl ended up being a six foot deep storage pit.

Gwen at the dig. 

One large block and a screening shade to the right.



The Michigan State University students and teachers along with Dickson Mounds Museum staff

Sunday, July 20, 2014

Book Review ~ Every Bone Tells a Story

Every Bone Tells a Story
by Jill Rubalcaba and Peter Robertshaw

Are you interested in learning about our ancestors? Have you ever wondered what life would have been like for a Neandertal child, or the first Native Americans to inhabit North America? Maybe you ask yourself more difficult questions- how did language evolve, or when ritual burial developed. All around the world, people are asking those questions. Some people, like the archaeologists and anthropologists in this book, can find out.

Every Bone Tells a Story narrates the tales of four hominin discoveries who are the ancestors of today's humans: Turkana Boy, a young Homo erectus child who lived and died over a million years ago; Lapedo Child, the offspring of a Neandertal and a modern human; Kennewick Man, an ancient Paleo Indian who hints at a dangerous life in ancient North America; and Otzi the Iceman, the mummified remains of a five thousand-year-old man murdered in the icy mountains of Austria.

This skillfully written book breaks each story into three short sections. 'Discoveries' retells the finding of each specimen. In 'deductions,' you learn the facts scientists have uncovered. 'Debates' discusses various arguments and controversies that the hominin finds bring about. In the end, a bibliography lists websites and books commemorated to the hominin in each chapter.

Although Every Bone Tells a Story was written for a younger audience (filed in our library under juvenile nonfiction), it is an excellent read for anyone interested in archaeology, anthropology, paleontology, or just looking for an entertaining, educational work.


~ Blog Author's Insight ~

The story of Kennewick Man was very compelling to me. When scientists attempted to run tests on the bones, local Native American tribes objected. They thought Kennewick Man belonged to them, and took the anthropologists to court. For two years, the courts fought to determine who got rights to the skeleton. All the while, Kennewick Man was drying out and deteriorating. Those with custody did not know how to properly care for the ancient skeleton.

Although I feel enraged with the tribes, I can understand their reasons for disagreeing. The tribes in that area believe that the Creator will someday ressurect their ancestors. In order for that to happen, the skeleton has to be complete. In addition to their religious beliefs, when European-American colonists first came to this country, they nearly destroyed the Native Americans by accidentally infecting them with smallpox. Later, they took their land and forced them to live on reservations. Many years later, America went to war with the Nazis for doing similarly to the Jews what was done to the native tribes. Now, we want to dig up their ancestors and study them. European-Americans tried to wipe out the tribes, and now they want to learn more about these native people. The Native Americans know who they are. Some say they don't need scientists to tell them anything different.

Later on in Kennewick Man's story, the courts hired unqualified individuals to date the skeleton. The scientists took no precautions, destroying whole bones to retrieve samples, which were contaminated. The whole time, they had well-experienced anthropologists who could do the job for them. Qualified scientists are able to run the same tests with minimal damage to the skeleton. For example, before the tribes objected to research on Kennewick Man, James Chatters, the head anthropologist on the research team, decided to run a test on the remains to date them. Chatters went out of his way to find the lab who could run the test with the least amount of bone. When he finally found a proficient lab, Chatters chose a small bone which the lack of would be least offensive to the tribes, assuming the skeleton did turn out to be Native American.

Despite the destruction to Kennewick Man's skeleton, the scientists' work payed off. When the results returned, it was discovered that Kennewick Man was 9,000 years old; too old to belong to any modern tribe. Chatter's earlier test uncovered the same result. The anthropologists were allowed to study Kennewick Man, much to the disappointment of the tribes.

Scientists should be allowed to run radio-carbon dating tests on skeletons as soon as they determine that it is not modern. Then it can be determined who should have jursidiction over the remains without spending time and energy debating in court who gets rights to the find. In Kennewick Man's case, the tribes objected to scientific studies for two years only to discover that the remains were far too old to belong to any of them. 

Who knows how much evidence was destroyed during the two year battle in court. If scientists could run basic dating tests, then other Paleo Indian remains, like Kennewick Man, would not have to degrade. We could learn more about life for these ancient individuals by minimizing time spent in court and maximizing our ever improving science skills and technology.


Written by Gwen McDaniel