Until relatively recently, the view of Late Pleistocene hunter-gatherers in the Americas was dominated by the “Clovis-first” paradigm. However, recent discoveries have challenged traditional views and forced reconsiderations of the timing, processes, and scales used in modeling the settlement of the Americas. Chief among these discoveries has been the recognition of a wide range of early cultural diversity throughout the Americas that is inconsistent with previously held notions of cultural homogeneity. During the Late Pleistocene-Early Holocene, the development of widely varying economic, technological and mobility strategies in distinct environments is suggestive of a range of different adaptations and traditions. It is argued that colonization was a disjointed process involving alternative, perhaps competing strategies at local and regional levels. Individual groups likely employed distinct strategies for settling new landscapes. These different strategies are reflected in the cultural variability that has been documented in the Late Pleistocene-Early Holocene archaeological records of South and North America. A scalar framework for conceptualizing and modeling this variability on local, regional, and continental scales is introduced. Although primarily focused on local and regional reconstructions, the results can be integrated with other regional studies to generate more comprehensive, continental-scale models of the peopling of the New World. This research provides insight into the local and regional variability—in terms of settlement patterns and economic and technological strategies—present in the archaeological record of at least two formally recognized Late Pleistocene-Early Holocene complexes (Fishtail and Paiján complexes) in the Quebradas del Batán and Talambo of the lower Jequetepeque Valley, northern Perú. Results of extensive survey, excavation, and materials analyses are used to characterize mobility strategies and settlement organization. This research indicates that two distinct patterns of site types, settlement, subsistence, and technology existed at the local level between the Fishtail (ca. 11,200-10,200 B.P.) and Paiján (ca. 10,800-9,000 B.P.); these patterns are indicative of differing regional strategies of colonization. Lastly, it is suggested that the adaptations and behaviors pursued during regional settlement, particularly by Paiján groups, set in motion an increasing reliance on plant foods and an early trend toward sedentism that carried forward into the Holocene period.

In this paper we present the results of two campaigns of survey in the Quebrada Orcón-Pacaybamba in the middle Chancay Valley. We also discuss the preliminary data produced from our fieldwork in terms of the local economy and site distribution for each of the different Preceramic stages on the Central Coast and in the highlands of Perú. We conclude by interpreting the evolution of several economic strategies employed by different groups occupying the Central Coast of Perú until the formation of stratified societies of the Preceramic Period. / En este trabajo se presentan los resultados de dos temporadas de reconocimiento sistemático en la quebrada Orcón-Pacaybamba, ubicada en el valle medio de Chancay. Los datos obtenidos se confrontan con la información conocida con respecto a la economía y distribución de sitios durante el Periodo Precerámico en la costa y sierra central del Perú. Finalmente, a manera de hipótesis, se exponen algunos planteamientos en relación con la evolución de las diversas estrategias económicas desarrolladas desde la llegada del hombre a la costa central del Perú hasta la formación de sociedades estratificadas al final de este periodo.

The archaeological site of Bandurria, located near the modern town of Huacho, on the North-Central Peruvian coast, is a Late Preceramic settlement known since the 1970’s. However, new research has discovered an unreported sector with monumental architecture. This sector covers an area of 20 hectares and contains 10 structures divided into 4 main mounds of 8 to 12 meters high and 6 minor structures that had auxiliary or secondary functions. This article presents the archaeological excavation of one of the main structures, Mound 1. This excavation revealed a cobble and mud mortar truncated pyramid associated with a circular sunken plaza that reflects the same architectural features and forms of other Late Preceramic monumental architecture. / El sitio arqueológico de Bandurria corresponde a un asentamiento del Periodo Precerámico Tardío y es conocido desde la década de los setenta. Nuevas investigaciones, realizadas por el autor, han descubierto un sector de arquitectura monumental nunca antes reportado por investigadores previos. Este sector, de 20 hectáreas, presenta un total de 10 estructuras compuestas por cuatro montículos principales, con alturas de entre 8 a 12 metros, y seis estructuras menores que, probablemente, cumplieron funciones auxiliares o secundarias. El presente artículo da a conocer los trabajos de excavación en una de las estructuras principales, el Montículo 1, que revelaron una pirámide trunca y una plaza circular hundida construidas con cantos rodados unidos con argamasa de barro y que mantienen las mismas características y formas de la arquitectura monumental de otros sitios del mismo periodo.

