Survey Methodology in the Şərur Plain

July 14, 2014

Hello again from Azerbaijan, and günortanız xeyr (good day)! Our work on the Naxçıvan Archaeological Project Survey (Director: Dr. Emily Hammer, Oriental Institute) is proceeding smoothly here, but only two weeks remain on the survey before we wrap it up for the season. With so little time remaining, we are moving ahead full-steam to get as much coverage as we can before our departure. In my last post, I briefly introduced the scope of our project and our main research questions. The questions themselves are straightforward enough, but figuring out how to answer them is a constant challenge. One of the main methods we are using to learn about the settlement at Oğlanqala is archaeological survey.

Surveying the wall at Qarabağlar Qalası
Surveying the wall at Qarabağlar Qalası

The Naxçıvan Archaeological Project involves many different components including excavations, aerial photography, and geological prospection; our survey is just one part of the larger international and multidisciplinary effort – on a typical day the survey team numbers just three people, an Azerbaijani representative, and sometimes several local day laborers. Surveys are typically a much leaner operation than any given excavation, but surveys generate just as much valuable data about ancient societies.

Archaeological Survey (Google Stock Photo)
Archaeological Survey (Google Stock Photo)

When most people think of archaeology, they think of excavation, but really, digging is just one phase in the archaeological research process. Before any trenches can be opened, ancient sites must be located, identified, characterized, and evaluated for their utility in terms of our research aims – excavation is expensive and time-consuming, after all. Survey is the preliminary groundwork that allows excavators to be surgically precise in their targeting of archaeological features and monuments to investigate. We use satellite imagery, historical maps, geological maps, historical registers, local guides, and our own foot-power to search for archaeological sites and to gather information about the distribution and organization of ancient human occupation across a particular landscape.

Surveys can be intrusive or non-intrusive, meaning they can involve digging small excavation units, or they can leave subsurface deposits of artifacts and architecture intact. Surveyors usually do background research to identify areas likely to contain archaeological materials using the published records, maps, satellite imagery and local knowledge and then visit these areas to ‘ground-truth’ the veracity of the information provided by the background sources. This ‘ground-truthing’ involves a number of different methods depending on the terrain and dispersal of artifact concentrations, habitation sites, burial monuments and so forth. Some of the methods we are using this year include systematic field walking, areal collections, shovel-test-pits and geophysical prospection.

Recording the location of each artifact with the GPS device and red flags
Recording the location of each artifact with the GPS device and red flags (Mt. Ararat in the background)

Field walking is the method we use in cultivated agricultural areas. It is perhaps the most contingency-ridden of our methods because in any given year only a select number of fields in any given village have been left fallow or have been recently plowed.  We can only systematically field-walk where the ground surface is highly visible – as a result, any field that has been planted with wheat, fodder-plants, large vegetables, or where chaff has been left to dry is inaccessible to us for this kind of survey. But, when conditions are right, we measure out equally spaced transects across the fields, placing blue flags at the beginning and end of each transect-line. We then walk in a straight line between the flags and collect all the ceramics and tools visible on the surface, leaving a red flag at each artifact location. Our director follows along behind and records the location of each potsherd with a handheld GPS unit; this information gets uploaded to a digital database every day and forms the raw data that we use to generate an artifact density map of the landscape. This method is most useful when we already know that an area has archaeological materials on the surface and that the density of artifacts is quite high. In other situations, when we are less sure and when the density of artifacts is likely to be lower, we use methods such as areal collections.

Fields near Sədərək settlement
Fields near Sədərək settlement

Areal collection is when we patrol a landscape for artifacts following ground features such as ridges or watercourses and traverse open pastureland or foothill zones. This is a much less systematic method than field walking, but we still use handheld GPS devices to keep track of where we have walked and where we find artifacts. This method is especially useful when a large territory needs to be covered, or when we visit a site for the first time and have no prior knowledge of its surface features. During areal collection we frequently encounter surface features such as linear alignments (walls or architecture of various kinds), stone piles left by recent shepherds, burial grounds of varying age, canals both ancient and modern, in addition to the ancient ceramics and stone tools we are most interested in. Areal collection helps give us a better idea about where it would be worth investing our time in systematic methods collections such as field walking or shovel-test-pits.

