Este trabajo discute la secuencia de desarrollo histórico prehispánico en el Norte Semiárido de Chile a partir del estudio de las dinámicas espaciales y temporales de las ocupaciones humanas en la cuenca hidrográfica del río Limarí. A partir del estudio de asentamientos, materiales depositados en colecciones y arte rupestre se observa una secuencia de transformaciones y desarrollo desde el Arcaico Temprano hasta el período Incaico que diverge de lo tradicionalmente planteado para la región, reconociéndose ritmos de cambios sociales diferenciales dentro de la misma zona, especialmente en relación con la tradicional asociación entre incorporación de cerámica y la constitución de un modo de vida agrícola. La incorporación del arte rupestre permite articular sus características espaciales y representacionales con procesos más amplios, discutiéndose las relaciones establecidas entre dinámi-cas y cambios sociales con los flujos de información que producen las representaciones rupestres y sus respectivas audiencias.Palabras claves: norte semiárido, cuenca hidrográfica del río Limarí, secuencia histórica, patrón de asentamiento, arte rupestre. This paper discusses the pre-Hispanic sequence of historical development in the semiarid north of Chile through the study of spatial and temporal dynamics of human occupation in the

In this paper we present an overview of the process of mapping and field surveying of an area of ancient fields and irrigation canals around the pre-Hispanic sites of Topaín, Paniri and Turi, in the Andean highlands of northern Chile. As opposed to the usual conditions for prospection in temperate or tropical regions, where the surface visibility of archaeological features is often poor and confusing, here the extreme aridity of the landscape has permitted an extraordinary degree of both preservation and visibility of the fields, canals and other constructions. A field methodology based on a combination of an aerial approach (with relatively low-cost resources: high resolution satellite images, GIS, UAV) and field survey has allowed us not only to document the sites but to

Bedrock mortars recur in the record of many prehispanic communities. However, few studies discuss their relationship with social processes. In the present work, we discuss a regional study of bedrock mortars in the semiarid north of Chile, specifically the Limarí River basin (30° S). Using a combination of formal, spatial, contextual, archaeobotanical, and absolute dating analyses, we assess the chronology of bedrock mortars and how they related to social processes of hunter-gatherer populations of the region (2000 BC to AD 1000). In particular, we suggest that an increase in production of bedrock mortars among pottery-using hunter-gatherer groups (AD 1–1000) can be observed, associated with a greater intensity of plant collection and use, and a diminution in the importance of hunting. This situation led to a set of new social relationships structured on the practice of collective grinding and shared use of bedrock mortars. These results show the importance of this material record as a means of approaching aspects of prehispanic social life, and demonstrates a methodological framework within which to interrogate this materiality by combining different analytical levels of bedrock mortars’ variability.

We examined the response of leaves of 3-week-old maize (Zea mays 1.) t o short-term (5 h) fumigation with O,-enriched air (O, 0.12, 0.24, or Tropospheric O, is a major component of photochemical air pollution and has phytotoxic effects on vegetation, including decreased photosynthesis, leaf injury, reduced growth of shoots and roots, accelerated senescence, and reduced crop yield (Heck et al., 1988; Heagle, 1989). Levels of tropospheric O, range from 0.02 to 0.05 pL/L in unpolluted areas to as high as 0.40 pL/L in the most polluted urban environments (Seinfeld, 1989). Plant resistance to elevated O, levels can result from either avoidance or tolerance mechanisms (Taylor, 1978). Avoidance involves the physical exclusion of pollutants from the plant such as through stomatal closure. Tolerance can result from avoidance and/or biochemical responses such as increased detoxification and repair processes or induction of biochem-

No abstract