Operation 46

Operation 46 encompasses 18 structures located in western La Sierra. A shallow, dry stream channel runs directly west/northwest of the Op. 46 buildings, the land dropping away slightly and gradually east/southeast of the quebrada. A second seasonal watercourse, trending southeast-northwest, joins the former channel immediately north of Op. 46. The topographic effect of these quebradas is to isolate Op.46 from the bulk of the center to the east as well as dense settlement to the north (Op. 23) and west (Ops. 47 and 48). Structures making up Ops. 44 and 45 lie immediately east and south of Op. 46, the 44 buildings and building remnants comprising the three operations most likely constituting a dispersed settlement that we arbitrarily segmented for recording purposes.

Operation 46 edifices cover a wide range of sizes. Four large platforms, Strs. 189, 190, 200, and 201, define the northern, western, and southern margins of an extensive patio the eastern flank of which is delimited by three small constructions (Strs. 202, 203, and 270). A second patio-focused group, composed of more modest platforms (Strs. 182-185, 187-188), lies on the operation's northern margins. Most of the remaining, generally small, buildings are scattered over the 43m separating these two foci.

Seven structures were excavated in Op. 46. Six of these buildings were extensively cleared in 1995 (Strs. 187, 188, and 46-Sub1, directed by E. Laine) and 1996 (Strs. 190, 203-A, and 203-B, directed by M. Turek and R. Johnson). The remaining edifice, Str. 183, was investigated by means of a single trench dug against its southwest flank during an initial testing program conducted in 1988 (carried out as part of Op.23, under M. Dall's direction, but reported here). A total of 277m2 were cleared in the course of this work. E. Laine's detailed report (1996) on her studies is the basis for the description of Strs. 187, 188, and 46-Sub1 that follows, accounts of the remaining excavations being drawn from records provided by the investigators.

Structure 183-1st, therefore, is a stone-faced platform standing ca. 0.9m high, ascended by three low terraces on the southwest, and aligned roughly 312 degrees. Surviving recorded construction was fashioned primarily of unmodified river cobbles though masonry blocks were scattered among the stones comprising U.1-4. Terrace and summit surfaces appear to have been earthen.

Structure 187-1st covers 4.1x5.7m, is aligned roughly 29 degrees, and contains two rooms encompassing 5.27m2 and 5.02m2. These compartments are divided by a ca. 0.25m high by 2.05m long stone-faced construction that probably served as a bench. Facings and foundations are made primarily of unmodified river cobbles measuring 0.01-0.4m along their largest dimension (most are less than 0.3m long). Unit 2 contains five masonry blocks ranging up to 0.5m along their greatest dimension; one at the U.1/2 junction (the edifice's east corner) and four near U.2's center at the point where U.5 intersects U.2. A large faced block is also located where U.1 joins U.4, the building's north corner.

Time Span 1

The erection of Str. 188-2nd may have spanned two building phases discernible now by subtle changes in U.14. Features 1 and 2 may be remnants of those disjunctions. The former is a line of cobbles resting 0.41m below Str. 188-2nd's reconstructed summit. This level may be a fragment of former summit pavement or simply represents a break in the build-up of U.14. Feature 2 is a comparable stone level separated from F.1 by the addition of roughly 0.2m of stone-and-earth fill (U.14 both covers and underlies F.1). Both features are eminently vague, their architectural significance far from certain. Nevertheless, they at least imply that Str. 188-2nd was the end-product of a lengthy construction effort.

Structure 188-2nd is a stone-faced platform that stands an estimated 0.6m (on the southeast) to as much as 0.9m tall (on the northwest), covers 3.7x6m, and is oriented approximately 60 degrees. The superstructure is fronted on the southeast by a 0.9m wide open area, a small portion of which near the center is paved with cobbles (U.8). A low cobble foundation (U.7) and the tops of U.2-4 bound the summit building which, itself, is partitioned into two rooms encompassing 5.25m2 (southwest) and 8.28m2 (northeast). Doorways situated at the termini of the interior dividing wall (U.5) facilitated movement between these enclosures while the superstructure itself was entered through a gap in its eastern corner. The northeast and southwest compartments were featureless save for a cobble pavement covering a small portion of the former (U.6). The edifice described above may have been antedated by at least one earlier version of Str. 188-2nd, the latter ca. 0.4m lower than its successor. All foundations and facings are made of river cobbles that range between 0.1-0.3m across their longest dimension. The U.6 and 8 floors mostly consist of smaller rocks (0.01-0.1m longest dimension) among which are mixed a few of the larger cobbles. A brown mud mortar was used as a binding agent in every case.

