Return to El Pilar!

 

We made our first working trip to El Pilar last Thursday, April 27th, which included a return to a small mound cluster on the periphery of the low-lying, seasonal swamp in the northeast of the Reserve. We took James on a short tour of the site on Easter Monday, which you can read about here, but we were only on-site for a short time and didn't do any actual work. On our first real working day, we rechecked a number of mounds that were flagged in the lab for having problematic data and tested a new method of uploading GPS points directly for our GIS system. Unfortunately, only the former endeavor was successful, but we still have our original GPS protocol to fall back on.

 

 

Above you see some of the tools of our trade, which we used to field-check problematic structures. This is the fourth year of this particular survey project, and we have recorded hundreds of structures with multiple metric attributes for each one. Combine that with the amount of data Anabel has gathered over more than three decades working in the area, and you're bound to have some quality-control issues, especially when multiple people are involved in data collection and transcription. We're fortunate to have the system that Anabel developed in place, which features built-in checks and methods to resolve these problems. Once we identify problematic structures - that is, structures with missing data - we locate them in our GIS, print maps at various scales showing the structures and their surroundings, and load their associated waypoints into our GPS units. This allows us to efficiently make our way to our destinations in the heavily forested area.

 

The blue line in the map above is a track of our movements generated by one of the GPS units we took with us. We had a bit of a problem with several of our units - the new uploading system apparently maxed out their waypoint-handling capacity, so that we had to delete existing points in order to take new ones. Luckily, all still recorded our tracks without a hitch, and our newest unit had no problems taking additional points along the way. Our work took us from the swamp periphery into the area north of the monumental core, across the causeway to Pilar Poniente in the west, and back across the sunken plaza to a ballcourt and through several settlement groups on our way out at the end of the day. We estimate our total walking distance to have been between 9 and 10 kilometers, which may not sound like much to those who do 10K's on a regular basis. But you have to remember that El Pilar is located in the tropics, and this is still the dry season. Temperatures ranged between 95 and 100 degrees F (35 - 38 degrees C) from late morning onward, and we were only able to travel so far by roads and trails when walking to each point. Needless to say, we were all pretty tired by the end of the day, but we accomplished everything we set out to do in less time than we expected to finish. Here are a few pictures of what we found:

 

Here is a picture of the first mound we visited in the swamp periphery. James is standing on top of it. You may recall from previous Lab Notes that with small mounds, there's often not much to see. But this was definitely an ancient Maya structure and not some heap of natural materials, as we confirmed by observing limestone platform foundations and some associate artifacts.

 

Some of the features we find are ambiguous, even if we observe limestone cobbles in the area. Tree roots can move smaller stones around, as can activities by more recent occupants of different areas. But finding ancient pottery fragments associated with a mound feature will pretty much seal the deal. Here you can see a scatter of sherds located just off the edge of the mound pictured above. The ancient Maya liked having trash strewn around their homes about as much as we do today, so they regularly dumped their garbage outside and behind their structures in heaps that we call middens. We didn't excavate around this mound, so we don't know if these surface sherds represent such a midden, but they certainly seemed to be in the right location.

 

Other mounds are far less ambiguous. I apologize for not being able to turn this photo around - I'm not sure what the problem is here - so I guess you'll have to take my word for what you're looking at, or save it to your computer and rotate it yourself. This is James standing halfway up a mound that rises about 2.5 meters above the surrounding terrain. When we encounter mounds like this, there is little doubt that they were made by humans in the past. This mound has the unassuming name 2G6-01 in our cataloging system, and it is located at the foot of a small hill to the northwest of the mound described above. If you look at the ends of the "T"-shaped part of our blue track line, you'll have an idea of where both of these mounds were located.

All in all, our first day out was quite the success, even if we had problems with our experimental GPS system. Identifying problems before the real work begins is always a good thing, and we should have a much smoother time in the weeks of fieldwork to come. We'll be posting more results on here later, so please stay tuned!