Salvage, Conservation, and Consolidation at the Classic Maya Site of Tecolote, Guatemala
The Classic period (AD 250–900) Maya site of Tecolote is located in the Sierra del Lacandón National Park in the northwestern corner the department of Petén, Guatemala. Tecolote is believed to have been inhabited primarily during the late 7th–early 9th centuries AD. The major area of settlement is located approximately 2.2 km east from the Usumacinta River, near a set of rapids called "Anaite" or "Chico Sapote." It lies in the presumed Classic period border zone between the major archaeological sites of Yaxchilán and Piedras Negras (Fig. 1).
The site was initially documented in 2003, and mapping at Tecolote in 2004 revealed a large core area defined by a series of hills covered with complexes of collapsed-vaulted buildings, including a large palace complex in the southeastern corner of the mapped area, and in the northwest a large masonry platform abutting a hill, which dominates an extensive, formal plaza (Fig. 2).
Structure D3-1, located on this large platform, is the only structure at Tecolote that still retains intact vaults in all of its rooms. Within these rooms are fragments of painted murals containing figural elements and legible pieces of hieroglyphic texts. Unfortunately, the building has suffered the depredations of looters, and trees growing from its roof threaten to pull apart the fabric of the vault and walls. Str. D3-1 was, therefore, the subject of conservation efforts supported by Dumbarton Oaks, and carried out by Leslie Rainer, Kimberly Machovec-Smith, and Margaret Kipling in the May 2004 field-season of the Sierra del Lacandón Regional Archaeology Project.
Structure D3-1 is a three-roomed vaulted structure built on a northeast–southwest axis using quarried limestone blocks and mortar (Figs. 3 and 4). Stairs lead up one terrace level from the plaza to the platform on which it was constructed. The back of Structure D3-1 faces a cliff that is only slightly higher than the level of the roof. There are remains of plaster on every wall and vault of Structure D3-1, and as already noted, several walls still retain some imagery.
The interior of the building was constructed as a single vaulted room. Two interior walls were most likely added to the building after the primary construction phase. The walls were placed to the north side of the doorways for Room 1 and Room 2. The walls span the entire width of the building between the east and west walls, but the stones were not integrated into the construction of the exterior walls. Each room displays several rafter-holes located on the East and West vaults as well as the north wall of Room 1 and the north and south wall of Room 2. Many, but not all, of the rafter-holes show evidence of the application of plaster to their interior. Loop holes cut into the stone blocks are seen on the interior of either side of the doorways, possibly for the attachment of some sort of a door or curtain tie. These holes are observed on, or next to the lintels, near the middle of the wall, and where visible, near the floor.
At least one bench was constructed in each room. Rectangular cut limestone was used to build up the height of the bench, a layer of rubble was spread across the top surface and then one to five layers of plaster were applied to the surface of the rubble. As was observed in the layered application of the floor and crypt plaster, the layers of bench plaster generally alternated in color, with the base layer above the rubble being buff, followed by tan and then white layers on top, or just white if there were only two layers. These layers were probably put on the in one primary plastering episode. There did not seem to be a distinct line between any of the plaster layers. The benches were constructed with slight differences and vary in their orientation from room to room.
The floors in each of the rooms were constructed using cut limestone blocks, covered with a layer of rubble and one to three layers of coarse plaster, alternating in color. In each case, the base layer of plaster was buff in color with either tan or white layers on top, or both. The multiple layers of floor plaster appear to have been applied in one phase.
In rooms 2 and 3, a crypt was installed beneath the floor levels. In general, large stone slabs covered the crypts and at least two plaster layers; a buff colored base layer and a tan or white top layer. The stone slabs of the crypts do not appear to have been covered with a layer of rubble before the application of the plaster layers. It is likely that a similar crypt was constructed in Room 1; however, it was either completely destroyed or concealed by looters' rubble at the time of this condition survey.
Despite the desire of project members to immediately address and remedy the damage to Str. D3-1 in the 2004 field season, the primary conservation need at Tecolote was an initial assessment of the condition of the building fabric and painted murals in order to develop a long-term conservation plan to be undertaken in future seasons. The conservation team, therefore, focused on an evaluation of the condition of the wall paintings and architectural fabric, as well as a thorough photographic documentation of the building, and an environmental assessment of the interior room spaces.