Two late additions may have been appended to Str. 188-1st's southeast and northwest flanks, burying at least a portion of U. 9 and 11 in the process. This interpretation is suggested by the recognition in section of two stacks of more-or-less flat-laid cobbles set against the southeastern (F.4) and northwestern (F.3) basal walls. Clearing away from the axial trench where F.3 and 4 were first recognized did not reveal clear continuations of these entities, their lateral dimensions, their very reality, being open to question. If F.3 and 4 are the poorly preserved remnants of a late addition, however, they would have expanded the platform up to 0.7m on the southeast and 1.16m on the northwest and might have completely buried U.9 and 11 wherever the features were located along those facings.

Units 18-20 are 0.1-0.2m high cobble walls that define the northeast, northwest, and southwest sides of an earthen-floored space encompassing 2.3 (minimally)x6.4m off Str. 188-1st's southeast side. The platform is ca. 0.5m northwest of this construction and connected to the latter's north corner by a 0.4m wide, 0.2m tall cobble wall (U.17). A 2.75m wide gap between U.19 and 20 provides passage between Str. 188-1st and the southeast enclosure. Units 17-20 are built of medium-size river cobbles (0.1-0.3m, maximum dimension) set in a brown mud mortar. Three large masonry blocks were noted in positions suggesting that they had fallen from U.18, indicating that this material was sporadically included in TS.3 construction.

Structure 188-1st is a 0.7m (southeast) to 1.36m high (northwest) stone-faced platform faced by a single 0.55-1.2m wide terrace that completely wraps around and buries the lower portions of its predecessor (Str. 188-2nd). The reason for the slight increase in the building's height on the southeast and northwest is that the aforementioned terrace is set slightly further downslope than were Str. 188-2nd's basal facings. Structure 188-1st, therefore, covers 5.25x8.25m and generally preserves Str. 188-2nd's orientation (the above figures do not include F.3 and 4). The summit was largely unchanged from TS.2, the principal modifications apparently being the addition of a bench to the southwest room and laying of a cobble floor on the southern terrace corner. That floor lines up with the broad passageway into an extensive surface-level construction lying immediately southeast of the platform. The latter is seemingly open to the southeast. Given its proximity to, and linkage with, the Str. 188-1st platform, it is likely that the enclosure's functions are tied to activities conducted on the adjacent edifice. The area enclosed by the surface-level buildings is approximately 14.72m2 and it is aligned roughly 58 degrees.

Structure 46-Sub1-1st measures 3.3x3.7m, is oriented roughly 53 degrees 30 minutes, and contains two rooms that each cover 2.5m2. Approximately 65% of the southwest enclosure is filled with a low, stone-faced bench while its northeastern counterpart lacks any built-in features. Movement between the rooms was channeled through a 0.55m wide door set between the medial wall and northwestern foundation. No breaches in the boundary foundations signaling an entryway were noted, though it is unlikely that such low walls posed significant obstacles to traffic. Footings and facings are made primarily of unmodified river cobbles measuring 0.01-0.4m across their largest dimension (most fall between 0.01-0.3m). Three large (0.3-0.4m, longest dimension) cut blocks were incorporated into the building's west and north corners; one on the former's exterior, one each on the interior and exterior of the latter. Structure 46-Sub1-1st is raised atop S.2 , unit elevations dropping as that soil level descends from northwest to southeast; no effort was apparently expended in leveling this terrain prior to construction

Investigation of Str. 190 was largely restricted to two 1m-wide trenches that cut across the platform east-west (Subop. 46M) and north-south (Subop. 46N) meeting at the building's center. Units exposed in these narrow probes were followed to limited extents as time and the significance of the constructions traced warranted (conducted as part of Subop. 46O). Overall, ca. 52.m2 were cleared in Subop. 46M-O, excavations being carried down to maximum depths of 1m below modern ground surface outside construction and 1.48m beneath ground level into architectural fill. At least two building phases were identified in the course of this work. All excavations were overseen by M. Turek from April 16-May 17, 1996.

