Santa Elena Peninsula Research Articles

The ultramafic flora of the Santa Elena peninsula, Costa Rica: A biogeochemical reconnaissance

The Santa Elena peninsula in the northwest of Costa Rica protrudes about 30 km westwards into the Pacific Ocean, and measures about 8–16 km in a north–south direction. Several geological studies have been carried out since 1953, showing that much of the peninsula is made up of peridotite, cut by mafic dykes. Only one previous brief examination appears to have been made of the vegetation in relation to the composition of the soils. We present here the results of a survey of some soils and plants of the eastern part of the peridotite massif, in which 73 plant specimens representing 51 identified species were collected and analyzed. The soils sampled all showed extreme ultramafic characteristics: Fe 10–16%, Mg 4–16%, Ca 0.5–1.4%; Ni 3000–7500 mg/kg, Cr 1400–3650 mg/kg, Co 150–325 mg/kg. The plants collected include several from genera such as Arrabidaea, Chamaesyce, Helicteres, Hyptis, Lippia, Oxalis, Polygala, Turnera and Waltheria that are also represented on ultramafics elsewhere in the Americas (e.g. Cuba, Puerto Rico, Brazil). Few of the species appear to be endemic to Costa Rica or to the ultramafics of Santa Elena. None of the specimens collected exhibited hyperaccumulation of nickel, the highest Ni concentration being 275 mg/kg in Buchnera pusilla.

Plio-Quaternary uplift of the Manta Peninsula and La Plata Island and the subduction of the Carnegie Ridge, central coast of Ecuador

This paper quantifies the uplift of the Manta Peninsula and La Plata Island (Ecuador) using marine terraces. These marine terraces are part of a more extensive segment of uplifting coast extending all along the Talara arc, from 6.5°S to 1°N. Along this arc, the highest terraces are observed on the Manta Peninsula with five marine terraces up to 360 ± 10 m. On La Plata Island, four marine terraces are raised up to 170 ± 10 m. The terraces are dated using infrared-stimulated luminescence (IRSL) and U–Th methods. The calculated uplifts range from 0.3 to 0.5 mm yr −1 for the past 300 ka. The oldest terraces show a transition to the synsedimentary uplifted Plio-Pleistocene deposits of the Canoa Formation. In comparison with the lower uplift rates documented in the Santa Elena Peninsula to the south and the Esmeraldas area to the north, the uplift of the Manta Peninsula gives an account of the effect of the subduction of the Carnegie Ridge since the late Pliocene. The coastal uplift ends to the north outside the projection point of the border of the Carnegie Ridge but extends southward along the northern margin of the Gulf of Guayaquil, outside of the effect of the Carnegie Ridge, which suggests that other elements must be considered for uplift in this area. A weak scan pattern of the Carnegie Ridge along the coast is observed, but instead of a true scan motion, the context suggests the possibility of a segmented ridge and the head-on introduction in the trench of a new segment with a beveled front trending parallel to the Grijalva fracture zone. The onset of subduction of the Carnegie Ridge seems correlated with a change in the tectonic deformation of the coast, from compression conditions before the middle–late Pliocene to extension conditions during the subduction of the ridge.

Irrigation Potential of the TRASVASE System (Santa Elena Peninsula, Guayas, Ecuador)

The objective of this study was to determine the total irrigable area in the Santa Elena Peninsula Water Delivery System (TRASVASE) under several land use scenarios based on a simple water budget model requiring estimation of: (1) crop water requirements (CWR); (2) irrigation efficiency; and (3) dams and canals evaporation utilizing weather data. CROPWAT, a software package developed by the United Nations Food and Agriculture Organization (FAO), was used to calculate CWR and irrigation requirements. The reference evapotranspiration (ET0) was calculated using Santa Elena Peninsula historical average weather data and results used to create average monthly ET0 surface maps using ArcMap. Nine scenarios were created to calculate available agricultural water and irrigable area. The total calculated irrigable area during the dry season (June–November) was compared to estimate from the Commission for the Development of the Guayas River Basin in Ecuador (CEDEGE) and to the average estimate done by the farmers. CEDEGE estimate was 23,000ha, 48% more than the most water conservative scenario (CB) analyzed in this study, whereas farmers’ projected average was 16,500ha or 0.06% more. The advantage of this method is that it requires minimal climatic and geographic information coupled with well-established FAO models to produce tangible results. It can be of important use in locations where climatic data is limited, reducing dependency on weather stations to calculate system wide irrigation requirements.

Aplicação do Índice Global de Sustentabilidade na explotação de coquina na Península de Santa Elena

Na Península de Santa Elena (Equador), desenvolvem-se, paralelamente, a explotação artesanal e a mecanizada da rocha coquina. Para estabelecer a sustentabilidade da explotação, foram estabelecidos indicadores, suficientemente flexíveis à realidade local e de fácil aplicação. Para determinação do quão sustentável é a explotação de coquina, usou-se o Índice Global de Sustentabilidade (IGS). Esse estudo apresenta os resultados do IGS aplicado ao caso da explotação artesanal no Morro Tablazo.

Magmatic and geotectonic significance of Santa Elena Peninsula, Costa Rica

We present a new integrated interpretation of the geochemistry and geotectonic significance of the Santa Elena Peninsula, which is divided in three units: 1) an overthrust allocthonous unit of ultramafic and mafic rocks, the Santa Elena Nappe; 2) an autochthonous basaltic sedimentary suite, resting immediately below the overthrust, the Santa Rosa Accretionary Complex; and 3) Islas Murcielago pillow and massive basaltic flows. In the Santa Elena Nappe three petrological affinities have been recognized: 1) the ultramafic complex, that corresponds to depleted (MORB-like) mantle serpentinizated peridotites, with very low TiO2 and high Ni and Cr; 2) the pegmatitic gabbros, layered gabbros and plagiogranites and basaltic dikes with low TiO2 ( 0.89%). These mafic associations have geochemical signatures that suggest an island arc origin and petrographic evidences of low grade metamorphism and hydrothermal alteration. The Santa Rosa Accretionary Complex includes pelagic and volcanoclastic sediments, tuffs and alkaline magmatic rocks, originated by low degree melting of enrichment OIB mantle source, and probably related with seamount portions incorporated into the accretionary prism. Islas Murcielago pillow and massive basalts show no clear structural relationship with the rest of the units, but are geochemically similar to the dolerites of the Santa Elena Nappe. Sr, Nd, and Pb isotopic ratios of the Santa Elena Nappe and the Santa Elena Accretionary Complex samples do not correspond to the Galapagos Mantle array, and have different mantle reservoirs and geochemical characteristics than the Nicoya Complex.

Selling their Best for Little: The Riddle of Ecuador's Failed Attempt to Assist Communal Farmers

In the 1980s, Ecuador began an expensive project providing primary irrigation canals to the Santa Elena Peninsula. The intended beneficiaries were the region's communal farmers. Instead, virtually all irrigable lands have been sold to large farmers and land speculators, usually at exceedingly low prices. While political and economic abuses explain some of these sales, introduction into a communal setting of an innovation which improved returns to capital relative to labor made land divestitures almost inevitable. With effectively no access to credit, communal farmers had little ability to invest in secondary irrigation systems. Moreover, because users of irrigable lands did not fully control communal sales decisions, as these lands became attractive to others, dispossession risks rose. The net result was that reservation prices for holding these lands fell among communal farmers at the same time of increased demands for these assets by those outside the comunas. Implications for development strategies are also discussed.
 

