Lower Permian stems as fluvial paleocurrent indicators of the Parnaíba Basin, northern Brazil

A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit Tocantins Fossil Trees Natural Monument In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry seasons. Thick mudstones and some coquinites below and above the sandy interval may represent lacustrine facies formed in probably more humid conditions. The taphonomic history of the preserved plants began with exceptional storms that caused fast-flowing high water in channels and far into the floodplains. In the eastern site region, many tree ferns only fell, thus sometimes covering and protecting plant litter and leaves from further fragmentation. Assemblages of the central and western sites suggest that the trees were uprooted and transported in suspension (floating) parallel to the flow. Heavier ends of stems (according to their form or because of attached basal bulbous root mantle or large apical fronds) were oriented to upstream because of inertial forces. During falling water stage, the stems were stranded on riverbanks, usually maintaining the previous transport orientation, and were slightly buried. The perpendicular or oblique positions of some stems may have been caused by interference with other stems or shallow bars. Rare observed stems were apparently waterlogged before the final depositional process and transported as bedload. The differences of interpreted channel orientations between the three sites are expected in a braided fluvial system, considering the very low gradients of the basin and the work scale in the order of tens of kilometers. The mean direction of the drainage probably was to east and the flows apparently became weaker downstream. This study seems to provide reliable data for paleocurrent interpretations, especially considering areas with scarce preserved sedimentary structures. © 2013 Elsevier Ltd.

Report of the videoconference of specialized agencies and other organizations of the United Nations system on preparations for the gender parity observatory for Latin America and the Caribbean

Includes bibliography

Situación jurídica de la mujer latinoamericana y del Caribe definida según las resoluciones y mandatos del sistema de las Naciones Unidas = Legal situation of women in Latin America and the Caribbean defined according to the resolutions and mandates of the United Nations system

Incluye Bibliografía

Review and appraisal of the achievements of the United Nations Decade for Women: Equality, Development and Peace in the Caribbean

Contiene una evaluacion de los logros alcanzados y problemas encontrados en el cumplimiento de las metas y objetivos del decenio de las NU para la mujer, en particular en el area salud, empleo y educacion, y recomienda una estrategia para el ano 2000.

Report on the Meeting of delegates from CDCC countries attending the Regional Meeting of Latin America and the Caribbean Preparatory to the World Conference to Review and Appraise the Achievements of the United Nations Decade for Women: Equality, Development and Peace = Informe de la Reunión de delegados de los países del CDCC que participaron en la Reunión Regional de América Latina y el Caribe Preparatoria de la Conferencia Mundial para el Examen y Evaluación de los Logros del Decenio de las Naciones Unidas para la Mujer: Igualdad, Desarrollo y Paz

Informa sobre la reunion realizada con el objetivo de intercambiar informacion y buscar una posicion comun del Caribe en los temas a considerar en la Reunion Regional: problemas y logros alcanzados en la region en la implementacion de las metas y objetivos del decenio de las NU para la mujer, estrategia para el ano 2000.

Resoluciones de otros órganos de la Organización de las Naciones Unidas que traen consecuencias para el Comité de Desarrollo y Cooperación del Caribe = Resolutions of other United Nations bodies with implications for the Caribbean Development and Co-operation Committee (CDCC) = Résolutions d'autres organismes de l'Organisation des Nations Unies ayant des incidences sur le Comité de Développement et de Coopération des Caraïbes (CDCC)

Se refiere a resoluciones que emanan de otros organos de la ONU, incluso la CEPAL, el Consejo Economico y Social y la Asamblea General. El documento pretende llamar a la atencion del Comite las acciones de seguimiento tomadas acerca de ciertos asuntos que el Comite ha considerado en sesiones anteriores y que tengan alguna implicacion directa o indirecta para el CDCC o que sean de interes para el trabajo de la Secretaria.

Informe de la Reunión Regional de América Latina y el Caribe Preparatoria para la Conferencia Mundial para el Examen y la Evaluación de los Logros del Decenio de las NU para la Mujer: Igualdad, Desarrollo y Paz = Report of the Regional Meeting for Latin America and the Caribbean in Preparation for the World Conference to Review and Appraise the Achievements of the United Nations Decade for Women: Equality, Development and Peace = Rapport de la Réunion Régionale de l'Amérique latine et des Caraïbes Préparatoire de la Conférence Mondiale Chargée d'Examiner et d'Evaluer les Résultats de la Décennie des Nations Unies pour la Femme: Egalité, Développement et Paix

Contiene: asistencia y organizacion de los trabajos, resumen de los debates, y evaluacion del decenio y estrategias y medidas concretas de ejecucion para el adelanto de la mujer hasta el ano 2000, aprobadas por la Reunion.