Condition of Structure D3-1
The structural stability of the building is severely threatened by a variety of factors including tree and plant growth, biological growth, infiltration of rainwater and inhabitation by insects and animals. The integrity of the structure is particularly vulnerable to damage from the roots of trees and plants that are growing on the roof and sides of the building, some of which have caused dramatic damage to the structure (Figs. 5–7). This growth has lead to the partial collapse of the northeast corner of the building, a large loss on the exterior east wall, and several very large structural cracks in the exterior and interior walls of the building. It has caused two areas of the structure to begin to bow outwards on the front of the building to the south of Room 1 as well as on the back wall of the structure between Room 2 and Room 3. Tree growth on the roof has also caused the disruption and displacement of the mortar and many of the flat paving stones and the loss of stone on the top front horizontal register on the south side of the building where a second recessed area may have existed to hold sculpture or decoration. This growth also adds considerable weight to the roof of the structure, causing significant strain on the 1200-year-old construction.
The building is extremely susceptible to further damage caused by water infiltration from the heavy rains that occur almost daily between the months of May and November and periodically throughout the rest of the year. The displacement of stone blocks on the roof by tree roots has contributed to greater water infiltration into the three rooms through the capstones in the vault. Heavy leaks between capstones were noted during and after rain showers. Thick areas of green biological growth and white accretions on the surface of the vaults and walls tend to appear in drip-like formations and indicate the type of damage that is being caused by leaking over a long period of time. Although environmental monitoring could not be set up during the 2004 season due to technical difficulties with installing the Boxcar software, we did have access to a small Arten Dial hygrothermograph during the first four days. The temperature and relative humidity fluctuated between 70–78° F and 82–85% RH between the hours of 11 AM and 2 PM in Room 2 on May 2 and 3.
Each room has been severely damaged by looting. Looters destroyed the greater part of all three benches and dug deep pits into the floors in an attempt to find caches of objects or tombs that might be buried underneath. The dirt, limestone blocks used in the bench and floor construction, and the bulk of the bench and floor plaster were thrown outside the building forming large piles of debris in front of the doorways (see Fig. 3). Plaster fragments that had already fallen were scattered around the rooms and interspersed with dirt, and some remaining stone and fragments of bench and floor plaster. The piles of debris have created further problems for the building. As a result of the slant of the debris pile toward the interior of Rooms 2 and 3, rainwater is allowed to run into the rooms. An area of heavy moisture (seen as beads of water) was observed daily on the east wall to the south of the doorway in Room 1. This moisture appears to be associated with the looters' pile heaped against the exterior wall in the corresponding location. There are two possible explanations for the consistent presence of this moisture. The looter's pile is either holding moisture against the wall, forcing it through the wall where it can evaporate on the interior of the room, or it is keeping that area of the wall cooler than other areas and consequently allowing condensation to form preferentially.
The most notable damage to the entire structure can be seen on the northeast corner on the building, on the exterior of Room 3 (Figs. 6 and 7). A large tree is growing on the top of the corner, sending large roots down through the walls. At least one visible root extends down into the northeast corner of the room. The growth of this root has caused the exterior corner to partially collapse, leaving a hole in the corner 39 cm high by 31 cm wide (measured across the corner on the interior). There is a large pile of associated rubble on the exterior.
Additional severe cracks can be seen on the exterior of the building, including a particularly large crack through the exterior of the north wall. This crack runs nearly all the way from the roof above the doorway, diagonally to the ground on the west side of the door. Some stones from the bottom portion of the medial molding were lost from this area as well. There is also a large crack on the west wall, towards the north end, visible on both the exterior and the interior. No associated roots can be seen. There are gaps between the stones from 3–6.5 cm in width, and some stones have been forced out of plane.