Time Span 1

At least 0.11m of S.1, a fine-textured brown clay, was found underlying construction dating to TS.2, minimally 0.26m of this earth level being located beneath architecture pertaining to TS.3. It, therefore, seems quite likely that natural deposition of S.1 preceded both construction events. Exactly how much of S.1 was introduced during this span cannot be ascertained as the earth level's base was not encountered in our excavations. Artifacts were recovered from S.1 where it was found beneath TS.3 construction; no cultural material was clearly derived from S.1 where it underlay Str. 190-2nd. The limited nature of the latter exposures militated against recovering relevant items. Consequently, we cannot be certain that there was human occupation associated with S.1's deposition prior to TS.2, but it seems likely.

The restricted nature of our excavations precludes definitive statements concerning the form and dimensions of Str. 190-2nd. Instead, we hypothesize that this building consists of a series of rooms built directly on ground surface, the exposed upper portions of S.1 serving as floors. Foundations evidence considerable care in their construction, being fashioned primarily of small, tightly packed cobbles set in a light tan, fine-textured soil matrix. A few medium-size cobbles are interspersed among the more diminutive rocks, occasionally forming up to four horizontal courses. The preponderance of small stones in TS.2 construction, coupled with the use of a light tan earth mortar, distinguishes components of Str. 190-2nd from those pertaining to its successor. This early building covers at least 8.8m east-west by 9.9m north-south (including U.11 on the west) and is aligned roughly 106 degrees.

The remaining flanks seem to have been ascended by single, thick, steep stone facings U.9, 11, and 6 on the south, west, and north). Unit 6 seems to have been built on and over the earlier U.5, enhancing that wall's height by ca. 0.6m. Unit 11 may have been raised a similar amount (0.66m), building on a foundation erected during TS.2 (if this entity was initially part of Str. 190-2nd). Unit 9 was probably built de novo, no evidence of earlier construction being found underlying this facing. Units 6, 9, and 11 are 1.9m, 1.95m, and 2.2m wide and have reconstructed heights of 1m, 1.3m, and 1.15m, respectively. The relationship between U.4 and 6 remains uncertain. Roughly 0.6m was added to the former's original height in TS.3, making it equivalent to the top of U.6. The U.19 fill of rocks and earth that buried Str. 190-2nd's northern room, however, also obscured all of the standing portions of U.4, suggesting that this entity was not visible on the final version of Str. 190-1st. It is unlikely U.4 would have been elevated just to be buried and it may be that the construction was augmented in TS.3 to serve a currently unknown purpose. The high density of stone tumble found overlying U.4 (part of F.3) hints at a substantial construction in this area, possibly the superstructure's northern footing. Unit 4 might have undergirded this heavily disturbed architecture. If that was the case, U.6 would define the northern limits of a terrace that extends 3.6m southward to the limits of whatever construction was raised above U.4.

Structure 190-1st's fill has been given different designations depending on where it was found (U.18 between U.5 and 6; U.19 between U.4 and 5; U.16 between U.1 and 11; U.20 within U.9; and U.15 between U.1 and 14). In all cases it generally consists of numerous small to large cobbles set in a brown soil matrix. The principal exception to this pattern is found in the lower 0.4-0.5m of U.15, 16, and 19. Here stones are less densely packed, are smaller, and the earth matrix is lighter in color than in the overlying levels. These distinct layers correspond precisely to those portions of U.15, 16, and 19 that fill Str. 190-2nd's rooms. Such a break in fill units may signal many things. An intriguing possibility is that the above-noted division indicates a temporal disjunction between the termination of Str. 190-2nd and the raising of Str. 190-1st. This discontinuity might well correspond to a third building phase intermediate between the two outlined here, marking the first steps in transforming the earlier surface-level edifice into a platform. There is no other evidence to support the forgoing suggestion but it remains a viable possibility.