A model for the Holocene extinction of the mammal megafauna in Ecuador

This paper presents the results of multidisciplinary research in the Ecuadorian coastal regions, with particular emphasis on the Santa Elena Peninsula. The new evidence, together with previous data gathered on the Ecuadorian cordillera during the last 12 years, allows us to formulate a model that accounts for most of the mammal megafauna extinction at the Pleistocene/Holocene transition. After the illustration of geomorphological and paleontological evidences of the area of the Santa Elena Peninsula (and other sites), and of a summary of the paleoclimatic data, the main results and conclusions of this work are: (1) Late Pleistocene mammal assemblages survived in the Ecuadorian coast until the Early Holocene sea level rise; (2) Prior to the extinction of most of the megafauna elements (mastodons, ground sloths, equids, sabre-tooth felids), the mammal communities at Santa Elena Peninsula comprise elements with differing habitat requirements, attesting conditions of high biological pressure; (3) At the El Cautivo site (Santa Elena Peninsula), we have discovered Holocene sediments containing the first known occurrences in Ecuador of lithic artifacts that are associated with mammal megafauna remains; (4) During the last 10,000 years, the coastal region of Ecuador underwent significant changes in vegetation cover. At the Pleistocene/Holocene transition the climate changed from very arid conditions to humid conditions. Our data indicates that the megafauna definitively abandoned the Cordillera areas around 12,000 yr bp due to t he increasing aridity, and subsequently migrated to coastal areas where ecological conditions still were suitable, Santa Elena Peninsula and mainly Amazonian areas being typical. We conclude that the unusual high faunal concentrations and the change to dense vegetation cover (due to a rapid increase in precipitation in the lower Holocene) at 8000–6000 yr bp, caused the final collapse and extinction of most elements of the mammal megafauna. Vegetation cover in the area of Santa Elena should have been extensive, and even more so in the Guayas and Guayabamba valleys. The newly densely vegetated areas, and fluvial barriers, transformed the refugia into lethal traps for large animals already under biological stress, such as were mastodons, ground sloths and equids. Within the megafauna, only tapirs and artiodactyla (Cervidae and Camelidae) survived. In our opinion, the most suitable model to justify the great crisis of the mammal megafauna at the Pleistocene/Holocene transition, also in areas out of Ecuador, must be mainly based on the three parameters: high aridity, high humidity and geographic factors.

Terminal Pleistocene/Early Holocene human adaptation in coastal Ecuador: the Las Vegas evidence

Preceramic sites located on the Santa Elena Peninsula in southwestern Ecuador and occupied in the Terminal Pleistocene and during the Early Holocene (10,800–6600 BP) have produced evidence of a durable Las Vegas adaptation focused on marine, estuarine and terrestrial resources. The Las Vegas people were among the earliest cultivators in America who participated in the domestication of useful plant species and progressively intensified their efforts in both fishing and horticulture.

Petrological and structural significance of the Santa Elena-Nicoya ophiolitic complex in Costa Rica and geodynamic implications

Detailed structural and petrological investigations were carried out on the Santa Elena-Nicoya ophiolitic complex in Costa Rica, which is represented by a classic association of mantle tectonites (Santa Elena Peninsula), a cumulitic gabbroic-plagiogranite sequence, and basaltic volcanics and sills (Matapalo and Esperanza Units of the Nicoya Peninsula), with discontinuous radiolarian covers. Despite biostratigraphically different ages (Late Jurassic for Matapalo and Mid-Late Cretaceous for Esperanza) in both units, the major and trace element data, Sr-Nd isotope systematics, and mineral phase crystallization order show identical tholeiitic fractionation trends, where the marked Fe-Ti enrichment of the volcanics is reflected in the gabbroic-Fe gabbroic-plagiogranite intrusives which, in turn, represent the cumulitic counterparts of an essentially analogous magmatic system. Parental basaltic magmas for the Nicoya complex share geochemical features with both Pacific MORB and oceanic plateaus, as indicated by the characteristic flat REE patterns, Zr/Y and Zr/Nb ratios, and Sr-Nd isotopic data ( 87 Sr/ 86 Sr: 0.70295-0.70323; 144 Nd/ 143 Nd: 0.51309-0.51275). On the other hand, basalts and gabbros from Santa Elena display typical N-MORB affinity, as shown by their LREE-depleted patterns. These data, together with the unusual abundance of Fe-Ti differentiated rocks, suggest that the Santa Elena-Nicoya ophiolites may have been generated at oceanic spreading centres in a mantle plume region, analogous to the present Galapagos ridge/hot spot system. The present fore-arc structural setting of the deformed Costa Rica ophiolites is the result of several tectogenetic events recorded by three main ductile deformation phases (from Late Cretaceous to Tertiary): the oldest d1 related to W-E convergent tectonics, followed by d2 related to N-S compression, and the youngest d3 related to NE-SW convergence. The oceanic lithosphere represented by the Costa Rica ophiolites may have been generated at the westernmost termination of the spreading system, leading to the formation of the Caribbean plateau, and later involved in complicated intra-oceanic convergence and rotation processes. These resulted in the progressive building and insertion of the Chorotega block (present Costa Rica) between the Maya-Chortis and Choco-South America continental blocks.