A large root from the tree growing on top of the northeast corner of the building enters through this corner of the building about 1/3 of the way down the vault, and exits near the floor causing severe displacement of the stones and cracking. Its growth has lead to the partial collapse of the exterior of the building and as a result there is a hole in this corner roughly 39 cm high and 31 cm wide. A narrow crack on the north wall extends from where the tree root enters the room in a discontinuous path to the floor, located on the east side of the doorway halfway between the doorway and the corner. Another crack is visible on the north wall to the west side of the door. It is 5 cm at the maximum width and under 1 cm in other areas. It runs from the floor up to the lower west vault, at the same height as the top of the doorway. There is a narrow crack to the east side of the doorway near the middle of the wall that runs from the floor up to the lower half of the north vault and east vault.
Significant damage has also been caused to the east wall as a result of the large root growing down through the northeast corner of Room 3. It has caused cracking and displacement of the stones on the north side of the wall, adjacent to the root. A second crack can be seen near the center of the room extending from the floor to the upper half of the vault. Two roots are seen growing out of this crack in the lower half of the wall. The upper root is thick and squeezes through the stones to enter the room about halfway down the wall from the spring vault. The diameter of the root is smaller where it emerges from the stone than its diameter inside the room. It was cut off close to the wall prior to our arrival. The second root enters the room about 1/3 down the wall from the vault line, below the other root.
Evidence of painted imagery applied on a multi-layered plaster substrate is observed in all three rooms in Structure D3-1. The wall paintings show some similarity in application of the plaster and paint to the wall from room to room, but differ in the degree to which the plaster covered the wall from floor to ceiling. The stratigraphy of the plaster and the preparation layers indicates that they were built up in at least two to four different layers during one phase in each room. Each room shows a thick layer of dense, rosy – buff colored plaster applied directly to the limestone walls. In some areas, where the plaster is lost, some chipping or keying of the stone surface is observed. This was probably done in order to encourage better adhesion of the first plaster layer to the wall. The surface of this layer appears to have been smoothed over before the application of the preparation layer.
A white, preparation layer was smoothed over the plaster layer and served as a ground for the painted imagery. Some painting is visible on one or more walls in all three rooms. Room 1 currently has the most recognizable figurative painting, including a black line drawing of a bird with its claw outstretched on the south wall. Room 2 has the remains of what appear to be glyphs on the west vault, as well as some less recognizable line drawings, also in black. Room 3 shows simple line drawings, in red and blue-green on the west vault.
Very little painted decoration is still visible on the walls. The majority of the remaining imagery in Room 1 and 2 is black in color. A red and a blue-green drawing are observed on the west vault of Room 3. It is difficult to determine how the paint was applied at this point. The identity of the pigments and the presence of a pigment binder have also not yet been determined.
Room 1, at the southwestern end of the building, has the most remaining clearly figurative drawing. Much of the imagery is concentrated on the south wall. There are black line drawings in at least 3 major locations on the wall; the west side, the center and the east side. The most discernible of these three areas is a black line drawing of a bird-like figure with a claw on the west side of the wall (Fig. 8). Large areas of black are also seen in these same areas of the south wall. Other areas of black line drawing can be observed on the east, west and north walls as well as on fragments recovered from the perimeter of the room.
Room 2 has some imagery present on the surface of the preparation layer on several of the walls and vaults. The most distinctive drawings are present near the center of the west vault. It appears as if there are glyphs, drawn in black, just above the spring vault line. To the north side of the proposed glyphs is another area of black line drawings consisting of a grouping of glyphs (Fig. 9). Where still present, many of the glyphs are legible, but they represent the fragmentary remains of a text that once consisted of perhaps hundreds of glyph-blocks, and their subject matter is unclear. Personal names, verbs, and partial dates do seem to be present, and further analysis may allow for this text to be connected to otherwise known historical figures from the region (James Fitzsimmons and Stephen Houston, personal communication 2004).
Some red pigment can be seen below this area, although it appears to have been randomly applied. More black line drawing is observed on the west wall, north of the center. An area to the south of the center of the west wall shows small scratches that appear to have been made in the wet plaster. It is not possible to tell if the scratches were made in any sort of recognizable pattern.
Black lines can also be distinguished on the north wall on the lower east side, as well as on the upper half of the wall near the capstones, adjacent to the east wall. It is difficult to determine at this time what the imagery may consist of. There is also one small unsual area of black lines directly on the base wall plaster layer, just east of the center on the lower half of the north wall.