A 0.25-0.5m high stone wall (U.22) was identified 0.5m west of Str, 190-1st's western flank (U.11). Unit 22's behavioral significance is far from clear. It may be a fragment of relatively insubstantial construction raised between the investigated building and the quebrada on the west. It is impossible to evaluate this interpretation given the limited portion of U.22 uncovered in 1996.

Structure 190-1st measures 16.6m north-south by 14.3m east-west, stands a reconstructed 1-1.3m high, and is oriented roughly 10 degrees. The summit was reached by ascending three relatively low terraces on the eastern flank, no other access features having been identified in our admittedly limited excavations. The summit encompasses 8.5x11.2m (taking U.4 as the northern limit) and is bisected into more-or-less equal eastern and western portions by a 1.2m wide medial wall (U.1). Movement between these two sides was through a door set into the medial wall's northern end, that entry being formalized through the addition of a low step-up fronting the passage on the east. At least two rooms were tentatively reconstructed on the eastern summit, measuring 2.5m and 5.6m across (the latter is between U.2 and 9). Too little is known about the western summit to support even a hypothesis about space organization on this side of the medial wall. Unit 1 may have doubled as a bench or shelf during TS.2. Summit and terrace floors seem to have been primarily made of earth, the clearest exception being the stone pavement that floors the entryway at the northern terminus of the medial wall. The poor preservation of most TS.3 construction prevents making inferences concerning the nature of final-phase architecture. River cobbles of varying dimensions, mostly large and medium-size, are the primary constituents in facings and foundations. A few cut masonry blocks were included in U.6 and 9, but nowhere are they common. The binding agent used throughout Str. 190-1st construction is a brown mud mortar.

Structure 203-A (Figures **-**) [2 sections, 1 plan; D96-59]

Stratum 1 drops 0.14m over 9.95m north-to-south beneath Str. 203-A. Recovery of artifacts from the limited portions of S.1 uncovered in Subops. 46J, 46K, and 46L points to human occupation in the immediate area prior to Str. 203-A's construction.

The northern enclosure measures 1.8x2.5m, while its southern counterpart encompasses 2.2x2.75m. The floors of both rooms consist of a pavement of small stones set in an orange to red-orange clay matrix (U.6 on the south and U.7 on the north). The distinctive color of the earth matrices in each case probably is a result of intense burning. Rising approximately 0.45m above U.6 in the southern enclosure is an L-shaped bench (U.5). Unit 5's western arm is 0.2m north of U.3 and runs 1.95m north to abut U.1, the northern arm continuing 0.8m east along U.1's south face, ending near the northeast room corner. The elements comprising U.5 are 0.7-0.8m wide. Erection of U.5, which clearly postdates construction of U.1 and 6, may have partitioned the southern room into two diminutive cubicles covering 0.85x1.45m east of U.5 and 0.8x2.2m to the west. Both of Str. 203-A-3rd's enclosures were open to the east.

Overall, Str. 203-A-3rd covers 3.25-3.65m east-west by 5.45m north-south, contains two stone-floored rooms open to the east, and is aligned roughly 359 degrees. The enclosures are set in a north-south line and measure 4.5m2 (northern) and 6.1m2 (southern). The latter contains a 0.45m high, L-shaped bench whose arms are 0.7-0.8m wide and run 1.95m north-south before turning to extend 0.8m east along the compartment's northern wall. Construction of this element apparently divided the southern enclosure into two cubicles encompassing 1.2m2 east of the bench and 1.9m2 to the west. Foundations and bench facings were built using river cobbles primarily, their naturally flatter aspects oriented outwards, and set in one to five surviving horizontal courses. Chinking stones are packed around the larger rocks in each case. Cut blocks are sparingly incorporated into U.1 but are a common component in the west face of U.5's western arm. In the latter case, the basal course is made up of faced tuff blocks set on end, the succeeding two courses being fashioned using a combination of flat-laid tuff blocks and cobbles. Average stone sizes range from 0.14x0.26m to 0.3x0.31m and all rocks are set in a brown mud mortar.