Forum: Health and the environment

As an extension of the theme presented during the conference plenary session, "Health and the environment", the forum focused on a case study, with a discussion of the results, methods and strategies of "Proyecto Salud Para el Pueblo ", a highly successful health promotion/environmental health development project on the Santa Elena Peninsula of Ecuador.

An Initial Consideration of Obsidian Procurement and Exchange in Prehispanic Ecuador

We have examined the role of long-distance trade in Prehispanic Ecuador using X-ray fluorescence (XRF) and neutron-activation analysis (NAA) of obsidian artifacts from the archaeological sites of El Inga, Chobshi Cave and Site OGSE-46 on the Santa Elena Peninsula. Results indicate that two geological sources east of Quito, Yanaurco-Quiscatola and Mullumica, were the principal source of raw obsidian at these sites. We situate our findings within a broader archaeological context through a review of the literature and a discussion of an earlier provenience study undertaken by us. We express concerns about recent attempts to apply ethnohistoric models to early periods of Ecuadorian prehistory, and argue that despite early exploitation of the principal obsidian sources, long-distance trade in obsidian was initiated at a relatively late date and remained at a surprisingly low level in southern Ecuador during most of prehistory.

Excavations at Pirincay in the Paute Valley of southern Ecuador, 1985–1988

The Formative in the northern AndesThe northern Andean regions, encompassing northernmost Peru, all of Ecuador and the southern provinces of Colombia, remain archaeologically very poorly known. Although the past 30 years have witnessed an increasing number of archaeological projects in coastal zones, especially the Santa Elena Peninsula, work in the highlands outside of the greater Quito commute zone has lagged sadly behind. Southern Ecuador, in particular, has had little investigation since earlier this century when first Max Uhle, then Donald Collier, John Murra and, finally, Wendell Bennett, demonstrated the existence of ‘Formative’ cultures in Ecuador through their investigations at sites along the Tomebamba and Paute rivers of Azuay province and at Cerro Narrío, just to the north in the Cañar Valley (Uhle 1922; Collier & Murra 1943; Bennett 1946; FIGURE 1).

On the waterfront: Quaternary environments and the formative occupation of Southwestern Ecuador

AbstractThe occurrence of tectonic uplift in coastal South American prehistory is discussed and evidence of emerged shoreline features is presented for the area of the Santa Elena Peninsula in Ecuador. It is hypothesized that this activity, once thought to be exclusively Pleistocene in timing, continued on into the Holocene. Given this perspective and field data, the role of the Early Formative Period Valdivia phase (3500‐1500 B.C.) site of Real Alto is examined, as is the economic structure of Real Alto society. the pattern of site distribution and data from geological units indicate a long period of tectonic activity that restructured the Ecuadorian coastline and affected northern Andean prehistory. the implications for the origins of Valdivia and New World pottery are reconsidered in light of new information on the Quaternary environments of Ecuador.

Petroleum Geology of Pacific Margin of Central America and Northern South America, from Guatemala to Ecuador: ABSTRACT

Exploration for hydrocarbons along the Pacific margin of Central America and northern South America has been limited and spasmodic. Less than 100 exploration wells have been drilled, with nearly 50 of these being in the Santa Elena, Progreso, and Guayas basins in Ecuador. Shows have been reported in some wells, and a few oil seeps are known. The only commercial production established to date has been from the Santa Elena Peninsula in Ecuador in the extreme south of the study area. Understanding of the geology in this part of the continental margin is incomplete at best. This paper reviews present-day knowledge in an attempt to define the sedimentary basins better, to characterize their structure and stratigraphy, and to assess their petroleum prospects. The area of continental margin reviewed is to the north, located northwest of the trench system where oceanic crust of the Cocos plate subducts under the Caribbean plate, and to the south, where the northern part of the Nazca plate collides with the South American plate. This plate tectonic setting forms the framework on which local structural and sedimentary events have created a series of relatively small trench-slope and forearc basins in what is now the coastal plainmore » and adjacent offshore area of Central and South America, south or west of a line of mountain ranges with active volcanism. Sedimentary fill is generally of Tertiary age. The basins and subbasins recognized and described include: in Ecuador - Guayas, Santa Elena, Progreso, Valdivia, Bajo Grande, Manta, Muisne-Esmeraldas, and Borbon; in Colombia - Choco-Pacific; in Panama - Gulf of Panama basin complex (Santiago, Tonosi, Sambu), and Burica-Chiriqui; in Costa Rica - Terraba and Coronado/Tempisque; in Nicaragua - San Juan del Sur; and in the Honduras, El Salvador, and Guatemala - the Pacific coastal basin.« less

