Ana M. Abarzúa

USO DEL ESPACIO DE CAZADORES RECOLECTORES Y PALEOAMBIENTE HOLOCENO EN EL VALLE DEL RÍO CISNES, REGIÓN DE AISÉN, CHILE

**** Y ANA M. ABARZuA ***** . ABSTRACT This paper presents results on archaeological research conducted at the Cisnes river basin (~44° S), valley which passes through several environments in western Patagonia, from the westernmost limits of the steppe to the Pacific channels. These are assessed in light of a palaeoenvironmental reconstruc - tion spanning from the Late Pleistocene to the Holocene. Results allow interpreting different ways for approaching the environment; these are exposed both spatially and chronologically. Cultural units defined occupied the space discontinuously and ranking it differentially attending to environmental variability. We

Multiproxy evidence for leaf-browsing and closed habitats in extinct proboscideans (Mammalia, Proboscidea) from Central Chile

Significance The multiproxy approach represents a novel methodology and a unique opportunity to obtain a more detailed view of ancient resource use. Our multiproxy study, carried out on gomphotheres from Chile, widens potential occupied habitats to closed-canopy forests. This habitat variability supports the hypothesis that the diet of gomphotheres appears to be more constrained by resource availability than by the potential dietary range. We strongly recommend the use of a multiproxy approach, where morphology analyses are complemented by other sources of information. This approach prevents misleading conclusions about the origin of the proxy’s signal from arising, such as a leaf-browsing diet inferred from the dental calculus and microwear not necessarily being indicative of humidity. Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.

Environmental Responses to Climatic and Cultural Changes

Geological sediment cores from the Puren-Lumaco Valley are analyzed for the sedimentological, geochemical, pollen, chironomids, diatoms, and charcoal patterns during the last 26 years.

Potencial de los anillos de crecimiento de Pilgerodendron uviferum para el estudio histórico de las Iglesias de Chiloé, Patrimonio de la Humanidad

Las iglesias de Chiloe son antiguas estructuras de madera reconocidas patrimonio de la humanidad por la UNESCO. Gran parte de su historia de construccion y reparaciones aun se desconoce. Considerando que muchas de las iglesias de Chiloe fueron construidas utilizando madera de Pilgerodendron uviferum, el objetivo de este trabajo fue evaluar el potencial de esta especie para datar piezas de madera de dos de estas historicas construcciones: las iglesias de Vilupulli e Ichuac. En Vilupulli se dataron piezas de 311 y 181 anos provenientes de los pilares de la torre. Estas piezas fueron fechadas con cronologias de ancho de anillos de P. uviferum cercanas a las dos iglesias. Tambien utilizando estas cronologias se dataron piezas de 79, 89, 97 y 135 anos obtenidas a partir de los pilotes que sostienen el piso de la iglesia de Ichuac. Considerando que Vilupulli fue construida a principios del siglo XX, es posible que las muestras de la torre que presentaron fechas cercanas a 1918, sean parte del proceso tardio de construccion de la iglesia o de una restauracion posterior. Por su parte, Ichuac fue construida a finales del siglo XIX, por lo que las piezas del piso que dataron entre 19201929, formarian parte de una posible restauracion no descrita previamente en archivos historicos, la cual pudo ocurrir incluso varios anos posterior a la fecha del anillo mas reciente encontrado en las piezas estudiadas. Se concluye que P. uviferum tiene alto potencial para estudios historicos en estructuras patrimoniales en el sur de Chile.