Boxes of Rockses

Recently, Team Paleo member Katie downsized her vast collection of fossils and rocks. Most were donated by her grandfather, who is active in Peoria Academy of Science Geology Section. Contained in several large moving boxes, the collection was jumbled together with little sorting or identification. Being an avid fan of the geological field, I graciously agree to take the extra objects in the collection.

I got the collection home and hauled the ridiculously heavy boxes upstairs to a sorting table, where I laid each specimen out so I could see in entirety the rocks. Some of the objects had been bagged and labeled, while others were thrown higgledy-piggledy into tupperware containers. At this point, I knew I had to further sort and narrow down the specimens in order to make them manageable.

The rock and fossil collection when first unpacked ~ vast and jumbled

Thanks to opportunities to sort and catalog the type collection at Dickson Mounds Museum, I have had experience with sorting specimens into manageable groups for labeling and organizing. I used the same techniques I learned at Dickson Mounds to tackle my own recently acquired rock collection.

My end goal is to have everything carefully cataloged and boxed or bagged, with any duplicates, extras, or unwanted specimens in storage. I would like to eventually have a series of shelves where the specimens can be laid out without being broken or damaged. My criteria for what I would like to keep is 1. things I find interesting, 2. specimens of strange or rare minerals and fossils, and 3. some of the most common fossils and minerals, along with multiple variations of each.

~~~~~

Determining what specimens I have is part of sorting. While some specimens were labeled, others were just stuck in a box with no designation. Using my geology handbooks and research websites, I began to lengthy process of identifying the unlabeled specimens.

I'm not 100% certain what this rock is, but I think it is shale, due to the numerous layers and light color. The sample is very light-weight and chalky, of a mostly fine-grained material like silt or mud. However some layers appear to be made up of  larger grains. 

The top specimen is sandstone, which has become partially geodized. The specimen below is likely limestone, which has also become host to a geode. Both rocks are similar, however the sandstone seems to be made up of larger grains and has cross-bedding and deposits other minerals (beside the geode). Whereas the limestone is much siltier and smooth. The weight of each rock is similar.

Geodes are formed similarly to chert, where a hollow irregularity in sandstone or limestone matrix becomes filled with mineralized water. In some cases, such as in the creation of chert and jasper, the irregularity completely solidifies. In the case of geodes, quartz and other minerals form around the exterior circumference of the hollow area. In most geodes, the crystals never grow enough to completely fill the area, however there are specimens of solid geodes.

This is a GNEISS rock. (You pronounce gneiss as 'nice') Although similar in appearance to granite, gneiss has a different breaking pattern and is generally 'banded' in appearance, displaying the different layers of deposition. If you were to compare a piece of gneiss next to granite, you would see that the particles in gneiss all align in the same direction while the particles in granite are wacko skitzy all over the place. Wacko skitzy meaning muddled and chaotic. Gneiss would shear off with the grain like slices, while granite, since the particles are chaotic, it breaks in many directions at once, or in chunks and crumbles. All rock wants to break along a particle line, but with granite, the particles go in so many directions the break wanders around finding the easiest path.

Volcanic basalt- formed by lava flows and is a classic igneous rock. While hard to see in the picture, the rock has a fine crystalline structure that is often overlooked. 

After much research, I identified this as the petrified branch of a tree. While most people are accustomed to using the term 'petrified', the scientific term is 'permineralized'. Petrified means 'turned to stone, while permineralization is the process by which organic material is turned to stone. When the material is buried by sediment, mineralized water seeps over time into the organic object, replacing organic materials with minerals. In this case, the organic material was a tree branch or wood.

Another possibility is that this is a fossilized long bone, however generally fossilized bone has a porous appearance, while this specimen appears to be smooth. I will continue to research and seek a professional opinion.

Article and commentary written by Gwen McDaniel

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

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

Hidden Treasure

Gwen snapped a few cell phone pics last week during the dig. While clean scraping a house basin she uncovered three (of many) artifacts. 

Decorated pottery sherd. Punctated along the top, with incised curvilinear lines. Likely Mississippian.

