Chocolate Chaco

Archaeologist Patricia Crown of the University of New Mexico and collaborator Jeffrey Hurst of the Hershey Center for Health and Nutrition (yes, THAT Hershey) recently published a study in the Proceedings of the National Academy of Sciences where they identified chocolate residue in some ceramic vessels at Pueblo Bonito in New Mexico's Chaco Canyon. Is anyone surprised to find that Native American groups in North America consumed chocolate 1,000 years ago? It's delicious, why wouldn't they have enjoyed this delicious foodstuff as so many others do today?

Archaeologists are VERY excited about this study, and rightfully so -- it's a big deal.  In order to understand why we are so excited, a little background information is required.  When archaeologists talk about Chaco Canyon, they are usually referring to a complex of large stone buildings, pueblos or "great houses", that were constructed in what is now northwestern New Mexico between about AD 1000-1150, although, other groups, including the Navajo, were present in the region at various times.  The largest and one of the longest occupied pueblos in Chaco Canyon is Pueblo Bonito, which includes between 650-800 rooms.  Chaco remains a place of great importance to different modern Native American groups today.

Aerial photograph of Pueblo Bonito

The great houses at Chaco Canyon are unique in the prehistory of the American Southwest, in that the structures were huge and were clustered together in an area that was less than ideal for agriculture.  Archaeologists still hotly debate Chaco, for example some argue that Chaco was occupied by a small number of people for most of the year with other people periodically gathering there for special occasions, and others believe a larger population stayed year-round.  Archaeologists do agree that Chaco was an enormously significant place for the people of the prehistoric southwest, and that Pueblo Bonito was a place of particular importance within the canyon.  Archaeologists also agree that ritual observance was a big part of the Chaco phenomenon, and one indication of this are the larger than expected numbers of imported objects including turquoise and shell jewelry, macaw bones, and unusual ceramic vessels, such as the "cylinder jars" pictured below. 

Example of "Cylinder Jars" from Chaco Canyon*

Less than 200 of these jars have ever been found, and 166 of these jars were found at Pueblo Bonito.  111 jars were found in a single room!

Cache of cylinder jars excavated from Pueblo Bonito

The researchers in this study took some broken pieces of these cylinder jars and some tall-necked pitchers that are sometimes found with them and extracted residues that had been absorbed by the pots.  Chemical tests of the residues revealed the presence of theobromine, a biological marker of cacao (from which chocolate is derived).  Crown and Hurst give four reasons why this discovery is so significant.

First, the chocolate found at Pueblo Bonito was a long way from home.  As seen in this map, the next closest area from which cacao could have been grown is thousands of kilometers from Chaco Canyon.  Someone carried the beans from Mexico or another place in Central America all the way to what is now northern New Mexico.  That there was a special ceramic vessel for consuming chocolate indicates that chocolate was consumed on several occasions, this was not a one-time occurrence.   

Cacao production area relative to Chaco Canyon*

Second, we now know what these unusual vessels were used for.  The Maya and other prehistoric Mesoamerican people consumed chocolate by pouring spiced ground cacao seeds mixed with water from elongated container to container to create a frothy beverage.  We now know that the elongated vessels found at Pueblo Bonito were used for this same purpose.

Third, if Pueblo Bonito was a center of ritual activity during its time, details about a specific ritual performed in that place are extremely interesting.  One of the rituals performed at a center for such activity in the American Southwest has explicit ties to Mesoamerican ritual.  It has long been argued that elite individuals in Chacoan society tied into Mesoamerican ideas.  The presence of the chocolate ritual at Pueblo Bonito supports this connection.

Fourth, that a ritual was performed at Pueblo Bonito fairly exclusively underscores the idea that Pueblo Bonito is at the center of Chaco ritual activity.  That the ritual is explicitly associated with Mesoamerica makes this situation all the more interesting.  

* Figure appeared in the original article by Crown and Hurst in the February 2009 Proceedings of the National Academy of Sciences

Site Potential and Jurisdiction

Navigating the world of archaeological consultation can be confusing.  Some of our developer clients have reported that they were required to do extensive archaeological work on some projects, and then almost no archaeology on other projects of a similar size and nature.  There are two reasons for this -- jurisdiction and site potential.  

Jurisdiction 

There are a number of different laws designed to protect archeological resources.  These laws have been enacted by various government entities, and there is a surprising amount of variation between states and even between counties and municipalities.  For example, a state law in Arizona protects burials equally on both privately and publicly held land, whether the remains are determined to be Native American or not.  Laws in other states vary considerably.  Various developments may also trigger the involvement of the Federal government, invoking an additional set of laws.  Another issue related to jurisdiction is variation in the enforcement of cultural resource laws.  Different counties and agencies have some leeway in how they choose to enforce the statutes.  An archaeological consultant familiar with the area in which your development is occurring can assist you in navigating jurisdiction.  This issue is also discussed by Thomas F. King in his excellent book "Cultural Resource Laws and Practice."