Additional black lines are visible on the east wall, near the center, lower half of the wall, south of the doorway. There is also one small area of drawing on the north side of the door, near the middle of the wall. No distinguishable black lines are observed on the south wall of this room.
In addition to areas of black lines there are several large areas of black that are probably related to soot which accumulated on the wall surface as a result of fires burned in the room. There are large concentrations of black on the plaster in the four corners of the room and in the center of the west wall. These black areas are visible only on the preparation layer and not on the exposed plaster layer, suggesting that fires were probably burnt early in the life of the building.
Some coloring is visible in the doorway of Room 2. There are some red and black areas on the north and south sides of the doorway that seem to be applied directly on the base plaster surface. A red line runs north-south across the middle of the lintel in the doorway, directly on the stone surface, and there is some blotchy red coloring on the south half of the lintel (Fig. 10). There does not appear to be any plaster surface on the lintel.
Room 3 is located in the northernmost position of the building. Room 3 is the only room with clear polychrome imagery. However, it is also the simplest of all the painted decoration. There are, what appear to be, two figures, one in red and one in blue-green (Fig. 11). Both are located on the lower west vault, towards the south end. There may be some further imagery, in black, located on the east wall; what can be seen includes a line. On the west wall, there is something which appears to be a hook shape: like the number "7" with a rounded top. There are some blotchy areas in black and brown on the west wall, the west side of the south wall, the south side of the east wall, the south side of the east vault, and the west side of the door on the north wall. There are several areas of what appears to be soot, particularly concentrated in the southwest corner, but appears to a lesser degree in the northwest corner.
Conclusions and Recommendations for Further Conservation
At the conclusion of the 2004 field-season, we attempted to provide some minimal stabilization to Structure D3-1, while at the same time developing a plan for more extensive and longer-term conservation at Tecolote. Before the end of the field season, all three rooms in Str. D3-1 had been filled to just below their original floor level, using looters' backfill. Cut blocks taken from backfill were also used to make dry-laid retaining walls in those areas where looters had undermined the superstructure of D3-1. This should bring some degree of protection to the interior of the building, and in removing some of the backfill from in front of the doorways it is hoped that the problem of water entering the rooms and being held against the walls of the structure via these piles of dirt will be somewhat alleviated.
The recommendations for future work are as follows: a structural engineer and/or architectural conservator should be consulted on the structural integrity of the building. These specialists will be able to provide valuable information on the degree to which the structure has been damaged by tree roots and plant growth, and the potential ability of the roots to hold some stones in place. It is not advisable to remove the trees or other plant growth without this consultation. Considerable structural reinforcement of the building will likely be necessary. A structural engineer can also advise on the contribution of plant growth to the water infiltration observed in all the rooms, and advise on the best course of action to prevent this leaking in the future.
Environmental monitoring should be set up as early as possible in order to assess the fluctuations of temperature and relative humidity within the rooms though-out the year. Ideally, this would include at least one datalogger within each room, and one on the exterior of the building so that outside conditions can be compared to the interior conditions and the buffering capacity of the building itself can be assessed.
Multi-spectral imaging should be performed on the walls and vaults of all of the rooms. Additional imagery may be extant beneath thick wall accretions. Multi-spectral imaging could provide clearer images of the drawing that remains on the walls. This may provide a clearer picture of the imagery that remains, in addition to allowing the conservation treatment to prioritize the areas of the greatest need within the structure regarding the imagery that remains and the stability of the plaster in that region.
Once the structural stability of the building has been addressed, further conservation can take place on the murals remaining in the rooms. This would consist of stabilizing plaster which remains on the walls (edging and grouting), attempting to reconstruct existing fragments, and testing surface cleaning in order to reveal more imagery masked by accretions. Subsequent field seasons should also concentrate on testing a variety of conservation treatment techniques on the murals.
We hope to be able to follow through on these recommendations and carry out further conservation efforts in the summer of 2005. Structure D3-1 represents an unusually complete example of Classic period Maya architecture in the Usumacinta River zone, and we hope to be able to stabilize and protect the structure for future generations of visitors and researchers.