Structure 203-A-2nd is a platform that stands ca. 0.5m tall, measures 3.7m east-west by 5.85m north-south, and retains the orientation of its immediate predecessor. The northern and southern rooms maintain their earlier dimensions, now elevated atop a stone-and-earth fill. Both enclosures possesses benches, the newly added construction in the northern room being surfaced with a fine-textured clay that was burnt orange. No clear entryways are apparent and it is uncertain how the interiors of Str. 203-A-2nd's rooms were attained. Foundations and the bench facing added during this interval are fashioned primarily of river cobbles, their naturally flatter faces oriented outwards, and set in up to three horizontal courses. Chinking stones are packed around the larger rocks, the average dimensions of the latter ranging from 0.18x0.3m to 0.23x0.28m All rocks are set in a brown mud mortar.

Modifications on the east were more extensive, culminating in the creation of a surface-level construction delimited by stone foundations (U.13-16) and the eastern platform facing. The northern footing (U.13) overlaps U.12 by approximately 1.45m, burying the latter's inset corner, and extends a reconstructed 2.25m east of U.8, the northern segment of the platform's eastern basal wall. Unit 14 projects 0.95m south of U.13, its southern terminus marking the northern edge of a 1.15m wide doorway. Unit 15 extends 2.45m south of this entrance where it corners with U.16. The latter foundation runs westward for 1.25m where it is integrated with U.17. Unit 17, built against, and nearly obscuring, U.9, projects 1.7m north from U.16 to abut U.1's eastern extension. The U.1 extension, as noted earlier, may have been erected during this interval. Bordering foundations (U.13-16) measure 0.18-0.29m high and 0.75-1m across, U.13 on the north having the greatest width. The room they delimit has an area of approximately 6.15m2. Unit 1's extension protrudes 0.3m and 0.9m east of U.8 and 17 into the enclosure, essentially dividing the interior space into northern and southern components. The former covers 3.52m2, the latter 2.19m2, and passage between them is via the 0.9m wide gap separating U.1 and 15. The southern compartment is floored with earth while its northern counterpart is surfaced with a mixture of earth and pebbles (U.18). Unit 18's soil matrix is red-orange, probably the outcome of intense burning in this area.

The architectural significance of U.17 is eminently unclear. Adding a footing in front of U.9 appears superfluous, no comparable renovation being noted north of U.1 sealing U.8. Unit 17 is equivalent in height to U.9, 13-16, thereby rendering its use as a bench or step within the eastern room improbable. More likely, U.17 was added to U.9 either to bolster that construction or to create a relatively wide (0.9m across)stone surface on the eastern margin of the southern summit room. As no comparable buttress was needed to support U.9's northern analogue (U.8), the latter interpretation is the more probable.

The platform's western and southern flanks were now faced by low (0.16-0.26m high) cobble terraces (U.19 and 21) that retain a fill composed of stones set in a brown earth matrix (U.24). Unit 19 borders 6.05m of the edifice's western flank, ending on the south at its junction with U.20, a comparable architectural element that slants back southeastward to abut U.2, 0.5m north of the latter's corner with U.3. Unit 21 extends 2.2m southeast from its abutment with the U.19/20 junction before running east/southeast for an additional 4.6m. About half way along its east-southeast length, U.21's south face steps back ca. 0.3m to the south. Whether this indentation was part of the builders' original plan or a product of erosion is not certain. Units 19/21 define terraces that are 1.3m wide and had, most likely, earthen surfaces. Units 19 and 20 appear to have been added prior to U.21's construction, though it may well be that the elapsed time was very short. Outside of the U.20 junction, evidence for how these elements were articulated with the platform has not survived. Units 19 and 21 simply end on the north and east, respectively, without linking up to the principal edifice. This observation may suggest that U.19/21 were unfinished at the time of Str. 203-A-1st's abandonment and/or be a consequence of poor preservation of relevant architectural elements. Unit 22 is a 0.3m wide cobble wall that projects at least 0.45m west of its abutment with U.19 on the north. Limited excavation in this area makes any inferences advanced concerning U.22's architectural significance highly conjectural. This wall might hint at the presence of surface-level constructions raised off Str. 203-A-1st's western flank, a pattern akin to that recounted on the east.