Madison point with evidence of heat treatment

An undecorated rim sherd, likely Mississippian. 

Here is an interesting page that describes pottery decoration in Woodland and Mississippian pottery: 

http://www.beloit.edu/logan_online/exhibitions/virtual_exhibitions/north_america/woodland/techniques.php

Excavation Finds at Morton Village

This week brought some interesting finds at the Morton Village dig site near Lewistown, Illinois....

An unusually large pit feature measuring over four feet deep. It may have been a storage pit that was emptied at one point and refilled with garbage. The depth is typical of storage pits.

At the top of the picture you notice the hole is straight and flat like a wall. This is how the profile (center slice) of the pit feature is exposed. If you look in a profile, you can see the shape and border of the pit, making it easier to excavate the other half of the pit. Some pits have post molds or other pits dug into the same area. Profiles help distinguish these different overlapping features.

In this image it is easy to see the layers and different colors of earth. On the profile wall, you can see 'layers' of different colored dirt. This is likely because the people who used it as a garbage pit would place a layer of garbage down, then 'cap' it with a layer of dirt. This continues until the pit is full. This dig showed evidence of capping, and because the soil content was acidic here, much organic material breaks down. We don't see evidence of the organic remains as whole artifacts. We did, however, find a chunk of red ochre (or possibly hematite) and a huge limestone rock.

Also of note is the whitish colored earth at the bottom of the pit, located in the upper left-hand corner of the excavated hole. On the left side, midway down the hole, a scoop is removed from the wall. This is where several pottery sherds were found, likely from an Oneota pot. 

It might be hard to see, but along the middle of the image are two darker colored streaks going from bottom to top. They look a bit like tire tracks from a vehicle. However they are evidence of wall trenches that form a large circular structure. Here is only a few feet of the wall trenches. When we say LARGE structure, we are talking 40 to 60 feet in diameter!

Wall trenches result when people dig into the soil a certain depth, then place upright logs in the trench to make a palisade-like wall. Think privacy fence made of whole logs. What we see is the discolored stain of either the organic remains of the posts or fill dirt that drifted in after the wall trench was emptied. Some of the graduate students working on the dig mused that this great circle may have been open at the top- no roof.  The trench walls are concentric- one wall within another wall not because there was a double wall, but because one feature may have been constructed first, while a second was constructed to replace or enlarge the first feature.

Around the edges of this image you can see several post mold excavations. 

Here we see an exceptionally dark post mold discoloration, easily defined by the dark blackish soil. You can also see the circular shape. Of course, it could also be the remains of a tree root. Excavation will provide more information. The first post mold Gwen excavated was about 9 inches deep. Some run 2 to 3 feet deep. 

Commentary provided by Gwen McDaniel

Gwen Digs a Hole

Gwen decided she'd like to try her hand at a real dig this year. She sent in a letter to Dickson Mounds with her qualifications and interests and was accepted as a volunteer. Each day starts early and ends late with a little sunburn and a lot of fatigue. But Gwen is having the time of her life! The dig is hosted by Dickson Mounds Museum and Michigan State University.

Screening dirt to isolate small artifacts such as chert flakes, pottery sherds, pebbles, and charcoal. 

Gwen's first post mold excavation! 

The screening station 

The excavation 'block' with a tarp over half of it to prevent the dirt from drying out. Each block is 4 meters by 4 meters. This block contains a post mold and another pit feature... so far!

Cleaning the equipment is important! Rusty tools don't work well.

We use wire brushes to clean off the dirt, and files to sharpen the shovels and trowels. 

Searching for Artifacts at the Ogden-Fettie Site

After a wonderful afternoon working with the crew at Dickson Mounds Museum, Team Paleo hit the local ice cream joint in Havana, Illinois. The Team savored some single scoops while we chatted about the day's work.

Three beautiful oaks crown the ancient mound at the Ogden-Fettie site

So, you went out to the Ogden-Fettie site today...

Katie: Yes, we combed the fields looking for artifacts.