Site Potential

Site potential refers to the probability that an archaeological site is present on a given property based on the previous archaeological work in an area.  A simple way to look at site potential is with the old adage "where there's smoke, there's fire."  Past human activity tended to re-occur in the same places over time, often in places where resources were abundant.  Parcels in places where archaeologists have recorded many sites are considered to have high site potential, and parcels with few or no previously recorded sites are considered to have low site potential.  Exceptions to this can occur in places where archaeologists have previously not looked for sites, in which case, archaeological site potential cannot be assessed.  In some cases, a parcel includes all or part of known archaeological sites.  In these cases, a project has a site or sites, rather than site potential.  Summarizing previously recorded archaeological sites and previously undertaken archaeological investigations are standard procedure for archaeological consultants, but site potential in many areas can be inexpensively estimated before a property is even purchased for development.  There is no need to be surprised when you apply for a permit, have a preliminary site file check performed before you purchase a property for development.

What does an archaeologist do?

I admit it, I have a fairly unusual occupation.  When people find out that I am an archaeologist, they usually respond with surprise, varrying levels of interest, and some follow-up questions as to what it is we actually do.  After several years of these conversations, I have compiled the following short list of what archaeologists do, and what we do not do.  Contrary to what you may have heard in the popular media, it's not all fisticuffs with Nazis* and running around with beautiful people.

Archaeologists DO study the material remains of human beings.  People in the past left stuff behind in the places where they lived.  We find this stuff and learn whatever we can about the people who originally left it behind.  Most archaeologists work in one of four general job categories.  Academic archaeologists work as instructors and researchers in colleges and universities.  Museum archaeologists manage archaeological collections and help create exhibits for the public.  Government archaeologists work for land-management agencies to ensure that archaeological sites on government land are protected, and that other laws pertaining to archaeology are complied with.  Finally, many archaeologists work as consultants for governments and private businesses.   Clients, most often land developers, utility companies, government agencies, or mining interests, seek the services of cultural resource consultants to assist them in complying with a variety of federal, state, and municipal laws pertaining to archaeological resources.

Archaeologists DO NOT deal with dinosaurs or other extinct animals.  These creatures are primarily studied by paleontologists, who are trained in geology.  Some archaeologists who work in early time periods do excavate extinct animals, but as a rule, only become involved when humans were in some way associated (an example of this might be a mammoth skeleton associated with spear points).  Archaeologists to not deal with rocks like geologists, except to investigate the ways in which humans in the past used rocks (to make arrowheads, for example).

*I did have an archaeology professor who actually fought the Nazis in World War II.  I'm sure there are others out there too...

A Broken Tail?

During a recent excavation , we encountered this rock art panel on a rock outcrop near our dig.  The sites are located on the Agua Fria River north of Phoenix, Arizona.  In case you were wondering, that's me in the pith helmet, and excuse me, but yes it is really cool and it's critical to my archaeological heritage.  Dave and Travis are in the foreground.
As you can see in this close-up, the "Lizard Man" motif is prominent in this panel.  As City of Phoenix Archaeologist Todd Bostwick explains on page 55 of his excellent and very readable book, it can be difficult to tell the difference between a human and lizard figure in Hohokam rock art.  Typically, figures with no "middle appendage" are classified as human, figures with a "middle appendage" longer then their legs are classified as lizards, and figures with a "middle appendage" shorter than their legs are called "Lizard Men".  The panel pictured above has all three kinds of figures, as well as a fourth type with a broken tail.  

The backside of this boulder (the side facing the river) is covered in dots and some abstract curvilinear figures.  The pecking on this side of the boulder is very dark, and this heavy repatination indicates that these designs were the first to be made on the rock.  

One unique element featured on this panel was the sunburst pictured above.  Whoever created this element incorporated the rock face into the design, making it appear as though the sun, radiating out from a natural hole in the rock, was rising above a mountain range.  The pecking on this element is much brighter than the other rock art elements on this boulder, indicating that the darker, or more heavily repatinated elements were pecked into the rock first.  The sunburst may in fact be modern, although, there is no way to conclusively say one way or another with current technology.

If you encounter rock art (or other archaeological sites), do not destroy or otherwise negatively impact them.  Archaeological sites are protected by various laws, but they are also important to Native American groups today.  Be respectful when visiting archaeological sites.