The Preceramic Las Vegas Culture of Coastal Ecuador

This article begins with a description of excavations in the Las Vegas type site on the Santa Elena Peninsula, Ecuador. A pre-Las Vegas phase (11,000 to 10,000 B.P.) is defined provisionally, and the Early Las Vegas (10,000 to 8000 B.P.) and Late Las Vegas (8000 to 6600 B.P.) phases are described from artifacts, burials, settlement data, faunal remains, pollen, and phytoliths. The Las Vegas people were unspecialized hunters, fishermen, and gatherers living in a littoral zone who added plant cultivation to their subsistence system before 8,000 years ago. Evidence for bottle gourd (Lagenaria siceraria) and primitive maize (Zea mays L.) was found in the Las Vegas type site. The differences between the modern, semiarid environment and the environment of the preceramic period are accounted for without hypothesizing climatic change. Las Vegas is interpreted as a local manifestation of an early tropical forest cultural tradition out of which developed the ceramic-stage cultures of the Ecuadorian coast.

The geologic history of the Caribbean-Cocos plate boundary with special reference to the Nicoya ophiolite complex (Costa Rica) and D.S.D.P. results (Legs 67 and 84 off Guatemala): A synthesis

The Pre-Upper Senonian basement of Costa Rica crops out in the Santa Elena and Nicoya peninsulas. From south to north and from base to top the basement includes: the Esperanza, Matapalo and Santa Elena units. The Esperanza unit is Albian-Santonian in age and consists mainly of pillow basalt and massive basalt flows. The Matapalo unit includes Callovian to Cenomanian radiolarite and includes massive basalt flows, basalt, and dolerite basement. The Santa Elena unit contains ultramafic and mafic rocks in which harzburgite is the major component. The most important tectonic features of the Nicoya Complex are the large Santa Elena and Matapalo nappes. Nappe emplacement was from north to south during upper Santonian time. The sedimentary cover of the Nicoya Complex comprises: 1. (1) the Campanian El Viejo Formation that consists of shallow-water sediments in the north (Santa Elena Peninsula) and the Campanian-Maastrichtian Sabana Grande Formation of deep-water origin in the South (Nicoya Peninsula); 2. (2) Paleocene strata indicating deposition in a deep-water environment comprises the Rivas, Las Palmas and Samara Formations; 3. (3) a post-upper Eocene (?) sequence that consists of the shallow-water Barra Honda and Montezuma Formations. Two unconformities are significant geological features of the upper-Senonian to Tertiary history of Costa Rica. The lower one is at the base of the Sabana Grande Formation and marks a major change in the geologic conditions (basalt is scarce in the Campanian-Tertiary series); the upper unconformity at the base of the Barra Honda and Montezuma Formations is not as major as the lower one. During post-Campanian time, normal faulting occurred in two stages separated by a strong erosional phase. The geology of the landward slope of the adjacent Middle America Trench is outlined by interpreting multifold seismic reflection records off the west coast of Costa Rica and the DSDP Legs 67 and 84 transects off Guatemala. The western Caribbean plate boundary may have been under extensional stress for the last 75 m.y. The strong landward-dipping reflectors of the Middle America Trench landward slope off Guatemala could be equivalent to the on-land pre-Campanian overthrusts of Costa Rica. The available data are consistent with the Convergent Extensional margin concept.