Gwen: And gathered artifacts from certain grids so we could map out how densely packed the artifacts were in the area. As well as what major types of artifacts are in each location. The other kids found lots of pottery but we found mostly chert flakes and sandstone.

Katie: And we found a really small pink colored arrow point.

Gwen: I think I found the end of a drill. It was the right width and had chip marks on either side.

How did you find these artifacts?

Katie: We walked in rows looking for any artifacts sticking out of the ground. Any little flakes from the arrow points and bits of pottery... some things just stand out against the dirt and soil in the field.

Under the shadow of a Native American mound, the gals from Team Paleo scan a recently tilled field for artifacts.

So you were searching in a plowed farm field?

Gwen: Yes. The Ogden-Fettie site lies in what is now a farm field. There is a large mound in the center of field- I'm not sure if it was a platform mound for a building or burial mound. The mound is kind of square or rectangular shaped like the one at Cahokia, but this is not as big.

Katie: But we were searching near the mound, below it. It was really interesting being able to just look down and see an arrow point! When I found a raccoon skull, initially I just saw a few teeth, but by digging around I uncovered the whole thing.

To search for artifacts, each person (or team of people) tackles a 30 X 30 meter square. We simply walk up and down the square, covering a 3 foot swatch at each pass. After about 10 laps the square is covered. Depending on the density of artifacts, a square could take 20 minutes to an hour to search through.

What goes through your mind when you pick up an artifact?

Katie: It's interesting that Native Americans have touched these things and we are here hundreds of years later, touching the things that no one has seen in centuries.

Gwen: I'm always surprised that the artifacts are still there. I see something and know it is a chert flake, but others might just think it is a rock. One thing that I do is I try to imagine what it was like when there were houses here- or a settlement. Dr. Mike says there might be pit features there because we found areas dense with pottery sherds and chert flakes.

Katie: I love being able to work on uncovering all these artifacts. Ancient people LIVED here, worked here, spent their whole lives here- How interesting to work in the same place others did hundreds of years ago.

Team Paleo and Dr. Mike

Using the Total Station Transit To Prepare the Excavation Site

Last Friday Team Paleo found themselves working in the field at a local dig site, known as the Morton Village Site, to prepare for students from Michigan State University to excavate in a few weeks. When we arrived at the archaeological site, Dr. Conner, the person in charge of the dig, handed us a satellite map with a grid, and a long pole with a mirror on top. He showed us a rectangular box sitting atop of a tripod. The box was a device called a Total Station Theodolite. When we aimed the reflector pole at it, the Total Station would bounce a laser off of the mirror. The machine measured the time it took for the laser to return, and used trigonometry to figure how far away the reflector was.

We would be using the reflector to measure out 30 meter (98 feet) squares for magnetic surveying. After trekking approximately 30 meters through knee-deep grass, the team received information from Dr. Conner over a small radio, telling us how far we needed to move to get to the right spot. Finding the exact location to place a stake usually went something like this: * Static * “...Move it 1.6 meters towards me...”  * Static * “...6 inches to your left...” * More static * “...That looks good... Move it right 4 inches...” * Static * “...Go south 15 meters...” We would move back 15 meters and repeat the process all over again.

Several hours passed, and finally our work was complete. We returned with the reflector, where Dr. Conner informed us that in the next few weeks, the folks in charge of the survey would arrive with a magnetometer and scan the squares we laid out. A magnetometer scans the ground to detect minor differences in the magnetic properties of the soil. Dr. Conner invited us back to help with the survey. We all agreed, and are eager to try our luck with another expensive machine.

Total Station Transit

Reflector

More Information on the Total Station Transit 

A Total Station, which we used to determine the location of our dig site, is designed to measure the distance and angle between itself and another point. It starts by sending an electric laser to a reflector. When the beam returns from the reflector, the transit measures the return time and uses trigonometry to calculate the distance from the reflector. A grid, established in the 1980s at the Morton excavation site, allows us to pinpoint the coordinates of the point we want to find. Using the original grid as a starting point, a handheld computer calculates the coordinates so that we don't have to figure it in our heads.