A Revision of the Evidence of the Existence of Preceramic Maize in the Central AndesA revision of all archaeological sites in the Central Andes is presented in which preceramic maize was found. The contexts and proofs that certify the finding are presented, discarting the doubtful sites. At the same time the botanical evidence of those maize items is shown and discussed. One arrives at the conclusion that there is not any doubt at all to the existence of preceramic maize with clear and proper characteristics, that differentiates it from the Mesoamerican societies. / Se hace una revisión de todos los yacimientos arqueológicos de los Andes Centrales en los que se ha encontrado maíz precerámico. Se presentan los contextos y las pruebas que certifican los hallazgos, descartándose los sitios dudosos. Al mismo tiempo se indican y se discuten las evidencias botánicas de los maíces en cuestión. Se llega a la conclusión que no cabe la menor duda de la existencia de maíz precerámico con características muy claras que lo diferencian del mesoamericano.

La photo-catalyse est une voie très prisée pour la dépollution de l’eau ou de l’air. Le photo-catalyseur le plus employé est le dioxyde de titane (TiO2) mais l’activité photo-catalytique peut fortement varier d’une poudre à l’autre. De plus, il est très avantageux, voire nécessaire, de le déposer sur un support, pour une manipulation aisée, notamment s’il s’agit d’un monolithe poreux. Le but de cette thèse, menée en collaboration entre le LMCPA et l’IEM, est de produire un photo-catalyseur supporté : une mousse céramique, issue de précurseurs céramiques polymériques (voie PDC), revêtue de TiO2, tout en visant une cristallisation et une intégration du TiO2 dans la mousse, en une seule étape, par voie hydrothermale. Nous avons étudié la synthèse de TiO2 par voie hydrothermale formant ainsi des poudres de diverses natures (anatase, brookite, oxyde hydraté de titane et mélanges de ces phases) ; certaines présentent une activité photo-catalytique supérieure, dans certaines conditions, à celle de la référence commerciale le P25 de Degussa. Cette étude a également permis de produire de la brookite pure à une température relativement basse, bien plus performante que le P25 et l’anatase dans certaines conditions. Parallèlement, divers polymères précéramiques ont été investigués pour la confection de supports macro-poreux via la méthode des charges sacrificielles. Nous avons ainsi réalisé des mousses en céramique amorphe en SiBCN et SiBC, hautement poreuses, ouvertes et robustes. Enfin, les poudres de TiO2 les plus efficaces ont été déposées sur les mousses, par la voie hydrothermale, pour former le photocatalyseur supporté dont l’activité photo-catalytique a été évaluée. / Photocatalysis is a method of choice for water and air depollution. Titanium dioxide (TiO2) is the most used photocatalyst but photocatalytic activity can widely differ from one powder to another. Moreover, it is useful, or even necessary, to immobilize it on a support; in particular, a porous monolithic support for an easier handling. The purpose of this PhD thesis, consisting in a collaboration between the LMCPA and the IEM, is to produce a supported photocatalyst: an amorphous ceramic foam produced from polymeric ceramic precursors (PDC route) coated with TiO2. The objective is also to target a one pot process the crystallization and the incorporation of the photocatalyst, in a single stage, through a hydrothermal treatment. We studied the hydrothermal synthesis of TiO2 powders composed of various crystalline phases (anatase, brookite, titanium oxide hydrate and mixtures of thereof); some of them showed higher photocatalytic activity than the commercial reference, Degussa’s P25. This study also lead to the synthesis of pure brookite, at a relatively low temperature, much more efficient than P25 and anatase under certain conditions. At the same time, various preceramic polymers were studied for the production of macroporous supports through the sacrificial filler technique. We were able to produce highly porous, opened and robust amorphous ceramic foams in the Si-B-C-N and Si-B-C systems. Lastly, the foams were coated with the most efficient TiO2 powders in order to produce supported photocatalysts by the hydrothermal route; their photocatalytic activity was then evaluated.

Excavations Project at Paloma, Chilca Valley, PerúThe preceramic site of Paloma (12b-VII-613), Chilca Valley, Peru, was excavated over a number of seasons, first by Frédéric-André Engel and Bernardino Ojeda and later by Robert A. Benfer, Jr., in a joint project with the original investigators. The project was a multidisciplinary investigation of the largest site of its time period, 7800 to 4700 B.P. The Hypsithermal time of global warming, 6500-5000 B.P. was optimal for the central coast due to an increase in moisture. The principle occupation of Paloma, strata 300 and 200, were during the Hypsithermal. We studied the adjustments to sedentary life from an exceptionally extensive series of studies of the consequences of this life registered in the skeletons and teeth of the 201 individuals excavated from in and around over 50 domestic structures in 1900 square meters of excavations. Principal findings from the study of the human remains along with studies of animal and plant remains have been summarized elsewhere (Benfer 1990). Here I present details of the excavation and the stratigraphy of the site. In addition, new data are presented from analyses of mortuary customs and plant use. / El sitio precerámico de Paloma (12b-VII-613) se ubica en el valle de Chilca, Perú y fue excavado durante varias temporadas, originalmente por F. Engel y B. Ojeda y luego por R. Benfer, Jr. Este último dirigió una investigación multidisciplinaria del sitio ocupado entre 7800 hasta 4700 a.p. La epoca hipsitermal del calentamiento global (6500-5000 a.p.) fue el periodo más favorable para la Costa Central debido al aumento de humedad a la que corresponde la ocupación principal de Paloma (estratos 300 y 200). El autor investigó las adaptaciones a la vida sedentaria desde una serie extensiva y excepcional de estudios para encontrar las consecuencias de esta vida, registrada en los esqueletos y dientes de los 201 individuos excavados dentro y alrededor de más de 50 estructuras domésticas en 1900 m2 excavados. Los principales hallazgos de restos humanos así como restos vegetales y animales han sido resumidos anteriormente (Benfer 1990). Aquí se presentan detalles de las excavaciones y de la estratigrafía del sitio, así como nuevos datos producto de los análisis de las costumbres de los entierros y del uso de plantas.

