Abstract Formation processes and chronology of archaeological occupations of Horco Molle (Tucuman) were analyzed, this area is located in the south part of Northwestern Argentina. Pits and excavations, stratigraphic descriptions, pH measurements, trace of alteration analyses in ceramic assemblages, typological classifications, and a radiocarbon dating were made. Levels of occupation were located in the distal part of an alluvial fan, lying over a paleosoil, covered by alluvial deposits (with recent soil development) or gravels. The variable acidity of the soil (among 5,38 y 6,47) explains in part the near absence of organic archaeological materials. The collapse of an architectural structure made of mud above a surface of occupation preserved an archaeological context with de facto refuses. The trampling intervened in the fracture of pottery sherds belonging to the analyzed contexts. The variety of ceramic types present in the occupations is comparable to which characterizes the Chuscha (200-400 AD) and Choromoro (400-700 AD) phases, in coincidence with a dating of 1639 ± 57 BP. The results obtained highlight the adequacy of geoarchaeological perspective for the discovery and research of occupational surfaces in forested areas.

Resumen Se analizaron procesos de formación y cronología de niveles de ocupación de Horco Molle (Tucumán), localidad emplazada en la parte S de las Selvas Occidentales del Noroeste Argentino. Para ello se efectuaron sondeos y excavaciones, descripciones estratigráficas, determinaciones de pH, registro de trazas de alteración en conjuntos cerámicos, clasificaciones tipológicas y un fechado radiocarbónico. Los niveles de ocupación, ubicados en el sector distal de un abanico aluvial, se apoyan sobre un paleosuelo, cubiertos por depósitos aluviales sobre los que se formó el suelo actual o por grava. La acidez variable de los suelos (entre 5,38 y 6,47) explican en parte la casi ausencia de materiales arqueológicos orgánicos. El desplome de una estructura arquitectónica de barro sobre una superficie de ocupación preservó un contexto con desechos de facto. El pisoteo intervino en la fractura de tiestos de los contextos analizados. La variedad de tipos cerámicos presentes en las ocupaciones se corresponde con la que caracteriza a las fases Chuscha (200-400 DC) y Choromoro (400-700 DC), estimación cronológica que coincide con un fechado de 1639 ± 57 AP. Los resultados obtenidos destacan la adecuación de la perspectiva geoarqueológica para el hallazgo e investigación de niveles de ocupación prehispánicos en ámbitos selváticos.

Residence patterns, habitat use, range, and some population estimate of the coastal bottlenose dolphin, Tursiops truncatus (Montagu, 1821), were documented in two coastal sites in southern Brazil: Laguna (Santa Catarina) (28º30'S; 48º55'W), and Imbe/Tramandai (Rio Grande do Sul) (29º58'S; 50º07'W). Regular observations were carried out at the Laguna system for 27 months (August 1989 to December 1991). The dolphins were photo-identified using natural permanent marks. Over 4,500 photograps were taken from shore grounds 6 to 14 meters away. Up to 51 dolphins have used the estuaries of Laguna's canal and Imarui-Santo Antonio's lagoon system in 1991. A stable group of nine animals has inhabited the Imbe/Tramandai area for over 13 years. Both sites were considered distinctive geographical communities, with 5.7% interchange within their individuals. In Laguna 88.5% of the individuals were resident and the rest were nonresident. Four cases of movement along the coastline were followed and females were more resident than males.