We used a GIS, or Geographic Information System, to map information about the site. The GIS also stores coordinates for past excavations, allowing us to refer to them. Team Paleo identified new excavation areas we wanted to survey and then we placed the coordinates of the 30 x 30 meter blocks into the GIS. Then the information was transferred to the handheld computer. The computer signals the Total Station transit to find the first set of coordinates, and the transit calculates the angle and distance of the location. When the person manning the transit aims it in the given direction, the person in the field with the reflector lines up with the transit. They move back and forth until they find the coordinates indicated. In the last satisfying moment, an indicator stake is placed at the final coordinate.

Articles written by Gwen McDaniel

What Is an Abrader?

A well used sandstone abrader at Univesity of Iowa Museum of Natural History

Imagine you are walking through a field. A piece of sandstone catches your eye so you lean over and pick it up. The stone, roughly the size of your hand, is covered in deep grooves. What is the strange stone? What caused the elongated depressions? Has it been modified by human hands?

This unusual rock is an abrader, and its history is extensive.

4,000 years ago, in this widespread and misty valley, a tribe of Native American Indians dwell. A woman sews shell beads onto a pair of moccasins. As she works, her needle, which is made from a long bird bone, begins to dull. Eventually, she draws the needle off the sinew she uses as thread. The woman instinctively reaches for a piece of sandstone about the size of her hand. Down the center, a shallow channel runs.

She maneuvers the needle in smooth strokes along the stone until the needle is honed to a fine taper. At this point, the shallow groove in the sandstone has become deeper. Now she can continue sewing efficiently.
Later, a man returns to the settlement from his work. He has spent the whole day hollowing out a canoe with a stone celt. The tool needs to be polished and sharpened, or it will not function properly. He retrieves the grooved stone from it's place in the corner of the wikiup, and sharpens the edge of the celt, further deepening the grooves on the sandstone surface.

Many years pass; tools are sharpened and polished on the abrader hundreds of times. Eventually, the grooves become so deep it cannot be used any longer. The people discard the old tool, where it sits in the field for thousands of years for you to find. 

For more information on ABRADERS

Article by Gwen McDaniel

Trip to University of Iowa Museum of Natural History

Gwen and family took a great trip to the University of Iowa Natural History Museum this weekend.

Natural History Museum in Iowa City- Great place!

Observing fossils from each geological period, as they occur in Iowa's history

The mother of all abraders! 

Geological index complete with fossils found in each stratum.

There are fossils EVERYWHERE! Even the buildings are full of them! 

Book Review - Beyond the Body Farm, by Dr. Bill Bass

Beyond the Body Farm by Dr. Bill Bass is an excellent account of a selection of the author's cases meant to educate readers of the wonders of forensic science.

Beyond the Body Farm is written using simple writing. There is a useful glossary and a nifty diagram of the human skeleton, including a detailed drawing of the skull. I found myself referring to the anatomic illustrations frequently. Even if you don't know a thing about anthropology, you will be able to understand the terms the author uses through his simple definitions.

Bones of prey found under a tree

At times, Beyond the Body Farm can be, understandably, graphic, but the intrigue keeps you going. For example, in one chapter, Dr. Bass studies the victims of a mass killing caused when an illegal firework shop explodes. The only thing that kept me reading this chapter was my curiosity as to how this event occurred, and the suspenseful writing style Bill Bass uses. Another time, I advised my mother to buy a rubber car mat instead of a cloth one because of another chapter. In this one, a burned body is found in a car. Many of the remains were salvageable because the plastic floor mat melted, rather than burned, keeping them from falling out of the charred car. Beyond the Body Farm just didn't last long enough!

Not only does Beyond the Body Farm teach readers about forensic anthropology, it also talks about other forensic careers including entomology (the study of insects), art (using the skull of a victim to recreate their face), and odontology (the study of teeth).

Whether you are just learning about forensic anthropology, or have known about it for a long time, Dr. Bill Bass' book is a required read. His story has inspired me to learn more about forensic anthropology.

Book review by Gwen McDaniel