Archive for the ‘Survey Archaeology’ Category

Plotting Cut Blocks Across Pyla-Koutsopetria

September 21, 2010 Leave a comment

Between 2005 and 2006, the Pyla-Koutsopetria Archaeological Project documented over 500 features from the Koutsopetria plain.  Most of these features were cut blocks of various sizes, material and descriptions as well as a handful of features associated with ancient agricultural installations (bit of an olive press, some andesite mill fragments, et c.).  Over the past couple of days, I finally got to analyzing this data beyond simply observing that we have lots of cut blocks.  The field team in 2005 and 2006 recorded detailed information regarding the location, size, and in many cases generally descriptions of each block and keyed them into a database that we could integrate with our GIS.

Most of the architectural fragments including cut limestone and gypsum blocks, are concentrated in the immediate Koutsopetria plain where farmers have moved them to stone piles on the edges of the fields. Check out our newest additions (partially edited) to our Omeka Collection: Pyla-Koutsopetria from the Air to get an idea of what these stone piles look like. 

The most common type of cut block is made of local limestone and probably quarried on site. The majority of the blocks fall between 0.3 and 0.7 m in length and 0.3 and 0.5 in width. For the blocks where all three dimensions are visible, their volume falls between 0.06 and 0.03 cubic meters. This produced blocks of between 75 kg and 140 kg which would be relatively easily moved for construction. Some blocks, of course, could be much larger exceeding 1 m in length and weighing close to 500 kg. With blocks of this size, there is almost no doubt that some large scale, monumental architecture once stood in the immediate area.  Here’s a distribution map.  The grey grid in the background is our survey grid and the color of the dots relates to the volume of the stone.


We also documented a significant quantity of cut gypsum block.  Since marble did not naturally occur on the island, Cypriots often used gypsum as a substitute in more elaborate buildings.  These blocks are generally similar in size to the cut limestone blocks with lengths of around a half a meter and widths of 0.3 meters. The average volume of blocks was similar to that of the cut blocks with only a few blocks exceeding 0.1 cubic meters. There were slightly more smaller blocks owing most likely to the more friable character of gypsum. Most blocks fell between 0.01 and 0.06 cubic meters. Gypsum has a lower density than limestone and the blocks had correspondingly lower weight usually between 25 kg and 140 kg. Many, much smaller fragments of gypsum were scattered across the fields and several very large blocks appeared clustered together. Here’s a map:


Finally, we also discovered a small quantity of marble from across the site.  Most of these came from the central area of the Koutsopetria plain embedded in rock piles at the edges of cultivated tracks of land. The marble fragments are small < .30 m in maximum length and relatively thin <.04 m suggesting that all but one marble fragment was revetment or floor slabs. The wide distribution of material perhaps indicates that there were several marble clad buildings on the plain of Koutsopetria even though so little marble survives.  Here’s a map:


The next step in analyzing this material is considering its relationship to the re-used blocks found in the excavations at Koutsopetria and the construction techniques used in the fortification wall surrounding Vigla.  It certainly seems possible that the majority of cut stone blocks scattered around the Koutsopetria plain came from the easily quarried fortifications at Vigla and perhaps also the extensive walls surrounding the Bronze Age site of Kokkinokremos.  Gypsum blocks had fairly limited uses architecturally owing to their lack of strength and value as prestige materials.  The gypsum fragments from around the site probably served in specific places in buildings and comparing their sizes to in situ blocks from elsewhere on the island might give us some idea of how they were used.



More Experiments in Intensive Pedestrian Survey

More guest-posting brilliance from our esteemed guest blogger, David Pettegrew, the co-director the Pyla-Koutsopetria Archaeological Project and the 2010 Cyprus Research Fund speaker.  Be sure to check out his posts on TuesdayWednesday, and Thursday.

Last Thursday, we introduced the survey experiment that PKAP conducted in June 2010 to assess the relationship between the number of artifacts that we see when we walk across a survey unit and the number of artifacts actually on the ground.  In other words, we wanted to assess how effective our survey methods are in actually assessing what was on the ground.  On Thursday, we compared the artifact densities detected by the project’s untrained student fieldwalkers to those counted by trained senior staff members.  Today we will discuss the second phase in our 2010 experiment, an assessment of the total population of all artifacts on the surface of select subunits.  This part of the experiment was designed to give us a total count of all surface artifacts that can be compared with the artifact counts reported in yesterday’s discussion.