This paper endeavors to establish some basic points of reference to better understand the early culture-historical dynamics of the Casma Valley. The revised chronology presented here follows the ceramic sequence developed by Peter Fuchs (1990) on the basis of his Cerro Sechín stratigraphy, confirmed and amplified in its early sections by his recent excavations at Sechín Bajo. A systematic review of the different categories of archaeological data reveals many lacunae that still persist in our record. Monumental architecture most clearly expresses the socio-cultural complexity of the ancient Casma Valley polities. It first appeared during the Sechín Period (3400-1650 cal BC) which is part of the Late Archaic (Preceramic), followed during the Early Formative by the Moxeke Period (1650-1400 cal BC) and the Haldas Period (1400-1000 cal BC) with their diagnostic ceramics. Within this timeframe, some hypotheses formulated by Shelia and Thomas Pozorski (2006) about the socio-political transactions between major Casma Valley sites are evaluated in the light of the archaeological evidence. The tradition of monumental adobe architecture that goes back to about 3400 cal BC in the Casma Valley, reminds us of analogous developments in the Pre-Pottery Neolithic of the ancient Near East. There still remains the challenge to adapt Archaic Period terminology in the Andes to those new discoveries (Kaulicke 1994, 2007: 17-18). / Las investigaciones recientes permiten esbozar un nuevo cuadro cronológico del valle de Casma gracias a la secuencia cerámica elaborada por Peter Fuchs (1990) sobre la base de la estratigrafía de Cerro Sechín, confirmada y ampliada en su parte temprana por los descubrimientos en Sechín Bajo. Al mismo tiempo, el recuento sistemático categorizado de los datos revelará muchas lagunas en el registro arqueológico actual. El avance sociocultural de los habitantes del valle de Casma se expresa, más claramente, en su arquitectura monumental. Se da a conocer, primero, en el Periodo Sechín (3400-1650 a.C.), que forma parte del Arcaico Tardío y Final, seguido durante el Formativo Temprano —según los contextos cerámicos diagnósticos—, por los periodos Moxeke (1650-1400 a.C.) y Haldas (1400-1000 a.C. [calib.]). Dentro de este marco se tratará de evaluar, a la luz de las evidencias arqueológicas, algunos desarrollos sociopolíticos bosquejados por Shelia y Thomas Pozorski (2006) como si fuesen reales. La presencia de una arquitectura monumental de adobe que se remonta hacia 3400 a.C. (calib.) en el valle de  Casma, hace recordar los desarrollos análogos del Neolítico Precerámico (Pre-Pottery Neolithic) del Cercano Oriente. Permanece pendiente el reto de estructurar una terminología conveniente para el Periodo Arcaico andino, de acuerdo con los nuevos descubrimientos (Kaulicke 1994; 2009: 17-18).

Evidence for the earliest inhabitants of the territory known as Ecuador demonstrates the limitations of the archaeological record inthe highlands and along the Andean slopes, and the relative abundance of evidence for a long preceramic occupation on the Santa Elena Peninsula, including the Pre-Las Vegas phase. The Early and Late Las Vegas phases represent an early and well-studied adaptation to a rich coastal zone where people adopted the cultivation of plants at the beginning of the Holocene. Recent finds in the coastal lowlands (Guayas Basin) provoke this discussion of the peopling of Ecuador and an analysis of the development of regional adaptations in the Early Holocene. / Las evidencias de los primeros pobladores en el territorio conocido como Ecuador demuestran las limitaciones del registro arqueológico en la sierra y en la montaña andina, y, a la vez, la abundancia relativa de información para la larga ocupación precerámica en la península de Santa Elena. Las fases Las Vegas Temprano y Las Vegas Tardío representan una adaptación a los abundantes recursos del litoral, donde el cultivo de plantas se inició de manera temprana en el Holoceno. Nuevos hallazgos en las tierras bajas de la cuenca del río Guayas motivan la presente discusión acerca del poblamiento del Ecuador y un análisis del desarrollo de las adaptaciones regionales en el Holoceno Temprano.

