recording in 1965. At that time, the consolidation program had already begun (Fig. 4). For this work, the super-structure was cleared of all debris but the pyramid was left undisturbed except for removal of large trees near the top. Root systems of plants covering basal platform and pyramid terraces have been left intact to maintain stability of masonry facings pending future consolidation.
Construction Stages
The condition of the site prior to construction of Str. 5C-4 is not known. Earlier structures may have been present or the site may have been undeveloped. This latter option seems unlikely given the relatively late date of 5C-4 construction. Hence the kind of work needed to prepare for construction is unknown. The quarrying operation, mentioned above, may have extended over the area covered by the structure.
A hard plaster sustaining surface (see below) on 0.20 m of ballast (small stones) runs under facing masonry at the N corner of the basal platform stair side (Fig. 5a:1). This surface appears to be paving of the Tozzer/Maudslay Causeway. How far W it extends under Str. 5C-4 remains uncertain. The extant surface disintegrates rapidly with distance E from the terrace foot.
PRECINCT WALL
Surface profiles on the site map (TR. 11:Temple IV Sheet) imply that a wall encloses the area containing the basal platform. The term “precinct wall” (Fig. 2a,b) has not previously cropped up in relation to Tikal architecture. It is introduced here and for Str. 6F-27. Although apparently lower and less massive than causeway walls, the precinct wall may define an extension of causeway pavement provided as a sustaining surface for the structure about to be built. Were precinct and causeway walls cleared and rebuilt, Str. 5C-4 would appear to open directly onto the causeways.
Dimensional differences between causeway and precinct wall, as implied by surface contours, suggest that the latter (which was smaller) was seen as part of the structure and, hence, is considered here as a 5C-4 component. Details of height, mass, and position in the sequence of construction operations have not been established. Masonry for the precinct wall is not included in the volume estimates.
BASAL PLATFORM
Surface features indicate the presence of a basal platform (Fig. 2a,b, 5a; TR. 11:Temple IV Sheet). It appears to cover an area of about 150 m N-S by 100 m E-W to a height of about 5 m; this equates to a volume of approximately 102,000 m3. Surface profiles and minimal excavation indicate a simple rectangular format of two terraces with a stair on the E side debouching directly onto the causeway surface. The 5C-4 pyramid is centered on this platform. It appears to be an integral part of the structure, but this assumption needs to be tested because its plastered top surface runs under the pyramid. Though treated here as a 5C-4 component, the basal platform could belong to an earlier feature (see Basal Platform Sustaining Surface, and Terrace 1, below).
BASAL PLATFORM SUSTAINING SURFACE
At the stair-side excavation, a hard, smooth plaster surface on ca. 0.20 m of ballast runs under basal platform masonry (Fig. 5a:2). This appears to be a resurfacing over an earlier hard plaster surface that was not penetrated. One or both of these floors may relate to causeway construction. These floors raise the possibility that an earlier structure, now hidden by the basal platform, may exist. A drop of 0.10 m in a W to E, 5 m span is indicated along the base of the stair side.
TERRACE 1
The basal platform has two terraces. Plaster run-under (a floor or top surface that continues under a supra-positioned feature) at the top surface of terrace 1 implies that it was built as a distinct construction stage completed and plastered (both face and top surface) prior to commencement of terrace 2. Masonry characteristics, similar in both terraces, suggest they were installed during the same episode of construction (see also evidence for the stair, below).
Profiles, obtained by limited clearing at the junction of stair side and terrace, extend upward ca. 0.90 m with no indication of a basal molding (Fig. 5a). This implies absence of basal moldings and probably also absence of apron moldings, since Late Classic profiles generally do not have one without the other. Preservation did not extend high enough to test this assumption.
An excavation at the NE corner revealed a rounded form with a radius of four meters, greatly contrasting with the sharp corners of the pyramid and upper features. Structure 5C-4 is not unique at Tikal in presenting both rounded and sharp (arrised) corners. This report will bring together the various Tikal structures that possess this property.
BASAL PLATFORM STAIR
Construction of the second terrace coincided with installation of the stair following completion of terrace 1. A run of masonry facings of terrace 1, unplastered, extends 1.5 m behind core masonry of the stair. Terrace 2 facings, on the other hand, stop on the line of stair-side facings. Thus, it appears that the stair was built after terrace 1 had been completed but during construction of terrace 2.
Tread and riser dimensions are projected from the average of in situ observations (Fig. 5b). Extrapolating from limited observations, the stair probably consists of 14 treads, 0.50 m deep, and 15 risers, 0.33 m high, for an estimated total height at the E face of 5 m. Risers are vertical, formed by single masonry units sharply tapered in plan. The stair has no balustrade and the stair side is vertical (little or no batter). Stair-side facing masonry appears to consist exclusively of headers (Fig. 5a,b).
The top of the basal platform is a hard, white plaster surface running under pyramid masonry. A very thin topping, a mere skin coat, overlies this. It disintegrates a few centimeters away from the pyramid foot. The hard surface beneath it hints that an earlier version of 5C-4 may exist within the pyramid.
The basal platform had been resurfaced with a hard, white plaster finish on about 0.06 m of fine topping over about 0.20 m of graded ballast. This floor abuts the foot of the pyramid and precedes installation of St. P43 and Alt. P35. It is unclear whether resurfacing was primary or secondary to plastering of the pyramid terrace. Weathering and erosion have destroyed this floor beyond the zone protected by collapse debris.
PYRAMID
The pyramid (Fig. 2a,b, 6, 7) is distinctly rectangular; 82.2 (N-S) by 64.1 m (E-W mean) at its base as measured at inset corners. These would be the measurements most likely employed by the builders at the start of construction. Setting primary corners is always critical for initial layout. The length-to-depth ratio (length across the front:front to rear, at inset corners) is 1:0.78. That is, the front-to-rear depth is between three-quarters and two-thirds of the side-to-side length across the front. Designers may have arranged this relationship in order to emphasize frontality.
North-to-south lengths, that is rear length and front length at base level to inset corners, are equal as measured by Pearson using tape and transit; east-to-west lengths (N side and S side at base level) vary by 2 cm. In other words, dimensional control appears to have been remarkably precise, at least within the precision of our measuring techniques. The rectangle at the top of the pyramid measures 39.5 by 23 m (at inset corners), a ratio of 1:0.58 (Fig. 6). On axial lines the ratio is 1:0.42. By both measures, the top is distinctly more rectangular than the base. The change reflects the fact that the sides are slightly steeper than the front and the rear is slightly steeper than the sides.
At the pyramid base, that is terrace 1, corner angles measured at inset corners are close to 90° (90° at NE, 88.5° at NW, 91° at SW, and 89° at SW).
The error measured as the differences between lengths of the sides, which would be equal if corners were exactly 90°, is about 2%. The SE to NW diagonal exceeds the NE to SW diagonal by 2.2 m, that is, by 2%.
On the plan (Fig. 6), diagonals drawn to connect the inset corners cross exactly on the central axis