We began by selecting four 10 x 10 m subunits based on the densities of the 10 x 10 m artifact densities counted by the experienced senior staff members.  As with past experiments (published in the RDAC 2007), we selected our 4 subunits to represent the range of density variation: the lowest density quartile (G15), highest density quartile (G9), and two middle quartiles (G1 and G6).  Each total subunit was 10 x 10 m, representing 1/16 (6.25%) of the 1,600 sq m survey unit.


To vacuum a high-density unit, you really have to spend a lot of time picking individual artifacts off the ground.  For each of our units, students Andrew, Zane, Valerie, and Luke, and I  walked very slowly in adjacent passes across each selected square gathering together in 1 or 2 corners of the unit all the artifacts present.  An initial pass was never enough for we observed how many artifacts we missed initially.  Usually two additional passes were necessary to vacuum the surface completely, and each pass involved either crawling on hands and knees, or bending so that you had a closer view of the ground.  I have to admit that my back and neck got sore after a while of this.


The results of this “total collection”, shown below, are interesting to compare with the “pedestrian survey counts” discussed yesterday.  You have to keep in mind with the comparison that the pedestrian counts represent a 20% sample of each subunit while the total collection counts represent a 100% sample.  You have to multiply the pedestrian count by a factor of 5 to estimate the “total putative count” (i.e., an estimation of what the total count would be for 100% of the unit) for the pedestrian-walked unit.

The first outlined set of grid units below shows the total counts from each of the total collection units.


The second set of grids compares the total collection counts with the pedestrian survey counts in parentheses (multiplied by 5 to create the 100% putative sample).  


The third shows the factor difference between these two types of counts.  


Here is where it gets even more interesting.  We can estimate that the 940 artifacts experienced fieldwalkers counted through pedestrian survey across the entire unit (i.e., the pedestrian counts from 4 walker swaths) would produce a putative pedestrian survey count (factoring for the 20% sample) of 4,700 artifacts.  In other words, had we walked 100% of the unit, we would have counted about 4,700 artifacts.  Now, if total collection (vacuuming) produces on average 2.96 times the number of artifacts as pedestrian survey, we can estimate that there were 13,212 artifacts actually on the surface of the ground.  To provide some perspective, we collected and brought back to the museum 8,788 total artifacts from the 252 grid squares of Koutsopetria and 19,657 total artifacts from our survey of the entire Pyla-Koutsopetria area.  A single survey unit at Koutsopetria totally collected would produce 1.5 times the number of artifacts sampled from all 252 grid squares at Koutsopetria and .67 of the total artifacts sampled across the entire Pyla area.  If we were to apply the same multipliers to all 252 forty x forty meter grid squares, i.e., the main part of the site of Koutsopetria, the total artifact count of 19,182 would produce a putative total count of 95,910.  Our estimated total population of artifacts (based on the 2.96 factor) is at least 284,894 (and in reality, poor visibility in many units often limited our sample to 50% of the ground).  This is *why* sampling is important!

As for TIME, total collection requires a huge commitment.  Although we (for clarification here, “we” means David – Bill) initially considered surveying all 16 subunits, i.e., an entire 40 x 40 m unit, this proved unrealistic given the time it took for 5 individuals to vacuum a single subunit: 1.5 hours each for G1 and G6, 2 hours for G9, and 1 hour for G15.  Using the total time it took to hoover 25% of the grid square (6 hours) as an index for hoovering this unit, we estimate that 5 individuals could hoover a high-density 40 x 40 m unit in about 24 work hours or well over 100 work hours!  If the typical survey work day is 6 hours long (say, 6AM-noon), it would require 4 full days of a team collecting artifacts from the surface.  Truly this would be an incredibly time intensive task!  By contrast, sampling 20% of the unit through pedestrian survey takes about 20-30 minutes.  In this perspective, total collection requires 72 times more time than pedestrian survey collection!

