Sunday, July 14, 2013

A Piece of Cake

Our work in Room 28 is winding down.  We reached the level George Pepper and Richard Wetherill reached, found features that they did not expose, reopened areas that they dug beneath the floor, and took a small portion of the room to sterile soil.  We have spent the last week mostly recording the features, mapping, and taking samples.  There remain two beams in place that we still need to pull, more pollen samples to take, and a couple of pieces of ground stone incorporated into the architecture that we will also remove.  What did we find?  Pepper and Wetherill took many wonderful photographs and drew a schematic of the room, but they did not provide a complete description of the room and apparently did not uncover all of the walls and features.  We found and documented 27 postholes.  There probably were more that had been destroyed by their excavations.  We found a small thermal feature and ashpits.  We found a large pit dug by Wetherill and Pepper just outside Room 32, apparently to enlarge the space for working in that room.  We marveled that none of their crew was injured by falling walls (that we know of), when it took five sets of scaffolds to hold the walls in place for our excavations.  The artifactual finds will be described in the future.
Friday morning the student crew left Chaco and we began the LiDAR mapping of Room 28.  We continued mapping Saturday with rooms around Room 28 for context. Dr. Wetherbee Dorshow, President and Grand Poobah of Earth Analytic, Inc., Jed Frechette of Lidar Guys, and Scott Dillon of the Division for Historic Preservation in Vermont, collected over one-half billion data points that are accurate to less than a centimeter.  From these data, they will create a 3-D model of the room and surrounding area.   
At a going-away reception, Susan and Meredith, the campground hosts, made an incredible replica of the excavation in CAKE, with tiny cylinder jars and even a backdirt pile.  This was an entirely different 3D model of the excavation/room, and tasted better than the half billion data points.  Our thanks to them for their kindness and creativity!  And GB’s ice cream is the best version of chocolate ever consumed in Chaco. 
Our crew did a lot of work in a short period of time (23 work days!) with good humor.  As with all archaeological projects, we developed jokes, songs, and language that we all understood, but that folks outside the crew would probably find baffling and not as funny as we did.  The Park particularly asked us to limit our discussion of what we were finding—and in Chaco, where voices carry so far, to keep as quiet as possible.  This was both to keep from altering the Chaco experience by making noise and to avoid attracting vandalism.  So we often spoke in code.  The following list is for the crew, for the record, and everyone else may want to skip reading:
on the radio: This is Pueblo Bonito
8 foot tall men
Candy canes of terror
Code Blue
Code White
Code Scott
Code 8
Code Chip
Code tree-ring sample
a bat, a snake, and a packrat walk into a bar
Mr. Bucket
the Annex ("if I gave you a portapotty, would you drink more water?")
Won’t you screen my bucket?
That girl really works hard
Sheep corral
you need to take pictures of the sites you can't find
Look! it’s an MGM mock-up of an archaeological dig
this dirt is like buttah
Bucket launcher
Chaco trivia contest
big hats
the bob-dog
the bob-lion
bobcat spray
PhD school
Bob, the OSHA guy
primate vocalizations
HEE hole
I feel like Cinderella
the Pepperill Project
Elvis has left the building

I’ll add blog entries as the project analysis is underway.  Once we have backfilled, it will be possible to discuss the results in more detail.  In the meantime,
UNM clear

Tuesday, July 9, 2013

What SPF Sunscreen did Indiana Jones use?