On Climate and Occupation of the Santa Elena Peninsula: Implications of Documents for Andean Prehistory

Previous articleNext article No AccessDiscussion and CriticismOn Climate and Occupation of the Santa Elena Peninsula: Implications of Documents for Andean PrehistoryPeter Stahl and Allison C. PaulsenPeter Stahl Search for more articles by this author and Allison C. Paulsen Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 25, Number 3Jun., 1984 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/203147 Views: 5Total views on this site Citations: 2Citations are reported from Crossref Copyright 1984 The Wenner-Gren Foundation for Anthropological ResearchPDF download Crossref reports the following articles citing this article:L. G. Thompson, E. Mosley-Thompson One-Half Millennia of Tropical Climate Variability as Recorded in the Stratigraphy of the Quelccaya Ice Cap, Peru, (Mar 2013): 15–31.https://doi.org/10.1029/GM055p0015Lonnie G. Thompson, Mary E. Davis, Ellen Mosley-Thompson Glacial records of Global climate: A 1500-year tropical ice core record of climate, Human Ecology 22, no.11 (Mar 1994): 83–95.https://doi.org/10.1007/BF02168764

Review of the Early Preceramic Complexes of the Santa Elena Peninsula, Ecuador

Of the four late Pleistocene and early post-Pleistocene lithic complexes defined by Edward P. Lanning, only one, the Las Vegas complex, is supported by existing evidence from the Santa Elena Peninsula of southwest Ecuador. The Achallan culture, previously defined by Stothert and assigned to the post-Las Vegas period, is now unsupported by satisfactory evidence.

Holocene Mangrove Formations on the Santa Elena Peninsula, Ecuador: Pluvial Indicators or Ecological Response to Physiographic Changes

Evidence indicates that several temporally distinct periods of prehistoric occupation of the now dry Santa Elena Peninsula of Ecuador coincided with periods of mangrove formation on the Peninsula. This article challenges the premise behind the hypothesis that such hydrophytic vegetation indicates greater rainfall during these periods. An alternative hypothesis is suggested, based upon the argument that known coastal uplift and probable accompanying physiographic changes first created, and later destroyed, the edaphic requirements for such a formation. The need to invoke a hypothesis of climatic shifts is thus dispensed with.

Comment on Conrad

GEOFFREY CONRAD DESERVES PRAISE for providing a fascinating and convincing interpretation of the great compounds of Chan Chan (refer to American Antiquity 46:3-26). His discussion of split inheritance as a cultural rule which stimulated conquest state formation is equally fascinating, though it requires a great deal more documentation. However, his dismissal of materialistic processes in the evolution of expansionist Andean states is based on several serious errors. A much more attractive explanatory hypothesis can be formulated by combining the materialist and nonmaterialist arguments rather than simply trying to displace one with the other. After all, Conrad himself states that [i]f an explanation of cultural stability or change is to be satisfying, the relationships between material and nonmaterial factors are something to be demonstrated, not assumed a priori. A priori assumptions obviously underlie Conrad's rejection of Paulsen's (1976) correlation of decreasing production in dry periods with conquest states in the Central Andes. He offers no theoretical argument against the processual relationships which Paulsen describes, but attacks the inconclusiveness of her evidence for such changes, and for the generalization of a climatic sequence from Ecuador's Santa Elena Peninsula to the central Andean region. He fails to realize that the data in support of his proposition are no more conclusive than those presented by Paulsen in support of hers. The argument that the core of Chan Chan was composed of ten huge mortuary shrines constructed sequentially by successive kings is far more convincing than older impressions of densely occupied neighborhoods or barrios. The former interpretation, which implies that Chan Chan was more a ceremonial center than an agglutinated city, needs more documentation, although readers are assured that the data are forthcoming. Split inheritance among the Incas must be researched much more before its principles of operation and long-term consequences will be understood. Inca land tenure still confuses students of Andean culture, and it cannot be assumed that laws dealt with all forms of property in the same way. The rights of individual Inca kings, panacas, and the state remain obscure. Even in Cuzco it is not clear that panacas administered a dead king's estate consisting of a palace-mortuary shrine in the capital, accumulated portable wealth, all conquered lands, and servile populations. The palace-shrine of Topa Inca still cannot be identified (Rowe 1967), and it is entirely possible that we totally misunderstand the Inca capital by conceptualizing it in such terms (Zuidema n.d.). If it is true that successive Inca kings constructed palaces and accumulated estates to be inherited by their panacas, how is it that the palaces (Rowe 1967) associated with the last two Incas, Huayna Capac and Huascar, border the great plaza of Cuzco? The structural order of the buildings surrounding the plaza in 1532 seems far too perfect to be a coincidence of sequential construction (Isbell 1978a). If one accepts Conrad's arguments we must believe that the Incas were slowly obliterating the Puma form of Cuzco and apparently filling in the ceremonial plaza with palaces for each new king.