One final comparative result is interesting to note here.  The “other” category increases dramatically through total collection, including numerous pieces of ancient glass (9), lithic stone artifacts (7), shells (24), slabs (13), gypsum (141), ceramic bricks (2), stone vessel (1), marble revetment (3), and a ceramic tessera or gaming piece.  Although total collection was time intensive, this sort of qualitative information is quite useful in filling out our picture of the overall survey unit and indicates something of the functional variability within each survey unit.

Tomorrow, we will conclude our discussion of experiments with an overview of ceramic fabric categories.  Stay tuned!


Experiments in Intensive Survey at Pyla-Koutsopetria

Another guest post from our esteemed guest blogger, David Pettegrew, the co-director the Pyla-Koutsopetria Archaeological Project and the 2010 Cyprus Research Fund speaker.  Be sure to check out his posts on Tuesday and Wednesday.

When I announced my plans to conduct a survey experiment where we would “vacuum” an entire 40 x 40 m unit, Dimitri and Bill both laughed and told me that I had to try it simply for its absurdity.  The 40 x 40 m survey unit was our standard size for the 252 units that we laid out across the Koutsopetria plain .  As far as survey units go, 40 x 40 m (or 1,600 square meters) is a relatively small unit compared to that typically employed by those who conduct distributional survey.  At the same time, when on the group, 40 meters is still vast when compared to the dimension of most lived space.  After all, a 40 x 40 meter unit is over 130 square feet on a side and over 17,000 square feet which makes a single survey unit much larger than even the most over-sized suburban McMansions.  The reason that my suggestion was humorous, however, had to do with the method I proposed for collecting artifacts.  In our typical pedestrian survey, we only looked at 20% of the surface of the unit (for a more reasonable and suburban 3,400 square feet) and only collected each unique artifact from what we saw on the surface.  My proposal was more extreme: get down on our hands and knees and completely “vaccum” (or “hoover”) all the artifacts from 100% of the unit to produce an exhaustive (and exhausting!) total collection rather than a quick 20% sample.

Why?  I had the suspicion that the amount of artifacts we see when we walk across the unit is but a fraction of the total number of artifacts actually on the ground.  The suspicion was based on experiments conducted in 2004 & 2006 where we ‘vacuumed’ artifacts from a 5% sample of our 40 x 40 m units, producing on average artifact counts that were 4 times greater than that produced through our 20% sample using pedestrian survey.  We also proved through these experiments that the substantially larger number of artifacts did not really contribute much new chronological or functional information that warranted the additional investments of time and energy.  We published a report on those experiments in an article by the authors in the Report of the Department of Antiquities, Cyprus 2007.  However, we were aware of the substantial fluctuations of artifacts within 40 x 40 m units and the risk of a 5% sample (80 sq m) being unrepresentative of the unit as a whole (1600 sq m).  The point of our 2010 experiments, then, was to test the results with a much more robust sample.  While I initially wanted to vacuum 100% of the unit, time constraints prohibited me to vacuuming 25% of the unit.  Even still, 25% of the unit is 5 times greater than what we sampled in 2004 and 2006.

Due to the limited time for fieldwork this season (and time constraints were one of the reasons that we sampled the units to begin with!), we could only resurvey a single unit placed in the highest-density area immediately northeast of the excavated apse of the early Christian basilica.  We picked this unit to overlap with our very first Discovery Unit, a grid square of 40 x 40 m surveyed in 2004 northeast of the enclosed excavated part of the site of Koutsopetria.  We divided the 40 x 40 unit into sixteen 10 x 10 m subunits, each representing 6.25% of the overall unit area (1,600 sq m).  The grid squares have been given the prefix of G followed by a number between 1-16, as the following plan shows.

NewImage.jpgIn our interest in comparing artifact counts noted during pedestrian survey—where a surveyor walks across the unit examining a 2 m wide swath and counting all pottery, tile, lithics, and other artifact types—with the total population of artifacts actually on the surface, we implemented two stages to the experiments.  The first stage (pedestrian survey) we will report on today.

We began by having four fieldwalkers walk across the unit, recording all artifacts visible in their swath, giving a 20% sample of every 10 m of space across a 40 m transect.  We collected ‘sub-tract’ artifact counts every 10 meters to produce density figures for each of the subunits (G1-G16) and assess the fluctuating density of pottery, tile, and lithic artifacts within a survey unit.