It is an ongoing joke among archaeologists that if you don’t want to speak to the person next to you on an airplane, you tell them you are a theoretical physicist.  Saying you are an archaeologist usually leads to a conversation about:
a)    how they always wanted to be an archaeologist and/or
b)   how they LOVE dinosaurs
It seems that many people think archaeology is an exciting profession, a viewpoint promoted by Hollywood depictions of “archaeologists” who usually pillage sites in ways that no self-respecting, trained professional would consider.  I find that about half of the students who attend field schools realize quickly that they don’t like being dirty, working outside, working tirelessly, and often finding nothing—so one function of field schools is to weed out those who think archaeology is the most wonderful experience they’ve ever had versus those who can’t stand field work.  The reality is that archaeology is really hard work, particularly fieldwork. 
What is a typical day like in the field?  On the Room 28 project, a typical day goes like this: we rise at 5 AM, eat breakfast, make our own lunches, slather on sunscreen, pull on clothing with SPF rating (which usually means long sleeves and long pants), and finally don a neon vest—which in Chaco identifies us as project members.  By 5:45, we are at the trucks, loading equipment for the day, along with our packs, water, and food.  We drive to Pueblo Bonito at 6 AM and are the first people there every day (the gates don’t open for tourists until 7 AM).  We haul the equipment to the excavation area and begin the opening—this involves a lengthy process of removing sandbags from the tarps that hang from the Quonset-hut shaped garage over the excavation—and rolling the tarps up and fastening them to the frame using the wonderful bungee balls (truly an invention right up there with mousetraps).  The ravens scold us as we unlock the equipment left at the site and distribute screens and buckets, and set up the shade over the screening area.  As the designated “Competent Person” (for OSHA purposes—this means I have the power to tell everyone to get out of the excavation, make decisions on what is safe and what isn’t, and fill out a safety checklist every single morning before we enter the dig), I don my hardhat and fill out a safety checklist, monitoring cracks in the walls, watching for any telltale piles of dirt on the floor that weren’t there the night before, and checking the scaffolding to make sure it hasn’t slipped.  ALL excavators working in trenches must meet OSHA standards—we wear hardhats, have an exit within four feet of our work at all times, and have a safety plan in case a wall falls. 
Then we start to excavate.  We use shovels in some levels if the material is just backfill, trowels where it is important.  We put the resulting dirt into buckets, usually using dustpans for this task.  The buckets are either carried to the top of the steps in the dig OR lately we have used a bucket raising device that involves a pulley and ropes to move buckets straight up and then over to the screening area—we call it the buck-o-matic.  The Park Service Stabilization Crew put it up for us and it’s very ingenious,  but does require a lot of strength to raise buckets, now that we are down 3+ meters.  We usually have 2-4 crew members in the excavation area and 2-4 in the screening area—we’ve used 1/8th inch or window screen throughout most of the excavation, so screening a single bucket can take anywhere from 5 minutes to 30 minutes, depending on what is in it and how fine the mesh used for screening.  On a typical day, we screened around 150 buckets.
I think most archaeologists would agree on the qualities of an excellent crew member: they work tirelessly without complaint no matter the conditions; they take supervision well without any argument, but they often provide suggestions for ways to do things; they take a deep interest in archaeology and are always asking questions about the past and about what they are finding; they write thorough field notes every single day with lots of sketch maps; they are always looking around for what needs to be done; and they work quickly and efficiently in the field. 
We take cookie break at around 9 AM—a brief break for some food/drink.  Then back to work until lunch around 11:30.  Then more work until around 3:30-4 PM.  We take outreach seriously, so we talk to most visitors who stop at the “wayside exhibit” that is outside our excavation area.  Since we are located right ON the main trail through Pueblo Bonito, most people pass our area and stop and talk.  We have spoken to hundreds of visitors, in addition to field school groups and special interest groups.  Archaeological groups are sometimes invited to come into the excavation area, but we don’t have time to talk to everyone at length.  Some visitors from New York City stopped and looked at the dig area when we were inside the tent at lunch—they discussed how the Park Service had set up the area to look like a dig, but it wasn’t really realistic—more like MGM Studios version of a dig.  They were surprised when we popped up and chatted with them. 
Probably the most difficult part of the excavation is getting in and out of the excavation area—the five scaffolding pipes keep the walls from falling on us, but they make getting in and out a challenge.  We have stairs cut into the dirt, but we still have to negotiate the pipes—some require going under and others require stepping over.  As we’ve dug deeper, we bang our heads on the pipes less often, but it’s good we wear hardhats.  The location of the pipes prevents us from putting a ladder in—there is actually no place to put one where we could climb the ladder without running into the scaffolding.  So the stairs have been necessary. 
When close-up begins, we pull the tarps down, put sandbags on them, lock up some equipment and take the rest to the trucks.  After driving back to the residential area, the students unload the truck and do lab work until they are caught up—this means assigning field numbers, inventorying (counting) all artifacts in each category (sherds, chipped stone, ornaments, etc.).  There is a lot of paperwork to be done.  I sometimes meet with the Park Service personnel in the afternoons after work, meetings that can take minutes or hours.  Everyone eats around 6 PM—the students cook together in a cook trailer and they take turns cleaning up.  At 6:30 PM we reconvene for more lab work until it is finished.  Most of us are so tired, we go to sleep around 9-10 PM.  The students sleep in tents and have dealt with noisy birds, lizards under their tents, rain, wind, and dust storms since we got here.  Sometimes they barely sleep. 
The artifacts, samples, and fauna we’ve collected this summer will be taken to Albuquerque to analyze before being turned over the National Park Service for curation.  My NEH grant includes funding for the analysis, which will take place during the academic year.  Samples will be sent to specialists for analysis during that time too, including pollen, macrobotanical, and dated materials analysis. 
I don’t remember the Indiana Jones movies ever showing him drinking water or putting on sunscreen or cleaning the sand from his shoes (and ears) at the end of the day.  I never saw him write a field note or draw a sketch map.   I’m not sure he cleaned artifacts or even analyzed them once he had them.  This is my 39th year of doing archaeology in the American Southwest and I don’t ever regret going into this profession.  But I certainly didn’t learn about what archaeologists do by watching movies….

