La mineralización de Baritina de Purroy (Zaragoza, España)

The barite mineralization of Purroy (Zaragoza) is located in the Ordovician slates and sandstones, in the Structural Zone of Morata, the northern part of Unidad de Herrera (Eastern Iberian Chain). It is mainly composed of barite, quartz, goethite and hematite; fluorite and pirite with quartz and some Co-ore alteration minerals have also been recognized nearby. Although there is some filling-cavities barite, it occurs mainly in  NllOE veins, with an evident structural control; they present features of  contemporaneous mechanical deformation, related to prealpine distensive events. Barite occurs in a wide variety of aspects, very likely depending on the deposit conditions, and they bring out that at least some veins were filled in several stages, related with deformation events. Sr analysis in a cm scale shows an increase of Sr-content during the course of deposition; in a vein scale this pattern is alterated by mecanic deformations, disolutions and reprecipitations, related with a polyphasic deposit process. Analysis of trace elements suggest a geochemical influence of the environment on the formation of the barite deposit. Fe, Co & Mn are the most characteristic trace elements in this barite mineralization, and their patterns are partialy linked to barite precipitation conditions

19 de abril, Día del Aborigen Americano : Reconociendo voces y miradas sobre los objetos que se exhiben en el Museo de La Plata

Actividad virtual libre, gratuita y abierta a todo publico y con inscripción previa, realizada en abril de 2021 por docentes/guías, junto a referentes de pueblos indígenas.Museo de La Plat

Trajectory tracking of underactuated surface vessels: a linear algebra approach

This brief presents the design of a controller that allows an underactuated vessel to track a reference trajectory in the x−y plane. A trajectory tracking controller designed originally for robotic systems is applied for underactuated surface ships. Such a model is represented by numerical methods and, from this approach, the control actions for an optimal operation of the system are obtained. Its main advantage is that the condition for the tracking error tends to zero, and the calculation of control actions are obtained solving a system of linear equations. The proofs of convergence to zero of the tracking error are presented here and complete the previous work of the authors. Simulation results show the good performance of the proposed control system.Fil: Serrano, Mario Emanuel. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Godoy Bordes, Sebastian Alejandro. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mut, Vicente Antonio. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ortiz, Alberto Osacar. Universidad Nacional de San Juan; Argentin

Experiencias de lo común en el trabajo sociocomunitario con jóvenes : el dispositivo Casa Joven B. A.

Fil: González, Federico Martín. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

Experiencias de lo común en el trabajo sociocomunitario con jóvenes : el dispositivo Casa Joven B. A.

Fil: González, Federico Martín. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

Experiencias de lo común en el trabajo sociocomunitario con jóvenes : el dispositivo Casa Joven B. A.

Fil: González, Federico Martín. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina

Oldest Dryas hydroclimate reorganization in the eastern Iberian Peninsula after the iceberg discharges of Heinrich Event 1

This study examines the first precisely dated and temporally highly resolved speleothem record from Iberia that reconstructs the Oldest Dryas (OD). The onset of cold conditions in the study area, contemporary with the beginning of Heinrich Stadial 1, is recorded at 18.13 +/- 0.08 ka, with a pronounced drop of 6.1 parts per thousand in delta C-13 in 250 years. Henceforth, stadial conditions depict a period of instability in the Atlantic Meridional Overturning Circulation, peaking in freshwater input from iceberg melting during Heinrich Event 1. Anomalies in the delta O-18 of the stalagmite attributed to such a freshwater event are found from 16.17 to 15.89 ka. Such absolute dates given to the onset of the OD in Iberia and to the main iceberg discharges are reliable anchor points for non-absolute chronologies. Two periods are identified in the OD: OD-a (18.13-16.17 ka) is characterized by wet conditions and a faster growth rate, and OD-b (15.89-14.81 ka) exhibits relative dryness and a slower growth rate. The sudden release of fresh water is considered to be the reason for the disruption of rainfall patterns in eastern Iberia. The present study also highlights the existence of heterogeneous and complex hydrological conditions during the OD in Iberia when both Atlantic and Mediterranean realms are considered

Application of Anisotropy of Magnetic Susceptibility to large-scale fault kinematics: an evaluation

Major discontinuities in the Earth’s crust are expressed by faults that often cut across its whole thickness favoring, for example, the emplacement of magmas of mantelic origin. These long-lived faults are common in intra-plate environments and show multi-episodic activity that spans for hundred of million years and constitute first-order controls on plate evolution, favoring basin formation and inversion, rotations and the accommodation of deformation in large segments of plates. Since the post-Paleozoic evolution of these large-scale faults has taken place (and can only be observed) at shallow crustal levels, the accurate determination of fault kinematics is hampered by scarcely developed fault rocks, lack of classical structural indicators and the brittle deformation accompanying fault zones. These drawbacks are also found when thick clayey or evaporite levels, with or without diapiric movements, are the main detachment levels that facilitate large displacements in the upper crust