We collected the data for pedestrian survey three times.  The results of these three separate pedestrian survey exercises are shown in the four figures below.  The numbers represent artifact counts of each type (pottery, tile, other, and total), and the gray shaded columns with orange numbers represent the total artifact count for the swath per fieldwalker.  

The first time (see figure 1.1 below) a group of untrained students walked the units—Andrew, Luke, Valerie, and Zane—who who had only seen artifacts at the museum and not in their “natural” (or better, archaeological) contexts.


A steady light rain the following day provided the chance for these same students to rewalk the unit a second time (see figure 1.2 below) with artifacts slightly more visible as a result of the washing of the dust.


Finally, a group of experienced fieldwalkers—David Pettegrew (DKP), Dimitri Nakassis (DN), and Bill Caraher (WRC) —walked the unit and counted artifacts (see figure 1.3).


Hence, the variables in these three episodes of pedestrian survey were experience, and, to a lesser extent, the amount of dust and dirt obscuring the surface of the pottery.  Otherwise, between episodes environmental factors were constant, as were methodological factors and figure 1.4 shows the average of all the counts produced.


We walked these units on June 9 and 10 and each took between 15 minutes and half an hour.

Comparing simply the total artifact counts (the bottom right grid within each of the outlined figures), it is interesting to note that the rain appears not to have made a difference overall in density counts between units [1.1] and [1.2].  Although one student count went up significantly after the rain (LHM: 118  243), and another student count was slightly greater (AMH: 200  241), VAW’s total counts were essentially unchanged (335 to 334), while ZRB’s total counts actually declined (238).

As far as the other variable (experience) goes, there were some significant disparities between experienced walkers and inexperienced walkers as evident in counts for particular grid squares (compare G1 for [1.1] and [1.3]).  Otherwise, the overall artifact counts were comparable for the units: the lowest-density and highest-density subunits occurred between all three walking episodes.  If we look at total artifact counts for each unit as a whole, students counted 942 artifacts in [1.1] and 1056 artifacts in [1.2] while experienced walkers counted 940 artifacts in [1.3].  That is remarkably close!  

We noticed one major difference, however, in the “other” category, which includes all artifacts besides pottery and tile: marble revetment, gypsum, shell, ancient glass, and ground stone agricultural implements.  The experienced field walkers noted 2-4 times the number of other artifacts in [1.3] than inexperienced fieldwalkers in [1.1] and [1.2].  An experienced walker counted 4 lithic artifacts (chipped stone & ground stone) in G3 and G7 that an inexperienced walker missed.

Picturing Landscapes

I just finished reading Matthew Johnson’s Ideas of Landscape(Blackwell 2006).  In it, he argued that maps, air photos, and archaeological hachured plans formed the foundation of landscape archaeology in Great Britain (and, I’d contend, elsewhere).  Landscape archaeology in the Mediterranean has certainly benefited from maps and air (and increasingly satellite) photos which represent the first step, typically, in data gathering for an archaeological project. The first aerial photographs that we acquired in the study of our site of Pyla-Koutsopetria were the 1963 and 1993 series produced by the Cypriot Department of Maps and Surveys.



Since then, we were lucky enough to have a series of oblique, relatively low altitude air photos taken from an RAF helicopter in 2007.  These photos provide more detail, but the oblique angles make them more difficult to use for producing accurate maps. 

Picture 044

Picture 047

This past summer, we took even more low altitude and far more oblique air photographs using the infamous helikite (half helium blimp and half kite).  We only had enough helium for a limited number of flights and this tempted us to take the airship up in, let’s say, unfavorable conditions.  The results were blurry, but we were able to salvage some good quality aerial photographs from the set.  The camera was rocking furiously beneath the wind-buffeted helikite so the photos lack a good representation of the horizontal.  More disappointing is that the strong breeze from the sea made it difficult to photograph the fields closest to the busy Larnaka-Dhekelia road.  The 1963 and 1993 aerial photographs showed some feature near the intersection of the main road and the northeast running road that now leads to the water treatment facility.  While the feature does not stand out in the 2007 RAF photographs, they were taken after a particularly wet early summer which caused green wheat to be left in the field.  The nicely ploughed fields of summer 2010 may have provided a different image.