Wednesday, July 3, 2013

I love the smell of bobcat pee in the morning

The critter that has been spraying in the Room 28 quonset hut covering has eluded the Park Service critter-cam, but we all suspect it’s a bobcat.  Why?  You know that smell that tells you the kitty litter box is overdue for a cleaning?  That’s exactly what Room 28 has smelled like the last few days.  Park Archaeologist Dabney Ford has suggested it might be TWO bobcats fighting over whose territory the Quonset hut really belongs to.  Last night, the critter apparently decided that a large bag we keep our project plastic bags in posed a threat—and he sprayed it; since that bag was in the bottom of the room space, he is (or they are) apparently concerned about more than just the unexcavated part of Room 28A that is under the tent.  Hopefully the critter cam will catch him in the act tonight. 
In addition to the excavation of Room 28, the crew has been involved in Site Condition Assessment with funding from the National Park Service under a contract to UNM and Dr. Chip Wills.  Dr. Wills has been doing site condition assessments in Chaco for four years now and has developed a really efficient method for completing the process.  The crew has to go off-trail in order to do the work of finding sites in Chaco and assessing their conditions today.  But going off-trail attracts attention in a park where this is not allowed, so in order to signal that they are WORKING, the crew wears bright orange or green vests, carries an NPS radio to communicate with the Park Service personnel about where they are going and how long they are out, and generally keeps everyone apprised of their actions.   Despite the vests, visitors to Chaco often see people walking off trail and report the crew.  It’s hard to imagine that tourists going off-trail would wear neon vests, but it apparently can happen.  So we felt the crew needed some additional identifying clothing to distinguish them from people breaking the law.  See photo below.
We spent today mapping the room and cleaning out the postholes—Pepper had pulled the beams from all but a couple of them already, but they are very well preserved and lined postholes.  Today we had a lot of visitors:  Dr. Bruce Huckell came up from UNM for a few hours—it was great to have his perspective on our work in Room 28 and some of the chipped stone materials we are finding.  The SMU field school visited led by Dr. Kit Nelson.  Finally, Bob Dunnington from UNM visited to assess our safety.  He gave us the go-ahead to keep working and cut back a part of the profile and the balk covering the door to Room 32.  So we have some work ahead in the next few days.  We won’t take tomorrow off, so we’ll miss seeing fireworks, but somehow being in Chaco is even better.
Jennie Sturm, Leigh Cominiello, unknown person, and Chip Wills model latest fashion for Site Condition Assessment.  The hope is that someone reporting the crew as wearing neon vests AND tall hats might tip off the Law Enforcement group that it is our crew.  Thanks to Jim von Haden for the photograph.


Note: This post was written last night, but the Chaco wifi went down and I couldn't post it until today.

Today, July 2, 2013, we finally reached the surface to which Pepper and Wetherill excavated in 1896!  It was our thirteenth 20 cm level, meaning that we have excavated about 2.6 meters below the present ground surface—a long way to go in only 14 days of excavating.  The surface was fairly easy to find: a thick layer of powdered daub and chunks of daub covered the western half of the room and clearly represented the material Pepper described in his volume on Pueblo Bonito.  As we troweled this matrix away, we reached a stratum with no burned material at all, and we discovered all of the postholes that Pepper drew on his map of the room.  It was so strange to use photographs to help excavate a Pueblo room!  There is no question about this being the surface they excavated to—it is just deeper than anticipated.  Part of the problem in estimating how deep the Hyde Expedition excavated in Room 28 is that their photographs of the entire room only show the upper layers of the cache, while the photographs of the 2nd-5th layers are close-ups—so there is no way to evaluate how deep he excavated to reach these layers.  Now we know.  The doors in the room remained blocked, so they were not helpful in estimating the depth.  At any rate, it was very exciting to reach our first goal.  Now we just need to figure out a way to view the original stratigraphic profile safely.  The UNM OSHA Engineer, Bob Dunnington, will visit us this week to help determine how and if we can safely cut back the profile.  Using the backfill profile has actually been quite helpful these past weeks in evaluating how Pepper/Wetherill backfilled and where we might be in the room fill.
Patricia Crown and Jacque Kocer compare stratigraphic features to a photograph from the 1896 excavation of Room 28. 

