My Obsidian-Focused Session at GSA 2009 in Portland
Tuesday, February 3, 2009
My colleague, Josh Feinberg, and I are organizing a session titled "Obsidian from Magma to Artifact: Geological and Archaeological Perspectives" at the 2009 Annual Meeting of the Geological Society of America in October in Portland, OR. This session is intended to bring together archaeologists and geoscientists from diverse fields -- geochemistry, igneous petrology, volcanology, geomorphology, and more -- to present on the topic of obsidian research, from magma formation and eruption to
Recent News Round-Up -- I've Been Busy with Obsidian
Thursday, June 26, 2008
Keywords: ceramic sourcing, pumice sourcing, lake sediments, meteoric iron
I haven't been posting stories here because I've been too busy with my dissertation research: analyzing obsidian, illustrating lithic artifacts, improving my theoretical understanding of principal components analysis, etc. But I still have been collecting new stories over the last several weeks. I'm afraid, though, that I'll simply have to post them here as a lump sum without commentary on each story. I'll try to
Radiography -- Not Just for Egyptian Mummies Anymore
Saturday, May 10, 2008
Keywords: X-rays, computed radiography, Peruvian "false head" mask, curation
Egyptian mummies always seem to be getting x-rays, CT scans, and MRIs. It happens so often that I never post such stories here unless something really unique is done or found. Here, though, is an article about a new X-ray instrument -- a computed radiography system -- at the Field Museum in Chicago. Yes, one of the first things they did was run of their mummies through this device, but they've also imaged various
Microscopic Evidence That Boisei Didn't Eat Roots or Nuts
Friday, May 9, 2008
Keywords: microscopy, microwear, physical anthropology, human evolution
Physical anthropologists have long thought Paranthropus (or Australopithecus) boisei was a nut- and root-eater based on the shape of its jaw and teeth, earning it the nickname "Nutcracker Man." This has been an important assumption in human evolution and the role that diet played. Researchers have considered the consumption of roots and tubers to be a key point in hominid evolution. It also seems likely because nuts and
Lake Sediment Cores, the Sahara, and the Rise of Egypt
Thursday, May 8, 2008
Keywords: lake sediments, limnology, desertification, savanna, Sahara, Egypt
The rate at which the Sahara changed from a green savanna to a barren desert has been a matter of debate. A prior study suggested that the Sahara became arid within only a few centuries -- that research was based on the Sahara dust that blew over the Atlantic and settled into ocean sediments. Now researchers have recovered and studied sediment cores from a unique lake in a remote area of northern Chad. Almost all
Electron Microscopy and Mineralogy of Mayan Fabrics
Wednesday, May 7, 2008
Keywords: scanning electron microscopy (SEM), pigment, mineralogy, cinnabar
Fabrics don't receive much attention from ancient materials researchers simply because their preservation is so poor compared to stone, metals, ceramics, glass, and other artifacts. These articles discuss a rare find of intact Maya fabrics from a tomb at Copán in Honduras. The textiles had a surprisingly high thread count -- higher than most pairs of jeans. The researchers used stereomicroscopy and scanning electron
More on the Impact Hypothesis and American Extinctions
Tuesday, May 6, 2008
Keywords: climatology, extinctions, Clovis, Younger Dryas, meteorite, comet
About a year ago, last May, I posted about a new hypothesis that a cometary explosion 13,000 years ago cooled North America, leading to widespread extinctions near the end of the Ice Age. Their evidence consisted of small glassy spheres and nanodiamonds observed using scanning electron microscopy, and I posted a follow-up story about this evidence back in September. The hypothesis was a topic of debate at the recent
Shells Help Debunk the Pyramid "Concrete" Hypothesis
Monday, April 28, 2008
Keywords: pyramids, limestone, fossils, shells, petrography, x-ray diffraction
I just recently posted about MIT students testing a controversial hypothesis that blocks of the Egyptian pyramids aren't actually stone but a form of ancient concrete cast in situ. This idea has been touted by chemical engineer Joseph Davidovits and recently bolstered by materials scientist Michel Barsoum. Dipayan Jana, a petrographer, has recently demonstrated that samples from the Great Pyramid at Giza are
While We Are Talking About China's Terracotta Warriors...
Tuesday, April 22, 2008
Keywords: terracotta army, paint and pigments, archaeomineraology, symbolism
While we are talking about the Chinese terracotta warriors, we should discuss their paint. Did you know that the warriors were painted, at least in part, purple? Their distinctive purple pigment is known as "Chinese purple" (or "Han purple" less frequently). Like other stable, brightly colored ancient pigments (such as Maya blue), Chinese purple has been analyzed extensively using numerous, techniques like
Terracotta Warriors Have Egg on Their Faces -- Really!
Monday, April 21, 2008
Keywords: terracotta army, paint binder, organic chemistry, archaeomineraology
No, this isn't a story about the fake Chinese terracotta warriors recently displayed at the Museum of Ethnology in Hamburg, Germany (read about that story here, here, and here). This is about archaeological chemists finding a trace indicator of egg proteins in the paint on the terracotta warriors. Egg could have been used a binder to keep the paint adhered to a layer of lacquer over the clay figures. The egg may
Geophysicists Argue Importance of "Archaeoseismology"
Friday, April 18, 2008
Keywords: archaeoseismology, earthquake archaeology, ancient earthquakes
I've been posting a lot of articles recently about research into ancient tsunamis. Indeed paleotsunamis are all the rage right now. Tsunamis are produced, of course, when a great amount of water is displaced rapidly by volcanic eruptions, underwater earthquakes, or similar large mass movements. Today, geophysicists at the Seismological Society of America conference announced a collaboration in what these researchers
Students Testing Egyptian Pyramid "Concrete" Hypothesis
Thursday, April 17, 2008
Keywords: pyramids, limestone, concrete, geopolymer, petrography, quarrying
Perhaps you've heard of the unlikely hypothesis that blocks of the Egyptian pyramids aren't actually stone but a form of ancient concrete cast in situ. This unusual notion has been touted by French chemical engineer Joseph Davidovits, who studies, promotes, and sells geological-based polymers at his Geopolymer Institute -- you'll find details about his ideas below and at his website. Recently, Michel Barsoum, a
Electron Microscopy and the Kingdom of the Crystal Skull
Wednesday, April 16, 2008
Keywords: lapidary technology, crystal skulls, authenticity, electron microscopy
Yes, there is a new Indiana Jones movie coming out this summer. Yes, this film is called Indiana Jones and the Kingdom of the Crystal Skull. Yes, most archaeologists have written off almost all "crystal skulls" as fakes. And yes, the carved (or, more recently, cast) skulls are popular among pseudoarchaeologists, UFO enthusiasts, and new-age spiritual healers. So why bother posting about them on an archaeology
Reconstructing Greece's Bronze-Age Aegean Coastline
Tuesday, April 15, 2008
Keywords: coastline reconstruction, plate tectonics, Aegean Sea, Mycenaeans
The ruins of a partially submerged, but largely exposed, harbor town, likely a Mycenaean port dating back to the Bronze Age. Erosion has exposed much of the site, called Korphos-Kalamianos by researchers, and revealed a grid-based layout. Shifting tectonic plates, though, have submerged part of the site into the Aegean Sea. It isn't clear yet how much of the site now sits underwater, but archaeologists and
Can One Trace Turquoise Back to Its Geologic Source?
Saturday, April 12, 2008
Keywords: turquoise, sourcing, trace elements, isotopes, mass spectrometry
H. Kris Hirst over at About.com has written a post on turquoise and another on the research of doctoral student Sharon Hull and her advisor, Mostafa Fayek, to source this material. I had the pleasure of meeting Sharon and Professor Fayek last fall. I presented some of my obsidian research in a session they chaired (called "Sourcing Techniques in Archaeology") at the Geological Society of American conference in
Meteors vs Volcanoes: What Caused Cooling in 536 CE?
Friday, April 11, 2008
Keywords: climate shift, global cooling, volcanic eruption, meteorite, comet
Something during the year 536 CE caused global-wide dimming, climatic shifts, and crop failures. There are two main possible causes: a massive volcanic eruption or meteorite strike. Which scenario is most likely depends on whom you ask. One research group will tell you that the eruption of a supervolcano was most likely the cause of world-wide debris in the atmosphere, but another group contends that it was a
More on the Effects of the Recent Colorado River Flushing
Thursday, April 10, 2008
Keywords: Grand Canyon, Colorado River, flooding, erosion, preservation
As I posted about here and here, last month the Interior Secretary ordered Glen Canyon Dam to release roughly 1200 cubic meters of water per second down the Colorado River through the Grand Canyon for sixty hours over objections of the park superintendent. The U.S. Interior Secretary insisted that this flushing would restore sandy beaches and side pools for wildlife and campers. Park officials argued that their reasons
Retro Review: Geoarchaeology and the Earliest Americans
Wednesday, April 9, 2008
Keywords: peopling of the Americas, glaciation, climate, dating techniques
The earliest migrations of humans into the Americas is a matter of much study and debate, particularly regarding when and how that first occurred. It isn't really my thing, but I recently heard an excellent talk about this topic by one of the experts in this field: David Meltzer. Professor Meltzer came here to Minneapolis for our "Deep Time" conference last month, and I had a chance to talk with him briefly about the
On Tar's Trail at the Recent SAA Conference in Vancouver
Tuesday, April 8, 2008
Keywords: bitumen, tar, asphalt, organic chemistry, Olmec, sourcing, economics
I've posted about bitumen before: here and here. I did view this poster at SAA -- it was part of the "Archaeometry and Artifact Studies in Mesoamerica and Middle America" session on Thursday evening -- but only briefly, and I'll admit that I don't recall it well. I have good excuses, though... really. For one, I was eagerly awaiting posters in a session called "Innovations in Ceramic Analysis"... but, by the time
Ugh, More "News" about Re-Testing the Shroud of Turin
Monday, April 7, 2008
Keywords: radiocarbon dating, authenticity, experimental archaeology
About six weeks ago, I noted that the Shroud of Turin was back in the news (even the archaeological headlines) and the subject of a new documentary. It seemed quite likely, with this documentary in the works, sponsored by Shroud enthusiasts, we hadn't heard the last of re-dating this linen objet d'art. Well, there is good news and bad news. The bad news? It is back in the news again, and the Discovery Channel is still
"Archaeogeophysical" Research... Ugh, I Hate That Word!
Sunday, April 6, 2008
Keywords: geophysics, prospection techniques, etymology, roots and prefixes
Various prospection techniques, adapted from geophysical surveying, have been invaluable in archaeology. It is hard to overstate the effects that surveying techniques -- electrical resistivity, magnetic susceptibility, and ground-penetrating radar, for instance -- have had on archaeological research and excavation... But I really don't like the word "archaeogeophysics" at all. Sorry. Fortunately, I saw it only once
Analysis of the Oldest Worked Gold Found in the Americas
Saturday, April 5, 2008
Keywords: native gold, jewelry, signaling, social stratification, spectrometry
What appears to have been a necklace of gold and stone beads has been found in the Peruvian Andes. It is the oldest example of worked gold in the Americas, dating to roughly 4000 years ago. Archaeologists widely believe that hunter-gatherers lived in this region at that time, so the necklace came as a surprise -- the researchers state that such decoration would have worn by an elite to signal his or her status.
Even More on Paleo-Tsunamis and Predicting Future Ones
Saturday, April 5, 2008
Keywords: tsunamis, sediment layers, sand particle sizes, Indian Ocean
It looks like the funding is good for studying ancient tsunamis and earthquakes, so if you're an archaeologist or a geophysicist looking for research funds, try this emerging field. I have posted about this topic before: here, here, here, here, here, here and, most recently, here. The research discussed in the article involves searching for and studying buried sediment layers left on Indian coasts by tsunamis. One of
Mass Spectrometry Comes to the Aid of Dendrochronology
Friday, April 4, 2008
Keywords: dendrochronology, mass spectrometry, molecular ion analysis
Dendrochronology, or tree-ring dating, is a well-known method for dating wood found at archaeological sites, and probably every student in 'Introduction to Archaeology' learns about it. So what is news-worthy about this article? Dendrochronology relies on our ability to distinguish among the rings of sapwood and heartwood, but this can be difficult, even nearly impossible, in very old pieces of wood. Researchers, however,
Back with a Real Quack -- Meteors, Tablets, and Sodom
Friday, April 4, 2008
Keywords: pseudoarchaeology, meteorite, landslide, April Fool's Day???
Above: Photograph of the clay tablet in question. Credit: University of Bristol.
SAA is over, my poster session went well, and I'm back from Vancouver, so it's finally time to get back to the blog and post some of the stories from the last three weeks. And I'm starting with a doozy! It makes me wonder what the public relations office at the University of Bristol was thinking when they put out a press release about off-
Busy with My Poster for SAA about Ceramic Petrography
Thursday, March 13, 2008
Above: Backscattered-electron (BSE) image of a sherd from Tell Mozan, Syria.
It has been a while since I've blogged here about my own research, and even then I'm typically discussing either obsidian or native copper. I have also been collaborating on a ceramic petrography project at the archaeological site where I work -- Tell Mozan (ancient Urkesh) in northeastern Syria -- and I am currently preparing a poster on this research for the upcoming Society for American Archaeology conference in
More on Using Ancient Tsunamis to Predict Future Ones
Wednesday, March 12, 2008
Keywords: tsunami, geophysics simulation, earthquake, fault, subduction zone
Ancient tsunamis and earthquakes are all the rage in archaeology and geophysics, as evidenced here, here, and here... oh, and here, here, and here too. In this study, researchers reexamined a tsunami described by a Roman historian in 365 CE. It is generally believed that this tsunami was triggered by an intense earthquake off the west coast of Crete. These researchers propose, however, that the subduction zone --
Studying Effects of the Recent Colorado River "Flushing"
Tuesday, March 11, 2008
Keywords: flooding, erosion, sediment, preservation, luminescence dating
As I discussed here, last week a plan to flush sediment down the Grand Canyon started over objections from the Park Superintendent. The Interior Secretary ordered Glen Canyon Dam to release roughly 1175 cubic meters of water per second down the Colorado River through the Grand Canyon for sixty hours. Park officials argued their research showed that such artificial flooding could damage some of the parks' archaeological
Retro Review - 2004 - Chiefdoms and Soil Geochemistry
Sunday, March 9, 2008
Keywords: Hawaii, soils, chiefdoms, population growth, sustainable agriculture
Differences in soil geochemistry seem to explain why some Hawaiian chiefdoms grew sweet potato while others grew taro. These researchers learned that the ancient Hawaiians knew of nutrient-rich areas best for each crop. Climate and elevation did not fully explain the agricultural patterns found by archaeologists -- this addition of soil chemistry did. The researchers argue that small chiefdoms were able to
Evidence of Ancient Gypsum Mining in Kentucky Cave
Saturday, March 8, 2008
Keywords: archaeomineralogy, gypsum, selenite, speleology, mining
A local Kentucky spelunking club has discovered evidence of mining deep within a cave dating back at least two millennia. Native Americans, possibly during the Woodland Period, mined gypsum, including a variety known as selenite, in this cave, which has remained largely untouched for thousands of years. Archaeologists in Kentucky are calling it a significant, even unique, find. Gypsum is calcium sulfate dihydrate (CaSO4 •
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Geo/Arch/Sci Blog: Geoarchaeology, Archaeological Science, Archaeological Geology, Archaeometry, Archaeomineralogy, Archaeological Chemistry, Petroarchaeology
Blog Author: Ellery Frahm
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