A Reexamination of the Development of the Late Preceramic Complex Society through the Radiocarbon Dates and Archaeological Researches in Casma ValleyIn many aspects, the preceramic sites of Casma are typical of preceramic occupations in other parts of Peru. Nevertheless, the beginnings of nondomestic or monumental architecture are present at the Casma sites of Tortugas and Huaynuna. In addition, at the site of Huaynuna there is evidence of an "aceramic" occupation that coexisted with the first settlements associated with ceramics in the Early Formative or Initial Period. The existence of aceramic sites in Casma called attention to other sites that, though lacking ceramics, have radiocarbon dates later than 1800 a.C., that is, during the time period typically considered as the Early Formative. This realization has implications with respect to the maritime hypothesis and the development of complex society along the Peruvian coast. / En muchos aspectos, los sitios precerámicos de Casma son típicos de las ocupaciones precerámicas del resto del Perú. Sin embargo, en los sitios de Tortugas y Huaynuná de Casma se encuentran los inicios de la arquitectura no doméstica o monumental. Además, en el sitio de Huaynuná tambien hay evidencia de una ocupación "acerámica" que coexistía con los primeros asentamientos con cerámica del Periodo Inicial o Formativo Temprano. El reconocimiento de los sitios acerámicos en Casma llamó la atención a otros sitios que, aunque carecen de cerámica, tienen fechados radiocarbónicos después de 1800 a.C., es decir durante lo que típicamente se consideraba como el Formativo Temprano. Este hallazgo tiene implicaciones con respecto a la hipótesis marítima y el desarrollo de la sociedad compleja en la costa peruana.

Le développement de protections balistiques toujours plus légères et performantes reste un sujet de recherche très actif. Malgré de très hautes performances, la difficulté de mise en forme du SiC conduit généralement à l’utilisation d’aides au frittage en quantité importante, favorisant la formation de phases secondaires pouvant fragiliser le matériau. De plus, les hautes températures de mise en forme induisent la présence de phase α, conférant au matériau des propriétés mécaniques anisotropes et inférieures à celles de la phase cubique β.Dans ces travaux de thèse, l’objectif a été d’élaborer un matériau SiC cubique de très haute pureté, avec une densité de 100% et une stœchiométrie Si/C idéale afin d’optimiser les performances de cette céramique. Deux types de précurseurs ont été envisagés : une poudre commerciale et une poudre issue de la conversion d’un précurseur polymère précéramique.Dans un premier temps, une étude paramétrique de frittage par SPS a permis d’atteindre des densités de 95% pour les 2 précurseurs, tout en conservant la phase cubique seule. Ces résultats, bien qu’encourageants mais n’étant pas suffisants pour l’application visée, l’étude s’est tournée vers l’ajout d’aides au frittage. Des densités de 100% ont ainsi été obtenues sur des échantillons préparés à partir de poudre commerciale, même pour de très faibles teneurs en additif. Un second aspect de ces travaux a permis de mettre en évidence une dépendance de la température de transition β -> α du SiC vis-à-vis de la pression de frittage mais également vis-à-vis du type de précurseur, l’utilisation du précurseur polymère étant plus favorable à la stabilité de la structure cubique. Enfin des mesures de dureté ont été réalisées sur les meilleurs échantillons et ont permis de souligner le rôle prépondérant de la densité sur cette propriété. / The development of light and high performance ballistic protections is currently a sensitive subject of research. Despite promising mechanical characteristics, the complexity of SiC shaping generally leads to the use of high content of sintering aids, favouring secondary phases formation which could weaken the material. Nevertheless, high sintering temperatures induce the presence of the α form of SiC, conferring to the material anisotropical and lower mechanical properties than the one obtained with the cubic β phase.The goal of this PhD work is the development of high purity cubic SiC, with density close to 100% and perfect Si:C stoichiometry to optimize the performances of this ceramic. Two kinds of precursors were considered: a commercial powder and a powder from the conversion of preceramic polymer precursor.Firstly, the parametric study of SPS sintering allowed to reach densities of 95% for both precursors, while conserving only the cubic phase. These encouraging results being not sufficient, this study switched to the use of sintering aids. Densities close to 100% were thus reached on samples sintered with prepared mixtures from commercial powder, even for very low content of additive. The second subject of this thesis highlighted a dependence of the β -> α transition temperature of SiC as a function of sintering pressure, but also according to the kind of precursor. Indeed, the use of polymer precursor is favourable to cubic structure stability. Then, hardness measurements were performed on the most promising samples and allowed to highlight the major role of density on this property.