We’ve had a visitor the past two nights.  Some critter (some of us are betting bobcat, others badger) has been spraying in the room at night.  It provides a pungent atmosphere for excavation.  The OSHA safety form I’m required to fill out every day asks about exposure to a hazardous atmosphere—and we think this might be exactly the condition they had in mind.  The Chaco Chief of Natural Resources, Jim von Haden has set up a camera to try to catch our new friend in the act, so we’ll see what tomorrow morning brings.
We have a lot of work yet to do to document the room and its features, to pull posts for tree-ring dating, and search for the floor, but we are very happy to have reached the level Pepper did 117 years ago.  We have been working ten hour days in the field in 90-100 degree heat followed by evening lab sessions, so the extraordinary crew is tired—but pleased to have accomplished so much to date.  
Room 28 at surface excavated by Pepper and Wetherill.  The scaffolding is ours. 
We continue to have a lot of visitors: yesterday brought a group (staff and students) from Crow Canyon Archaeological Center, including Kari Schleher, Karen Adams (the project macrobotanical expert), Randy McGuire and the CCAC interns.  Today we had a large group of tourists from Slovenia, all of whom spoke excellent English.  AND I forgot to mention in this blog on our work last Friday that we had excellent help that day from Brenda Shears of Arizona State University—she worked tirelessly with the crew on a day when we were particularly in need of extra hands. 

Sunday, June 30, 2013

One week after Solstice

Excavations on Friday (June 28, 2013) brought some surprises.  We reached the bottom of our 11th 20 cm level, meaning that we have now excavated 2.2 m below the surface.  It’s getting harder to get in and out of the room.  The eastern wall of the room does not really appear in the photographs from Pepper and Wetherill’s excavations, so we were uncertain what this wall would look like, especially in the SE corner of the room.  We knew that the partition wall between 28 and 28A was about 1’ wide (according to Pepper) and masonry.  On Friday, we uncovered a post-reinforced adobe or plaster wall directly in front of the masonry wall (see photo below).   The tops of the post holes were filled with ash, but the slightest tap and the ash fell into a seemingly bottomless hole.  Measurement with a carpenter’s rule revealed that the postholes are 1.2 meters deep!  It feels as if there is a flagstone at the bottom of each.  In the SE corner of Room 28, two flat stones are positioned—there was burned daub atop them, so it is likely they are actually part of the wall, but they are definitely shaped stone.  
Postholes in partition wall between Rooms 28 and 28A.  Note flat stones in SE corner of room.
Work in the western part of the room revealed several surprises.  A mass of burned material surrounded a glass bottle.  Our resident historical archaeology expert, crewmember Leigh Cominiello, is working on finding out more about the bottle and its contents.  The bottle, two rusted cans, and several nails constitute the historic artifacts we have found.  Along the south wall of the room, about midway between the west and east walls, we encountered a wooden plank that is over a meter in length.  The plank is in good condition.  Because Pepper did not describe finding any planks in Room 28, the recovery of this plank helps confirm that Room 28 was backfilled with material from another room or rooms.  Nearby were two other pieces of wood, probably posts or roofing material.  We took all of these for identification of the wood and possible tree-ring dating.  Having read about planks in Pepper and Judd’s volumes on Pueblo Bonito, it is instructive to see how uniformly shaped and thin they are.  It is hard to imagine creating these with stone tools.
Near the center of the room, we found a complete trough metate.  It is in excellent condition, but Pepper and Wetherill probably decided it was too cumbersome to ship back East and left it in the room.  
Base of Level 11 in Room 28.  Note the beautiful screw-jacks!  The metate is visible in the center of the photograph. 
I believe we are now within about 20 cm of the surface where Pepper and Wetherill found the cylinder jars.  The matrix is sandy loam, but there are lots of rocks just beneath this level, so the next level may take some time to excavate.  Note our two new screw-jacks, which provide novel ways to challenge our hard hats! 