One of my jobs for this summer is labeling these photographs and moving them to Omeka.  For now, enjoy a different perspective on the site of Pyla-Koutsopetria.

Preliminary Analysis of Pyla-Koustopetria Archaeological Data or Thinking Out Loud 4

March 15, 2010 1 comment

In September, I began a series of posts in which I thought out loud about the survey data from the Pyla-Koutsopetria Archaeological Project.  The posts mainly focused on overall ceramic densities across the entire study area.  Over the last two or three weeks, I’ve begun working on the final analysis of the period data from the survey.  To do this, I take the finds data produced by R. Scott Moore and Mara Horowitz and plot is against the survey maps produced in the field by David Pettegrew and myself.  In most cases, this work has confirmed our long held (and argued) perspectives on the distribution of material at our site, but sometimes, bringing finds data together with our survey maps shows patterns that were not entirely apparent on the ground.

While we have dedicated much of our attention to activities along the Pyla-Koutsopetria coastal plain or in the area of the known Bronze Age site of Kokkinokremos, it may be that some important activity is taking place on the coastal ridge running north of the Koutsopetria plain and the very prominent coast height of Vigla.  The main concentration of activity in what we call Zone 4 sits along its southern edge.  The site in this area first appears during the Iron Age.


This image shows the site from the Iron Age to the Hellenistic period.  The blue dots are Iron Age material (1050-475 BC).  The assemblage in the red circle included everything from Classical era terracota figurines to fine wares and kitchen wares and utility wares (amphoras, medium coarse and coarse wares).  The material is highly localized in an area of 25 units or so and does not appear to extend further north. The assemblage from these periods on Vigla (the concentration of material to the southwest of the red circle) is contemporary, but far less robust and diverse.  The activity at this area appears to persist into the later Hellenistic and Early Roman period as well.


In this map, the triangles are Early Roman material, the pentagons are Hellenistic-Early Roman material and the green dots date to the more generic Roman period.  While there is evidence that the activities at the site begin to extend further to the north along the plateau, the main concentration of material is still in the southern most units of along our north to south transect.  Like for earlier periods, the assemblage is reasonably diverse including fine wares, lamp fragments, and a full range of utility wares. 

The most remarkable thing about the site is that it suddenly, within the limits of our chronological resolutions, stops in the Late Roman period.


In this map, the different colored dots are all Late Roman material and, as you can see, there is not much Late Roman activity in the area of the earlier site.  So, the question is what kind of site of sees consistent activity for close to 1200 years and then is suddenly abandoned.  To my mind, there are three options.  First, Late Roman activity does not decline over the study area as a whole.  In fact, the coastal plain becomes the center of unprecedented activity during this period. It may be that the center of settlement shifted from the more protected top of the coastal plateau to the more convenient coastal plain during the relatively peace epoch of Late Antiquity.  Second, the area on the plateau could be a religious sanctuary of some description.  The scholar of Late Antique Christianity in me is drawn to the idea that the site is a long-standing pagan sanctuary abandoned with the growing prominence of Christianity on the island.  Perhaps the very fabric of the sanctuary was quarried for the building of the excavated Early Christian basilica on the plain below.  Finally, it may be that this coastal height served as the local cemetery.  While the diversity of the assemblage at the site hints at habitation or even religious uses (which could include the same material signature as domestic activity), it may be that the main settlement was on the fortified height of Vigla (as our excavations at least hints) and they buried their dead outside the city walls to the north.  The abandonment of burial in this area occurred in Late Antiquity where (I can’t resist) Christian conventions gently resisted burial among pagan ancestors.  At the same time, the persistent sanctity of the long-standing burial ground made it impolitic or even impious to use the space for more mundane activities.  As a result, the area was largely abandoned even as activity along the northern part of the plateau continued.

We do not have any definitive evidence for any of these hypothesis, although ground-penetrating radar transects recorded in 2009 might provide us with some hints once they are analyzed.  At the same time, the clear shift in activity away from this site stands out as one of the most definitive changes in the distribution of material across our site.

Walking Home and the Phenomenology of Landscape

March 8, 2010 2 comments


In a recent article, by John Bintliff ("The Implications of a Phenomenology of Landscape," in E. Olshausen and V. Sauer, Die Landschaft und die Religion. (Stuttgart 2009), 27-45) offers (another) harsh critique of Christopher Tilley's efforts toward a phenomenology of ancient landscapes. Bintliff, in particular, takes issue with Tilley's efforts to produce an landscape rooted in its "emotional and symbolic significance" to the exclusion of a more holistic view that includes an emphasis on the landscape as economically productive space. He argues that Tilley's view of the landscape as "really just about feelings, and symbolic behaviors…" represents a distinctly British reaction to historical phenomenon of the last century or two: namely the gradual abandonment of the countryside by a large part of the population who moved to cities and the consequent inability of most of the population to understand the countryside as productive space. Instead, the countryside has become a kind of "enormous themepark for the urban millions".

Reading this and contemplating my own walks home made me question the authenticity of my own experience. After all, I don't need to walk home or even be outside in the cold. I don't walk home for environmental reasons – my wife happily drives to and from campus in the relative warmth of our relatively inefficient little Honda. I do not even do it for convenience, bowing to our more than hectic schedules my wife and I indulged in the ultimate symbol of middle class affluence, when we purchases a second car. I always thought that I walked home because the outdoors offered an experience that was common not only to members of my community today, but also to historical members of this community who would braved the brisk walks across the exposed prairie for over a century. In short, I was imitating, in my own hopelessly local way, Tilley's call for phenomenological approach to the local landscape.



At the end of the day, I suppose my walks home did lack the kind of authenticity necessary to allow me to engage with the past in anything but the most superficial way. The cold, bracing, North Dakota evenings existed only in contrast to the forced-air warmth of my home and office. Our knowledge of space and place can only ever be relative to our historical engagement. Bintliff's holistic view of the past, of course, is just as easily subsumed into this paradigm. His call for a holistic view of the landscape is clearly fed by the modern roots of archaeological practice and the political drive to document exhaustively the natural, cultural, social, political, and economic resources of a place. So, if the critique of Tilley's methods for understanding the landscape derives exclusively from its unabashedly urban, 20th century, bourgeois position, then Bintliff's calls for a holistic view of the landscape must certainly have roots in the modern or even colonial dream of documenting the entire world.  

Old School Computer Generated Maps

When tracking down a few footnotes, I stumbled upon an article J. M. Adovasio, G.F. Fry, J.D. Gunn, and R.F. Maslowski, “Prehistoric and historic settlement patterns in western Cyprus (with a discussion of Cypriot Neolithic stone tool technology),” World Archaeology 6 (1975), 339-364. This team conducted an extensive style survey “reconnaissance survey” of the Khrysokhou drainage in Western Cyprus not far from the site of Polis. I was mostly interested in their documentation of a “large settlement of the Cypro-Archaic Age (600-400 BC) and “very large Hellenistic town” (325-50 BC) thinking that I might find some useful parallels between these sites and our site at Pyla-Koutsopetria.  The description of the sites are pretty superficial, although the observation that the settlement are in defensively advantageous positions is vaguely useful.  That being said, the effort of the survey team to document sites systematically with an eye toward computer analysis must represent one of the earlier efforts along these lines in the Eastern Mediterranean (the field work was conducted in 1972).  They also were explicitly diachronic in their approach and mapped not the location of Ancient material but the location of Medieval/Byzantine material and even modern settlement.

What really caught my eye were the fantastic, old school computer generated maps of the area.

Here’s the map of the Cypro-Geometric to Hellenistic components of their survey area:


Here are maps showing a slightly larger area and including the Roman and Medieval and Byzantine sites.



The project used Harvard’s SYMAP software (check out this cool little movie talking a bit about the history of SYMAP) run on the University of Pittsburgh mainframe to produce these images.  The images themselves include both elevation data (zone data) and archaeological data. While I’ll concede that these maps are not immediately legible, they do reflect a very early effort on Cyprus to take data from the field, process it by a computer, and present this analyzed data in a relatively transparent way (that is in a way that does not hide the computer produced character of the analyses).  At the same time, there is something aesthetically pleasing about these maps which, after all, were basically contemporary with the first generation of computer generated art.