Three construction intervals culminated in the complex edifice glossed as Str. 203-A-1st. The central platform, ca.0.5m high and supporting two summit rooms, remained largely unchanged from TS. 3, save for a modest expansion of its north-south dimensions (the building now covers roughly 3.7x6.8m, exclusive of U.19/21). Stone-faced terraces were appended to this structure's western and southern facings, though whether these additions were ever completed remains unknown. Two interconnected rooms, arranged in a north-south line, were erected on ground surface immediately east of the platform. This complex was entered through a 1.15m wide doorway on the east and is delimited by low cobble footings along with the substructure's eastern facing. The latter element was augmented on the south by the addition of the enigmatic U.17. The earth-and-stone floor of the northern enclosure (covering 3.52m2) was apparently burnt at some point during, or immediately following, use while its earthen-floored southern counterpart (encompassing 2.19m2) yielded no evidence of a conflagration. A 0.9m wide door connects these two compartments. Additional surface-level edifices may have been raised against the eastern terrace, though this is no more than a tentative hypothesis. All facings and foundations built during TS.4 are fashioned primarily of river cobbles set in a brown mud mortar. Average stone sizes range from 0.16x0.22m to 0.27x0.32m. Cut tuff blocks were incorporated into U.13's and U.21's facings while schist slabs appear as a minority component of U.15.

Structure 203-A-1st is, therefore, a complex of adjoining constructions, incorporating surface-level and elevated elements, that covers an area of roughly 59.25m2 (7.5x7.9m). The orientation of this agglomeration generally maintains the nearly north-south alignment initiated in TS.2.

Structure 203-B-1st is a 0.24-0.36m high stone-faced platform that covers 4.45m north-south by at least 4.1m east-west and is aligned roughly 11 degrees. Limited exposure of the summit rules out inferences concerning the type of superstructure that Str. 203-B-1st supported. All we can say at present is that the substructure might have been topped with a stone pavement and did support a square unit defined by upright blocks and slabs on its southern margin. The summit could have been easily attained by stepping up and over the low western and southern basal facings. Some energy may have been expended in linking Strs. 203-A-1st and 203-B-1st by means of the F.1 blocks. The latter might have also served as a formal step-up to Str. 203-B-1st. Units 1 and 3 are fashioned primarily from cobbles not set into clear horizontal courses. Unit 3 is built mostly of river-rounded stones, though here cut tuff blocks and schist slabs are intermixed with the cobbles. Once again, horizontal coursing is not in evidence. Average rock sizes in U.1-3 range from 0.25x0.25m to 0.34x0.41m. As noted above, F.1 consists exclusively of faced masonry tuff blocks and U.4 was built using a combination of blocks and schist slabs.

Late Classic II is well-represented in Op. 46 excavated collections, relevant items coming especially from strata underlying exposed architecture pertaining to Strs. 183, 188, 203A, and 203B. Construction of Strs. 183, 187, and 188-2nd may have taken place near the end of this span. Erection of Strs. 188-1st, 46-Sub1, 190-2nd, 190-1st, 203A-3rd, 203A-2nd, 203A-1st, and 203B-1st might well have followed soon afterwards. Given that most materials derive from secondary contexts, it is difficult to be more specific in tracing Op. 46's occupation history (in fact, we may already have exceeded reasonable limits with the above reconstruction). The general impression obtained from this data is that the Op. 46 zone experienced a significant upsurge in settlement during Late Classic II/III, all investigated buildings being raised and in use probably for slightly more than a century on either side of that divide.

Occupation in Op. 46 dwindled rapidly in succeeding periods. Early Postclassic diagnostics were found in small amounts on and around Strs. 188-1st, 46-Sub1, and 203-A-1st. No construction is clearly linked to this interval, though some of the late, fairly casual additions appended to Strs. 188-1st (e.g., F.3 and 4) and 203-A-1st (e.g., U.19-21) are good candidates for inclusion here. Late Postclassic materials are present in diminutive quantities around Str. 46-Sub1, one of the few find-spots for such late prehistoric items anywhere in La Sierra. No signs of settlement dating to the Historic period were recognized.