Auguring at Oğlanqala settlement
Auguring at Oğlanqala settlement (Photo Courtesy of Dr. Emily Hammer)

Shovel-test-pits (hereafter, STP’s) are field walking’s intrusive sibling. When we do STP’s we follow the same basic principle – we lay out transects and cover them systematically – but in this case, we dig a 50x50cm hole into the earth to a minimum depth of one meter and then use a bucket augur to drill another meter under the surface. This method is extremely labor intensive and time consuming – on a good day, a team of an excavator and a workman can do just four! When we dig STP’s we cut through 50 centimeters of earth at a time, recording not just artifacts but also the soil, its color, composition, and texture. This allows us to get a better sense of post-depositional processes that affect the preservation of the archaeological record; it is important to record the soil’s features to know how human behavior and natural climatic events might have altered the archaeological remains between the time that they were discarded by their users and our discovery of them in the present.

Surveyor's Toolkit
Surveyor’s Toolkit

This information then goes into a spreadsheet that we can manipulate to produce a map of the subsurface deposits of a particular area. We can then compare this map with the map of the surface distribution of artifacts to gauge the degree of preservation of intact archaeological deposits. These maps can then be combined with geophysical data to get a sense of where architecture and features might be located.

Getting an STP started at Sədərək settlement
Getting an STP started at Sədərək settlement

Geophysical survey encompasses a wide variety of techniques and instruments, the most commonly used in archaeology including magnetometry, electro-resistivity, ground-penetrating radar, and electromagnetic conductivity, among others. Generally, these instruments and techniques measure the earth’s electromagnetic field in order to detect magnetic anomalies that signal the presence of burned material, disturbed sediments, or otherwise culturally modified subsurface materials. This year NAP brought out a team of geologists from Franklin & Marshall College in Lancaster, Pennsylvania to conduct a magnetometry survey of a variety of linear wall features surrounding the fortress of Oğlanqala. They operated their equipment to produce georeferenced spectrograms of the subsurface deposits so that we could visualize the distribution of magnetic anomalies to better understand the construction, features, and preservation of the wall system identified in previous seasons of the NAP survey.

Dr. Rob Sternberg of Franklin & Marshall College operating the Magnetometer
Dr. Rob Sternberg of Franklin & Marshall College operating the Magnetometer (Photo courtesy of Sam Feibel)

Over the course of this year’s season we have used each of these different survey methods in order to address the research questions discussed in the previous post. Because we are still in the data-generating stage of research, it is difficult to provide any hard and fast answers, but we have identified new sites, and acquired a great deal of information about ones already known. One of our most significant findings this season has been the discovery of a large 20+ hectare multi-component site with occupations dating to the Middle Bronze Age (ca. 2500-1500 BCE) and the Iron Age (ca. first millennium BCE), located approximately five kilometers north of a fortress already identified in previous seasons. This settlement and its relationship to the nearby fortress will provide an important comparative example to the settlement-fortress complex at Oğlanqala. It will be interesting to see in coming seasons whether the relationship between fortress and settlement are different or similar between this new site and Oğlanqala, and what these differences and similarities are. Hopefully this information can help us identify additional settlements associated with already identified fortresses in the area.

In closing I would like to acknowledge my appreciation for the hard work of the directors of NAP, Dr. Lauren Ristvet, Dr. Hilary Gopnik, Dr. Emily Hammer, and Dr. Veli Baxshaliyev. It takes an unbelievable amount of commitment and dedication to finance, organize, and run a field project in a foreign country, and none of what I was able to participate in this summer would have been possible without all of their pioneering efforts over the last eight years! I want to extend special thanks to Dr. Emily Hammer, the NAP Survey director for all of her expert guidance and direction over the course of this season.

I hope this short reports have helped give some insight into one of the less-widely known but very important aspects of archaeological field research! Görüşunuz (see you around)!

Last day of auguring at Sədərək Settlement
Last day of auguring at Sədərək Settlement (Photo courtesy of Dr. Emily Hammer)