Thursday, June 27, 2013

Room 28: The Movie

If Room 28 ever becomes the subject of a movie, the trailer would go something like this (and please read with a really deep voice):
In a World made of sandstone, nothing is what it seems.  Only the rough survive. 
Anyone who has worked in Chaco can verify that sandstone aspires to be anything but a rock.  It tries hard to look like broken pottery, chipped stone, and even shell.  It was the most common stone used for groundstone artifacts, such as manos and metates, in Chaco, and yet most of the time sandstone is just sandstone.  Sometimes it was shaped for use as masonry or for features (hearths, hatches).  And sometimes it was actually used as a groundstone artifact.  Figuring out which pieces of sandstone are actual artifacts takes some time and experience.  We have now removed at least six wagonloads of non-artifactual sandstone from Room 28 and it is clear that there is still much to remove.  Pepper and Wetherill apparently preferred to throw lots of rocks in front of doors as they backfilled.  Part of the room is sandy loam and easy to excavate and the rest is a tangled mess of rocks.  We are getting closer to the floor, but still have about 20-40 cm to go before we reach the level where Pepper stopped digging.
One filled doorway collapsed yesterday, with rocks filling the upper part falling downward into the lower part as we cleared it.  We were clearing it to have one of the NPS crew members, Harold Suina, fill it with new masonry to keep it from collapsing.  And then part of it collapsed.  He is truly a master mason and did a beautiful job building a new filler for the door.  This will then be covered with yet another screwjack and plywood to hold the opposite wall in place.  The other two doorways in Room 28 are not faring much better. The doorway in the NE corner has a collapsed lintel, so we can’t work in that area at all—the entire wall above it might fall.  The doorway in the NW corner also has a fallen lintel—this time made of wood instead of stone, so we are carefully avoiding the area until we have excavated the rest of the room. 
Harold Suina fills the SE doorway of Room 28 to keep it from collapsing.

Level 10 completed for Room 28.  Large balk on right is to protect collapsed NE door to Room 28.  Smaller pedestal at northwest corner of room is to protect door into Room 32.  Burning is evident on south wall of room.  The stratigraphic profile clearly shows the backfill thrown against the south wall by the Hyde Expedition. 

We had a lot of visitors yesterday.  The UNM Department of Anthropology Staff visited: Jennifer George, JoNella Vasquez, Carla Sarracino, Ann Braswell, Matt Tuttle, and Joanne Kuestner visited the site, followed by a crew from the Office of Contract Archaeology led by Kevin Brown, then Cottonwood Gulch, then the Campfire Boys and Girls, and finally a group from the University of Georgia (led by John Kantner).

Tuesday, June 25, 2013

Little Room in the Pueblo

We returned to the excavations in Room 28 at Pueblo Bonito today after a hiatus.  The complex way in which the room was backfilled continues to surprise us.  In the NW corner of the room, we continue to find charred roofing beams suitable for tree-ring dating (although we don’t know exactly which room they came from).  In the SW corner, there is a clear area of sand that may be: an unexcavated area left by George Pepper OR blow sand that filled a void in the room once it was excavated OR blow sand from some other room thrown here by Pepper as he excavated adjoining rooms.  This area is easy and fun to excavate.  The center of the room from west to east is filled with rocks—masonry from some place, often with air pockets between the rocks.  The rocks seem endless—the Park Service provides a wagon for the rocks and takes them away to use in stabilization activities.  They have hauled away five or six wagon loads of rocks so far.  
Panorama view of excavation area.  On the left, screens set up on top of a tarp.  In the center, stabilization crew carries plywood by little green wagon filled with rocks from the excavation.  To the right, the gray 'garage' covering Room 28. 
The NE door, which led into Room 51A has largely collapsed—the lintel is broken and leaning at a dangerous angle.  So despite our interest in working in this area, it is too dangerous to remove any more supporting dirt in front of the door.  The door to the plaza, located in the SE corner of the room had been filled with rock at some point in the last hundred years—just in front of the door is an iron can surrounded by rock, all clearly located within a pit.  The entire feature may have been placed here to support the rocks in the door.  This was a door that had steps that led up into the plaza adjacent to Room 28.  Because of the rocks filling the door, we will have to forego excavating the door further—once again, it’s too dangerous.  Another screwjack will be placed from door to door on the eastern end of the room sometime in the next couple of days.  We are getting a lot of exercise bobbing up and down around the screwjacks.
As we get closer to the area where George Pepper found the cylinder jars, we have begun screening everything with 1/8th inch mesh and some areas with windowscreening.  It takes longer to screen this way, but it ensures that we aren’t missing artifacts and fauna in the screens.  Dr. Wills located a corncob in the screen today!  Only our second in this room. 
Some friends in Alaska graciously sent us a vintage game called Mr. Bucket to play in our spare time.  We appreciate the opportunity to spend more time with buckets.  Thanks to Will and Mark for the excellent gift!