Paleoenvironmental model of La Flecha Formation (Upper Cambrian) from Jáchal region, San Juan province

La Flecha Formation (Upper Cambrian) in Precordillera Central is composed of microbiolitic buildups, with a shallowing upward tendency. This paper includes the study of mega, meso and microstructure of thrombolites and stromatolites and the microfacial analysis of the muddy sequence. The following microbiolitic facies were recognized: F1: stratiform and domal stroms, with low synoptic relief, F2: stratiform thrombolites, F3: stratiform-domal thrombolites with low synoptic relief, F4: inverted cone-shaped thrombolites and F5: domal thrombolites. The associated muddy microfacies are represented by: MF6: mudstone with microbial lamination and fenestral fabric, MF7: mudstone with grumous microestructure, MF8: bioturbed mudstone and MF9: floatstone, related to storms. The depositional model of this sequence was interpreted as a carbonatic platform with a complex of non-emergent microbialitic mounds and ponds with restricted circulation.Fil:Armella, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Cabaleri, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Valencio, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Desastres, ordem social e planejamento em defesa civil: o contexto brasileiro

A pesquisa sociológica em desastres tem muitas abordagens voltadas para as instituições e relações de poder. Desastres têm implicações sobre a ordem social, bem como a ordem social pode colaborar para a produção do desastre. As rupturas sociais provenientes de situações de desigualdade têm influência na resposta dos eventos de desastre, incluindo fatores políticos e econômicos que aumentam a vulnerabilidade. Este artigo analisa o discurso institucional e as práticas de defesa civil no contexto brasileiro. Antes de tudo, descreve as principais abordagens da sociologia dos desastres: o consenso mínimo, a polaridade e dicotomia, e mostra uma abordagem sobre a relação entre desenvolvimento desigual, vulnerabilidade e planejamento de defesa civil. A situação atual nas cidades brasileiras é de restrição de acesso a terra e isso resulta em aumento dos desastres. Se não ocorrer mudança no planejamento do Estado, com a adoção de novas estratégias explicitamente formuladas para quebrar o ponto de vista ideológico que submete grupos pobres, os desastres continuarão acontecendo. Na atual dimensão estrutural do planejamento, o sistema brasileiro de defesa civil classifica os grupos vulneráveis sem considerar a complexidade social. Desastres não destroem por completo os sistemas sociais existentes, mas são capazes de manter contínuos processos de indiferença social. Assim, este artigo conclui dando ênfase no desenvolvimento de uma agenda participativa no planejamento e no nível decisório em defesa civil.Sociological research on disasters has many approaches targeted at institutions and power relationships. Disasters have implications on the social order, and the social order can collaborate to produce disasters. The social disruption deriving from inequality situations influences the response to disaster events, including political and economic factors that increase vulnerability. This paper analyzes the institutional discourse and the civil defense practices in the Brazilian context. First of all, it describes the main approaches of the sociology of disasters: the minimal consensus, the polarity and dichotomy, and shows one approach about the relationship between unequal development, vulnerability and civil defense planning. The present situation in Brazilian cities is of restriction to land access and it results in an increase in disasters. If changes do not occur in State's planning, with the adoption of new strategies explicitly formulated to break up the ideological point of view that subjects the poor groups, the disasters will continue happening. In the present structural dimension of planning, the Brazilian civil defense system classifies the vulnerable groups without considering social complexity. Disasters do not completely destroy the existing social systems, but they are capable of maintaining continuous processes of social indifference. Thus, the paper concludes by emphasizing the development of a participatory agenda in civil defense planning and decision-making processes

Paleoenvironmental model of La Flecha Formation (Upper Cambrian) from Jáchal region, San Juan province

La Flecha Formation (Upper Cambrian) in Precordillera Central is composed of microbiolitic buildups, with a shallowing upward tendency. This paper includes the study of mega, meso and microstructure of thrombolites and stromatolites and the microfacial analysis of the muddy sequence. The following microbiolitic facies were recognized: F1: stratiform and domal stroms, with low synoptic relief, F2: stratiform thrombolites, F3: stratiform-domal thrombolites with low synoptic relief, F4: inverted cone-shaped thrombolites and F5: domal thrombolites. The associated muddy microfacies are represented by: MF6: mudstone with microbial lamination and fenestral fabric, MF7: mudstone with grumous microestructure, MF8: bioturbed mudstone and MF9: floatstone, related to storms. The depositional model of this sequence was interpreted as a carbonatic platform with a complex of non-emergent microbialitic mounds and ponds with restricted circulation.Fil:Armella, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Cabaleri, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Valencio, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina